Broadly, research in my lab seeks to understand how animals adjust their behavior in response to changing environmental conditions. This work draws from the fields of behavior, physiology, ecology, and evolution. We are interested in both how environmental cues are used to adjust behavior and the physiological mechanisms underpinning such responses. Ultimately, this line of research addresses the fundamental biological question of how animals cope with environmental variability.
Major themes of our current research are highlighted below.
Much of this research has been supported by NSF IOS 1456954/1756976 and NSF IOS 1755227.
Facultative migration
Every year billions of animals around the world and across the animal kingdom undertake migrations. These migrations are critical to the dynamics of ecosystems, have impacts on human health, and are especially prone to disturbance by global environmental change. Much of what we know about migratory biology comes from migrations that reflect regular and predictable movements that take animals to and from the same places each year, at the same time each year. But not all migrations are this predictable. Migrations can also occur much less predictably with respect to timing and/or destination. These less predictable migrations, known as facultative migrations, have proven to be much more difficult to study. Our research has been among the first to systematically and comprehensively study the drivers of facultative migration. This has been possible because of our development of the pine siskin as a captive model with which to experimentally study facultative migration. We have been investigating both the environmental cues (e.g., food availability, temperature, social cues) that animals use to time facultative migratory transitions and the hormonal mechanisms involved in mediating these transitions.
Social cues in decision making
Social interactions and social cues are potentially important in myriad decisions that animals make throughout their lives. We are interested in understanding the use of social cues in behavioral decision-making, particularly in the context of migratory decisions. Social cues, which can also be termed social information, may be especially important when animals must make decisions in the face of considerable uncertainty about environmental conditions. The process of migration is particularly fraught with uncertainty and the potential for the use of social cues is quite high; yet, until recently we have known very little about how social cues influence migratory timing decisions. Our research is investigating the use of social cues in migratory initiation and termination decisions. Beyond a focus on migratory timing, we are also conducting research aimed at understanding the mechanisms by which social information is transferred between animals, particularly the role of vocalizations in transmitting information about local food availability. We have also used modeling to investigate how social information can influence the accuracy of environmental assessments.
Endocrine regulation of transitions across the annual cycle
Another theme of research in my lab is to develop a more complete understanding of the endocrine mechanisms that regulate migration and life history transitions more broadly. Our research examines the potential role of changes in circulating hormone levels in migratory transitions. But we have also expanded our focus to include other elements in endocrine signaling pathways. Thus, we have begun to investigate the potential role of changes in local hormone synthesis and inactivation (via enzymatic activity) and changes in availability of hormone receptors in both the brain and peripheral tissues (e.g., skeletal muscle). The goal of this approach is to considerably broaden our understanding of how multiple components of the endocrine system interact to regulate migratory timing, and life history transitions more generally.
Environmental cue integration
It is widely assumed that animals use multiple environmental cues to time life history events, but our understanding of how suites of cues are integrated to generate observed patterns of timing across the annual cycle remains nascent. Thus, research in my lab investigates environmental cue integration. Past and ongoing work has experimentally tested how multiple cues are integrated to time reproduction and migration. The understanding of cue integration has taken on particular importance in the context of climate change, because evolved mechanisms of cue use – including cue integration – may facilitate or limit the capacity of organisms to adjust phenology in a changing world. Therefore, we have also begun using theoretical models to explore how variation in modes of cue integration may impact the ability of organisms to adjust phenology adaptively in the face of climate change. This theoretical approach allows us to explore complex scenarios that are logistically challenging to study in vivo but that capture important complexity of the natural world.