Le Gros et al. • URBANIZATION AND HOST-PARASITE INTERACTIONS 
791 
TABLE 1. Characteristics of parasite prevalence, parasite intensity, parasite intensity per nestling, and clutch size of 
Northern Mockingbirds at each site during the 2007 breeding season, Gainesville, Florida. ORD = Ordway-Swisher 
Biological Station, BRU = Beef Research Unit, and SF = Santa Fe River Ranch Beef Unit. 
Land-use 
Rural 
Habitat 
Preserve 
Pastures 
Site 
ORD 
BRU 
SF 
Sample size 
9 
1 1 
6 
Parasite prevalence 
0.44 
0.36 
0.50 
Mean parasite intensity 
26.00 
28.25 
11.00 
Standard error 
7.15 
20.35 
6.51 
Range 
8-41 
1-88 
4-24 
Mean parasite intensity/nestling 
11.63 
24.08 
3.89 
Standard error 
3.39 
21.35 
2.06 
Range 
4.00-20.50 
0.33-88.00 
2.00-8.00 
Mean clutch size 
2.89 
2.91 
3.00 
Standard error 
0.26 
0.21 
0.26 
Range 
2-4 
l^t 
2-4 
mean ± SE of 22.73 ± 7.64 parasites in 
parasitized nests in 2007. There were many nests 
with few parasites in both years, and few nests 
with many parasites (Fig. 1A). Parasite intensity 
per nestling followed that same trend, ranging 
from 0 to 21.25 with a mean ± SE of 6.59 ± 1.15 
parasites per nestling in parasitized nests in 2008 
Md from 0 to 88 with a mean ± SE of 14.05 ± 
7 - 6 l parasites per nestling in parasitized nests in 
2007 (Fig. IB). 
Habitat had a significant effect on prevalence of 
parasite infestation (x 2 = 10.58. df = 3, P = 
0.014). There were more nests parasitized in 
residential areas and pastures than in parking lots 
(pairwise Chi-square tests: x 2 = 8.94. df = 1, P — 
0.003, and x“ = 7 04 - df = 1, P = 0.008, 
respectively; Fig. 2). There was a non-significant 
trend for more parasitized nests in residential 
areas than in the wildlife preserve (x 2 = 2.73, df 
- \ p — 0.098; Fig. 2). Nest height also had a 
positive effect on the probability of being infected 
(^2 = 4.52, df = l, P — 0.033). There was a trend 
(^2 = 3 5 g df = 1, P = 0.058) for nests later in 
the year to have a higher probability of parasitism. 
TABLE 2. Characteristics of parasite prevalence, parasite intensity, parasite tntens.ly per nestling, and clutch size of 
Miem Mockingbirds at each site during the 2008 breeding season. Gainesv.lle, Florida. ORD Ordway-Swi. he 
Biological Station. BRU = Beef Research Unit, SF = Santa Fe River Ranch Beef Unit, DUCK - Duckpond, CAPRI 
c apri, 0M = Oaks Mall, and BP = Butler Plaza. 
Und-me 
Rural 
Urban 
__ Habiiat 
Preserve 
Pasluit 
Residential areas 
Parking lots 
Site 
ORD 
BRU 
SF 
DUCK 
CAPRI 
OM 
BP 
Sample size 
7 
13 
10 
7 
11 
15 
J^as'te prevalence 
0.20 
0.43 
0.69 
0.70 
0.57 
0.18 
0.13 
dean parasite intensity 
4.00 
49.67 
22.89 
17.29 
23.50 
19.50 
2.50 
Standard error 
3.00 
18.59 
6.19 
7.10 
9.63 
0.50 
1.50 
Range 
1-7 
22-85 
1-63 
1-52 
1-41 
19-20 
1-4 
Mf an parasite intensity 
Pee nestling 
1.00 
12.42 
6.80 
5.37 
7.54 
4.88 
0.83 
Standard error 
0 75 
4.65 
2.04 
2.34 
2.69 
0.13 
0.50 
Range 
0 25-1.75 
5.50-21.25 
0.33-21.00 
0.50-17.33 
0.25-10.25 
4.75-5.00 
0.33-1.33 
Mean clutch size 
3.60 
3.43 
3.23 
3.00 
3.00 
2.73 
3.40 
Standard error 
0.16 
0.43 
0.20 
0.26 
0.31 
0.33 
0.16 
Range 
3-4 
1-4 
2-4 
2-4 
2-4 
1-4 
2-4 
