Research Article |
Corresponding author: Martim Melo ( melo.martim@gmail.com ) Academic editor: Knud Jønsson
© 2022 Martim Melo, Bárbara Freitas, Philippe Verbelen, Sátiro R. da Costa, Hugo Pereira, Jérôme Fuchs, George Sangster, Marco N. Correia, Ricardo F. de Lima, Angelica Crottini.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Melo M, Freitas B, Verbelen P, da Costa SR, Pereira H, Fuchs J, Sangster G, Correia MN, de Lima RF, Crottini A (2022) A new species of scops-owl (Aves, Strigiformes, Strigidae, Otus) from Príncipe Island (Gulf of Guinea, Africa) and novel insights into the systematic affinities within Otus. ZooKeys 1126: 1-54. https://doi.org/10.3897/zookeys.1126.87635
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A new species of scops-owl (Aves, Strigiformes, Strigidae, Otus) is described from Príncipe Island, São Tomé and Príncipe (Gulf of Guinea, Africa). This species was discovered for science in 2016, although suspicions of its occurrence gained traction from 1998, and testimonies from local people suggesting its existence could be traced back to 1928. Morphometrics, plumage colour and pattern, vocalisations, and molecular evidence all support the species status of the scops-owl from Príncipe, which is described here as Otus bikegila sp. nov. Phylogenetic analyses suggest that this species descended from the first colonisation of the Gulf of Guinea islands, being sister to the clade including the mainland African Scops-Owl O. senegalensis, and the island endemics Sao Tome Scops-Owl O. hartlaubi and Pemba Scops-Owl O. pembaensis. The most diagnostic trait in the field is its unique call which, curiously, is most similar to a distantly related Otus species, the Sokoke Scops-Owl O. ireneae. The new species occurs at low elevations of the old-growth native forest of Príncipe, currently restricted to the south of the island but fully included within Príncipe Obô Natural Park. Otus bikegila sp. nov. takes the number of single-island endemic bird species of Príncipe to eight, further highlighting the unusually high level of bird endemism for an island of only 139 km2.
Descrevemos uma nova espécie de mocho-de-orelhas ou kitóli (Strigiformes: Strigidae: Otus) da Ilha do Príncipe, São Tomé e Príncipe (Golfo da Guiné, África). Esta espécie foi descoberta para a ciência apenas em 2016, embora suspeitas da sua existência tenham ganho força a partir de 1998, e testemunhos de habitantes locais sobre a sua ocorrência já estarem documentados em 1928. A morfometria, a cor e padrão da plumagem, as vocalizações e dados moleculares demonstram que esta população de mocho no Príncipe é uma espécie nova, que foi batizada de mocho-do-príncipe (lista mundial) ou kitóli-do-príncipe (nome nacional), Otus bikegila sp. nov. As análises filogenéticas indicam que esta espécie descende da primeira colonização das ilhas do Golfo da Guiné, sendo irmã do clado que inclui o mocho-d’orelhas-africano O. senegalensis, do continente, o mocho-de-são-tomé (ou kitóli-de-são-tomé) O. hartlaubi e o mocho-de-pemba O. pembaensis, ambos endémicos das ilhas que lhes dão o nome. No campo, a característica mais diagnóstica é o seu canto único que, curiosamente, é mais parecido com o da espécie de Otus mais afastada, o mocho-de-sokoke O. ireneae. A nova espécie ocorre nas zonas baixas da floresta nativa do Príncipe, atualmente restrita ao sul da ilha, mas totalmente inserida no Parque Natural do Obô do Príncipe. Otus bikegila sp. nov. eleva o número de espécies de aves endémicas restritas ao Príncipe para oito, sublinhando ainda mais o nível extremamente elevado de aves endémicas para uma ilha de apenas 139 km2.
Biodiversity, endemism, exploration, Gulf of Guinea, integrative taxonomy, Otus bikegila sp. nov., Principe Scops-Owl, systematics
Biodiversidade, endemismo, exploração, Golfo da Guiné, Kitóli-do-príncipe, Mocho-do-príncipe, Otus bikegila sp. nov., sistemática, taxonomia integrada
“But I discovered that the very same aggregations or groupings of individuals that the trained zoologist called separate species were called species by the New Guinea natives. I collected 137 species of birds. The natives had 136 names for these birds (…)”
Ernst Mayr - Interview - Omni Magazine, February 1983
Species are indeed the face of biodiversity with whom everyone relates to. The discovery of new species consistently makes headlines expressing wonder and joy. And yet, it has been estimated that only ca. 14% of extant species have been described, with invertebrates making most of the undescribed species (
The discovery of new species tends to have a higher impact when it occurs in familiar groups like mammals or birds. Birds in particular are likely the best studied animal group, making the discovery of new species more challenging and often restricted to remote locations and/or difficult-to-study groups (e.g.,
Owls (Aves, Strigiformes) are a charismatic bird group that made their way into most human cultures, where they are generally either symbols of wisdom or, on the contrary, omens of bad luck (
Still, compared to other groups, the current discrepancy in the number of owl species accepted by different authorities highlights the challenges associated with the taxonomy and systematics of this group. This stems from their nocturnal habits, making them difficult to study, and from being a group where, at the generic level, morphological variation between species can be similar or lower than within-species (
In contrast to plumage, vocalisations of members of the Strigidae family are species-specific. As with most non-passerines and suboscine passerines, owl songs are not learned (
The Gulf of Guinea, Central Africa, has three oceanic islands, Príncipe, São Tomé, and Annobón, in a northeast to southwest line, with São Tomé touching the equator. The rainforests of the islands constitute an independent ecoregion (
Although birds are the best-studied group of the Gulf of Guinea islands (
Príncipe Island (1°31.80'N–1°43.20'N, 7°19.80'E–7°28.20'E) is located in the Gulf of Guinea, ca. 220 km offshore Gabon (Fig.
Fieldwork for specimen and tissue sample collection, measurements, and additional bioacoustics recordings took place in May 2017, July 2018, and January 2019. All samples and vocalisation recordings were collected within Príncipe Obô Natural Park, in the south of Príncipe (Fig.
On May 29, 2017, in the Ribeira Porco area (1°33.03'N, 7°22.29'E, Fig.
Morphological measurements of the scops-owls specimens included in the present study with their respective institutional catalogue number (superscript letters, when present, indicate: HT, holotype; F, female; M, male) and sampling locality. All measures are in millimetres. NA – not available; STP – São Tomé and Príncipe; DRC – Democratic Republic of the Congo; EG – Equatorial Guinea. Morphological measurements – Bilen: bill length from bill tip to where culmen enters feathers; Biwid: bill width; Bidepth: bill depth; Binares: bill length from the anterior end of the nares to the tip; Hebi: head+bill, from the tip of the bill to the opposite point on the back of the skull; Midt: middle toe length; Tarlen: tarsus length; Wilen: wing length; Tailen: tail length; Bolen: body length; P10-4: length of primary feathers; Wing formula: sequence of primary feathers ordered by size; * specimens not collected, blood samples codes from the collection of MM at CIBIO-InBIO.
Taxon | Catalogue number followed by tissue sample (if available) | Locality | Bilen | Biwid | Bidepth | Binares | Hebi | Midt | Tarlen | Wilen | Tailen | Bolen | P10 | P9 | P8 | P7 | P6 | P5 | P4 | Wing formula |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
O. bikegila sp. nov. 1 |
|
STP, Príncipe | 16.0 | 9.0 | 11.3 | 11.3 | 38.9 | 19.9 | 32.3 | 147 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
O. bikegila sp. nov. 2 | NA; P8-001 * F | STP, Príncipe | 19.0 | 10.9 | 10.4 | 11.7 | 44.0 | NA | 34.0 | 148 | 85 | NA | 82 | 104 | 116 | 122 | 120 | 119 | 115 | 7 > 6>5 > 8>4 > 9>10 |
O. bikegila sp. nov. 3 | NA; P9-037 * F | STP, Príncipe | 19.0 | 11.8 | 11.9 | 12.6 | NA | NA | 35.1 | 151 | 85 | 205 | 84 | 108 | 118 | 121 | 120 | 119 | 115 | 7 > 6>5 > 8>4 > 9>10 |
O. bikegila sp. nov. 4 | NA; P9-038 * M | STP, Príncipe | 17.4 | 10.9 | 12.1 | 11.6 | NA | NA | 30.5 | 145 | 75 | 192 | 80 | 103 | 114 | 118 | 116 | 113 | 108 | 7 > 6>8 > 5>4 > 9>10 |
O. hartlaubi 1 | NA; ST03-294 * | STP, São Tomé | 16.1 | 6.5 | 9.7 | NA | NA | NA | 30.8 | 130 | 67 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
O. hartlaubi 2 | NA; ST-R16-0202 * | STP, São Tomé | NA | NA | NA | NA | NA | NA | NA | 139 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
O. hartlaubi 3 | NA; ST10-440 * | STP, São Tomé | 15.5 | 9.8 | NA | NA | NA | NA | 32.9 | 132 | 68 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
O. hartlaubi 4 | NA; ST-R17-0264 * | STP, São Tomé | NA | NA | NA | NA | NA | NA | 27.8 | 134 | 67 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
O. hartlaubi | NA; ST15-144 * | STP, São Tomé | 16.1 | 6.3 | 9.1 | 10.1 | 39.0 | NA | 31.9 | 135 | 65 | 170 | 74 | 86 | 101 | 107 | 106 | 104 | 100 | 7 > 6>5 > 8>4 > 9>10 |
O. hartlaubi |
|
STP, São Tomé | 17.1 | 6.1 | NA | 10.6 | 39.5 | 17.1 | 30.6 | 136 | 69 | 174 | 65 | 91 | 102 | 108 | 107 | 104 | 92 | 7 > 6>5 > 8>4 > 9>10 |
O. s. senegalensis | SMF 25448 | Gambia | 18.3 | 6.4 | 9.8 | 12.5 | 42.3 | 17.3 | 24.2 | 141 | 65 | 175 | 66 | 95 | 96 | 96 | 90 | 89 | 81 | 7 = 8>9 > 6>5 > 5>10 |
O. s. senegalensis | BMNH 1929.2.18.131 | Gambia | NA | 6.7 | NA | NA | 41.0 | 16.5 | 22.0 | 140 | 60 | 167 | 81 | 98 | 104 | 106 | 105 | 96 | 87 | 7 > 6>8 > 9>5 > 4>10 |
O. s. senegalensis | BMNH 1907.12.26.41 | Gambia | 17.0 | 8.0 | 10.2 | 9.4 | 42.0 | 19.0 | 23.0 | 140 | 60 | 190 | 73 | 92 | 99 | 103 | 100 | 94 | 87 | 7 > 6>8 > 5>9 > 4>10 |
O. s. senegalensis | BMNH 1955.6.N-20.3927 | Cape Verde | 17.0 | 6.0 | 11.0 | 9.0 | 39.0 | 18.0 | 22.0 | 135 | 60 | 170 | NA | NA | NA | NA | NA | NA | NA | NA |
O. s. senegalensis | BMNH 1955.6.N-20.3926 | Senegal | 15.3 | 6.5 | 10.7 | 8.2 | 40.0 | 15.5 | 23.0 | 145 | 65 | 170 | NA | NA | NA | NA | NA | NA | NA | 8 > 7>9 > 6>5 > 4>10 |
O. s. senegalensis | BMNH 1955.6.N-20.3930 | West Africa | 16.5 | 6.1 | 11.7 | 9.9 | 40.0 | 15.5 | 24.0 | 135 | 57 | 170 | 80 | 97 | 100 | 98 | 98 | 93 | 87 | 8 > 7=6 > 9>5 > 4>10 |
O. s. senegalensis | BMNH 94.8.15.28 | Ghana, Accra | 17.1 | 6.1 | 11.0 | 10.5 | 42.0 | 15.5 | 23.0 | 137 | 58 | 175 | 70 | 87 | 94 | 95 | 89 | 84 | 82 | 7 > 8>6 > 9>5 > 4>10 |
O. s. senegalensis | BMNH 1930.12.21.13 | Ghana, Tamatuku | 15.8 | 6.3 | 11.0 | 9.0 | 40.0 | 17.5 | 20.0 | 125 | 55 | 173 | NA | NA | NA | NA | NA | NA | NA | NA |
O. s. senegalensis | BMNH 1911.12.23.506 | Nigeria, Bauchi | 17.2 | 5.2 | 11.0 | 9.4 | 44.0 | 18.5 | 22.0 | 135 | 58 | 170 | 89 | 94 | 99 | 98 | 94 | 88 | 85 | 8 > 7>6 = 9>10 > 5>4 |
O. s. senegalensis | BMNH 1909.12.31.43 | DRC, Bunkeya | 16.4 | 6.3 | 11.1 | 9.2 | 40.5 | 21.0 | 23.0 | 140 | 60 | 165 | 76 | 92 | 103 | 105 | 108 | 98 | 93 | 6 > 7>8 > 5>4 > 9>10 |
O. s. senegalensis | BMNH 1909.12.31.42 | DRC, Katanga | 15.8 | 5.0 | 10.4 | 8.0 | 41.5 | 15.0 | 23.0 | 130 | 57 | 150 | 70 | 90 | 95 | 97 | 93 | 86 | 80 | 7 > 8>6 > 9>5 > 4>10 |
O. s. senegalensis | BMNH 1957.35.44 | Angola, Sumbe | 15.5 | 5.0 | 10.4 | 8.5 | 37.0 | 15.5 | 22.0 | 125 | 60 | 165 | 65 | 83 | 90 | 90 | 85 | 80 | 75 | 7 = 8>6 > 9>5 > 4>10 |
O. s. senegalensis | BMNH 1937.12.27.211 | Tanzania | 16.7 | 5.8 | 9.7 | 9.5 | 40.0 | 16.0 | 22.0 | 128 | 50 | 160 | 70 | 82 | 90 | 91 | 90 | 86 | 82 | 7 > 6=8 > 5>4 = 9>10 |
O. s. senegalensis | BMNH 1936.2.21.479 | Djibouti | 16.5 | 6.0 | 11.0 | 9.8 | 42.0 | 17.0 | 21.0 | 137 | 60 | 170 | 72 | 87 | 97 | 99 | 96 | 83 | 83 | 7 > 8>6 > 9>4 = 5>10 |
O. s. senegalensis | SMF 10119 | Ethiopia, Maki | 16.8 | 6.3 | 9.3 | 11.0 | 36.1 | 17.2 | 22.1 | 128 | 53 | 151 | 72 | 87 | 93 | 96 | 96 | 91 | NA | NA |
O. s. senegalensis | SMF 10121 | Somalia, Bardera | 16.5 | 4.8 | 8.0 | 10.1 | 32.7 | 13.8 | 21.5 | 103 | 40 | 126 | 54 | 65 | 72 | 72 | 74 | 72 | 64 | 6 > 5=7 = 8>9 > 4>10 |
O. senegalensis feae | BMNH 1911.12.23.4044 | EG, Annobón | 16.8 | 6.4 | 12.0 | 10.7 | 40.0 | 17.5 | 20.0 | 135 | 60 | 185 | 84 | 95 | 104 | 106 | 102 | NA | NA | 7 > 8>6 > 9>10 > 5>4 |
O. senegalensis feae | SMF 25452 | EG, Annobón | 16.9 | 6.8 | 9.2 | 10.9 | 36.6 | 16.9 | 24.1 | 130 | 55 | 165 | 74 | 89 | 97 | 96 | 94 | 91 | 85 | 8 > 7>6 > 5>9 > 4>10 |
O. pembaensis | BMNH 1937.2.14.1 HT | Tanzania, Pemba | 19.0 | 8.9 | NA | 12.2 | 49.0 | 20.0 | 28.0 | 152 | 73 | 210 | 75 | 97 | 108 | 111 | 104 | 98 | 90 | 7 > 8>6 > 5>9 > 4>10 |
O. pembaensis | BMNH 1937.12.14.2 | Tanzania, Pemba | 20.5 | 8.5 | NA | 12.7 | 47.0 | 21.0 | 30.0 | 155 | 75 | 212 | 76 | 100 | 109 | 111 | 102 | 97 | 90 | 7 > 8>6 > 9>5 > 4>10 |
O. pembaensis | BMNH 1937.12.14.3 | Tanzania, Pemba | 19.0 | 9.0 | NA | 12.2 | 48.0 | 20.0 | 28.0 | 155 | 78 | 212 | 75 | 98 | 109 | 110 | 107 | 95 | 91 | 7 > 8>6 > 5>9 > 4>10 |
O. pembaensis | BMNH 1937.12.14.4 | Tanzania, Pemba | 20.0 | 8.5 | 13.5 | 12.1 | 47.0 | 21.0 | 28.0 | 150 | 80 | 212 | 75 | 99 | 111 | 112 | 108 | 101 | 96 | 7 > 8>6 > 5>9 > 4>10 |
O. pembaensis | BMNH 1937.12.14.5 | Tanzania, Pemba | 18.2 | 7.5 | NA | 11.2 | 46.5 | 20.0 | 29.0 | 150 | 76 | 210 | 75 | 96 | 103 | 104 | 103 | 97 | 92 | 7 > 6=8 > 5>9 > 4>10 |
O. pembaensis | BMNH 1937.12.14.6 | Tanzania, Pemba | 18.9 | 8.0 | 11.5 | 11.9 | 47.0 | 20.0 | 28.0 | 150 | 76 | 210 | 70 | 95 | 107 | 114 | 113 | 109 | 103 | 7 > 6>5 > 8>4 > 9>10 |
O. pembaensis | BMNH 1956.29.9 | Tanzania, Pemba | NA | NA | NA | NA | NA | NA | NA | 152 | NA | 190 | 77 | 98 | 107 | 110 | 107 | 104 | 94 | 7 > 8=6 > 5>9 > 4>10 |
O. scops | BMNH 941.5.30.8805 | Spain, Ibiza | 16.2 | 5.7 | 9.2 | 9.5 | 39.0 | 18.0 | 22.0 | 154 | 65 | 190 | 98 | 113 | 116 | 112 | 106 | 101 | 96 | 8 > 9>7 > 6>5 > 10 > 4 |
O. scops | BMNH 87.11.11.43 | Spain, Seville | 15.1 | 5.8 | 11.0 | 9.1 | 37.0 | 16.5 | 23.0 | 152 | 70 | 182 | 94 | 109 | 107 | 105 | 98 | 92 | 90 | 9 > 8>7 > 6>10 > 5>4 |
O. scops | BMNH 97.11.10.292 | Spain, Malaga | 16.8 | 6.2 | 11.0 | 9.8 | 40.5 | 14.2 | 28.0 | 147 | 68 | 170 | 85 | 102 | 109 | 106 | 98 | 87 | 86 | 8 > 7>9 > 6>5 > 4>10 |
O. scops | BMNH 1947.4.89 | France, Var | 16.1 | 6.8 | 11.0 | 9.0 | 43.0 | 18.0 | 28.0 | 160 | 70 | 200 | 96 | 114 | 114 | 114 | 101 | 96 | 85 | 7 = 8=9 > 6>10 = 5>4 |
O. scops | BMNH 1934.1.1.1510 | Italy, Bibbiena | 16.5 | 7.0 | 10.5 | 9.5 | 43.0 | 17.0 | 24.0 | 157 | 71 | 186 | 100 | 117 | 118 | 115 | 111 | 98 | 96 | 8 > 9>7 > 6>10 > 5>4 |
O. scops | BMNH 1905.6.28.739 | Italy, Naples | 16.5 | 6.8 | 10.5 | 10.0 | 43.5 | 17.0 | 26.0 | 155 | 68 | 185 | 95 | 106 | 110 | 105 | 102 | 95 | 93 | 8 > 9>7 > 6>10 = 5>4 |
O. scops | BMNH 1905.6.28.740 | Italy, Naples | 16.9 | 6.6 | 11.0 | 9.7 | 46.0 | 16.1 | 27.0 | 159 | 70 | 200 | 92 | 110 | 113 | 109 | 100 | 92 | 90 | 8 > 9>7 > 6>10 = 5>4 |
O. scops | BMNH 1955.6.N-20.3874 | Morocco, Tangier | 16.7 | 7.8 | NA | 11.5 | 43.0 | 20.0 | 22.0 | 155 | 65 | 180 | 92 | 104 | 104 | 102 | 99 | 94 | 94 | 8 = 9>7 > 6>5 = 4>10 |
O. scops | BMNH 1919.12.11.8 | Morocco, Atlas | 15.0 | 6.5 | 9.8 | 10.0 | 39.5 | 14.0 | 22.0 | 150 | 80 | 178 | 94 | 107 | 109 | 107 | 92 | 88 | 88 | 8 > 9=7 > 10 > 6>5 = 4 |
O. scops | BMNH 73.5.28.10 | Algeria | 18.1 | 6.5 | NA | 11.0 | 42.0 | 17.0 | 26.0 | 154 | 70 | 180 | 91 | 105 | 106 | 106 | 98 | 94 | 87 | 8 = 7>9 > 6>5 > 10 > 4 |
O. scops | BMNH 1916.9.20.746 | Sudan, Trufikia | 15.5 | 6.7 | NA | 9.5 | 45.0 | 18.5 | 24.0 | 163 | 75 | 195 | 100 | 115 | 116 | 111 | 100 | 98 | 98 | 8 > 9>7 > 10 = 6>5 = 4 |
O. scops | BMNH 1977.20.227 | Liberia, Mt. Nimba | 15.0 | 6.5 | 11.5 | 10.0 | 42.0 | 17.0 | 23.0 | 154 | 70 | 185 | NA | NA | NA | NA | NA | NA | NA | 7 > 6>8 > 5>4 > 9>10 |
O. scops | BMNH 1977.20.229 | Liberia, Mt. Nimba | 14.0 | 5.5 | 10.3 | 10.3 | 42.0 | 19.0 | 26.5 | 155 | 70 | 195 | 94 | 112 | 112 | 107 | 98 | 96 | 91 | 8 = 9>7 > 6>5 > 10 > 4 |
O. scops | BMNH 1977.20.232 | Liberia, Mt. Nimba | 17.0 | 5.5 | 10.4 | 10.0 | 40.2 | 17.0 | 27.0 | 157 | 72 | 175 | 92 | 104 | NA | NA | NA | NA | NA | NA |
O. scops | BMNH 1977.20.228 | Liberia, Mt. Nimba | 17.3 | 6.0 | 10.2 | 9.5 | 40.0 | 17.0 | 23.0 | 165 | 73 | 190 | 105 | 115 | NA | NA | NA | NA | NA | 8 > 9>7 > 6>10 > 5>4 |
O. brucei obsoletus | SMF 25430 | Uzbekistan | 18.5 | 5.8 | 8.7 | 11.5 | 43.1 | 16.9 | 29.6 | 153 | 72 | 186 | 96 | 112 | 112 | 114 | 109 | 100 | 90 | 7 > 8=9 > 6>5>10>4 |
The candidate species of Otus from Príncipe A female specimen
In this study, species diagnosis was based upon four lines of evidence: morphometrics, plumage colouration and pattern, song, and DNA sequence data.
Species and subspecies limits of scops-owls are challenging to ascertain, leading to numerous taxonomic arrangements. This study follows the taxonomic arrangement and nomenclature of The Clements Checklist of Birds of the World (
Four scops-owl individuals from Príncipe (including the vouchered specimen) were captured in the field. These were measured together with representatives of four of the five species of the Afro-Palearctic clade (sensu
Measurements were taken as follows: bill length from the bill tip to where the culmen enter the feathers (Bilen); bill length from the anterior end of the nares to the tip (Binares); bill width (Biwid) and bill depth (Bidepth) at the anterior end of nares; head+bill (Hebi), from the tip of the bill to the opposite point on the back of the skull; middle toe length (Midt); tarsus length (Tarlen), from the tibiotarsus joint to the distal end of the tarsometatarsus, when the foot is held to the leg; tail length (Tailen), from where the ruler stops at the root of the central pair of rectrices and to the tip of this same pair (by sliding the ruler between the rectrices and the undertail coverts); body length (Bolen) from the top of the head to the tip of the central pair of rectrices; wing length (Wilen), flattened, from the carpal joint to the tip of the longest primary; wing formula, sequence of primary feathers ordered by size; and length of primary feathers (P4–P10, in which P1 is the closest to the body), which were transformed in shortfall of P4–P10 to tip of longest primary. Body, wing, and tail length were measured with standard wing and tail rulers to the nearest 1.0 mm. The length of the primary feathers was measured to the nearest 1.0 mm with a ruler with a pin at the origin; the pin is inserted between two primary feathers until it touches the skin (
The four individuals from Príncipe were sexed with a molecular protocol (
Morphometric differences were explored using a Principal Component Analysis (PCA), performed using the FactoMineR package (
We used colour standards (
We compared the calls of the candidate species with the calls of scops-owls from the Afro-Palearctic clade, O. brucei, and the Sokoke Scops-Owl O. ireneae Ripley, 1966 (Tables
Measurements (in Hz) of bioacoustic variables (frequency parameters) of Otus species of the Afro-Palearctic clade, O. brucei and of O. ireneae (the species whose vocalisations are closest to the ones of the candidate species from Príncipe). n: number of individuals. Average ± standard deviation; (minimum-maximum values). F1: frequency at start; F2: frequency at end; F3: frequency at 25% of total duration; F4: frequency at midpoint; F5: frequency at 75% of total duration; F6: frequency at maximum amplitude; F7: maximum frequency; F8: minimum frequency.
Taxon | n | F1 | F2 | F3 | F4 | F5 | F6 | F7 | F8 |
---|---|---|---|---|---|---|---|---|---|
O. bikegila sp. nov. (main call) | 5 | 891.0 ± 72.9 | 967.0 ± 32.3 | 1012.3 ± 44.2 | 981.3 ± 40.2 | 967.7 ± 35.8 | 1005.7 ± 47.6 | 1054.0 ± 30.1 | 910.3 ± 43.2 |
(781.7–961.7) | (933.3–1020.0) | (980.0–1090.0) | (950.0–1050.0) | (931.7–1020.0) | (976.7–1090.0) | (1035.0–1106.7) | (868.3–973.3) | ||
O. bikegila sp. nov. (cat-like call) | 2 | 966.7 ± 80.1 | 859.2 ± 27.1 | 1180.8 ± 121.4 | 1234.2 ± 62.5 | 1149.2 ± 140.2 | 1220.0 ± 70.7 | 1245.0 ± 77.8 | 853.3 ± 4.7 |
(910.0–1023.3) | (840.0–878.3) | (1095.0–1266.7) | (1190.0–1278.3) | (1050.0–1248.3) | (1170.0–1270.0) | (1190.0–1300.0) | (850.0–856.7) | ||
O. hartlaubi | 5 | 1236.2 ± 101.5 | 1220.7 ± 54.9 | 1409.7 ± 65.9 | 1396.3 ± 80.0 | 1340.5 ± 62.2 | 1383.2 ± 62.5 | 1461.8 ± 47.2 | 1178.2 ± 83.0 |
(1078.3–1360.0) | (1155.0–1285.0) | (1330.0–1478.3) | (1295.0–1483.3) | (1250.0–1418.3) | (1331.7–1480.0) | (1407.5–1526.7) | (1066.7–1267.5) | ||
O. senegalensis senegalensis | 4 | 1235.0 ± 184.2 | 1133.3 ± 112.7 | 1092.5 ± 123.3 | 1156.7 ± 60.5 | 1074.6 ± 83.9 | 1134.2 ± 84.3 | 1422.5 ± 341.5 | 963.3 ± 70.4 |
(1071.7–1433.3) | (1035.0–1260.0) | (1021.7–1276.7) | (1095.0–1236.7) | (1011.7–1198.3) | (1051.7–1251.7) | (1126.7–1908.3) | (885.0–1050.0) | ||
O. senegalensis feae | 3 | 1220.3 ± 146.6 | 1189.2 ± 50.6 | 1165.3 ± 76.3 | 1203.3 ± 92.5 | 1143.1 ± 46.8 | 1156.9 ± 75.1 | 1310.3 ± 54.9 | 1098.9 ± 68.1 |
(1060.0–1347.5) | (1132.5–1230.0) | (1120.0–1253.3) | (1145.0–1310.0) | (1110.0–1196.7) | (1107.5–1243.3) | (1250.0–1357.5) | (1050.0–1176.7) | ||
O. pembaensis | 5 | 575.3 ± 47.8 | 665.7 ± 65.3 | 693.7 ± 52.8 | 709.7 ± 52.7 | 711.0 ± 49.1 | 702.0 ± 50.0 | 726.0 ± 48.9 | 593.0 ± 49.5 |
(506.7–636.7) | (613.3–773.3) | (621.7–770.0) | (633.3–780.0) | (651.7–783.3) | (638.3–776.7) | (660.0–790.0) | (530.0–660.0) | ||
O. pamelae | 5 | 1116.3 ± 72.7 | 1190.0 ± 55.4 | 1219.0 ± 90.5 | 1241.0 ± 104.8 | 1179.7 ± 75.6 | 1250.3 ± 91.5 | 1349.0 ± 114.4 | 1054.3 ± 40.4 |
(1031.7–1213.3) | (1111.7–1268.3) | (1120.0–1363.3) | (1096.7–1366.7) | (1083.3–1291.7) | (1160.0–1403.3) | (1220.0–1516.7) | (1020.0–1123.3) | ||
O. scops | 5 | 1505 ± 137.5 | 1210.2 ± 44.1 | 1203.8 ± 39.0 | 1230.1 ± 34.9 | 1255.3 ± 44.7 | 1255.3 ± 46.2 | 1478.6 ± 121.8 | 1183.5 ± 43.4 |
(1335.0–1695.0) | (1152.5–1275.0) | (1155.0–1260.0) | (1200.0–1285.0) | (1193.3–1318.3) | (1210.0–1326.7) | (1336.3–1628.3) | (1140.0–1253.3) | ||
O. cyprius (long note) | 5 | 1312.6 ± 60.0 | 1079.7 ± 67.1 | 1084.6 ± 73.1 | 1091.0 ± 71.7 | 1101.4 ± 65.1 | 1139.4 ± 72.7 | 1391.1 ± 85.4 | 1059.7 ± 72.2 |
(1236.7–1400.0) | (1016.7–1193.3) | (1035.0–1213.3) | (1035.0–1216.7) | (1043.4–1213.3) | (1063.4–1231.7) | (1291.7–1520.0) | (996.7–1183.3) | ||
O. cyprius (short note) | 5 | 1128.1 ± 59.7 | 1038.5 ± 57.1 | 1094.8 ± 132.1 | 1046.6 ± 90.6 | 1045.7 ± 85.5 | 1067.2 ± 72.9 | 1212.9 ± 104.9 | 1007.9 ± 75.4 |
(1058.9–1223.3) | (998.3–1135.0) | (1015.0–1330.0) | (976.7–1200.0) | (960.0–1186.7) | (1020.0–1196.7) | (1124.4–1345.0) | (945.0–1138.3) | ||
O. brucei | 4 | 355.0 ± 48.8 | 358.3 ± 49.1 | 463.8 ± 75.5 | 447.1 ± 62.0 | 390.4 ± 50.2 | 462.1 ± 63.6 | 469.6 ± 69.5 | 336.3 ± 48.0 |
(285.0–388.3) | (285.0–388.3) | (356.7–530.0) | (356.7–493.3) | (335.0–450.0) | (370.0–510.0) | (370.0–530.0) | (270.0–373.3) | ||
O. ireneae | 2 | 936.7 ± 99.0 | 919.2 ± 38.9 | 943.3 ± 75.4 | 945.0 ± 73.1 | 926.7 ± 51.9 | 946.7 ± 61.3 | 958.3 ± 58.9 | 892.5 ± 43.6 |
(866.7–1006.7) | (891.7–946.7) | (890.0–996.7) | (893.3–996.7) | (890.0–963.3) | (903.3–990.0) | (916.7–1000.0) | (861.7–923.3) |
Measurements (in Hz) of bioacoustic variables (temporal parameters) of Otus species of the Afro-Palearctic clade, O. brucei and of O. ireneae (the species whose vocalisations are closest to the ones of the candidate species from Príncipe). n: number of individuals. Average ± standard deviation; (minimum-maximum values). DT1: total duration; DT2: time to maximum amplitude; DT3: time to maximum frequency; DT4: internote interval; DF1: frequency drop from start to end; DF2: frequency range; DFT1: slope from 25% to 75% of total duration; DFT2: slope from midpoint to end.
Taxon | n | DT1 | DT2 | DT3 | DT4 | DF1 | DF2 | DFT1 | DFT2 |
---|---|---|---|---|---|---|---|---|---|
O. bikegila sp. nov. | 5 | 0.238 ± 0.007 | 0.100 ± 0.014 | 0.057 ± 0.021 | 1.046 ± 0.053 | 76.0 ± 62.8 | 143.7 ± 25.8 | -374.4 ± 252.1 | -120.9 ± 110.2 |
(0.231–0.248) | (0.078–0.112) | (0.032–0.083) | (0.992–1.121) | (6.7–178.3) | (110–175) | (-581.5–45.2) | (-250.3–21.7) | ||
O. bikegila sp. nov. (cat-like call) | 2 | 0.347 ± 0.009 | 0.161 ± 0.002 | 0.138 ± 0.025 | - | -107.5 ± 53.0 | 391.7 ± 73.1 | -185.7 ± 117.8 | -2158.6 ± 146.7 |
(0.341–0.354) | (0.160–0.162) | (0.120–0.155) | - | (-145.0 – -70.0) | (340.0–443.3) | (-268.9 – -102.4) | (-2262.4 – -2054.9) | ||
O. hartlaubi | 5 | 0.292 ± 0.017 | 0.161 ± 0.054 | 0.078 ± 0.038 | 13.899 ± 2.847 | -15.5 ± 126.5 | 283.7 ± 106.5 | -468.4 ± 348.7 | -1209.4 ± 672.6 |
(0.267–0.315) | (0.113–0.241) | (0.030–0.110) | (9.181–15.998) | (-141.7–186.7) | (140.0–403.3) | (-773.0 – -61.0) | (-2034.1 – -312.7) | ||
O. senegalensis senegalensis | 4 | 0.337 ± 0.150 | 0.201 ± 0.135 | 0.058 ± 0.047 | 6.446 ± 2.426 | -101.7 ± 72.1 | 459.2 ± 381.1 | -155.8 ± 429.3 | -240.3 ± 500.7 |
(0.206–0.476) | (0.091–0.370) | (0.010–0.102) | (4.094–9.131) | (-173.3 – -30.0) | (191.7–1023.3) | (-769.7–230.9) | (-570.1–503.1) | ||
O. senegalensis feae | 3 | 0.420 ± 0.019 | 0.216 ± 0.087 | 0.119 ± 0.153 | 7.247 ± 0.201 | -31.1 ± 107.7 | 211.4 ± 71.1 | -92.5 ± 143.8 | -61.8 ± 301.4 |
(0.402–0.441) | (0.121–0.291) | (0.013–0.295) | (7.127–7.479) | (-142.5–72.5) | (146.7–287.5) | (-253.2–23.8) | (-364.3–238.5) | ||
O. pembaensis | 5 | 0.225 ± 0.017 | 0.112 ± 0.045 | 0.112 ± 0.041 | 6.121 ± 0.916 | 90.3 ± 38.8 | 133.0 ± 7.1 | 156.4 ± 121.3 | -409.1 ± 333.4 |
(0.207–0.246) | (0.061–0.171) | (0.043–0.155) | (5.043–7.570) | (48.3–136.7) | (126.7–145.0) | (-37.3–246.9) | (-784.9 – -58.1) | ||
O. pamelae | 5 | 0.390 ± 0.078 | 0.160 ± 0.035 | 0.103 ± 0.034 | 5.665 ± 4.550 | 73.7 ± 59.3 | 294.7 ± 80.7 | -202.1 ± 130.9 | -278.6 ± 443.4 |
(0.281–0.481) | (0.120–0.206) | (0.068–0.157) | (0.444–11.381) | (21.7–158.3) | (200.0–393.3) | (-407.3 – -65.4) | (-588.9–383.5) | ||
O. scops | 5 | 0.248 ± 0.033 | 0.102 ± 0.050 | 0.020 ± 0.017 | 2.608 ± 0.174 | -294.8 ± 95.4 | 295.1 ± 97.6 | 430.5 ± 193.2 | -187.5 ± 314.0 |
(0.206–0.291) | (0.047–0.169) | (0.010–0.050) | (2.423–2.789) | (-420.0 – -182.5) | (178.8–401.7) | (181.5–662.3) | (-730.4–66.1) | ||
O. cyprius (long note) | 5 | 0.226 ± 0.014 | 0.088 ± 0.039 | 0.019 ± 0.006 | 3.245 ± 0.236 | -232.8 ± 49.4 | 331.4 ± 56.8 | 141.9 ± 160.6 | -101.0 ± 114.6 |
(0.213–0.245) | (0.049–0.145) | (0.013–0.028) | (3.035–3.643) | (-283.3 – -165.0) | (241.7–395.0) | (-32.1–363.9) | (-211.4–34.0) | ||
O. cyprius (short note) | 5 | 0.124 ± 0.035 | 0.059 ± 0.024 | 0.014 ± 0.006 | 3.344 ± 0.227 | -89.6 ± 22.9 | 204.9 ± 72.7 | -938.8 ± 1357.8 | -357.5 ± 953.6 |
(0.084–0.159) | (0.042–0.100) | (0.008–0.020) | (3.116–3.714) | (-113.3 – -58.1) | (129.7–318.3) | (-3144.9 – -2.4) | (-1438.2–561.9) | ||
O. brucei | 4 | 0.115 ± 0.021 | 0.040 ± 0.010 | 0.032 ± 0.001 | 0.756 ± 0.140 | 3.3 ± 15.5 | 133.3 ± 44.5 | -1166.5 ± 960.3 | -1545.8 ± 115.2 |
(0.090–0.133) | (0.032–0.053) | (0.032–0.033) | (0.629–0.922) | (-11.7–25.0) | (100.0–198.3) | (-2457.3 – -377.4) | (-1653.0 – -1387.3) | ||
O. ireneae | 2 | 0.173 ± 0.026 | 0.091 ± 0.008 | 0.063 ± 0.055 | 0.428 ± 0.027 | -17.5 ± 60.1 | 65.8 ± 15.3 | -173.7 ± 245.7 | -273.8 ± 353.7 |
(0.154–0.192) | (0.085–0.097) | (0.023–0.102) | (0.409–0.447) | (-60.0–25.0) | (55.0–76.7) | (-347.5–0.0) | (-523.9 – -23.7) |
Recordings were sampled using a 16-bit accuracy and a sampling rate converted to 12 kHz in Avisoft-SASLab pro v. 4.3 (Avisoft Bioacoustics). The following 16 variables were collected for each note: F1, frequency at start (peak frequency at 0s, Hz); F2, frequency at end (peak frequency at last of four call intervals, Hz); F3, frequency at 25% of total duration (peak frequency at the first interval, Hz); F4, frequency at midpoint (peak frequency at the second interval, Hz); F5, frequency at 75% of total duration (peak frequency at the third interval, Hz); F6, frequency at maximum amplitude (frequency at maximum amplitude of note, Hz); F7, maximum frequency (maximum frequency through the note, Hz); F8, minimum frequency (minimum frequency through the note, Hz); DT1, total duration (duration, s); DT2, time to maximum amplitude (time to maximum amplitude of note, s); DT3, time to maximum frequency (time to maximum frequency of note, s); DT4, internote interval (start time – end time of previous note, s); DF1, frequency drop from start to end (F2-F1, Hz); DF2, frequency range (F7-F8, Hz); DFT1, slope from 25% to 75% of total duration ([F5-F3]/∆t, Hz/s); DFT2, slope from midpoint to end ([F2-F4]/∆t, Hz/s). The 16 variables were extracted from the analysis of the spectrograms. We used a Fast Fourier Transformation size of 512 points, a 100% frame size and a temporal resolution overlap of 87.5% (flat top window type), resulting in a frequency resolution of 86 Hz and a temporal resolution of 4.5 ms. Frequencies were analysed between 0.5 Hz (highpass) and 2.25 Hz (lowpass), except for O. brucei with the highpass set at 0.0 Hz; the greyscale was set to 30%. When background noise hampered the measurement of the variables, frequencies were filtered and adjusted by shortening the interval between the highpass and the lowpass.
For each recording, variables were measured on six notes and their means (Suppl. material
PCA was performed using the FactoMineR package (
Blood samples were collected non-destructively from the brachial vein of mist-netted individuals and were stored in 96% ethanol for genetic analysis (see molecular dataset: Table
List of scops-owls (Otus) samples and GenBank accession numbers for the gene fragments used in this study. Accession numbers in bold indicate sequences newly produced for this study. STP – São Tomé and Príncipe; EG – Equatorial Guinea; DRC – Democratic Republic of the Congo; CHIMERA – sequences for a given taxon obtained from different individuals.
Taxon | Locality | 12S | 16S | ATP6 | COI | CYTB | ND2 | ND3 | KIAA | MYO2 | RAG1 | SACS | TGFB2 | TTN |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
O. bikegila sp. nov. 1 | STP: Príncipe | OM978880 | OM978895 | OM913485 | OM937282 | OM937307 | OM937351 | ON016156 | OM937319 | OM937336 | ON016107 | ON016118 | ON016136 | ON016141 |
O. bikegila sp. nov. 2 | STP: Príncipe | OM978881 | OM978896 | OM913486 | OM937283 | OM937308 | OM937352 | ON016157 | – | – | ON016108 | ON016119 | ON016137 | ON016142 |
O. bikegila sp. nov. 3 | STP: Príncipe | OM978882 | OM978897 | – | OM937284 | OM937309 | OM937353 | ON016158 | – | OM937337 | ON016109 | ON016120 | ON016139 | ON016143 |
O. bikegila sp. nov. 4 | STP: Príncipe | OM978883 | OM978898 | OM913487 | OM937285 | OM937310 | OM937354 | ON016159 | OM937320 | OM937338 | ON016110 | ON016121 | ON016140 | ON016144 |
O. hartlaubi 1 | STP: São Tomé | OM978884 | OM978899 | EU601139 | OM937286 | EU601108 | EU601032 | EU600995 | OM937321 | EU601072 | – | ON016122 | EU600952 | ON016145 |
O. hartlaubi 2 | STP: São Tomé | OM978885 | OM978900 | – | OM937287 | OM937303 | OM937349 | ON016160 | OM937322 | OM937329 | ON016111 | ON016123 | ON016130 | ON016146 |
O. hartlaubi 3 | STP: São Tomé | OM978886 | OM978901 | – | OM937288 | OM937304 | OM937347 | ON016161 | OM937323 | OM937330 | ON016112 | ON016124 | ON016131 | ON016147 |
O. hartlaubi 4 | STP: São Tomé | OM978887 | OM978902 | OM913483 | OM937289 | OM937305 | OM937348 | ON016162 | OM937324 | OM937331 | ON016113 | ON016125 | ON016132 | ON016148 |
O. senegalensis senegalensis | South Africa | – | – | EU601166 | – | EU601127 | EU601056 | EU601019 | – | EU601098 | – | – | EU600976 | – |
O. senegalensis feae | EG: Annobón | OM978891 | OM978908 | OM913484 | OM937293 | OM937306 | OM937350 | ON016155 | OM937327 | OM937333 | ON016116 | ON016128 | ON016138 | ON016151 |
O. pembaensis 1 | Tanzania: Pemba | – | – | EU601157 | – | EU601123 | EU601048 | EU601010 | – | EU601090 | – | – | EU600967 | – |
O. pembaensis 2 | Tanzania: Pemba | – | – | EU601158 | – | EU601124 | EU601049 | EU601011 | – | EU601091 | – | – | EU600968 | – |
O. pamelae | Saudi Arabia | – | – | – | – | – | KC138819 | KC138827 | – | KC138812 | – | – | – | – |
O. scops 1 | France | – | – | EU601146 | – | EU601115 | EU601039 | EU601001 | – | EU601079 | – | – | EU600958 | – |
O. scops 2 | France | – | OM978906 | – | – | OM937314 | – | ON016164 | OM937325 | OM937334 | ON016114 | ON016126 | ON016135 | ON016149 |
O. scops 3 | France | – | OM978907 | – | – | OM937313 | – | ON016165 | OM937326 | OM937339 | ON016115 | ON016127 | ON016133 | ON016150 |
O. scops 4 | France | OM978890 | OM978905 | OM913488 | OM937292 | OM937312 | OM937355 | ON016163 | – | – | – | – | – | – |
O. cyprius | Cyprus | – | – | – | KT803674 | OM937311 | – | – | – | – | – | – | – | – |
O. brucei | CHIMERA– United Arab Emirates; Oman | – | – | – | – | EU348985 | KC138817 | KC138825 | – | KC138811 | EU348920 | – | – | – |
O. longicornis | CHIMERA– Philippines – Isabela, Luzon; Unknown | U83751 | OM978909 | EU601151 | OM937294 | EU601119 | OM937356 | EU601005 | – | EU601084 | – | – | EU600962 | – |
O. mirus | CHIMERA– Philippines: Mindanao; Unknown | U83752 | – | – | – | EU601126 | EU601057 | EU601020 | – | EU601099 | – | – | EU600978 | – |
O. elegans | Unknown | – | – | – | AB842985 | EU123899 | – | – | – | – | – | – | – | – |
O. mayottensis | Mayotte | – | – | EU601154 | – | EU601122 | EU601046 | EU601008 | – | EU601087 | – | – | EU600965 | – |
O. madagascariensis | Madagascar | OM978893 | OM978911 | OM913489 | OM937295 | OM937315 | OM937357 | ON016166 | – | EU601082 | – | – | EU600960 | – |
O. rutilus | Madagascar | – | – | EU601135 | – | EF198270 | EF198304 | EU600989 | – | EU601066 | – | – | EU600946 | – |
O. capnodes | Comoros: Anjouan | – | – | EU601145 | – | EU601114 | EU601038 | EU601000 | – | EU601078 | – | – | EU600957 | – |
O. insularis | Seychelles: Mahe | – | – | EU601128 | – | EU601101 | EU601022 | EU600983 | – | EU601059 | – | – | EU600940 | – |
O. sunia | CHIMERA– China x 2; Thailand | OM978894 | OM978912 | OM913491 | ON016106 | OM937316 | OM937358 | ON016167 | – | EU601081 | EU348927 | – | EU600959 | – |
O. socotranus | Socotra | – | – | – | – | – | KC138824 | KC138832 | – | KC138816 | – | – | KC138810 | – |
O. pauliani | Comoros: Grande Comore | – | – | – | – | EU601125 | EU601058 | EU601021 | – | EU601100 | – | – | EU600979 | – |
O. moheliensis | Comoros: Moheli | OM978892 | OM978910 | OM913490 | – | OM937317 | EU601045 | ON016168 | OM937328 | OM937335 | ON016117 | ON016129 | ON016134 | ON016152 |
O. icterorhynchus holerythrus | CHIMERA– Cameroon: Efulan; DRC: Kivu | – | – | – | – | OM937318 | OM937359 | ON016169 | – | – | – | – | – | – |
O. icterorhynchus icterorhynchus | Liberia: Lofa County | – | – | – | – | – | OM937360 | ON016170 | – | OM937332 | – | – | – | – |
O. bakkamoena marathae | India: Wadi | – | – | – | – | – | OM937340 | – | – | – | – | – | – | – |
O. lempiji | CHIMERA– Singapore: Indonesia (captive); Unknown | OM978888 | OM978903 | OM913481 | OM937290 | OM937296 | OM937341 | ON016153 | – | EU601076 | EU348922 | – | EU600981 | – |
O. lettia | CHIMERA– Russia; China; Laos | – | – | EU601140 | GQ482285 | EU601109 | EU601033 | EU600996 | – | EU601073 | EU348923 | – | EU600953 | – |
O. megalotis | CHIMERA– Philippines – Isabela: Luzon | – | – | EU601133 | JQ175645 | EU601105 | EU601027 | EU600988 | – | EU601064 | – | – | EU600944 | – |
O. nigrorum | CHIMERA– Philippines: Panay; Unknown | U83755 | – | – | – | JN131497 | KF792802 | – | – | – | EU348924 | – | – | – |
O. everetti | CHIMERA– Philippines: Mindanao; Unknown | U83754 | – | – | U83779 | JN131492 | JN131480 | – | – | – | – | – | – | – |
O. semitorques | CHIMERA– Russia; Unknown | AY513588 | – | EU601142 | AB843645 | EU601111 | EU601035 | EU600998 | – | EU601075 | – | – | EU600955 | – |
O. angelinae | Indonesia: Java | – | – | – | – | – | OM937342 | – | – | – | – | – | – | – |
O. silvicola | Indonesia: Flores | – | – | – | – | OM937302 | – | – | – | – | – | – | – | – |
O. spilocephalus vandewateri | Sumatra | – | – | – | – | OM937297 | OM937343 | – | – | – | – | – | – | – |
O. spilocephalus vulpes | Malaysia: Perak | – | – | – | – | OM937298 | OM937344 | – | – | – | – | – | – | – |
O. spilocephalus luciae | Borneo | – | – | – | – | OM937299 | – | – | – | – | – | – | – | – |
O. spilocephalus spilocephalus | CHIMERA– China; Unknown | – | – | EU601147 | – | EU601116 | EU601040 | – | – | EU601080 | KJ456094 | – | EU600980 | – |
O. spilocephalus hambroecki | Taiwan: Horisha | – | – | – | – | OM937300 | OM937345 | – | – | – | – | – | – | – |
O. spilocephalus latouchi | CHIMERA– Laos; China | OM978889 | OM978904 | OM913482 | OM937291 | OM937301 | OM937346 | ON016154 | – | – | EU348926 | – | – | – |
O. ireneae | Kenya | – | – | EU601144 | – | EU601113 | EU601037 | EU600999 | – | EU601077 | – | – | EU600956 | – |
Bubo bubo | France | – | – | EU601137 | – | AJ003969 | EU601029 | EU600992 | – | EU601069 | – | – | EU600949 | – |
Strix aluco | France | – | – | EU601138 | – | EU601107 | EU601030 | EU600993 | – | EU601070 | – | – | EU600950 | – |
Total genomic DNA was extracted from blood and tissue samples using an overnight Proteinase K digestion (10 mg/ml concentration) followed by a standard high-salt extraction method (
Mitochondrial and nuclear markers (mtDNA and nuDNA, respectively) were amplified and sequenced for the samples that were available to us. For mtDNA we amplified a fragment of the 12s and 16s ribosomal RNA genes (12S and 16S), ATPase subunit 6 (ATP6), cytochrome oxidase subunit I (COI), cytochrome b (CYTB), nicotinamide adenine dinucleotide dehydrogenase subunits 2 and 3 (ND2 and ND3). The nuDNA markers were: leucine-rich repeat and WD repeat-containing protein (KIAA1239), myoglobin intron-2 (MYO2), Recombination Activating Gene 1 (RAG1), sacsin (SACS), TGFb2 intron-5 (TGFB2), and titin (TTN).
Standard polymerase chain reactions (PCR) were performed in a final volume of 25 µl using 1 µl of each primer (10 pmol), 0.4 µl of total dNTPs (10 mM; Promega), 0.1 µl of 5 U/ml GoTaq Flexi DNA Polymerase (Promega), 5 µl of 5X Green GoTaq Flexi Buffer (Promega), 4 µl of MgCl2 (25 mM; Promega). The first PCR of the fragments amplified using a nested PCR approach (KIAA1239, SACS, TTN) were performed in half total reaction volume (12,5 µl). Primers and PCR conditions are provided as Suppl. material
PCR amplification of CYTB and ND2 sequences of O. cyprius, O. i. icterorhynchus, Wallace’s Scops-Owl O. silvicola (Wallace, 1864), and four subspecies of the Mountain Scops-Owl (Blyth, 1846) [O. spilocephalus vandewateri (Robinson & Kloss, 1916), O. s. vulpes (Ogilvie-Grant, 1906), O. s. luciae (Sharpe, 1888), and O. s. hambroecki (Swinhoe, 1870)] was performed in seven fragments of ca. 180–200 bp using custom-made primers (see Suppl. material
Chromatograms of newly generated sequences were checked by eye, edited and aligned using BioEdit v. 7.0.5.3 (
Six different datasets were compiled for different purposes, detailed below.
ND2 sequences of the species belonging to the Afro-Palearctic clade and of O. brucei, whose taxonomic affinities are not resolved, although it appears to be closer to African and Indian Ocean islands species than to the Asian species (
Molecular dataset used for the phylogenetic and divergence time analyses. This dataset comprised 51 individuals from 39 taxa and a final concatenated sequence alignment of 12,925 bp. This dataset was built with the sequences produced in this study together with previously available sequences. We used homologous sequences of the Tawny Owl Strix aluco Linnaeus, 1758 and of the Eurasian Eagle-Owl Bubo bubo (Linnaeus, 1758) for outgroup rooting. The input files for phylogenetic inference were prepared in “Pipelogeny” (
Bayesian inference (BI) analyses were computed in MrBayes v. 3.2.6 (
We estimated divergence times (one partition per locus) using Beast 1.10.4 (
The alignments of each nuclear gene were analysed separately to obtain evidence for genetic differentiation of lineages from unlinked loci and, hence, to provide further support to their status as distinct species following the criterion of genealogical concordance (Avise and Ball 1990;
This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the ICZN. The LSID (Life Science Identifier) for this publication is: urn:lsid:zoobank.org:pub:0731A37D-B363-43C9-A1AC-69F5E10F6810. The electronic edition of this work was published in a journal with an ISSN, and has been archived and is available from the following digital repositories: https://zookeys.pensoft.net/.
Molecular data are deposited in GenBank. Photographs and audio recordings are deposited in Macaulay Library and Xeno-canto, respectively. All other datasets underpinning this article are available as supplementary files (Suppl. materials
Following the integration by congruence approach (
Genetic divergence, in % base pairs difference, between and within (bold) Otus taxa of the Afro-Palearctic clade, estimated from uncorrected pairwise distances of the ND2 fragment (1037 bp). For taxa with a single sample, within-taxon variation could not be calculated (nc).
Taxon | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
---|---|---|---|---|---|---|---|---|---|
O. bikegila sp. nov. (n = 4) | 1 | 0.0% | |||||||
O. hartlaubi (n = 4) | 2 | 4.1% | 0.1% | ||||||
O. senegalensis senegalensis (n = 1) | 3 | 4.4% | 3.3% | nc | |||||
O. senegalensis feae (n = 1) | 4 | 4.7% | 3.6% | 0.7% | nc | ||||
O. pembaensis (n = 2) | 5 | 4.5% | 3.9% | 4.2% | 4.5% | 0.0% | |||
O. pamelae (n = 1) | 6 | 6.2% | 3.6% | 3.4% | 3.0% | 4.5% | nc | ||
O. scops (n = 2) | 7 | 4.1% | 4.7% | 4.9% | 5.0% | 5.3% | 3.2% | 0.1% | |
O. brucei (n = 1) | 8 | 9.1% | 7.0% | 6.9% | 6.5% | 7.1% | 6.7% | 7.7% | nc |
A Principal Component Analysis scatterplot of morphological measurements of Otus species and B the correlation circle in which ‘contrib’ corresponds to the contribution of the variables in accounting for the variability in the Principal components. Morphological measurement abbreviations – Bilen: bill length from bill tip to where culmen enters feathers; Binares: bill length from the anterior end of the nares to the tip; Biwid: bill width; Tarlen: tarsus length; Tailen: tail length; Wilen: wing length.
Oscillograms and spectrograms of 2-s sections of the song of O. bikegila sp. nov. (XC619448), O. hartlaubi (XC673669), O. senegalensis senegalensis (XC45502), O. senegalensis feae (XC340505), O. pembaensis (XC253581), O. pamelae (XC371431), O. scops (XC383983), O. cyprius (XC256102), O. brucei (XC158086), and O. ireneae (XC147630). Each section refers to an individual owl. For more information about the recordings used see Suppl. material
A Principal Component Analysis scatterplot of bioacoustics variables of Otus species and B the correlation circle in which ‘contrib’ corresponds to the contribution of the variables in accounting for the variability in the Principal components. Bioacoustic parameters – F1: frequency at start; F2: frequency at end; F3: frequency at 25% of total duration; F4: frequency at midpoint; F5: frequency at 75% of total duration; F6: frequency at maximum amplitude; F7: maximum frequency; F8: minimum frequency; DT1: total duration; DT2: time to maximum amplitude; DT3: time to maximum frequency; DT4: internote interval; DF1: frequency drop from start to end; DF2: frequency range; DFT1: slope from 25% to 75% of total duration; DFT2: slope from midpoint to end.
Multi-locus phylogeny of scops-owls (Strigidae: Otus). Phylogram (50% majority rule consensus tree) from a Bayesian Inference analysis of the dataset 2, including 12S, 16S, ATP6, COI, CYTB, ND2, ND3, KIAA, MYO2, RAG1, TGFB2, and TTN gene fragments. Asterisks denote posterior probabilities values: (*) 0.85–0.94, * 0.95–0.98, ** 0.99–1. Scale bar corresponds to 0.02 substitutions per site. Strix aluco was set as outgroups (not shown on the figure).
Haplotype network reconstruction for the nuclear KIAA, MYO2, TGFB2, and TTN gene fragments in Otus bikegila sp. nov., O. hartlaubi, O. senegalensis senegalensis, O. senegalensis feae, O. pembaensis, O. pamelae, O. scops, and O. brucei (when available). Area of circles is proportional to the number of individuals with that haplotype. The smallest circles (white) represent unsampled or extinct haplotypes.
In the PCA, the first two components presented eigenvalues higher than one (Suppl. material
For the Welch’s ANOVAs, O. brucei obsoletus was not included due to the small sample size. All variables differed significantly between species (P < 0.05), except Bidepth (Suppl. material
In the PCA, four components presented eigenvalues higher than one (Suppl. material
Means of all bioacoustic variables differed significantly (P < 0.05) between species (Suppl. material
The ND2 sequences (Dataset 1; 1037 pb) of the four samples of Otus bikegila sp. nov. were identical (Table
The concatenated sequences of the phylogenetic dataset (Dataset 2; 12,925 bp; Suppl. material
The topology of the majority rule consensus tree (Dataset 2; Fig.
Otus bikegila sp. nov. samples were recovered as monophyletic, and formed a clearly distinct lineage belonging to the Afro-Palearctic clade. It was recovered as the sister lineage (PP = 1) of the clade formed by O. senegalensis senegalensis, O. senegalensis feae, O. hartlaubi, and O. pembaensis (Fig.
The best model of sequence evolution for each marker used for the divergence times analyses are listed in the Suppl. material
Nuclear markers independently supported the evolutionary independence of the taxa of the Afro-Palearctic clade. The taxa included in the analysis shared no haplotypes for markers KIAA1239 and TGFB2; the latter was the most variable of the analysed nuclear markers with a total of 19 haplotypes (Fig.
Holotype.
The new species (Figs
We provide here a diagnosis relatively to the closely related species belonging to the Afro-Palearctic clade and also to O. ireneae due to the similarity in their calls. The diagnosis is based on the following analysed morphological characters: 1) Biwid; 2) Binares; 3) Tarlen; 4) Wilen; 5) Tailen); 6) SP10; 7) SP9; 8) SP4; on the following analysed bioacoustics characters: 9) F1; 10) F2; 11) F3; 12) F4; 13) F5; 14) F6; 15) F7; 16) F8; 17) DT1; 18) DT2; 19) DT4; 20) DF1; 21) DF2; 22) DFT1; 23) DFT2; and on the 24) list of diagnostic substitutions identified at the analysed nuclear markers (Tables
In overall appearance, O. bikegila sp. nov. is most similar to O. hartlaubi from which it differs in one morphological and 10 bioacoustic characters: longer Wilen (145 to 151 mm vs. 130 to 139 mm), lower F1 (781.7 to 961.7 Hz vs. 1078.3 to 1360.0 Hz), lower F2 (933.3 to 1020.0 Hz vs. 1155.0 to 1285.0 Hz), lower F3 (980.0 to 1090.0 Hz vs. 1330.0 to 1478.3 Hz), lower F4 (950.0 to 1050.0 Hz vs. 1295.0 to 1483.3 Hz), lower F5 (931.7 to 1020.0 Hz vs. 1250.0 to 1418.3 Hz), lower F6 (976.7 to 1090.0 Hz vs. 1331.7 to 1480.0 Hz), lower F7 (1035.0 to 1106.7 Hz vs. 1407.5 to 1526.7 Hz), lower F8 (868.3 to 973.3 Hz vs. 1066.7 to 1267.5 Hz), shorter DT1 (0.231 to 0.248 s vs. 0.267 to 0.315 s), shorter DT4 (0.992 to 1.121 s vs. 9.181 to 15.998 s). Otus bikegila sp. nov. differs from O. hartlaubi also by the following molecular characters: KIAA (T vs. C in site 347); TTN (G vs. C in site 91); MYO2 (G vs. A in site 2); TGFB2 (C vs. A in site 28, G vs. A in site 33, G vs. T in site 47, T vs. C in site 99, A vs. G in site 178, G vs. T in site 305, C vs. G in site 369).
Otus bikegila sp. nov. differs from O. senegalensis senegalensis in seven morphological and one bioacoustic characters: higher Biwid (9.0 to 11.8 mm vs. 4.8 to 8.0 mm), larger Binares (11.3 to 12.6 mm vs. 8.0 to 12.5 mm), longer Tarlen (30.5 to 35.1 mm vs. 20.0 to 24.2 mm), longer Wilen (145 to 151 mm vs. 103 to 145 mm), longer Tailen (75 to 85 mm vs. 40 to 65 mm), longer SP10 (37 to 40 mm vs. 10 to 32 mm), longer SP9 (13 to 18 mm vs. 1 to 16 mm), lower F4 (950.0 to 1050.0 Hz vs. 1095.0 to 1236.7 Hz); and in the following molecular characters: TGFB2 (A vs. G in site 178, T vs. G in site 344).
Otus bikegila sp. nov. differs from O. senegalensis feae in one morphological and four bioacoustic characters: larger Biwid (9.0 to 11.8 mm vs. 6.4 to 6.8 mm), lower F2 (933.3 to 1020.0 Hz vs. 1132.5 to 1230.0 Hz), lower F7 (1035.0 to 1106.7 Hz vs. 1250.0 to 1357.5 Hz), shorter DT1 (0.231 to 0.248 s vs. 0.402 to 0.441 s), shorter DT4 (0.992 to 1.121 s vs. 7.127 to 7.479 s); and in the following molecular characters: KIAA (T vs. C in site 347, T vs. C in site 503); TGFB2 (A vs. G in site 178, T vs. C in site 285, G vs. C in site 392).
Otus bikegila sp. nov. differs from O. pembaensis in one morphological and nine bioacoustic characters: shorter SP4 (6 to 9.5 mm vs. 11 to 21 mm), higher F1 (781.7 to 961.7 Hz vs. 506.7 to 636.7 Hz), higher F2 (933.3 to 1020.0 Hz vs. 613.3 to 773.3 Hz), higher F3 (980.0 to 1090.0 Hz vs. 621.7 to 770.0 Hz), higher F4 (950.0 to 1050.0 Hz vs. 633.3 to 780.0 Hz), higher F5 (931.7 to 1020.0 Hz vs. 651.7 to 783.3 Hz), higher F6 (976.7 to 1090.0 Hz vs. 638.3 to 776.7 Hz), higher F7 (1035.0 to 1106.7 Hz vs. 660.0 to 790.0 Hz), higher F8 (868.3 to 973.3 Hz vs. 530.0 to 660.0 Hz), shorter DT4 (0.992 to 1.121 s vs. 5.043 to 7.570 s); and in the following molecular characters: TGFB2 (A vs. G in site 178, T vs. C in site 285, C vs. T in site 345).
Otus bikegila sp. nov. differs from O. pamelae in seven bioacoustic characters (morphology not analysed): lower F1 (781.7 to 961.7 Hz vs. 1031.7 to 1213.3 Hz), lower F2 (933.3 to 1020.0 Hz vs. 1111.7 to 1268.3 Hz), lower F4 (950.0 to 1050.0 Hz vs. 1096.7 to 1366.7 Hz), lower F5 (931.7 to 1020.0 Hz vs. 1083.3 to 1291.7 Hz), lower F6 (976.7 to 1090.0 Hz vs. 1160.0 to 1403.3 Hz), lower F7 (1035.0 to 1106.7 Hz vs. 1220.0 to 1516.7 Hz), lower F8 (868.3 to 973.3 Hz vs. 1020.0 to 1123.3 Hz).
Otus bikegila sp. nov. differs from O. scops in seven morphological and 11 bioacoustic characters: higher Biwid (9.0 to 11.8 mm vs. 5.5 to 7.8 mm), larger Binares (11.3 to 12.6 mm vs. 9.0 to 11.5 mm), longer Tarlen (30.5 to 35.1 mm vs. 22.0 to 28.0 mm), shorter Wilen (145 to 151 mm vs. 147 to 165 mm), longer SP10 (37 to 40 mm vs. 12 to 24 mm), longer SP9 (13 to 18 mm vs. 0 to 7 mm), shorter SP4 (6 to 9.5 mm vs. 10 to 29 mm), lower F1 (781.7 to 961.7 Hz vs. 1335.0 to 1695.0 Hz), lower F2 (933.3 to 1020.0 Hz vs. 1152.5 to 1275.0 Hz), lower F3 (980.0 to 1090.0 Hz vs. 1155.0 to 1260.0 Hz), lower F4 (950.0 to 1050.0 Hz vs. 1200.0 to 1285.0 Hz), lower F5 (931.7 to 1020.0 Hz vs. 1193.3 to 1318.3 Hz), lower F6 (976.7 to 1090.0 Hz vs. 1210.0 to 1326.7 Hz), lower F7 (1035.0 to 1106.7 Hz vs. 1336.3 to 1628.3 Hz), lower F8 (868.3 to 973.3 Hz vs. 1140.0 to 1253.3 Hz), shorter DT4 (0.992 to 1.121 s vs. 2.423 to 2.789 s), higher DF1 (6.7 to 178.3 Hz vs. -420.0 to -182.5 Hz), lower DFT1 (-581.5 to 45.2 Hz/s vs. 181.5 to 662.3 Hz/s); and in the following molecular characters: KIAA (T vs. C in site 347, A vs. G in site 632); TTN (T vs. C in site 535, G vs. A in site 536, G vs. T in site 634); TGFB2 (G vs. A in site 33, G vs. T in site 47, A vs. G in site 178, T vs. C in site 285).
Otus bikegila sp. nov. differs from O. cyprius in four bioacoustics characters (morphology and nuclear markers not analysed): presence of a monosyllabic primary song (O. cyprius has a distinctive di-syllabic primary song), lower F1 (781.7 to 961.7 Hz vs. 1236.7 to 1400.0 Hz [long note] and 1058.9 to 1223.3 Hz [short note]), shorter DT4 (0.992 to 1.121 s vs. 3.035 to 3.643 s [long note] and 3.116 to 3.714 [short note]), and having a higher DF1 (6.7 to 178.3 Hz vs. -283.3 to -165.0 Hz [long note] and -113.3 to -58.1 [short note]).
Otus bikegila sp. nov. differs from O. brucei in 11 bioacoustic characters (morphology not analysed): higher F1 (781.7 to 961.7 Hz vs. 285.0 to 388.3 Hz), higher F2 (933.3 to 1020.0 Hz vs. 891.7 to 946.7 Hz), higher F3 (980.0 to 1090.0 Hz vs. 356.7 to 530.0 Hz), higher F4 (950.0 to 1050.0 Hz vs. 356.7 to 493.3 Hz), higher F5 (931.7 to 1020.0 Hz vs. 335.0 to 450.0 Hz), higher F6 (976.7 to 1090.0 Hz vs. 370.0 to 510.0 Hz), higher F7 (1035.0 to 1106.7 Hz vs. 370.0 to 530.0 Hz), higher F8 (868.3 to 973.3 Hz vs. 270.0 to 373.3 Hz), longer DT1 (0.231 to 0.248 s vs. 0.090 to 0.133 s), longer DT2 (0.078 to 0.112 s vs. 0.032 to 0.053 s), higher DFT2 (-250.3 to 21.7 Hz/s vs. -1653.0 to -1387.3 Hz/s); and in the following molecular characters: MYO2 (T vs. C in site 22; C vs. T in site 118; C vs. T in site 129).
Otus bikegila sp. nov. differs from O. ireneae in one bioacoustic character (morphology and nuclear markers not analysed): longer DT4 (0.992 to 1.121 s vs. 0.409 to 0.447 s).
Morphological measurements available in Table
General colouration : Back, Burnt Amber 48 with Robin Rufous 29 shades; front, Pale Buff 1 feathers with Cinnamon 21 and Dusky Brown 285 markings (forming stripes defined by Dusky Brown 285 lines) with Robin Rufous 29 shades.
Head : Chin feathers Pale Buff 1 with Sayal Brown 41 shading along shaft, ending with a bristle-like barb Sepia 286. Throat feathers Pale Buff 1 with Pale Pinkish Buff 3 and Sepia 286 dots and markings sometimes forming bands; Pale Buff 1 shaft proximally becoming Pale Pinkish Buff 3 and Sepia 286 distally. Feathers of forehead Sepia 286 and few Pale Buff 1 shading. Tip of the head triangle Prout’s Brown 47. Triangle outside facial disk with an overall appearance Prout’s Brown 47, triangle with feather with Sepia 286 middle stripe along shaft, Prout’s Brown 47 and Sepia 286 in their internal portion and Sepia 286 and Pale Buff 1 in the outer portion but always ending with Prout’s Brown 47 or Robin Rufous 29 in the distal portion. Triangle delineated by Pale Buff 1/Smoke Grey 266 stripes (the eyebrows). Eyebrows Pale Buff 1/Smoke Grey 266 down to the bill: Pale Buff 1 feathers ending with a thin Cinnamon 21 line followed by a broader Jet Black 300 band; Pale Buff 1 feathers with middle Sepia 286 stripe along shaft and densely vermiculated with Sepia 286 and Cinnamon 21 shades; eyebrows feathers in distal portion are Pale Buff 1 densely vermiculated with Sepia 286 and Cinnamon 21 shades, ending in Prout’s Brown 47. Crown feathers Prout’s Brown 47 with Sepia 286 middle stripe along shaft, Pale Buff 1 in proximal section and Prout’s Brown 47 with Sepia 286 vermiculation along mid and distal portion. Ear tuft not visible in the mounted specimen, but with feathers Pale buff 1 in proximal section becoming Cinnamon 21 with densely Sepia 286 vermiculation and ending with Prout’s Brown 47; ear feathers pull up some of the eyebrow feather with Sepia 286 and Cinnamon 21 dense vermiculation. Nape feathers Pale Pinkish Buff 3 with well-defined Sepia 286 irregular stripes, ending with middle Sepia 286 stripe along shaft and Burnt Amber 48. Neck feathers with longer underfeathers (then in nape) with middle Sepia 286 stripe along shaft with Pale Pinkish Buff 3, Pale Buff 1, Pale Pinkish Buff 3 and becoming Pale Buff 1 and Burnt Amber 48 all with Sepia 286 irregular markings. Overall appearance of rictal bristles: Jet Black 300 patches with Cinnamon 21 and Pale Buff 1 shades next to the bill (following with Pale Buff 1/Smoke Grey 266 eyebrows); bristles with terminal Jet Black 300 colour; bristles closer to the bill Pale Buff 1 in proximal position, changing into Cinnamon 21 and ending in Jet Black 300 or Pale Buff 1 in the proximal section and Jet Black 300 in distal section; bristles closer to the eye Jet Black 300 in proximal position, changing into Cinnamon 21 and ending in Jet Black 300 or only Jet Black 300 (the shortest one). Rim with two narrow Raw Umber 23 bands, one on each side, not extending to the centre; Pale Buff 1 feathers with Sepia 286 irregular markings, becoming Cinnamon 21 (with no Sepia 286 markings), ending with Raw Umber 23. Facial disk feathers Pale Buff 1 with multiple bands of Sepia 286 (generally 3), the terminal Sepia 286 bands is preceded by a thin Robin Rufous 29 band; feather ending with 2 to 5 bristle-like barbs.
Upperparts : Overall colour of mantle (i.e., upper back) and rump: Burnt Amber 48 with Robin Rufous 29 shades. Feathers Sayal Brown 41 with middle Sepia 286 line along shaft, and with irregular Sepia 286 markings in the proximal section. Feathers turning Cinnamon-Rufous 31 with Sepia 286 markings in the distal portion of the feather. Mantle is delimited distally (neck) by a Cinnamon-Rufous 31 band and laterally by a series of 8 feathers that are lighter in colour (Cinnamon-Rufous 31): outer vane Light Buff 2 with Cinnamon-Rufous 31 shades and with a Sepia 286 curve line that defines a Raw Sienna 32 colour close to shaft, one or more Sepia 286 spots on distal outer vane; outer vane ending distally with Raw Sienna 32 with Sepia 286 markings; inner vane is Raw Sienna 32 with Sepia 286 irregular markings. These feathers appear to make a line that delineates the outside of the mantle. Similarly, the feathers of the mantle at the base of the neck form a lighter Cinnamon Rufous 31 line that follows the external side of the folded wings, making a triangle. Scapulars as upperparts. Proximal shaft Pale Buff 1, Vandyke Brown 282 in distal portion; Vandyke Brown 282 middle stripe along shaft. Outer vane is Cinnamon 21 with Sepia 279 markings and inner vane is Sepia 279 with Cinnamon 21 markings.
Underparts : Breast overall Pale Buff 1 with Sepia 286 irregular markings and Robin Rufous 29 shading. Breast feathers Pale Pinkish Buff 3 with Sepia 286 dots and markings proximally and Pale Pinkish Buff 3 shaft, distally Sepia 286 with Pale Pinkish Buff 3 dots and markings forming irregular bands, middle Sepia 286 stripes along shaft. Belly overall similar to breast but with colours more defined and with Light Buff 2 shadings. Belly feathers Pale Pinkish Buff 3 in proximal section followed by a Sepia 286 V stripe. This is followed by a Pale Buff 1 broad band delimitated distally with a thin Pale Pinkish Buff 3 line followed by a Sepia 286 line. Distally, these feathers are Pale Buff 1 with irregular spots Sepia 286 and Pale Pinkish Buff 3. Some feathers on the belly and the vent have a marked middle and broad Sepia 286 line along shaft. Vent is similar to breast and belly but with feathers Cinnamon 21 in proximal section followed by a Sepia 286 stripe. This is followed by a Pale Buff 1 broad band delimitated distally with a thin Cinnamon 21 followed by a Sepia 286 line. The feather then becomes Pale Buff 1 with a Cinnamon 21 thin band followed by a Sepia 286 line, ending with a Pale Buff 1 colouration with Sepia 286 irregular dots and markings. Flank feathers Pale Buff 1 with Cinnamon 21 shading followed by a broad Cinnamon 21 V stripe followed by a Sepia 286 line, ending with a broad Pale Buff 1 section with Sepia 286 markings only in the very distal portion. Undertail coverts are similar to flanks but with more defined bands. Feathers are Pale Buff 1 followed by a broad Cinnamon 21 band defined distally by a thinner warm Sepia 40 line. This colouration is repeated twice. Feathers end with a broad Pale Buff 1 band followed by a Cinnamon 21 band with irregular Warn Sepia 40 markings. Tarsus covered with feathers to base of toes. Feathers overall similar to flank but with less Pale Buff 1 and more Cinnamon 21 shading and one or two Sepia 286 dots in distal section. Tarsus feathers have a larger proportion of Pale Buff 1 close to toes. Tarsus feathers are Pale Buff 1 proximally, followed by Cinnamon 21 shading and Sepia 286 markings distally (approximately 1/4 of the feather distally), no middle stripe along shaft. Toes feathers are Pale Buff 1 with Cinnamon 21 shadings and Sepia 286 markings only in the distal section.
Wing : Overall Prout’s Brown 47 with Dark Greyish Brown 284 leopard blotches. Primaries shaft Vandyke Brown 282. Outer vane of primaries with six or seven ‘leopard’ Dark Greyish Brown 284 spots in Cinnamon 21 background becoming Pale Buff 1 in some instances. Spots interior with a gradient of Cinnamon 21 to Dark Greyish Brown 284 with lighter spots on outer primaries. Spots circumference with Dark Greyish Brown 284 to Jet Black 300. ‘Leopard spots’ start faint (P1-P2-P3) and become stronger moving outwards. Inner vane of primaries with Dark Greyish Brown 284 with Cinnamon 21 shadings towards the distal section of the feather. Exterior edge makes a Pale Buff 1 line. Under-primaries have a Pale Buff 1 shaft proximally becoming Cinnamon 21 towards the distal portion. Outer vane of under-primaries is proximally Hair Brown 277 with Pale Pinkish Buff 3 irregular triangles, becoming Cinnamon 21 in distal section with Sepia 279 lines delimiting the leopard spots that are fading towards the distal portion of the feather. Inner vane of under-primaries is Hair Brown 277 with Light Buff 2 markings in proximal section and Cinnamon 21 markings in distal section. Secondaries shaft Vandyke Brown 282. Outer vane of secondaries is similar but much less marked pattern than primaries: spots on outer vanes less marked, fading into the background towards S10. Inner vane of secondaries with Sepia 279 with Cinnamon 21 shadings and markings especially towards the distal section of the feather. Under-secondaries have a Pale Buff 1 shaft proximally becoming Cinnamon 21 and later Sepia 279 towards the distal portion. Outer vane of under-secondaries with Hair Brown 277 with Cinnamon 21 markings. Inner vane of under-secondaries with Hair Brown 277 with six to seven Light Buff 2 triangles only on the outer part of the inner vane, which become irregular markings (Cinnamon 21 in colour) towards the distal portion of the feather. Tertiaries shaft like primaries (Vandyke Brown 282). Outer and inner vane of tertiaries similar in colour and similar to the outer vane of the secondaries. Under-tertiaries have Pale Buff 1 shaft proximally becoming Cinnamon 21 and later Sepia 279 towards the distal portion. Outer and inner vanes of under-tertiaries are similar: Cinnamon 21 with irregular Sepia 279 lines in the proximal portion, becoming irregular dots towards the distal section; terminal 1/5 with a Sepia 279 middle stripe along shaft. Primary coverts with Vandyke Brown 282 shafts. Outer vane of primary coverts with Sepia 279 with Cinnamon 21 markings becoming more packed towards the distal portion of the feather. Inner vane of primary coverts is similar to outer but with less packed Cinnamon 21 markings. Secondary coverts are overall Sepia 279 with Cinnamon 21 markings. Shaft is Vandyke Brown 282. Outer vane of secondary coverts with a Pale Buff 1 blotch delimited proximally by a Sepia 279 thin and sharp line. This blotch can have in its inner parts a Cinnamon 21 blotch delimited by a Sepia 279 thin and sharp line. Additional Sepia 279 lines distributed heterogeneously can be found on the outer vane. Inner vane of secondary coverts Sepia 279 with Light Buff 2 markings in proximal section and Cinnamon 21 markings in the distal portion of the feather. Lesser coverts with shafts Pale Buff 1 proximally and Vandyke Brown 282 in distal portion. Vandyke Brown 282 middle stripe along shaft. Outer vane of lesser coverts Cinnamon 21 with Sepia 279 markings and Pale Pinkish Buff 3 markings delimited irregularly by Sepia 279 dashed lines. Inner vane of lesser coverts Sepia 279 with Cinnamon 21 markings. Coverts in the under-wings with Pale Buff 1 shaft. Outer vane on the coverts from the under-wings is Pale Buff 1 and Light Buff 2 with one Sepia 279 leopard spot and some additional (but rare) Sepia 279 markings. Inner vane of the coverts from the under-wings Pale Buff 1 and Light Buff 2 with Light Neutral Grey 297 colouration that become Sepia 279 distally. Alula shaft is Vandyke Brown 282. Outer vane of alula with five Verona Brown 37 ‘leopard’ spots delimited by Sepia 279 lines which is sharper in distal portion. Leopard spots separated by Pale Pinkish Buff 3 with Cinnamon 21 shadings. Inner vane of alula Sepia 279 with four Light Buff 2 partial bands.
Tail : Verona Brown 37 with Sepia 286 markings that fades towards the distal portion of the feather. Shaft Sepia 286. Outer feathers of the tail have an outer vane Verona Brown 37 with broad Sepia 286 bands, and an inner vane with broad poorly defined Sepia 286 bands intercalated by Light Buff 2, Pale Pinkish Buff 3 and more distally Verona Brown 37 bands.
Bill : Dusky Brown 285 and lower bill Light Buff 2.
Iris : Yellow.
Vocalisations : Call recordings collected at the moment of specimen collection included the call of the holotype and a second individual (XC audios: XC619445, XC619447): one emitted the main call type (the single repetitive note used in the bioacoustic analyses), and the other the cat-like call. We believe that the holotype individual was the one giving the main call, but this was uncertain. Thus, it is not possible to provide bioacoustics parameters specific to the holotype.
Variation
: Morphometric variation in O. bikegila sp. nov. is based on the analysis of three additional individuals, of which one is a male (Table
Vocalisations were recorded at the type locality by MM in 2002, 2007, 2011, 2018 and 2019 and at Boca do Inferno in 2019, and by PV at the type locality in 2016. The call of O. bikegila was described in
The species name is a patronym honouring Ceciliano do Bom Jesus, known as ‘Bikegila’ (Suppl. material
Bikegila, a native of Príncipe Island, began the ‘Príncipe Scops-Owl saga’ in 1998, when he shared with MM reports of two sightings of birds that looked like owls in parrot nests. Since then, Bikegila took part in every field effort that led to the bird’s discovery for science; he also led the capture of all sampled individuals, including the holotype, which required ingenious ways to erect canopy nets. For almost 25 years, Bikegila has put all his resources, including bottomless fieldwork skills and a vast knowledge of Príncipe, towards the successful completion of innumerable research projects in a terrain that the collector José Correia considered to be the “bad among the bad or the worse among the worse” [sic] (Diary, 2 September 1928, Archives
We believe that most field researchers are grateful to the ‘Bikegilas’ with whom they are/were honoured to work with. As such, the name is also in recognition of all the people, around the world, who through their deep relationship with and knowledge of the regions they inhabit, play key roles in the description of new species and of new sites to science.
We propose the English common name Principe Scops-Owl, the name for São Tomé and Príncipe as Kitóli-do-príncipe, and the name for the Portuguese list of the birds of the world as Mocho-do-príncipe. All common names refer to Príncipe Island, from where it is endemic.
All records from O. bikegila sp. nov. come from old-growth native lowland rainforest with mid-height (14–20 m) trees (Fig.
The holotype (Figs
Otus bikegila sp. nov. starts calling at dusk and continues throughout the night. Contrarily to the Sao Tome Scops-Owl O. hartlaubi that regularly vocalises during the day, O. bikegila sp. nov. seems to require darkness to sing, although on a single occasion one individual was heard during the day (
Multiple lines of evidence were brought together to demonstrate, unambiguously, that the recently discovered population of scops-owls on Príncipe Island makes a well-differentiated species, Otus bikegila. Genetic distances, and associated divergence times, to its closest relatives were in the range of those separating currently accepted species (Table
Although it may seem odd for a bird species to remain undiscovered for science for so long on such a small island, this is by no means an isolated case when it comes to owls. For example, the recently described Rinjani Scops-Owl O. jolandae Sangster, King, Verbelen & Trainor, 2013 was found to be a previously undescribed species from Lombok Island, Indonesia (
Our phylogenetic analyses confirmed the supported nodes from previous phylogenies (
In relation to African taxa, the most interesting result came from the inclusion of samples from the two subspecies of the only African Otus species never sequenced before: the Sandy Scops-Owl O. icterorhynchus. Together with O. ireneae, this is the only species on the African continent that is a lowland forest specialist (albeit each species occupies very distinct forest types), and the two species were widely hypothesised as being closely related (
This study better resolved the branching sequence within the Afro-Palearctic clade, except for the position of O. pamelae that could not be determined, contra
The internodes separating O. senegalensis (mainland and Annobón Island), O. hartlaubi (São Tomé Island), and O. pembaensis (Pemba Island) are very short, indicating that the divergence between these three species (i.e., the colonisation of both islands from their mainland ancestor) occurred almost simultaneously, creating a hard polytomy. Our analyses failed to identify solid lines of evidence for the distinctiveness of O. senegalensis feae from O. senegalensis senegalensis, although we did identify a diagnostic morphological character (bill length from tip to nares, Suppl. material
Our sampling increased considerably the taxon coverage for the centre of the diversity of the Otus genus, the Indo-Malayan region (
Our molecular dataset confirmed the low levels of divergence (well within intraspecific variation) of three taxa pairs that are currently treated either as separate species or subspecies. These pairs are: i) O. senegalensis senegalensis (mainland Africa) and O. s. feae (Annobón Island), treated as separate species by
The discovery of a new bird species inhabiting the forests of Príncipe Island in 2016 (here formally described as Otus bikegila) underscores both the actuality of field-based explorations aiming at describing biodiversity (
We thank An Bollen (first in Principe Trust Foundation, later in Forever Principe) for the support for the expeditions from 2016 onwards that led to the discovery of the new species, and that subsequently allowed the collection of the data required to confirm its status and prepare its description; An also participated in a field expedition. Felipe Spina (Fauna & Flora International, Principe Trust Foundation) provided invaluable fieldwork support and enthusiasm for the 2016 and 2017 expeditions (discovery of the owl and holotype collection, respectively). We thank Augusto Faustino for his technical advice on the use of isoflurane. We thank everyone at Forever Principe for the full logistic support of the 2018 and 2019 expeditions and in particular: Rombout and Ella Swanborn, Myles Oates, Walter Jubber, and everyone at Roça Belo Monte. We thank the additional logistic support from the Príncipe Foundation, of its director Estrela Matilde and staff. We are extremely thankful to our field assistants Dy, Ni and Nidi. Veerle Dossche assisted PV on the 2016 expeditions that first confirmed the irrefutable occurrence of a scops-owl on Príncipe Island. We thank the former director of the Department of the Environment, Arlindo Carvalho, and the former director of Príncipe Obô Natural Park, Daniel Ramos, for their full support and the emission of the necessary permits. We are especially indebted to Vanya Rohwer (Curator of Birds and Mammals, Museum of Vertebrates, Cornell University) for the holotype preparation, and to David Gonçalves and Daniele Cataldo (FCUP, Porto) for the skeleton preparation. We thank all curators who kindly gave us access to collections under their care: Hein van Grouw (Natural History Museum, NHM, Tring), Gerald Mayr (SMF, Frankfurt), Martin Päckert (
This project was supported by Forever Príncipe Conservation Alliance (from Africa’s Eden to MM and BF) with additional funding from National Geographic Society (Early career grant - EC-364C-18 to BF), and was developed in collaboration with the Príncipe Obô Natural Park and Fundação Príncipe, which provided key logistic support for fieldwork. This work benefited from the use of the Portuguese Infrastructure of Scientific Collections (PRISC.pt). The Portuguese Foundation for Science and Technology (FCT) supported the post-doc grant FCT/MCTES - SFRH/BPD/100614/2014 to MM, the PhD grant (2020.04569.BD) to BF, the Investigador FCT (IF/00209/2014) and 2020.00823.CEECIND/CP1601/CT0003 research contracts to AC, and provided structural funding to CIBIO (UIDB/50027/2021) and cE3c (UID/00329/2021). GS was supported by a postdoctoral grant from the Swedish Research Council (grant 2015-06455). This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement nº 854248.
Fieldwork in Príncipe Obô Natural Park, collection of the specimen and samples were authorised by Arlindo Carvalho, Director of the Department of the Environment of São Tomé and Príncipe, Daniel Ramos, Director of the Príncipe Obô Natural Park and Plácida Lopes, Director of the Príncipe Biosphere Reserve. CITES export permit nº 18ST0015; CITES import permit nº 20STP.
Timeline
Data type: Text report.
Explanation note: Timeline of the discovery for science of the Principe Scops-Owl Otus bikegila sp. nov.
Alignment
Data type: Docx file.
Explanation note: Concatenated sequences of the phylogenetic dataset.
Figure S1. Topography Owls
Data type: Image (pdf file).
Explanation note: Figure S1. Topography of owls, with the terms used for the description and diagnosis of the Principe Scops-Owl Otus bikegila sp. nov. Illustration by MNC.
Figure S2. Song oscillograms and spectrograms
Data type: Image (pdf file).
Explanation note: Figure S2. Oscillograms and spectrograms of 10s sections of the call of O. bikegila sp. nov.: (A) primary call of an individual, recorded on January 20, 2019, XC619448; (B) two different individuals duetting, recorded on July 28, 2018, XC619439; (C) cat-like “kee-a-u” call of one individual, recorded on January 15, 2019, XC619443; (D) two different individuals duetting, in which one emits a cat-like “kee-a-u” call, recorded on January 20, 2019, XC619448. Codes from Xeno-canto.org database.
Figure S3. Bikegila
Data type: Image (pdf file).
Explanation note: Figure S3. Photograph taken at Boca do Inferno, Príncipe Island, January 27, 2019, showing the Principe Scops-Owl Otus bikegila sp. nov., the two first authors of the paper (BF on the left and MM on the right), and Ceciliano do Bom Jesus, known as ‘Bikegila’ (centre), who started the 20-year saga that led to this discovery, and in honour of whom the new species was named (see ‘Etymology’).
Table S1. Description
Data type: Morphological.
Explanation note: Table S1. Plumage colour and pattern description of O. bikegila sp. nov., O. hartlaubi, O. scops scops, O. senegalensis senegalensis, O. senegalensis feae and O. pembaensis. Colour definition follow the colour standards of
Table S2. Details of song recordings
Data type: Database: song recordings
Explanation note: Table S2. Details of the recordings used for bioacoustic analyses. Recording codes - XC: Xeno-canto; IBC: The Internet Bird Collection (now under the Macaulay Library); AV: Avian Vocalizations Center (AVoCet). STP: São Tomé and Príncipe.
Table S3. Song measurements
Data type: Statistics: Bioaucoustics.
Explanation note: Table S3. Measures taken for the songs in each recording used for bioacoustic analyses. Bioacoustic parameters - F1: frequency at start; F2: frequency at end; F3: frequency at 25% of total duration; F4: frequency at midpoint; F5: frequency at 75% of total duration; F6: frequency at maximum amplitude; F7: maximum frequency; F8: minimum frequency; DT1: total duration; DT2: time to maximum amplitude; DT3: time to maximum frequency; DT4: internote interval; DF1: frequency drop from start to end; DF2: frequency range; DFT1: slope from 25% to 75% of total duration; DFT2: slope from midpoint to end.
Localities
Data type: excel file.
Explanation note: Coordinates of tissue sampling localities for Otus bikegila sp. nov. and O. hartlaubi.
Table S4. Genomic regions, primers and amplification conditions
Data type: Database: Genomic regions and primers.
Explanation note: Table S4. Gene name, primer name, sequence, source, and amplification conditions used in the present study. PCR conditions start with temperature (in °C) of each step followed by the time in seconds. * primers used to amplify internal fragments (used for the amplification of DNA from toe-pad extractions). # custom-made primers used to amplify CYTB and ND2 fragments from Otus cyprius, O. i. icterorhynchus, O. silvicola, O. spilocephalus vandewateri, O. s. vulpes, O. s. luciae, and O. s. hambroecki.
Table S5. PCA factor loadings of morphological variables
Data type: Statistics: Morphological.
Explanation note: Table S5. Factor loadings of morphological variables on the first two principal components for seven Otus taxa (O. bikegila sp. nov., O. hartlaubi, O. senegalensis senegalensis, O. senegalensis feae, O. pembaensis, O. scops, O. brucei). Eigenvalues and percentage of variance explained by the respective components are given at the bottom of the table. Morphological measurements – Bilen: bill length from bill tip to where culmen enters feathers; Binares: bill length from the anterior end of the nares to the tip; Biwid: bill width; Tarlen: tarsus length; Wilen: wing length; Tailen: tail length.
Table S6. Morphological differentiation
Data type: Statistics: Morphology.
Explanation note: Table S6. Results of Welch’s ANOVA and Games-Howell post-hoc comparisons performed with the morphometric variables of six Otus taxa (O. bikegila sp. nov., O. hartlaubi, O. senegalensis senegalensis, O. senegalensis feae, O. pembaensis, O. scops). Superscript values indicate significance levels (* P < 0.05; ** P < 0.01; *** P < 0.005; **** P < 0.001) and NA (Not Available, significance level not possible to obtain due to low sample size). Some individuals had missing data, not allowing for the test performance (indicated by -). Morphological measurements – Bilen: bill length from bill tip to where culmen enters feathers; Biwid: bill width; Bidepth: bill depth at the anterior end of nares; Binares: bill length from the anterior end of the nares to the tip; Hebi: head+bill, from the tip of the bill to the opposite point on the back of the skull; Midt: middle toe length; Tarlen: tarsus length; Wilen: wing length; Tailen: tail length; Bolen: body length; SP: shortfall in relation to tip of longest primary (P1 is the closest to the body), SP10: shortfall of P10; SP9: shortfall of P9; SP5: shortfall of P5; SP4: shortfall of P4.
Table S7. PCA factor loadings of bioacoustic variables
Data type: Statistics: Bioaucoustics.
Explanation note: Table S7. Factor loadings of bioacoustic variables on the four principal components in 10 Otus taxa (O. bikegila sp. nov., O. hartlaubi, O. senegalensis senegalensis, O. senegalensis feae, O. pembaensis, O. pamelae, O. scops, O. cyprius, O. brucei, O. ireneae). Eigenvalues and percentage of variance explained by the respective components are given at the bottom of the table. Bioacoustic parameters - F1: frequency at start; F2: frequency at end; F3: frequency at 25% of total duration; F4: frequency at midpoint; F5: frequency at 75% of total duration; F6: frequency at maximum amplitude; F7: maximum frequency; F8: minimum frequency; DT1: total duration; DT2: time to maximum amplitude; DT3: time to maximum frequency; DT4: internote interval; DF1: frequency drop from start to end; DF2: frequency range; DFT1: slope from 25% to 75% of total duration; DFT2: slope from midpoint to end.
Table S8. Bioacoustics differentiation
Data type: Statistics: Bioacoustics.
Explanation note: Table S8. Results of Welch’s ANOVA and Games-Howell post-hoc comparisons performed with the bioacoustic variables of 10 Otus taxa (O. bikegila sp. nov., O. hartlaubi, O. senegalensis senegalensis, O. senegalensis feae, O. pembaensis, O. pamelae, O. scops, O. cyprius, O. brucei, O. ireneae). Superscript values indicate significance levels that are indicated with asterisks (* P < 0.05; ** P < 0.01; *** P < 0.005; **** P < 0.001) and NA (Not Available, significance level not possible to obtain due to low sample size). Bioacoustic parameters - F1: frequency at start; F2: frequency at end; F3: frequency at 25% of total duration; F4: frequency at midpoint; F5: frequency at 75% of total duration; F6: frequency at maximum amplitude; F7: maximum frequency; F8: minimum frequency; DT1: total duration; DT2: time to maximum amplitude; DT3: time to maximum frequency; DT4: internote interval; DF1: frequency drop from start to end; DF2: frequency range; DFT1: slope from 25% to 75% of total duration; DFT2: slope from midpoint to end.
Table S9. Phylogeny: sequence partition and evolution models
Data type: Analysis: Partitioning scheme and selected models of evolution.
Explanation note: Table S9. Best-fitting partitioning scheme, and respective best model of sequence evolution, inferred with PartitionFinder2 for the dataset used to infer the phylogenetic affinities within the genus Otus (Suppl. material
Table S10. Divergence times: sequence evolution models
Data type: Analysis: Selected models of evolution for divergence times.
Explanation note: Table S10. Best models of sequence evolution, inferred with MEGA X, for the markers used in divergence time analyses of the genus Otus.