SHORT COMMUNICATIONS 
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usually accompanied by enlarged ear openings. 
Nests were classified as ‘infested il they 
contained at least one nestling with larvae or 
larvae-evidence. 
Larvae were not counted but. in some cases, 
samples were removed from ears for identification 
of the parasite. We also examined the decaying 
nesting material in the bottom of the nest at one 
nest in 2010 and six nests in 201 1 in an effort to 
find pupal forms of the ectoparasite; the remain¬ 
ing nests were not examined due to time 
constraints. Presence or absence ot pupae in the 
nest material was recorded and pupae were 
collected. Larvae and pupae were stored with a 
small amount of sawdust in plastic zipper hags 
and shipped to T. L. Whitworth of Washington 
State University, Pullman, for identification. 
Larvae and some pupae were raised until adult 
Hies hatched; adult flies were identified by T. L. 
Whitworth based on (Sabrosky et al. 1989); pupae 
were identified based on a key to the puparia ol 
Norih American Protocalliphora (Whitworth 
2003). 
Estimation of Nestling Age and Reproductive 
Rate— We estimated nestling age based on first 
and second secondary feather lengths, using the 
age-feather length regression model lor Red¬ 
shouldered Hawks of Penak (I9S2). We averaged 
Ihe estimated ages of the nestlings in each nest to 
create a mean nest-age. as nestling age may allect 
the visibility and location of parasite larvae/pupae 
(Sabrosky el al. 1989, Bennett and Whitworth 
1991). 
Nestlings were counted as Hedged il they were 
at least 3 weeks of age. At sites where nestlings 
were <3 weeks of age at handing, we viewed the 
nest front the ground when nestlings were well- 
grown (4.5—6 wks) and counted nestlings using a 
spotting scope. Reproductive rate was defined as 
the total number of Hedged young/number ol 
nests examined. 
Nest Re-use. —Some studies suggest nest re-use 
can affect some parasite infestation rates (Bennett 
and Whitworth 1992, Rendell and Verbeek 1996), 
and we recorded whether each nest had been used 
>n the previous breeding season. We used 
information from our historical data base for 
-909 nests (JLH. unpubl. data). 
Statistical Analyses.— We used Kolmogorov- 
Smirnov tests to compare infestation rates of nests 
in SWOH and HH because data were non- 
normally distributed. The nests were considered 
ihe unit of measurement, as it was likely that 
siblings’ infestation status were not independent. 
We used a Munn-Whilney U- test to compare the 
number of young Hedged per nest at SWOH with 
that al HH. 
We used a Chi-square test for nests in the 
Hocking Hills region to examine whether infes¬ 
tation status of nests was related to nest use in the 
previous breeding season. Nest use in the previous 
season was unknown for three nests because these 
nesting areas were first found by us in the year 
that we studied Protocol I iphora infestation there, 
these nests were excluded from this test. We used 
Mann-Whitney U- tests to compare mean nestling 
age and the number of young fledged per nest at 
infested nests with that at nests that were not 
infested. 
RESULTS 
We examined nestlings in 56 independent nests 
(147 nestlings) at SWOH and 25 independent 
nests (67 nestlings) at HH. Fifteen of 25 nests at 
Hocking Hills were infested with Protocalliphora 
avium. Nineteen nestlings were infested with 
larvae in one or both ears, an additional 14 had 
evidence of larvae. 32 were not visibly infested, 
and two were either not examined or their status 
was inadvertently not reported on the data sheets. 
No nests and no nestlings were infested at SWOH. 
which differed significantly from infestation rate 
of 1-111 nests (P < 0.001). Reproductive rate (mean 
± SE; young fledged/nest) did not differ between 
SWOH and Hocking Hills (2.4 ± 0.1 young/nest 
at SWOH vs. 2.7 ± 0.2 al HH; U = 813.0, P - 
0.214. n = 56 and n = 25). 
We checked nesting material for pupae at seven 
nests at Hocking Hills. Pupae were found in five 
nests, all of which also had nestlings with larvae 
or larvae-evidence; the other two nests had neithei 
pupae in nesting material nor larvae in the 
nestlings’ ears. 
Infested nests at HH were no more likely to 
have been used in the previous breeding season 
than non-infested nests (Pearson’s y = 0.903, P 
= 0.342, n = 22). Mean nestling age at infested 
nests did not differ from that at nests that were not 
infested (U = 101.50. P = 0.140. n = 25: mean ± 
SE nestling age = 22 ± I days vs. 24 ± 1 days at 
infested and non-infested nests, respectively). The 
number of young fledged/nest at infested nests did 
not differ from non-infested nests (U = 75.0. P = 
1.00. n = 25: mean ± SE number of young = 2.7 
± 0.3 vs. 2.7 ± 0.3 at infested and non-infested 
nests, respectively). 
