384 
THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 123. No. 2. June 2011 
TABLE 1. Black-backed Woodpecker nest parameters within a 93-ha study area consisting of burned mature pine 
forest on the Baraga Plains, Baraga County. Michigan. 2008. Projected June fledge dates indicate an estimated da:: c 
fledging ± half the number of days between last young heard and date of empty nest. 
Nest number 
Date of 
discovety 
Date of 1st 
young heard 
Projected June 
fledge ilate (days) 
Species of 
nest tree • 
Type of 
nest tree “ 
DBH of 
nest tree (cm! 
Orientation of 
nest opening i i 
Height uf Ne» 
1 
21 Apr 
4 Jun 
24.5 ± 1.5 
JP 
KBF 
19.05 
156 
1.82 
Fledged 
2 
5 Jun 
23 Jun 
Failed 
JP 
Snag 
22.86 
0 
7.31 
Failed 
3 
12 May 
10 Jun 
24.5 ± 1.5 
JP 
KBF 
25.4 
117 
8.32 
Fledecd 
4 V 
16 Jun 
16 Jun 
30.0 ± 1.0 
JP 
Dead 
31.75 
144 
5.18 
Hedecd 
5 
21 Apr 
4 Jun 
17.5 ± 1.5 
JP 
DBF 
24.13 
269 
1.52 
Hedzed 
6 
12 May 
5 Jun 
24.5 ± 1.5 
JP 
KBF 
17.78 
246 
3.04 
Fledged 
7 
14 Apr 
5 Jun 
17.5 ± 1.5 
JP 
DBF 
17.78 
104 
3.65 
Hedge; 
8 
16 Jun 
16 Jun 
27.5 ± 1.5 
JP 
KBF 
30.48 
290 
6.40 
Hedged 
9 
7 Apr 
Failed 
JP 
KBF 
22.86 
223 
4.87 
Failed 
10 
14 Apr 
4 Jun 
17.5 ± 1.5 
JP 
KBF 
16.51 
237 
1.95 
Fledged 
11 
12 May 
5 Jun 
20.0 ± 1.0 
JP 
KBF 
24.13 
293 
1.52 
Fledged 
12 
12 May 
5 Jun 
17.5 ± 1.5 
JP 
KBF 
24.13 
244 
1.16 
Hedged 
13 
1 May 
4 Jun 
22.0 ± 1.0 
JP 
KBF 
21.59 
291 
1.21 
Hedged 
14 
4 Jun 
10 Jun 
30.0 ± 1.0 
JP 
KBF 
24.13 
250 
0.71 
Hedged 
15 
24 Mar 
5 Jun 
17.5 ± 1.5 
JP 
KBF 
27.94 
42 
3.04 
Hedged 
16 
14 Jun 
14 Jun 
24.5 ± 1.5 
JP 
KBF 
30.48 
225 
5.18 
Hedges! 
17 
8 Jun 
8 Jun 
22.0 ± 1.0 
WP 
Snag 
40.64 
167 
2.26 
Fledged 
18 
5 Jun 
14 Jun 
27.5 ± 1.5 
JP 
KBF 
16.51 
74 
1.39 
Hedged 
19 
8 Jun 
10 Jun 
Failed 
RP 
Snag 
20.32 
152 
0.93 
Failed 
20 
21 Apr 
16 Jun 
24.5 ± 1.5 
JP 
KBF 
26.67 
67 
4.87 
Fledged 
21 
19 Jun 
19 Jun 
30.0 ± 1.0 
JP 
Snag 
19.05 
309 
2.43 
Hedged 
" JP = Jack Pine. WP - White Pine. RP = Red Pine 
k'RI 1 -111.*.I K, r\nr . . . 
the pre-fire forest in March-July 2008. ihe second 
breeding season post-tire. Greater food resources 
per unit of area may be available in burned rather 
than unbumed forests as wood-boring beetles 
( Ceramhycidae) capitalize on fire-killed or weak¬ 
ened trees, laying large quantities of eggs which 
hatch in the cambium as first-instar larvae the first 
year post-fire (Holsten et al. 1980). Wood-boring 
beetle larvae are one of the most common prey 
items ot Black-backed Woodpeckers in unburned 
forests (Dixon and Saab 2000). However, our data 
support the conclusions of numerous researchers 
that Black-backed Woodpeckers occur al higher 
densities in burned forests (Hcinselman 1973. 
Hutto 1995, Murphy and Lehnhausen 1998). most 
likely because of higher abundance of beetle 
larvae. We believe the densities in our study for 
both the 93-ha study area and 19-ha stand are the 
highest reported in the literature: 0.42 and 0.63 
individuals/ha, respectively (2 birds/located nest) 
These values are 1.68 and 2.52 limes higher than 
the highest reported density of 0.25 individuals/ha 
in a 67-ha plot of mature white spruce (Piceci 
glauca) at a recent burn periphery (Murphy and 
Lehnhausen 1998). A study by Apfelbaum and 
Haney (1981) yielded a density of 0.1 individuals' 
ha higher than the density in our 19-ha stand (O.W 
vs. 0.63). but the small urea sampled (6.25 '>• 
19 ha) and low number of individuals (4 vs. 1- 
lead us to discount this density from direct 
comparison. A more comparable 15 individuals/ 
40 ha in uncut burned spruce in central Montan- 
(Dixon and Saab 2000) gives a density ofO> 
slightly lower than the density in our 93-ha siud) 
area. Our data indicate a nest density nearl) •'" ia 
as high as recorded in severely burned ■ s P nke 
forest in Quebec (Nappi and Drapeau -009 Im¬ 
possible that burned jack pine provides a ^ vl 
prey base than spruce, leading to higher nc4 'l- 
densities. Higher nest density in our siu) 
occurred in a stand of pure burned jack P ilK 
compared with stands of mixed pines (jack. 
and red). 
Several factors may influence the densities ^ 
our study. Black-backed Woodpeckers 
observed to do most of their foraging within ^ 
burned mature stands, but were also ot * cr ^ 
foraging outside those stands, indicating a 
