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THE WILSON JOURNAL OF ORNITHOLOGY • Vo/. 124. No. 1. March 2012 
FIG l. Single-entrance cavity with Brown Creepei 
■n El Salvador (A) Adult Brown Creeper amving at c 
necdlcTZ m Tr ?' A " 0pen nest CU P constructed of dry 
cav1v .rfr h " Che, I: and mos “* ^ « the bottom o 
cavity. (C) The nestlings climbed up the cavity will , 
researchers measured 1,0 **. PhotoA* by Ab* 
DISCUSSION 
The timing of breeding in the middle of the dry 
season, when insectivores generally arc noi 
nesting and populations of visiting migratory 
birds are high, is of interest. We found nestlings. 
— 1 week of age. on 5 February. Given an average 
incubation period of 15 days for Brown Creepers 
(He jl et al. 2002). and laying of one egg per day. 
we estimate that egg-laying in El Salvador began 
~I2 January. Most other insectivorous bad. 
gleaners in Central America are reported to breed 
later in the year (Table I). The only other 
insectivorous bird species in Central Amenca 
reported to breed in January or February iSkutch 
1969) is the Lineated Woodpecker (Dnwopus 
lineatus) which occupies a similar feeding niche 
(tree bark) as the creeper, hut is more than 
times heavier. Some Golden-fronted Woodpeck¬ 
ers (Mekmerpes aurifrons) may also begin egg- 
laying in early February (Skutch 1969). 
We do not have evidence that creepers or an) 
other birds breed regularly or frequently during 
the dry season in the pine-oak forest ecosystem :n 
El Salvador. We searched the La Montanona pine- 
oak forest for birds during 5 days each winter 
from 2007 to 2010, and invested equal efforts at 
three similar sites in El Salvador where Brown 
Creepers also were found. We spent 16 weeks 
observing the drv-season bird communities in 
pine-oak forest of El Salvador. The only indica¬ 
tion of nesting behavior of any bird species other 
than the nest reported here was the observation ot 
a pair of Lineated Woodpeckers widening a 
potential nest hole in December 2008. Bird 
monitoring data from a mist-netting station m 
pine-oak forest at Montecristo National Park 
provided no indication of insectivorous birds in 
breeding condition during January or February, 
despite 5.600 net hrs during those month' 
(SalvaNATURA. 2003-2009. unpubl. data). 
One Brown Creeper at Montecristo National 
Park, captured on 10 April 2008 and classified as 
second year, was molting contour feathers and 
still retained heavily worn juvenile flight feathers- 
this is consistent with hatching during February 
2007. The bird had a completely ossified skud 
(confirming it was likely born the previous year', 
and no fat, consistent with a resident, non- 
migratory individual. The bird w as not in breeding 
condition. We have heard Brown Creepers singing 
from February to July at Montecristo National 
Park. Singing is suggestive of breeding behavior. 
