1988] 
Kozol, Scott , & Traniello — Nicrophorus 
171 
Table 2. 
Carrion Burials— 
-Field Studies 
Prey Size 
N 
Na 
Buried By 
Nm 
No 
20-25 
14 
0 
0 
3 
60-80 
5 
2 
1 
1 
80-100 
10 
6 
2 
0 
100-200 
6 
0 
0 
0 
200-300 
2 
1 
0 
0 
>300 
7 
0 
0 
0 
Species abbreviations are same as those for Table I. 
N = sample size. 
Island. N. americanus showed a preference for prey ranging from 
80-100 grams. N. marginatus also buried prey in this size category 
(Table 2). 
Sixteen of the 20 broods reared in the laboratory resulted in 
eclosed tenerals. There was a significant positive correlation 
between carcass weight and total brood weight (r = 0.60, p = 0.01, 
Fig. 1). There was also a significant positive correlation between the 
number of tenerals eclosed and carcass weight (r = 0.69, p = .007) 
but no significant correlation between carcass weight and either 
mean weight or mean pronotal width of tenerals eclosed. A partial 
correlation analysis removing the effect of total brood weight indi- 
cated a highly significant negative correlation between the number 
of adults eclosed (per brood) and their average weight (r = -0.77, 
p = .0001). 
Discussion 
N. americanus is considered to be a potentially endangered spe- 
cies because its distribution may have declined to only two known 
populations. It is difficult to predict whether the estimated popula- 
tion size of N. americanus on Block Island alone is viable for the 
survival of the species. Fluctuations in environmental factors such 
as weather, resource availability, changes in vegetation and the 
presence of parasites or predators can cause natural oscillations in 
the size of insect populations (New 1984). Human activity can also 
have a major impact on insect populations. 
The Gazey and Staley (1986) population estimate appeared to be 
the best one to use for N. americanus because sample sizes were 
