Bicknell's and Swainson's thrushes in
regenerating New Brunswick clearcuts:
niche separation by nest site and diet
Emily A. McKinnon, Kevin C. Fraser,
Antony W. Diamond
University of New Brunswick, Fredericton
– BITH and SWTH
– NB context
• Part 1: Nest site
– nest patch vegetation
• Part 2: Diet
– trophic niche width
Intro: study species
Catharus bicknelli = BITH
Catharus ustulatus = SWTH
• Stunted, dense balsam fir and spruce
• High elevation
• Endemic to NE NA
• Found in
• BITH choose nest patches on a small
• Suggests ability to nest in small patches?
• SWTH nest patches are less specific
• less affected by management?
• BITH - Type 2 generalists
• Individual specialization?
• SWTH - Type 1 generalists
• reduced competition with BITH?
• Nest patch
flexible are they?
• Diet throughout the
• Could blood tell us
where BITH or SWTH
• Committee: Dr. D. MacLean, Dr. D. Keppie
• T. Vanbuskirk, B. Whittam, G. Campbell, C. Rimmer, K.
McFarland, A. Albert, R. Aracil, H. Askanas, K. Friars, M. Godin,
C. Wegenschimmel, Operations 1 Staff, Mark McLelland at the