The Wilson Journal of Ornithology 123(4):699-708, 2011 
EFFECTS OF STOP-LEVEL HABITAT CHANGE ON CERULEAN 
WARBLER DETECTIONS ALONG BREEDING BIRD SURVEY ROUTES 
IN THE CENTRAL APPALACHIANS 
PATRICK M. McELHONE, 14 PETRA BOHALL WOOD/’ AND DEANNA K. DAWSON 3 
ABSTRACT.—We examined ihe effects of habitat change on Cerulean Warbler (Dendroiea cerulea) populations at 
stops along Breeding Bird Survey (BBS) routes in the central Appalachians. We used aerial photographs to compare early 
(1967/1971), middle (1982/1985). and late (2000/2003) periods and compared 1992 and 2001 National Land Cover Data 
(NLCD). Mean Cerulean Warbler detections per stop decreased at 68 BBS stops between the early (0.05) and middle (0.01) 
time periods and their distribution became more restricted (15 vs. 3% of stops), but the amount of deciduous/mixed forest 
increased. Mean detections at 240 stops decreased from the middle (0.09) to the late (0.06) time periods, but the deciduous/ 
mixed forest land cover and fragmentation metrics did not change. The amounts of deciduous/mixed forest, core forest area, 
and edge density in the NLCD analysis decreased from 1992 to 2001. whereas the amount of non-forest land cover 
increased. The number of Cerulean Warbler detections did not change (1992 = 0.08. 2001 = 0.10; P = 0.11). The lack of 
concordance between Cerulean Warbler detections and broad habitat features suggests that smaller, microhabitat features 
may be most important in affecting Cerulean Warbler breeding habitat suitability. Received 10 October 2009. Accepted 31 
March 2011. 
The Cerulean Warbler (Dendroiea cerulea) is 
considered a species of high conservation concern 
by Partners in Flight and has been reviewed for 
listing as a threatened species (USDI 2006). 
Analyses of data from the North American 
Breeding Bird Survey (BBS) indicated Cerulean 
Warbler populations declined range-wide at 4.1% 
per year during 1966-2007 (Sauer et al. 2008). 
The consistent decline of Cerulean W'arblcrs in 
the core breeding range over the 40 years of the 
BBS elevated this species to a high level of 
conservation concern, and led to creation of the 
Cerulean Warbler Technical Group (Hamel et al, 
2004). 
The Ohio Hills and Cumberland Plateau 
physiographic areas of the Appalachian Mountain 
Bird Conservation Region (BCR 28; http://www. 
nabci-us.org/map.html) are the core breeding 
range for Cerulean Warblers (Hamel 2000b, Sauer 
et al. 2008). Mesic upland forests, particularly 
ridgetops, are important habitat within the core 
range (Rosenberg et al. 2000, Weakland and 
1 West Virginia Cooperative Fish and Wildlife Research 
1 nit. Division of Forestry and Natural Resources. West 
Virginia University. Morgantown, WV 26506. USA. 
’U.S. Geological Survey. West Virginia Cooperative 
Hsh and Wildlife Research Unit. Division of Forestry and 
Natural Resources, West Virginia University. Morgantown. 
WV 26506. USA. 
U.S. Geological Survey. Patuxent Wildlife Research 
Center. Laurel. MD 20708. USA. 
Corresponding author; e-mail: 
pmcclhone25@gmaiI.com 
Wood 2005). Cerulean Warblers require large 
tracts of mature forests with tall deciduous trees to 
sustain viable breeding populations (Oliamyk 
1996. Hamel 2000a). 
Habitat loss and fragmentation from land use 
changes are thought to be major factors contrib¬ 
uting to declining populations in the core breeding 
range (Hamel et al. 2004, Buehler et al. 2008). 
Donovan and Flather (2002) identified the effects 
of land use changes on Cerulean Warbler 
populations in the Appalachian Region as high 
priority for research, Recent research has begun to 
assess the effects of large-scale habitat change and 
fragmentation on Cerulean Warbler populations in 
the region (Weakland and Wood 2005; Wood et 
al. 2005, 2006). Analysis of the relationship of 
changes in Cerulean Warbler counts to habitats 
along BBS routes in the core breeding range may 
provide insight into the role habitat change has in 
long-term population declines. 
The BBS, established in 1966 to monitor 
breeding bird populations, is the primary data 
source for population status of landbirds across 
North America (O'Connor et al. 2000). Each 40- 
km BBS route consists of 50 point-count stops, 
0.8 km apart along secondary roads. Routes are 
surveyed once each year by volunteer observers, 
who identify and count all birds seen within 400 m 
or heard within a 3-min period at each stop 
(Robbins et al. 1986). Routes are distributed 
randomly and are assumed to reflect representa¬ 
tive habitats (Donovan and Flather 2002). BBS 
counts used in analysis of population trends are 
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