Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014
We studied the east-to-west migration of the endangered Steppe Eagle (Aquila nipalensis) in Nepal at Thoolakharka (elevation 2050 masl) from mid-September to early December 2012 – 2014, to estimate the age structure of the population and describe its annual migration pattern. We counted 6100 to 8700...
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| Format: | Article |
| Language: | English |
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Raptor Research Foundation
2017
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| Online Access: | http://psasir.upm.edu.my/id/eprint/62780/ http://psasir.upm.edu.my/id/eprint/62780/1/Population%20structure%20.pdf |
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| author | Subedi, Tulsi Ram Decandido, Robert Baral, Hem Sagar Gurung, Surya Gurung, Sandesh Chong, Leong Puan Mohd Sah, Shahrul Anuar |
| author_facet | Subedi, Tulsi Ram Decandido, Robert Baral, Hem Sagar Gurung, Surya Gurung, Sandesh Chong, Leong Puan Mohd Sah, Shahrul Anuar |
| author_sort | Subedi, Tulsi Ram |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | We studied the east-to-west migration of the endangered Steppe Eagle (Aquila nipalensis) in Nepal at Thoolakharka (elevation 2050 masl) from mid-September to early December 2012 – 2014, to estimate the age structure of the population and describe its annual migration pattern. We counted 6100 to 8700 individuals/year, and aged approximately 60% of the eagles that passed: 20% juveniles (902), 37% subadults (1679) and 43% adults (1910). We observed the bulk (67%) of eagle migration after 1200 H, with a peak between 1400 – 1500 H. For these 3 yr, the median passage date of juveniles was earlier than the median passage date of subadults and adults. The proportion of different age classes in 2012 was significantly different from that in 2013 (G = 18.4, P < 0.001) and 2014 (G = 147.4, P < 0.001). There were no significant differences among years in the number in each age class (χ2 = 1.655, P = 0.437; χ2= 1.125, P = 0.570; and χ2= 3.240, P = 0.198, respectively for juveniles, subadults and adults), however median of the number of total migrating Steppe Eagles counted each year were significance different (χ2= 6.318, P = 0.042). We did not see a difference in the yearly migration pattern of Steppe Eagles but we observed high proportion of juveniles earlier, adults later in the season and also fewer Steppe Eagles passing through the area than previous short-term studies had estimated. |
| first_indexed | 2025-11-15T11:13:28Z |
| format | Article |
| id | upm-62780 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T11:13:28Z |
| publishDate | 2017 |
| publisher | Raptor Research Foundation |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-627802022-11-09T00:32:14Z http://psasir.upm.edu.my/id/eprint/62780/ Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 Subedi, Tulsi Ram Decandido, Robert Baral, Hem Sagar Gurung, Surya Gurung, Sandesh Chong, Leong Puan Mohd Sah, Shahrul Anuar We studied the east-to-west migration of the endangered Steppe Eagle (Aquila nipalensis) in Nepal at Thoolakharka (elevation 2050 masl) from mid-September to early December 2012 – 2014, to estimate the age structure of the population and describe its annual migration pattern. We counted 6100 to 8700 individuals/year, and aged approximately 60% of the eagles that passed: 20% juveniles (902), 37% subadults (1679) and 43% adults (1910). We observed the bulk (67%) of eagle migration after 1200 H, with a peak between 1400 – 1500 H. For these 3 yr, the median passage date of juveniles was earlier than the median passage date of subadults and adults. The proportion of different age classes in 2012 was significantly different from that in 2013 (G = 18.4, P < 0.001) and 2014 (G = 147.4, P < 0.001). There were no significant differences among years in the number in each age class (χ2 = 1.655, P = 0.437; χ2= 1.125, P = 0.570; and χ2= 3.240, P = 0.198, respectively for juveniles, subadults and adults), however median of the number of total migrating Steppe Eagles counted each year were significance different (χ2= 6.318, P = 0.042). We did not see a difference in the yearly migration pattern of Steppe Eagles but we observed high proportion of juveniles earlier, adults later in the season and also fewer Steppe Eagles passing through the area than previous short-term studies had estimated. Raptor Research Foundation 2017-06 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/62780/1/Population%20structure%20.pdf Subedi, Tulsi Ram and Decandido, Robert and Baral, Hem Sagar and Gurung, Surya and Gurung, Sandesh and Chong, Leong Puan and Mohd Sah, Shahrul Anuar (2017) Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014. Journal of Raptor Research, 51 (2). pp. 165-171. ISSN 0892-1016; ESSN: 2162-4569 https://bioone.org/journals/journal-of-raptor-research/volume-51/issue-2/JRR-16-70.1/Population-Structure-and-Annual-Migration-Pattern-of-Steppe-Eagles-at/10.3356/JRR-16-70.1.short 10.3356/JRR-16-70.1 |
| spellingShingle | Subedi, Tulsi Ram Decandido, Robert Baral, Hem Sagar Gurung, Surya Gurung, Sandesh Chong, Leong Puan Mohd Sah, Shahrul Anuar Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 |
| title | Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 |
| title_full | Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 |
| title_fullStr | Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 |
| title_full_unstemmed | Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 |
| title_short | Population structure and annual migration pattern of Steppe Eagles at Thoolakharka Watch Site, Nepal, 2012-2014 |
| title_sort | population structure and annual migration pattern of steppe eagles at thoolakharka watch site, nepal, 2012-2014 |
| url | http://psasir.upm.edu.my/id/eprint/62780/ http://psasir.upm.edu.my/id/eprint/62780/ http://psasir.upm.edu.my/id/eprint/62780/ http://psasir.upm.edu.my/id/eprint/62780/1/Population%20structure%20.pdf |