Hello everyone,

With the influx of Mountain Chickadees this winter, it is an excellent time to observe and record interactions among the three species of chickadee: Chestnut-backed, Black-capped and Mountain. In particular, we are very interested in dominance hierarchies among these three species, and we are requesting the help of birders who may have more than one species coming to their feeders in the northwest US or southwest Canada. Observations away from feeders are also welcome.

We are interested in compiling information on overt aggressive interactions between the three species of chickadee. Overt aggressive interactions can take the form of 1) displacement, where one chickadee flies to the perch of another and forces it to leave the perch, 2) chases, where one chickadee pursues the other, or 3) lunges, where one chickadee lunges with its bill at another nearby chickadee. While other subtler forms of aggression among species are common (e.g. vocal interactions, posturing), they are difficult to interpret, and thus we are excluding them from our tally. The following information on the interactions would be most helpful:

Dominant (aggressor) species:
Subordinate species:
Description of interaction:
Location:
Date:
At feeder?
Additional notes:

We hope to use the information gathered in a publication on dominance hierarchies and aggressive interactions among the three species of chickadees. Anyone contributing information will be duly acknowledged.

Please send observations by email to fb2 at u.washington.edu.

Thanks for your help!

Paul Martin & Fran Bonier

Department of Biology
University of Washington
Seattle, WA