SHORT COMMUNICATIONS 
385 
area was being used than the 93 ha intensively 
studied. Conversely, we found an active Black- 
hacked Woodpecker nest in a clear-cut 100 m 
outside the 19-ha stand and these birds moved into 
the 19-ha stand to forage. Prior to salvage logging 
m late April-early March 2008. the 19-ha stand of 
mature burned jack pine was actually a 35-ha 
stand (Fig. 1). Sixteen of the 35 ha were clear-cut 
atthattime. creating the 19-ha stand studied. This 
sudden reduction of habitat early in the breeding 
season may have introduced an artificial con¬ 
straint on Black-backed Woodpeckers using the 
bum. causing pairs to establish nests at higher 
densities in the remaining 19 ha. Hairy Wood¬ 
peckers were also observed displacing Black- 
backed Woodpeckers from foraging sites during 
eight of 13 interspecific contacts, partially sup¬ 
porting the observations of Villard and Beninger 
< 1993) that Black-backed Woodpeckers may 
compete with other Picoides woodpeckers for 
food resources in a bum. Black-backed Wood¬ 
peckers were only observed to displace Hairy 
Woodpeckers five times, all within 50 m of an 
active Black-backed Woodpecker nest. 
The earliest date of nest excavation (24 Mar) is 
slightly earlier than reported excavation phenol¬ 
ogies (Dixon and Saab 2000). Continued moni¬ 
toring after nests in the study area were located 
indicated an 85% projected fledging success rate 
during the second possible breeding season after 
the fire (2008). Nests were initially located on 
surveys at different stages during breeding 
development, precluding precise delineation of 
nesting phenology, but projected mean fledge 
dates in successful nests had a fairly high 
wnchronicity with a standard deviation of 
-Ml days over a 14-day range. The high 
proportion of jack pines selected for nests may 
he misleading as a majority of nests located in the 
hum were in stands dominated by mature jack 
pme. Compass direction was apparently not a key 
factor in nest entrance placement, although the 
relatively small sample size may have masked 
statistical trends. 
We believe the high nest densities in this study 
raise several intriguing questions beyond the 
'Cope of the present study. We do not know il 
high-density nesting, as found in this study, is 
actually the standard post-fire breeding strategy, 
or whether individual characteristics ol this bum 
caused the uncommonly high density. Research 
■hat may have implications for the high nesting 
densities in our study, indicates that Picoides 
woodpeckers’ saproxylic insect prey are most 
abundant in trees of early stage decay-classes, 
limited to recently dead conifers (Saint-Germain 
ct al. 2007). Timing of (he fire immediately 
following snowmelt in early April, may have 
presented optimal resources to saproxylic insects 
at a critical point in their life history: following 
adult emergence 1-3 months after the fire, they 
were able to quickly exploit the high-quality, 
freshly-burned substrate, establishing high larval 
densities that could be used by Black-backed 
Woodpeckers in the second year post-fire. Burns 
that occur later in the summer or fall may miss the 
window for heavy insect colonization the first 
year after the fire, decreasing the probability that 
high larval loads are ever established, and limiting 
woodpeckers to larger range sizes and lower 
densities. It is also possible the burned habitat in 
our study area, chiefly mature jack pine forest 
focused by limber cutting into discrete stands, 
provided a rich but confined food source for both 
wood-boring beetles and woodpeckers. 
Previous Black-backed Woodpecker studies 
have generally reported nest densities over the 
entire burned area regardless of where nests are 
actually distributed, implying a constant nest 
density per hectare even in unsuitable habitat. 
Where high-density nesting occurs, nest densities 
(not foraging densities) in this format do not 
reflect the actual clustering of Black-backed 
Woodpecker nests in u discrete region of a bum. 
A more precise approach, accurately describing 
the spatial proximity of nests, would: (l) calculate 
density via a “best fit” approach, delineating a 
burned area around which a maximum number of 
nests can be confined (as in this study); or (2) use 
spatial analysis (poim pattern analysis) to corre¬ 
late nests to an exact area. We believe factors 
influencing Black-backed Woodpecker nest site 
selection within a bum could be more easily 
identified using either of these methods. 
We question if the source-sink mode I described 
by Hutto (1995) may have limited application to 
Black-backed Woodpecker dynamics in the Upper 
Peninsula (near the southern range terminus of the 
species), where the fire interval is high due to both 
the isolated geographical nature of pyrophilic 
boreal forests (surrounded by mesic deciduous 
forest) and anthropogenic fire suppression (Dick- 
man and Leefers 2003). The fire response distance 
of Black-backed Woodpeckers in this region 
would have to be very great for bums to provide 
the only productive habitat, which are both too 
