Bicknell's Thrush
Common
Name: Bicknell's Thrush
Scientific
Name:
Catharus
bicknelli
Global/Continental
Conservation Status: IUCN 2004 Red List – VU
(Vulnerable)
National-level
Conservation Status:
U.S.
– Bird of Conservation Concern;
Canada
- Species at Risk Act (SARA) – Special Concern
Key
Reference(s):
BNA No. 592 (Rimmer et al. 2001)
Distribution:
Breeds (at least formerly) in s
Quebec
(including the
Magdalen
Islands
), the
Maritime Provinces
, e
New York
(Catskill and
Adirondack
mts.), w Massachusetts, c and n Vermont, New Hampshire, and c Maine.
Winters in
Cuba
, Hispaniola, and Puerto Rico, probably elsewhere in the mts of the
Greater Antilles
(AOU 1998).
Habitat
Associations:
Stunted deciduous and coniferous forest, often near mountain-tops;
in migration and winter, a variety of wooded habitats, primarily broadleaf
forest and woodland (AOU 1998).
Source(s)
of Research/monitoring Needs (Number in ( ) is Physiographic Area number):
Canadian Action Plan (Dunn 2002); BNA No. 592 (Rimmer et al. 2001);
Allegheny Plateau Bird Conservation Plan (24); Adirondack Mountains Bird
Conservation Plan (26); PIF Monitoring Needs document (Partners in Flight
Science Committee 2004)
PIF
Continental Plan Monitoring Needs Category: ** (Long-term population
trend monitoring considered adequate, but some issues (e.g., bias) may not
be accounted for)
RESEARCH/MONITORING NEEDS (source(s) of needs)
Monitoring
- Priority
monitoring action – Conduct high elevation surveys, noting that this
has begun (PIF Monitoring Needs doc)
- Second
priority monitoring action – Conduct other species-specific surveys
(PIF Monitoring Needs doc); (similar) Develop species-specific BITH
monitoring programs - Develop accurate, efficient monitoring
protocols to census populations, evaluate population trends, and
estimate densities of BITH (Adirondack Mts; BNA); Species specific
monitoring is needed (Canadian Action Plan); Continue/maintain
targeted monitoring program for tracking BITH population trends at all
sites (Allegheny Plateau and Adirondack Mts); Develop a standardized,
rangewide monitoring program on both breeding and wintering grounds to
clarify its conservation status (BNA); Clarify BITH distributional
status in coastal maritime forests of Canada (BNA)
- Develop
accurate calculations of total BITH population size based on GIS
projections of occupied habitat and density estimates (BNA)
- Identify
& designate the most important breeding sites as Important Bird
Areas and identify threats
(Adirondack Mts)
- Apply
demographic study results to source-sink dynamics modeling &
metapopulation analysis thru-out the region (Adirondack Mts)
- see
needs under "Landscape"
Habitat
Needs/Ecology/Life History
- Define
microhabitat requirements of BITHs, esp. in relation to changes due to
acid rain (Adirondack Mts)
- Investigate
mating system, habitat requirements, & breeding biology of BITH
(Canadian Action Plan)
- Additional
research on song and call repertoire (BNA)
Effects
of Management Practices
- Long-
and short-term effects of silvicultural practices on BITH (including
habitat use, breeding success, demography, etc.) (Canadian Action Plan
and BNA)
- Identify
real & potential threats to critical areas from conflicting
management activities or human disturbance (Allegheny Mts)
Effects
of Human Development/Disturbance
- see
needs under "Effects of Management Practices" and
"Demography"
Landscape
- GIS/GAP
analysis to determine distribution & conservation status of BITH
habitat (Adirondack Mts)
- Use
GIS analysis and ground-based surveys to identify the most critical
BITH habitat patches, catalog & prioritize forest stands
(Adirondack Mts and Allegheny Plateau)
- Information
on effects of patch size and isolation on repro success, demographics,
site persistence, source/sink population dynamics, etc. (BNA)
Species
Interactions
- Investigate
competition between BITH and Swainson's Thrush (Canadian Action Plan)
- Study
interactions with Gray-cheeked Thrush and investigate possible
existence of contact/hybrid zone with GCTH along n
shore
of
Gulf of St. Lawrence
(BNA)
Migration
- Information
on stopover ecology (including stopover length, physiological
condition, diet, habitat use) and routes and timing (BNA)
Wintering
- Develop
a better understanding of distribution and habitat use of BITH
wintering in Cuba, Haiti, and to lesser extent Jamaica
(including use of primary vs second growth habitat, sexual
habitat segregation, microhabitat use, survival, site fidelity, etc)
(BNA)
- See
needs under “Monitoring”
Invasives/Exotics/Disease/Parasites/Contaminants
- see
needs under "Demography"
Demographics
- See
needs under “Monitoring”, “Wintering” and “Landscape”
- Investigate
calcium availability in relation to acid precipitation & avian
reproductive success (Adirondack Mts)
- Research
on reproductive success in ongoing studies of forest health, in
relation to pollution and development (Adirondack Mts)
[Link
to References]
[Link
to PIF Bird Conservation Plans]
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