
EFFECTS OF SPRAYING ON VERTEBRATES 
Birds 
Species and Ecology 
Relatively few species of birds in this region confine their 
nesting to the coastal salt marshes. However, those that do are present 
in large numbers. Resident marsh species within or near the study area 
numbered only four: the clapper rail (Rallus longirostris), laughing gull 
(Larus atricilla), sharp-tailed sparrow (Anmospiza caudacuta) and seaside 
sparrow (Ammo iza maritima). A second group uses the salt marsh as only 
a part of their nesting habitat. In or near the study plots these included 
the black duck (Anas rubripes), long-billed marsh wren (Telmatodytes 
palustris) and red—wing Agelaius phoeniceus). 
In addition to species which nest in the salt marsh, others come 
here to feed during the summer months. Common members of this group are 
the great blue heron (Ardea herodias), American egret (Casmerodius albus), 
snowy egret (Leucophoyx thula), little blue heron (Florida caerulea), green 
heron (Butorides virescens), black-crowned night heron (Nycticorax cticorax), 
marsh hawk (Circus cyancus)» fish crow (Corvus Sbalerasuays tree swallow 
Il» 
(Iridoprocne bicolo and barn swallow (Hirundo rustica). Later in the 
year, numerous migrants, particularly shorebirds and waterfowl, frequent 
the salt marsh, 
Methods of Study 
The effects of spraying upon bird life of the marsh were determined 
by two procedures: (1) general observations in all study areas and (2) strip 
counts in the two higher dosage aréas (1.6 and 0.8). 
General Observations 
After the first spraying there was a decided decrease in the use 
of the 1.6 and 0.8 areas by tree swallows. The birds confined their 
activities more to untreated areas, seemingly in correlation with reduction 
of flying insects over the sprayed portions of the marsh. The 0. and 0.2 
areas had small swallow populations before spraying and no changes were 
observed there following treatment. Prior to the September spraying, 
swallows were again common in the 1.6 and 0.8 areas and remained so after- 
wards. 
Before the first spraying, laughing gulls were fairly common 
over the 1.6 area and roosted regularly part of the day on a few favored 
beds of saltmeadow cordgrass. Four counts revealed an average of 61 birds 
frequenting one bed in this area. On the morning following treatment, 
several hundred gulls and a few common terns (Sterna hirundo) were observed 
at low tide feeding on dead fish in the larger creeks and calling excitedly. 
This behavior attracted additional gulls which were seen flying to the area. 
Undoubtedly some birds came from a distance as these were the first common 
