bird on box 2

A group led by Associate Professor of Biology Ethan Clotfelter and Visiting Scientist Daniel Ardia (now faculty member at Franklin & Marshall College) has been studying songbirds in the Wildlife Sanctuary since 2004.

Approximately 150 nest boxes have been erected since 2004.  Currently, tree swallows (Tachycineta bicolor) occupy more than one-third of the boxes, with other species (house wrens, Troglodytes aedon; Eastern bluebirds, Sialia sialis; black-capped chickadees, Poecile atricapillus) occupying another third of the boxes.  Many of these boxes are equipped with aluminum cones to deter potential nest predators.

Their research focuses on two central questions: how much do individual tree swallows invest in incubating their eggs, and what are the consequences of differential investment incubation for parental and offspring survival?  Over the past five years, they have used a series of observational and experimental approaches to address these questions.  To date, they have reached the following conclusions: (1) incubation is energetically costly for females, who incubate without assistance from their mates; (2) some females are better equipped to deal with the energetic challenges of incubation than others; (3) ambient temperature conditions can affect how much time females can afford to spend on or off their eggs; and (4) the consistency and degree to which females incubate their eggs can have lasting effects on the growth and health of their offspring.  These findings not only inform our understanding of life-history evolution in birds, but they also give us a glimpse as to how breeding birds may respond to environmental change.

Research Group
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Peer-reviewed Publications (undergraduate co-authors italicized)

Ardia, D.R., Pérez, J.H. and Clotfelter, E.D. 2010. Experimental cooling during incubation leads to reduced innate immunity and body condition in nestling tree swallows.  Proceedings of the Royal Society of London B 277: 1881-1888.

Morrison, E.S., Ardia, D.R. and Clotfelter, E.D. 2009. Cross-fostering reveals sources of variation in innate immunity and hematocrit in nestling tree swallows. Journal of Avian Biology 40:573-578.

Ardia, D.R., Pérez, J.H., Chad, E.K. and Clotfelter, E.D. 2009. Temperature and life history: experimental heating leads female tree swallows to modulate egg temperature and incubation behaviorJournal of Animal Ecology, 78, 3-14.

Pérez, J.H., Ardia, D.R., Chad, E.K. and Clotfelter, E.D. 2008. Experimental heating reveals nest temperature affects nestling condition in tree swallows (Tachycineta bicolor). Biology Letters, 4, 468-471.

Ardia, D.R. and Clotfelter, E.D. 2007. Individual quality and age affect responses to an energetic constraint in a cavity-nesting bird. Behavioral Ecology, 18, 259-266.

Ardia, D.R., Pérez, J.H. and Clotfelter, E.D. 2006. Nest box orientation affects internal temperature and nest site selection by tree swallows. Journal of Field Ornithology, 77, 339-344.

Undergraduate Honors Theses

Gabi Barmettler '10 "Nestling tree swallows (Tachycineta bicolor) as bioindicators of mercury contamination in the Pioneer Valley, MA"

Erin S. Morrison ’09 “Development of innate immunity in nestling tree swallows”

Jonathan H. Pérez ’07: Cross-fostering reveals the direct and indirect effects of developmental temperature on nestling growth in tree swallows (Tachycineta bicolor)

Elise K. Chad ‘07E: “Examining the reproductive costs incurred by female tree swallows (Tachycineta bicolor) within a single breeding bout”

Jessamyn S. Conell-Price ‘06: “Begging behavior of tree swallow broods at two stages of nestling development”