PARC Research
Prebasic Molt Research at Powdermill Avian Research Center
(PARC)
50 North American Species Studied
Each
year after the breeding season, most birds shed and replace all of their
feathers in a process called prebasic molt. Of research interest is to
gain a greater understanding of the timing and extent of prebasic molt, as
well as to understand age, sex, and geographic variations for North American
Species.
At PARC, Research Associate Dr. David Norman and Field Ornithology
Projects Coordinator Bob Mulvihill are studying the complete prebasic molt
of some 50 North American species by analyzing 5000 records and over 20
years of data for populations of selected species sampled at Powdermill.
The study’s goal is to produce a monograph able to serve as an important
reference for ornithologists and bird banders (the first of its kind for
North American species).
Of interest to bird banders and ornithologists, the analyses and
summarization of data will be presented in a standardized format, including
information on date ranges for the onset of molt and molt duration.
For species with a large sample size, the analysis will express age and
sex-related variation and, where possible, geographic variation. Where
especially large sample sizes present the opportunity for more in-depth
studies, these will be presented separately for publication in peer-reviewed
journals of ornithology.
International Collaboration
Dr. David Norman, a
chartered physicist by profession, is a resident of Cheshire in
England. He is one of the United Kingdom’s foremost
volunteer ornithologists, having been honored in 2002 with the
British Trust for Ornithology’s Bernard Tucker Medal for his
scientific contributions through ringing (banding),
nest-recording and surveying birds. He chairs Merseyside Ringing
Group, was a government-appointed member of the Council of
English Nature (1996-2002) and an elected trustee of the Royal
Society for the Protection of Birds (2004-2009), and is one of
two independent members of the UK’s Rare Breeding Birds Panel
(2005-present). His recent book Birds in Cheshire and Wirral:
a breeding and wintering atlas was judged the fourth best
British bird book of 2009.
A project at PARC in
which Dr. Norman takes an interest is the stopover behavior of
fall migrants. In this study, fattening and pre-migration
weight gains are compared with published data from other sites,
including those in Europe. Since birds at Powdermill experience
no significant ecological barrier before or after their visit,
they might differ in behavior from birds observed at other site
types. Coastal and island sites, for example, often
represent the birds’ last opportunity to feed before crossing an
ecological barrier, or their first opportunity after surmounting
one.
As an honorary research
associate of the Carnegie Museum of Natural History, Dr. Norman
spends three to four weeks resident at PARC in the fall of each
year, always bringing a welcome international dimension and
conservation focus to discussions and interactions with PARC
staff and visitors. He assists with the banding,
demonstrations, workshops, and some aspects of Breeding Bird
Atlas methodology.
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