The Wilson Journal of Ornithology 124 ( 3 ): 436 - 445 , 2012 
TEMPORAL AND SPATIAL PATTERNS IN ABUNDANCE OF 
THE WEDGE-BILLED WOODCREEPER (GLYPHORYNCHUS SPIRURUS) 
IN LOWLAND ECUADOR 
JOHN G. BLAKE 12 AND BETTE A. LOISELLE' 
ABSTRACT.— Glyphorynchus spirurus (Wedge-billed Woodcreeper) is one of the most common birds in the understory 
of many tropical forests of Central and South America bin few studies have focused on its abundance and distribution. We 
use data from mist nets and direct observations over a 10-year period to examine patterns of abundance and distribution on 
two 100-ha plots (Harpia, Puma). -1.7 km apart in lowland forest of eastern Ecuador. Birds were captured in mist nets 
(96 nets/plot) that were open for -6 hts/day for 1 day each in January and February; direct observations were made along 
transects within each plot during February (7 yrsl and April |4 yrs). We recorded 861 captures (447 recapturesi on Harpia 
and 963 captures (540 recaptures) on Puma: capture rates <birds/100 mist-net hrs) were slightly higher on Puma, largely j 
result of the greater numbers of recaptures. Number of individuals captured per year did not differ between plots. Mean 
(± SE) recapture distance w ithin a year was less on Harpia (94.5 £ 6.1 m) than on Puma (121.6 ± 7.3 m) but recapture 
distances between years did not differ between plots (108 and 97 m. respectively lor Harpia and Puma). Number of captures 
had a clumped distribution with some nets capturing many more individuals than others, number of captures per net was not 
correlated with captures at nearby nets. We recorded 490 Glyphorynchus during observations on Harpia (Feb samples) and 
e84 on Puma. Number ol observations was greater on Harpia during 6 of 7 years. Numbers of observations had clumped 
distribution patterns on both plots; significant autocorrelations likely rc-flcctcd the difficulty of delecting individuals by 
voice when >50 in from a transect. Comparisons with published data from other sites in Central and South America 
indicate considerable spatial variation in abundance but reasons for geographic variation in abundance need further 
investigation. Received 5 February 2012. Accepted 6 May 2012. 
The Wedge-billed Woodcreeper ( Glypho¬ 
rynchus spirurus-. Glyphorynchus hereafter) is 
the smallest of the woodcreepers (Furnariidae). 
It is widely distributed from southern Mexico to 
western Ecuador, northern Bolivia, and Amazonia 
to eastern Brazil (Hiity and Brown 1986, Ridgely 
and Tudor 1994). typically in mature forest 
but also in second-growth habitats (Blake and 
Loiselle 1991. 2001; Borges and Stouffer 1999). 
Glyphorynchus feeds on insects taken from the 
bark of trunks or branches, foraging alone, in 
pairs, or in mixed-species flocks (Hiity and Brown 
1986); it often forages in moss on trunks (English 
1998). 
Glyphorynchus is typically one of the most 
frequently captured species in mist nets (Blake 
and Loiselle 2009) and some (e.g., Remscn and 
Good 1996, Maria and Remsen 1997) have 
suggested its capture frequency reflects behavior 
rather than abundance. This suggestion apparently 
derives from an earlier paper (Gradwohl and 
Greenberg 1980) in which Glyphorynchus was 
described as having large and overlapping home 
langes. That conclusion may not be representative 
P 0 DC Box'MO a;;!' u MV "' e Et ’° logy :,nd Conservation. 
3261 I USA. ’ erS,ly 01 F|orida - Gainesville. FI. 
2 Corresponding author; e-mail. john.blake@ufl.edu 
436 
of the ecology and spacing patterns of the species 
in other forests, particularly where densities are 
higher than in central Panama. Glyphorynchus 
density (estimated from observations and map¬ 
ping) varies widely among geographic regions, 
from —6 to 10/100 ha (Panama: Karr 1971. 
Robinson ct al. 2000; Peru: Terborgh et al. 1990) 
to >50 (French Guiana: Thiollay 1994) or 100/ 
100 ha (Ecuador: English 1998). Thus, frequent 
captures of Glyphorynchus in mist nets may 
indicate the species is abundant in some regions, 
including Ecuador (Blake 2007. Blake and 
Loiselle 2009). 
Feu studies have focused on the ecology or 
behavior of Glyphorynchus. despite its abundance 
in the understory of many tropical forests. 
Stratford and Stouffer (2001) examined patterns 
of feather growth in Glyphorynchus to learn if 
fragmentation affected its growth (it did not) and 
several studies have examined occurrence of 
parasites and lice (e.g.. Price and Clayton 1989. 
McQuistion and Capparella 1997. Valim et al. 
2011). A variety of studies focused on mixed- 
species flocks included information on Glypho¬ 
rynchus (e.g.. Gradwohl and Greenberg 1980. 
English 1998) but have not had the woodcreeper 
as the primary focus. Glyphorynchus has also 
been included in studies that estimated survival 
i ates of tropical birds; the frequency of captures 
