Migratory stopover timing is predicted by breeding latitude, not habitat quality, in a long-distance migratory songbird

Journal Article · Mon Feb 06 00:00:00 EST 2017 · Journal of Ornithology

DOI:https://doi.org/10.1007/s10336-017-1435-x· OSTI ID:1410338

Loon, A. Van ^[1]; Ray, J. D. ^[2]; Savage, A. ^[3]; Mejeur, J. ^[3]; Moscar, L. ^[3]; Pearson, M. ^[3]; Pearman, M. ^[4]; Hvenegaard, G. T. ^[5]; Mickle, N. ^[6]; Applegate, K. ^[7]; Fraser, Kevin C. ^[1]

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1. Univ. of Manitoba, Winnipeg (Canada)
2. Consolidated Nuclear Security, LLC, Amarillo, TX (United States)
3. Disney's Animals Science and Environment, Lake Buena Vista, FL (United States)
4. Ellis Bird Farm, Lacombe (Canada)
5. Univ. of Alberta, Camrose (Canada)
6. Woodbridge (United States)
7. Mille Lacs Band of Ojibwe, Onamia, MN (United States)

The timing of migration can have important survival impacts, as birds must synchronize their movements with favourable environmental conditions to reach their destination. The timing of arrival at and duration of migratory stopover may be largely governed by environmental conditions experienced en route as well as by endogenous factors, but our understanding of these processes is limited. We used light-level geolocators to collect start-to-finish spatio-temporal migration data for a declining aerial insectivore, the Purple Martin (Progne subis), that travels seasonally between North and South America. Using data obtained for birds originating from range-wide breeding populations, our objectives were to test intrinsic and extrinsic hypotheses for migration stopover duration as well as to identify important stopover regions during fall migration. We examined whether breeding latitude, fall migration timing, age, sex or habitat quality at stopover sites (measured using Normalized Difference Vegetation Index) influenced the duration of stopovers. We found that most individuals rely on the eastern coast of the Yucatan Peninsula, Honduras, and Nicaragua for stopovers during fall migration, where duration ranged from 1 to 36 days (average 6.8 ± 8.2). Stopovers in these regions were later and of longer duration for more northern breeding populations. Only breeding latitude predicted stopover duration, and not habitat quality at stopovers, lending support to the hypothesis that duration is prescribed by endogenous factors. Lastly, the important core stopover regions we documented could be targeted for conservation efforts, particularly for steeply-declining, more northern breeding populations that have greater stopover duration in these areas.

• Research Organization: Pantex Plant (PTX), Amarillo, TX (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: NA0001942
• OSTI ID: 1410338
• Report Number(s): PX--2209
• Journal Information: Journal of Ornithology, Journal Name: Journal of Ornithology Journal Issue: 3 Vol. 158; ISSN 2193-7192
• Publisher: Journal of Ornithology
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
aerial insectivore
direct tracking
geolocator
migration behavior
migration phenology