| Research
Interests |
 The
aim of my research is to identify selection pressures that operate
on individuals in natural populations. My research interests are,
therefore, in ecology, behavior, behavioral ecology, evolution, genetics,
and conservation biology, mainly of birds. My research interests have
generated collaboration with molecular biologists and studies of populations
in fragmented habitats,of disease, predation, and inter-specific competition,
behavioral mechanism, quantitative genetics, etc. Most of my research,
and that of my students, has been a combination of population and
behavioral ecology that began by studying the fates of individually
marked individuals and has included various disciplines such as population
ecology, behavioral ecology, population genetics, epidemiology,… |
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 The
basic approach has always been the detailed long-term study of individually
marked animals, mainly birds. My long-term and experimental studies
on titmice have generated almost 60 papers on subjects about intra-
and interspecific competition, evolutionary biology, effects of
habitat fragmentation, population and quantitative genetics, mating
systems, effects of predators, reproduction, song and vocalizations.
Since about 1990 I have studied populations in a fragmented
landscape, in order to try and understand how populations are influenced
by fragmentation; how their social organization, reproduction, and
survival changes in fragments; how dispersal is affected by fragmentation;
and to what extent the loss of genetic variation in isolated populations
influences the performance of individuals.
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When I moved to Cornell University in 1994 I took advantage of
the great opportunities offered by the "Citizen
Science" approach to address questions at a continental
scale. I helped expand "Project Tanager" and start
"Birds in Forested Landscapes", two projects that
attempted to study effects of habitat fragmentation all across North
America.
 Confronted
with an apparent epidemic of an unknown eye disease in house finches
in mid-1994 I started the "House Finch Disease Survey".
This project was unusually successful at tracking the epidemic of
a new strain of the parasitic bacterium Mycoplasma gallisepticum
in house finches and was able to document how house finch numbers
declined by about 60% because of this newly emerged disease (see
Hochachka & Dhondt 2000).
Since September 2000 this project has developed into an NIH/NSF-funded
5-year attempt to understand in great detail the underlying mechanisms
that caused the epidemic and translate our understanding into a
spatio-temporal mathematical model.
The research team also includes several graduate students
in the departments of EEB, Natural Resources and the Vet School.
My new interest in disease in natural populations also led to collaboration
with Karel A. Schat, at the Cornell Vet School, and Kevin McGowan
at the Department of EEB, to study the evolutionary effect of West
Nile Virus on the genetics of the immune-response system in American
Crows.
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Another citizen-scienceproject addressed my long-standing interest
in dispersal and geographic variation in reproduction by setting
up a volunteer-based nest box network.This has led to the discovery
that seasonal variation in clutch size in Bluebirds varies geographically.
This is illustrated in the adjacent graph that shows that at 45°
N (triangles) clutch sizes declines with season, whereas at 30°
N (circles) mid-season clutches are larger than early and late broods.
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