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-        Mechanisms of Seasonal Timing
-        Biological Rhythms
-        Neuroendocrinology
-        Stress Physiology
-        Organism Environment Interaction
 
My research group is broadly interested in understanding how organism detect, integrate and respond to environmental information. More specifically, we have been focusing on how animals use light and other environmental cues to time major seasonal transitions. We seek to understand the physiological mechanisms underlying these processes in order to be better able to predict how individuals, populations and ultimately species will or will not be able to respond to rapid global change. To do so we take an integrative approach that combines observational studies with hypothesis driven experimental manipulations, while combining molecular, hormonal, and behavioral analyses.

Current research is focused in three main areas:

1.) How do birds use light cues to time seasonal migration?
Many birds (and other animals) rely on the seasonal change in daylength, known as photoperiod, as a reliable environmental cue to time migration. While the importance of light cues in triggering the development of migratory physiology and behavior has long been established, the mechanisms by which this occurs are still not fully understood. In our past work we’ve found that thyroid hormones are necessary for both migratory preparation and behavior. More recently we’ve found evidence that difference in thyroid hormone signaling related genes in the deep brain may distinguish birds that are year-round residents from seasonal migrants. Our current work is taking a comparative approach to further test this finding across multiple species. Additionally, we are using manipulative experiments to further probe the mechanism of light detection and response associated with migration.

2.) How are light cues regulating breeding detected?
As with migration, many species utilize photoperiod to time seasonal breeding. However, unlike migration we have a clear understanding of the neuroendocrine and endocrine pathways controlling breeding in both birds and mammals. Birds (and possibly other non-mammalian vertebrates) are particularly fascinating in that they detect relevant light cues directly in the deep brain. Working with collaborator we have been seeking to definitively identify the non-visual photoreceptors controlling seasonal reproduction.  

3.) How might exposure to light cues experienced in ovo shape development, hatch success and post-hatch welfare? What are the mechanism mediating these effects?
Emerging evidence has shown light can have effect early in develop, even before complete development of the eyes. We are in the midst of developing novel approaches to probe the role of non-visual photoreceptors in mediating these early life effects.

We also have active research projects in stress physiology, behavioral ecology and circadian biology.

Chmura HE, Krause JS, Pérez JH, Ramenofsky R, Wingfield JC. 2020. Autumn migratory departure is influenced by reproductive timing and weather in an Arctic passerine. Journal of Ornithology. 1-13.
 
Pérez JH, Swanson RE†, Lau HJ†, Cheah J†, Snell KRS, Reid AMA, Meddle SL, Wingfield JC, Krause JS. 2020.Tissue-specific expression of 11β-HSD and its effects on plasma corticosterone during the stress response. Journal of Experimental Biology. 223 (1).
 
Pérez JH, Tolla E, Dunn IC, Meddle SL, Stevenson TJ. 2018.  A comparative perspective on extra-retinal photoreception. Trends in Endocrinology and Metabolism. 10.1016/j.tem.2018.10.005
 
Krause JS, Pérez JH, Chmura HE. Hunt KE, Meddle SL, Gough L., Boelman NT, and Wingfield JC. 2018. Weathering the storm: Do Arctic blizzards cause repeatable changes in stress physiology and body condition in breeding songbirds? General and Comparative Endocrinology. 267, 183-192
 
Oliver R, Ellis D, Chmura HE, Gough L, Krause JS, Pérez JH, Sweet SK, Wingfield JC, Boelman N. 2018. Eavesdropping on the Arctic: Automated bioacoustics to reveal dynamics in songbird phenology in response to global change. Science Advances. 4 (6).
 
Pérez JH, Krause JS, Chmura HE, Gough L, & Wingfield JC. 2018. Tundra songbird community composition during recovery from the Anaktuvuk River Fire. International Journal of Wildland Fire. 27 (1), 69-71.
 
Pérez JH, Meddle SL, Furlow, JD, Wingfield JC, and Ramenofsky M. 2018. Effects of thyroid hormone knockdown and rescue on pre-nuptial molt, luteinizing hormone and gonadal growth in white-crowned sparrows (Z. leuchophrys gambelii). General and Comparative Endocrinology. 255: 12-18.

 
 
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