Swallow-tailed Kites 
193 
could have been gleaned while resting. Although these ants are only 
8-mm long, they may represent a major food source. Morrill (1974) 
studied imported fire ants in several habitats in northern Florida 
and found that emergence of alates averaged 187,000/acre/year 
(75,700/ha/year). The heaviest flights occurred between April and 
August, indicating that they could be an important food source 
throughout most of the kites’ period of summer residence. Haver- 
schmidt (1962) noted that the gizzard of one kite ( E . /. yetapa ) 
collected in Surinam was full of flying ants. 
The recovery of 21 individuals of Eriotremex formosanus, a 
horn tail, in five of the stomachs is of interest entomologically. 
This is an exotic species, and these individuals represented the first 
examples found east of Louisiana (J. Green, North Carolina Depart- 
ment of Agriculture, personal communication). 
Mercury analysis of body tissues indicated that these birds are 
not receiving much mercury in their diets. This is probably indica- 
tive of the intermediate trophic level of this species. Mean mercury 
loads for three adults of the series collected were 0.09 ppm for 
muscle, 0.25 ppm for liver, and 0.31 ppm for kidney tissue. The 
higher concentrations for liver and kidney tissue in the kites sug- 
gest that the birds are successfully regulating (excreting) mercury. 
Comparisons of various seabird species we examined at the same 
time and with the same methods show high mercury loads (0.23-98 
ppm for muscle, 0.61-60 ppm for liver, and 0.34-26 ppm for kid- 
ney) (P. Whaling and D. Lee, unpublished data). 
OTHER 
8.12 
TRUE BUGS 
5.2 
HORNTAIL 
6.1 
FIRE ANT 
6.1 
GRASSHOPPER 
42.4 
PALMETTO WEEVIL 
12.7 
LEAF-FOOTED BUG 
19.18 
Fig. 3. Percentages of major prey types recovered from eight swallow- 
tailed kites, Elanoides forficatus collected in July 1982. 
