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LUCAS LAB - MEMBERS Kerry Fanson | Ken Henry | Mark Nolen
STATUS: Ph.D (started in 2003) CONTACTS: Email: kfanson@purdue.edu; Office Phone: 765-494-9654
RESEARCH INTERESTS In this perpetually dynamic world, animals must find a way to prevent environmental changes from altering important physiological processes. The hypothalamic-pituitary-adrenal (HPA) axis is fundamental to achieving this. The hormones released from the HPA axis trigger a cascade of physiological changes that help the body maintain proper functions in the face of adversity. While this physiological response has been well studied in regards to short term stressors, the effect of long-term, or even permanent environmental perturbations remains unclear. Reintroductions, although a valuable conservation tool, often create drastic, permanent changes in an individual's environment. In order to gain a clearer understanding of how an individual's response to these changes may influence the success of the reintroduction effort, we must take a closer look at how reintroductions affect organisms. I hope to address this question by looking at hormonal changes in
CONTACTS: Email: kshenry@purdue.edu; Office Phone: 765-494-9654 RESEARCH INTERESTS Vocal communication is used for a variety of important functions in birds including mate attraction, territory defense, predator avoidance, and mediation of social interactions in groups. Across species there is extensive diversity in vocal communication, but the impact of this diversity on the auditory system is not clear. My research focuses on two broad questions about communication and hearing. First, do species with complex vocalizations also have specialized auditory systems with broader frequency sensitivity and finer temporal resolution? Second, do characteristics of the auditory system change seasonally to optimize the efficiency of vocal communication during courtship?
To answer these questions, I am monitoring the auditory characteristics of
four bird species across seasons.
The study species, white-breasted nuthatches, tufted titmice, Example responses:
STATUS: Ph.D (started in 2003) CONTACTS: Email: mtnolen@purdue.edu; Office Phone: 765-494-9654 RESEARCH INTERESTS I am broadly interesting in gaining a better understanding of the mechanisms governing the evolution of sociality and cooperation. In particular, I am interested in the role of signals in mediating interactions between individuals. Of special interest are signals directed towards other species in interspecific communication. Such signals are known to mediate a variety of mutualistic (both sender and receiver benefit) and manipulative (sender benefits) interactions. But perhaps more widespread is the use of information from a heterospecific signal that is not intended for heterospecific receivers (eavesdropping - in which the sender may benefit, be harmed, or not affected at all). Mixed-species forest bird flocks offer an interesting opportunity to investigate if and how individuals pay attention to vocal information provided by other species. Foraging flocks of birds containing individuals of different species and stable membership can be found in forests worldwide. Individuals in such groups, as in single species groups, are thought to receive some combination of benefits from higher foraging rates and lower predation risk. However, the costs and benefits in a mixed-species flock are likely to differ among species owing to their different anti-predatory behaviors, foraging strategies, and roles in flock formation.
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STATUS:
Mixed-species
flocks in the eastern temperate woodlands of North America consist of
Carolina or Black-capped chickadees (Poecile carolinensis), Tufted
titmice (Baeolophus bicolor, pictured to left wearing a
radio-transmitter), White-breasted nuthatches (Sitta carolinensis),
and Downy woodpeckers (Picoides pubescens), among a few others. All
of these species, except for the woodpecker, are highly vocal. White-breasted
nuthatches and Downy woodpeckers often follow chickadees and/or titmice for
variable periods of time during the non-breeding season (mid-June through
March or April). Flock formation and cohesion seems to be facilitated by
chickadee and titmouse vocalizations, but we know very little about vocal
information exchange within flocks and prior to mixed-species flock
formation. A more detailed understanding of individual behavior in
mixed-species flocks will allow us to make further inferences about the
importance of flocking for the species involved and about the nature of
information flow across species through vocal signaling.