Migratory orientation in a narrow avian hybrid zone
Background Zones of contact between closely related taxa with divergent migratory routes, termed migratory divides, have been suggested as areas where hybrid offspring may have intermediate and inferior migratory routes, resulting in low fitness of hybrids and thereby promoting speciation. In the Ro...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
PeerJ Inc.
2017-04-01
|
| Series: | PeerJ |
| Subjects: | |
| Online Access: | https://peerj.com/articles/3201.pdf |
| _version_ | 1797417686989275136 |
|---|---|
| author | David P.L. Toews Kira E. Delmore Matthew M. Osmond Philip D. Taylor Darren E. Irwin |
| author_facet | David P.L. Toews Kira E. Delmore Matthew M. Osmond Philip D. Taylor Darren E. Irwin |
| author_sort | David P.L. Toews |
| collection | DOAJ |
| description | Background Zones of contact between closely related taxa with divergent migratory routes, termed migratory divides, have been suggested as areas where hybrid offspring may have intermediate and inferior migratory routes, resulting in low fitness of hybrids and thereby promoting speciation. In the Rocky Mountains of Canada there is a narrow hybrid zone between Audubon’s and myrtle warblers that is likely maintained by selection against hybrids. Band recoveries and isotopic studies indicate that this hybrid zone broadly corresponds to the location of a possible migratory divide, with Audubon’s warblers migrating south-southwest and myrtle warblers migrating southeast. We tested a key prediction of the migratory divide hypothesis: that genetic background would be predictive of migratory orientation among warblers in the center of the hybrid zone. Methods We recorded fall migratory orientation of wild-caught migrating warblers in the center of the hybrid zone as measured by video-based monitoring of migratory restlessness in circular orientation chambers. We then tested whether there was a relationship between migratory orientation and genetic background, as measured using a set of species-specific diagnostic genetic markers. Results We did not detect a significant association between orientation and genetic background. There was large variation among individuals in orientation direction. Mean orientation was towards the NE, surprising for birds on fall migration, but aligned with the mountain valley in which the study took place. Conclusions Only one other study has directly analyzed migratory orientation among naturally-produced hybrids in a migratory divide. While the other study showed an association between genetic background and orientation, we did not observe such an association in yellow-rumped warblers. We discuss possible reasons, including the possibility of a lack of a strong migratory divide in this hybrid zone and/or methodological limitations that may have prevented accurate measurements of long-distance migratory orientation. |
| first_indexed | 2024-03-09T06:22:13Z |
| format | Article |
| id | doaj.art-d50f5e8dcea24518b18d62e68ebb61a4 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:22:13Z |
| publishDate | 2017-04-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-d50f5e8dcea24518b18d62e68ebb61a42023-12-03T11:34:52ZengPeerJ Inc.PeerJ2167-83592017-04-015e320110.7717/peerj.3201Migratory orientation in a narrow avian hybrid zoneDavid P.L. Toews0Kira E. Delmore1Matthew M. Osmond2Philip D. Taylor3Darren E. Irwin4Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, CanadaDepartment of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, CanadaDepartment of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, CanadaDepartment of Biology, Acadia University, Wolfville, Nova Scotia, CanadaDepartment of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, CanadaBackground Zones of contact between closely related taxa with divergent migratory routes, termed migratory divides, have been suggested as areas where hybrid offspring may have intermediate and inferior migratory routes, resulting in low fitness of hybrids and thereby promoting speciation. In the Rocky Mountains of Canada there is a narrow hybrid zone between Audubon’s and myrtle warblers that is likely maintained by selection against hybrids. Band recoveries and isotopic studies indicate that this hybrid zone broadly corresponds to the location of a possible migratory divide, with Audubon’s warblers migrating south-southwest and myrtle warblers migrating southeast. We tested a key prediction of the migratory divide hypothesis: that genetic background would be predictive of migratory orientation among warblers in the center of the hybrid zone. Methods We recorded fall migratory orientation of wild-caught migrating warblers in the center of the hybrid zone as measured by video-based monitoring of migratory restlessness in circular orientation chambers. We then tested whether there was a relationship between migratory orientation and genetic background, as measured using a set of species-specific diagnostic genetic markers. Results We did not detect a significant association between orientation and genetic background. There was large variation among individuals in orientation direction. Mean orientation was towards the NE, surprising for birds on fall migration, but aligned with the mountain valley in which the study took place. Conclusions Only one other study has directly analyzed migratory orientation among naturally-produced hybrids in a migratory divide. While the other study showed an association between genetic background and orientation, we did not observe such an association in yellow-rumped warblers. We discuss possible reasons, including the possibility of a lack of a strong migratory divide in this hybrid zone and/or methodological limitations that may have prevented accurate measurements of long-distance migratory orientation.https://peerj.com/articles/3201.pdfMigrationHybrid zoneMigration orientationHybrids |
| spellingShingle | David P.L. Toews Kira E. Delmore Matthew M. Osmond Philip D. Taylor Darren E. Irwin Migratory orientation in a narrow avian hybrid zone PeerJ Migration Hybrid zone Migration orientation Hybrids |
| title | Migratory orientation in a narrow avian hybrid zone |
| title_full | Migratory orientation in a narrow avian hybrid zone |
| title_fullStr | Migratory orientation in a narrow avian hybrid zone |
| title_full_unstemmed | Migratory orientation in a narrow avian hybrid zone |
| title_short | Migratory orientation in a narrow avian hybrid zone |
| title_sort | migratory orientation in a narrow avian hybrid zone |
| topic | Migration Hybrid zone Migration orientation Hybrids |
| url | https://peerj.com/articles/3201.pdf |
| work_keys_str_mv | AT davidpltoews migratoryorientationinanarrowavianhybridzone AT kiraedelmore migratoryorientationinanarrowavianhybridzone AT matthewmosmond migratoryorientationinanarrowavianhybridzone AT philipdtaylor migratoryorientationinanarrowavianhybridzone AT darreneirwin migratoryorientationinanarrowavianhybridzone |