Disertation Study
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Master theses
Behavior is a key link between the environment and fundamental
metrics of life history such as birth and death rate, yet studies
on life-history traits often neglect behavior because it is much
harder to quantify than, for example, clutch size. Incubation
behavior provides an opportunity for circumventing this difficulty
because it is an easily observable and highly variable link between
a bird’s behavior and several important life-history traits,
such as number of offspring and the frequency of nesting..
Incubation behavior is primarily determined by food availability
and ambient temperature. Food availability influences the time
that adults spend on the nest. Hunger levels will constrain how
long the adult can stay on the nest before it must leave to forage,
and food availability will determine how long it stays foraging
off the nest to meet its energy demands. The thermal environment
influences the time and energy necessary for successful incubation.
Both time and energy demands increase as ambient temperature departs
from a narrow range of optimal temperatures for incubation.
Because these factors are interdependent and have not been examined
simultaneously, our understanding of what determines variation
in incubation behavior is rudimentary. My main objective is to
experimentally evaluate the interaction and relative importance
of food availability and temperature for avian incubation behavior.
Specifically, I will test two predictions: 1) females in habitats
with high food availability will spend more time on the nest, as
hunger levels will be lower and foraging time off the nest will
be reduced and
2) females on nests in hotter microclimates will
decrease on- and off-bout duration and thereby increase total number
of trips to the nest per day, as predicted by Conway and Martin
(2000). These predictions will be tested by measuring incubation
behavior (on- and off bouts from the nests), field energy expenditure
using doubly-labeled water, and incubation effectiveness as indicated
by embryonic development. I will experimentally determine the interaction
and relative importance of food availability and temperature on
incubation behavior of Northern Mockingbirds (Mimus polyglottos)
on the University of Florida campus. Each nest will be randomly
assigned to one of four treatments (food +; food+/temperature+;
temperature+; control) in a 2 x 2 factorial design. At least forty
nests will be monitored, with ten nests per treatment.
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