Breeding Latitude and Annual Cycle Timing in a Songbird
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Abstract
In spring, songbirds undergo physiological changes such as migratory fattening and gonadal recrudescence in response to increasing day length. Past research suggests that the day length required to initiate physiological changes, known as the photoperiodic threshold, can vary by breeding latitude. In this study, we explored whether migrants breeding at higher latitudes require longer days in spring before physiological changes occur (i.e., whether breeding latitude of origin predicts photoperiodic threshold). We caught and housed male migrant and resident dark-eyed juncos (Junco hyemalis) in an indoor aviary. Photoperiod was increased incrementally from nine to sixteen hours over fourteen weeks. During each photocycle, morphological measurements of mass, subcutaneous body fat, and cloacal protuberance were measured as indicators of migratory and reproductive condition. Stable isotope signatures of hydrogen were used to estimate breeding latitude as an index of migratory distance. Our results show that migrants and residents differed in physiological changes, as migrants accumulated more subcutaneous fat, increased body mass, and displayed a significant delay in gonadal recrudescence relative to residents. Additionally, individuals breeding at higher latitudes deposited fat at a faster rate than individuals breeding at lower latitudes. These results supported our hypothesis that migratory strategy and breeding latitude may predict differences in photoperiodic threshold for both migratory and reproductive timing. Our findings contribute to the understanding of regulation of timing in annual cycles and improve predictions of how species might respond to changing environments.
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References
Bronson, F. H., & Heideman, P. (1994). Seasonal regulation of reproduction in mammals. Physiology of Reproduction, 2, 541–584.
Carey, C. (2009). The impacts of climate change on the annual cycles of birds. Philosophical Transactions of the Royal Society, 364, 3321-3330.
Chemineu, P., Malpaux, B., Brillard, J. P., & Fostier, A. (2007). Seasonality of reproduction and production in farm fishes, birds, and mammals. The Animal Consortium, 1(3), 419-432.
Clark, G. A. (1979). Body weights of birds: A review. The Condor: Ornithological Applications, 81(2), 193–202.
Cohen, J. M., Lajeunesse, M. J., & Rohr, J. R. (2018). A global synthesis of annual phenological responses to climate change. Nature Climate Change, 8, 224-228.
Dawson, A. (2001). Photoperiodic control of seasonality in birds. Journal of Biological Rhythms, 16(4), 365-380.
Dawson, A. (2015). Annual gonadal cycles in birds: Modeling the effects of photoperiod on seasonal changes in GnRH-1 secretion. Frontiers in Neuroendocrinology, 37, 52-64.
Dawson, A., Sharp, P. (2007). Photorefractoriness in birds—photoperiodic and non-photoperiodic control. General and Comparative Endocrinology, 153, 378-384.
Fudickar, A., Grieves, T. J., Atwell, J. W., Stricker, C. A, & Ketterson, E. D. (2016). Reproductive allochrony in seasonally sympatric populations maintained by differential response to photoperiod: Implications for population divergence and response to climate change. The American Naturalist, 187(4), 436-446.
Gwinner, E. (2003). Circannual rhythms in birds. Current Opinion in Neurobiology, 13(6), 770-778.
Hamel, P. (1979). Dark-eyed (Carolina) Junco Nest on Sassafras Mountain in South Carolina. The Chat, 40, 109-111.
Hau, M., Wikelski, M., & Wingfield, J. (2000). Visual and nutritional food cues fine-tune timing of reproduction in a neotropical rainforest bird. Journal of Experimental Zoology. 286, 494-504.
Hobson, K. A., & Wassenaar, L. (1996). Linking breeding and wintering grounds of neotropic migrant songbirds using stable hydrogen isotopic analysis of feathers. Oecologia, 109(1), 142-148.
Jenni, L., & Jenni-Eiermann, S. (1998). Fuel supply and metabolic constraints in birds. Journal of Avian Biology, 29, 521-528.
Kumar, V., Singh, S., Misra, M., & Malik, S. (2001). Effects of duration and time of food availability on photoperiodic responses in the migratory male Blackheaded bunting, Emberiza melanocephalia. The Journal of Experimental Biology, 204, 2843-2848.
Kumar, V., Wingfield, J., Dawson, A., Ramenofsky, M., Rani, S., & Bartell, P. (2010). Biological Clocks and Regulation of Seasonal Reproduction and Migration in Birds. Physiological and Biochemical Zoology, 83(5), 827–835.
McGlothlin, J., Whittaker, D., Schrock, S., Gerlach, N., Jawor, J., Snajdr, E., & Ketterson, E. D. (2010). Natural selection on testosterone production in a wild songbird population. The American Naturalist, 175(6), 687-701.
Nolan Jr., V., Ketterson, E. D., Cristol, D. A., Rogers, C. M., Clotfelter, E. D., Titus, R. C., ... Snajdr, E. (2002). Dark-eyed Junco (Junco hyemalis). Birds of North America. Retrieved from https://doi.org/10.2173/bna.716
Németh, Z., Bonier, F., & MacDougall-Shackleton, S. A. (2013). Coping with uncertainty: Integrating physiology, behavior, and evolutionary ecology in a changing world. Integrative and Comparative Biology, 53(6), 960-964.
Odum, E. (1960). Premigratory hyperphagia in birds. The American Journal of Clinical Nutrition, 8(5), 621-629.
Odum, E., Connell, C., & Stoddard, H. (1961). Flight energy and estimated flight ranges of some migratory birds. The Auk, 78(4), 515-527.
Perfito, N., Meddle, S., Tramontin, A., Sharp, P., & Wingfield, J. (2005). Seasonal gonadal recrudescence in song sparrows: Response to temperature cues. General and Comparative Endocrinology, 143, 121-128.
Pyle, P. (1997). Identification Guide to North American Birds, Part I: Columbidae to Ploceidae. Bolinas, CA: Slate Creek Press.Ramenofsky, M., Campion, A., Pérez, J., Krause, J., & Németh, Z. (2017). Behavioral and physiological traits of migrant and resident white-crowned sparrows. Journal of Experimental Biology, 220, 1330-1340.
Ramenofsky, M., Cornelius, J., & Helm, B. (2012). Physiological and behavioral responses of migrants to environmental cues. Journal of Ornithology, 153, 181-191.
Robinson, J. E., & Follett, B. K. (1982). Photoperiodism in Japanese quail: The termination of seasonal breeding by photorefractoriness. Proceedings of the Royal Society, 215, 95-116.
Rowan, W. (1926). On photoperiodism, reproductive periodicity, and the annual migrations of certain birds and fishes. Proceedings of the Boston Society of Natural History,38, 147-189.
Silverin, B., Massa, R., Stokkan, K. A. (1993). Reproductive adaptations to breeding at different latitudes in great tits. General and Comparative Endocrinology, 90, 14-22.
Visser, M., & Both, C. (2005). Shifts in phenology due to global climate change: the need for a yardstick. Proceedings of the