Short Communication |
Corresponding author: Nelson Colihueque ( ncolih@ulagos.cl ) Academic editor: George Sangster
© 2015 Nelson Colihueque, Alberto Gantz, Jaime Rau, Margarita Parraguez.
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:
Colihueque N, Gantz A, Rau JR, Parraguez M (2015) Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence. ZooKeys 534: 135-146. https://doi.org/10.3897/zookeys.534.5953
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In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy.
Aves , Common Barn Owl, Short-eared Owl, COI, taxonomy
The Common Barn Owl Tyto alba (Scopoli, 1769) (Strigiformes, Tytonidae) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) (Strigiformes, Strigidae) are nocturnal owls usually found in open habitats such as farmland and grassland associated with humanized areas (
The Common Barn Owl includes several subspecies, some of which may represent distinct and endemic species. To date, up to 25 distinct species have been recognized within the Tyto complex but the status of many of these forms remains poorly documented (
The mitochondrial cytochrome c oxidase subunit I (COI) gene is considered a powerful molecular tool for molecular identification (‘barcoding’) of bird species and may also help to clarify taxonomic relationships (
In this study, we sequenced a 648-bp region of the COI gene of the Common Barn Owl and the Short-eared Owl specimens from southern Chile with the aim of comparing these data with the COI sequences published for these species from other geographic areas. Given that no major information on genetic divergence of owls from Chile based on the COI gene is available, this study may contribute to clarifying the taxonomic status and evolutionary divergence at regional and global scales.
Owl samples (Common Barn Owl, n = 9; and Short-eared Owl, n = 1) were collected in 2012 and 2013 from dead birds found along the highways (Ruta 5, Ruta 215 and Ruta 207) that connect Osorno with neighboring cities, which run through the provinces of Valdivia, Ranco and Osorno in southern Chile (40°-41° S latitude) (Figure
COI sequences were amplified using the primer pair of BirdF1 (5’-TTCTCCAACCACAAAGACATT GGCAC-3’) and BirdR1 (5’-ACGTGGGAGATAATTCCA AATCCTG-3’) (
Summary statistics, variable and parsimony informative sites, and p-distances were calculated with MEGA 5.05 (
The sequence alignment of the COI gene obtained had 582 positions in nine specimens of Common Barn Owl from southern Chile, and 12 representative sequences from other regions (one from Argentina, five from North America, two from Central America, two from northern Europe and two from Australasia) obtained from Genbank (http://www.ncbi.nlm.nih.gov/Genbank) (Table
Haplotype designation, variable nucleotide positions of COI gene sequence analysis, with the haplotype frequency observed in each locality. A Haplotypes of Common Barn Owls (n = 21) B haplotypes of Short-eared Owl (n = 10). Number refers to positions identified in the alignment. For all haplotypes, variable nucleotides are indicated while identity is indicated by slashes.
List of all owl analysed in this study, with collection localities, coordinates and GenBank accession numbers of COI gene.
Species | Locality (Country/Continent) |
Locality abbreviation | Coordinates (Lat., Long.) |
Accession numbers |
---|---|---|---|---|
Tyto alba | Chile/ South America | CHI-SAM | 40.60S, 73.04W | KM377629 |
Tyto alba | Chile/ South America | CHI-SAM | 40.08S, 72.87W | KM377630 |
Tyto alba | Chile/ South America | CHI-SAM | 40.29S, 72.97W | KM377631 |
Tyto alba | Chile/ South America | CHI-SAM | 40.41S, 73.00W | KM377632 |
Tyto alba | Chile/ South America | CHI-SAM | 40.35S, 72.99W | KM377633 |
Tyto alba | Chile/ South America | CHI-SAM | 40.29S, 72.94W | KM377635 |
Tyto alba | Chile/ South America | CHI-SAM | 40.18S, 72.91W | KM377636 |
Tyto alba | Chile/ South America | CHI-SAM | 39.84S, 72.81W | KM377637 |
Tyto alba | Chile/ South America | CHI-SAM | 40.69S, 73.13W | KM377638 |
Tyto alba | Argentina /South America | ARG-SAM | 41.11S, 70.37W | FJ028529 |
Tyto alba | Canada/ North America | CAN-NAM | 49.10N, 121.57W | DQ434212 |
Tyto alba | Canada/ North America | CAN-NAM | 49.05N, 123.05W | DQ434213 |
Tyto alba | USA/ North America | USA-NAM | 25.48N, 80.38W | DQ433249 |
Tyto alba | USA/ North America | USA-NAM | NA | JN850741 |
Tyto alba | USA/ North America | USA-NAM | 21.97N, 159.33W | JF498906 |
Tyto alba | El Salvador/ Central America | ESA-CAM | 13.44N, 89.05W | KM894402 |
Tyto alba | El Salvador/ Central America | ESA-CAM | 13.44N, 89.05W | KM894403 |
Tyto alba | Sweden/ northern Europe | SWE-NEU | 55.60N, 13.06E | GU572154 |
Tyto alba | Sweden/ northern Europe | SWE-NEU | 55.65N, 13.14E | GU572155 |
Tyto alba | Australia/ Australasia | AUS-AAS | NA | JN801466 |
Tyto alba | Australia/ Australasia | AUS-AAS | NA | JN801467 |
Asio flammeus | Chile/ South America | CHI-SAM | 40.60S, 72.88W | KM377628 |
Asio flammeus | Argentina/ South America | ARG-SAM | NA | FJ027172 |
Asio flammeus | USA/ North America | USA-NAM | 21.31N, 157.95W | JF498831 |
Asio flammeus | Canada/ North America | CAN-NAM | 60.43N, 135.04W | DQ433331 |
Asio flammeus | Canada/ North America | CAN-NAM | 44.26N, 81.24W | DQ433330 |
Asio flammeus | Sweden/ northern Europe | SWE-NEU | 59.20N, 18.12E | GU571744 |
Asio flammeus | Norway/ northern Europe | NOR-NEU | 68.49N, 16.67E | GU571269 |
Asio flammeus | Norway/ northern Europe | NOR-NEU | NA | GU571270 |
Asio flammeus | Russia/ northern Asia | RUS-NAS | 51.38N,136.55E | GQ481380 |
Asio flammeus | Russia/ northern Asia | RUS-NAS | 59.70N, 151.23E | GQ481381 |
Five haplotypes for the Common Barn Owl specimens were observed, considering all studied localities, with haplotype 1 being exclusive to the New World (including Chile), and representing more than half of the individuals in the data set (61.9%) (Figure
Unrooted haplotype network of COI gene sequence, based on a median-joining network for the Common Barn Owl and the Short-eared Owl. The area of each circle is proportional to the number of individuals containing the haplotype. Open circles indicate mutational events and numbers refer to the variable nucleotide positions. A Common Barn Owl; Solid black: Chile/South America; white with cross lines: Argentina/South America; white with forward diagonal lines: USA/ North America; white with horizontal lines: El Salvador/ Central America; white with vertical lines: Canada/ North America; white with backward diagonal lines: Sweden/ northern Europe; white with backward diagonal cross lines: Australia/ Australasia. B Short-eared Owl; Solid black: Chile/South America; white with cross lines: Argentina/South America; white with forward diagonal lines: USA/ North America; white with horizontal lines: Canada/ North America; white with backward diagonal lines: Sweden/ northern Europe; white with horizontal lines: Russia/ northern Asia; white with cross diagonal lines: Norway/ northern Europe.
The nine sequences of Common Barn Owl from Chile showed low levels of sequence divergence, ranging from 0 to 0.2% uncorrected p-value. Similarly, genetic divergence between Common Barn Owls from Chile and those from elsewhere in the New World was low, ranging from 0.0 to 0.2%. In contrast, genetic divergence between Common Barn Owls from Chile and those from northern Europe and Australasia was much higher, with p-values ranging from 4.6 to 5.5%. The ML tree showed a cluster of sequences from the New World (including Chile), with a clear separation of sequences from northern Europe and Australasia; this tree had nodes with high (100%) bootstrap values (Figure
Phylogenetic estimate of relationships among specimens of the Common Barn Owl from different locations based on analysis of 582 bp of the mitochondrial cytochrome c oxidase subunit I gene (COI). The haplotype, locality and Genbank accession number (in parentheses) for each specimen are shown. The branch lengths are drawn proportional to the relative amount of volutionary change. Scale indicates the sequence divergence estimated from the number of nucleotide substitutions per site A Maximum likelihood tree with the bootstrap support (%) indicated for each node B Bayesian tree with the posterior probability values indicated for each node.
The sequence alignment of the COI gene for Short-eared Owl had 611 positions in one specimen from Chile, and nine representative specimens from other regions (one from Argentina, four from North America, two from northern Europe and two from northern Asia) (Table
Three haplotypes were found, with haplotype 1 (n = 2 individuals) being exclusive to Chile and Argentina, haplotype 2 (n = 5) exclusive to North America, northern Europe and northern Asia and haplotype 3 (n = 1) exclusive to northern Europe.
COI sequences from Chile and Argentina were identical. However, sequences from Chile/Argentina were highly divergent (3.1%) from those from North America, northern Europe and northern Asia. The ML and BI trees (results not shown) showed one cluster for specimens from Chile and Argentina and another cluster for specimens from North America, northern Europe and northern Asia.
The three major groups of Common Barn Owls inferred here by means of phylogenetic analysis of COI sequences (South America plus North America, Australasia and northern Europe) are similar to those identified in previous phylogenetic studies using other molecular markers (mitochondrial cyt b and nuclear LDHb) (
In addition, the genetic distance among the Common Barn Owls from Chile and northern Europe and Australasia, from 4.6 to 5.5%, is not surprising, given that previous studies have also documented high levels of sequence divergence among American and Old World populations of this species, ranging from 5.3 to 7.2% (
With regard to the Short-eared Owl, the intraspecific divergence of 3.1% is in accordance with previous studies that also used the COI gene, which reported a maximum divergence of 3.3% for the species (
The levels of sequence variation observed for the Common Barn Owls and the Short-eared Owl from Chile compared to those from other continents was well above the mean intraspecific distance reported for bird species, which ranges from 0.23% to 0.43% (
In previous studies, high levels of sequence divergence have often been interpreted as a possible taxonomic artifact, i.e. as an indication that more taxonomic study is warranted. For instance,
In conclusion this study provides further evidence that the Common Barn Owl and the Short-eared Owl show high levels of intraspecific COI sequence divergence across their geographic range. The level of genetic differentiation of both species collected in South America was above the upper limit of species reported for Strigiformes, suggesting that further studies are needed to evaluate the taxonomic position of these populations.
The suggestions and constructive comments of all those who helped to improve the final version of this manuscript are gratefully acknowledged, particularly, to the editor and two reviewers for their efforts that greatly improved the quality and clarity of the work. The English language editing of the manuscript by Susan Angus from the Dirección de Investigación of the Universidad de Los Lagos, is also appreciated.
Pictures of external morphology of specimens of Tyto alba and Asio flammeus collected in southern Chile
Data type: Specimens data
Explanation note: Pictures of ventral and dorsal views of specimens showing plumage color and overall appearance. Data on body mass of these specimens are also provided.