CLAPPER RAIL STUDIES - 1951 
Robert F. Stewart 
U. S. Fish and Wildlife Service 
1951 Breeding Season 
As a result of a survey of sample salt marshes in the eastern United 
States, Clapper Rails were found to be common to abundant in the Gulf 
coast marshes from east Texas to northwest Florida and in the Atlantic 
coast marshes from northeast Florida to northern Virginia. Along the 
coasts of central and southern Florida they were much more local and 
sparsely populated. On the Texas coast, from Galveston to Brownsville, 
Clapper Rails were either absent or of minor importance. In Maryland 
they were much less common than in La eae due to unsuitable habitat 
in the former state. 
At Chincoteague, Virginia actual counts of nests with eggs ina 
measured study area showed the adult breeding Clapper Rail population 
suffered a loss of hO percent from last year's population. However, 
the birds could still be considered as being common, and since last 
year's population was apparently much higher than usual, judging from 
conversations with local wardens, fishermen and oystermen, it is 
probable that this year's numbers approaches the normal more closely. 
Due to the effects of successive high storm tides, the hatching 
success of the first sets of eggs laid was less than 45 percent (com- 
pared with 9, percent last year). The actual loss this year was 
probably even greater than this since many of the nests which had not 
been destroyed were found at the last visit to be completely devoid of 
cover and, therefore, more vulnerable to predation. 
Up to the middle of June many adults were still attempting to 
renest. Some of these were undoubtedly making their third or fourth 
attempts due to the recurring storm tides. 
Age Classes of Immatures 
As a result of high storm tides during the early part of the nest- 
ing season the production of young was greatly staggered. The earliest 
hatching was observed on May 28 (June 1 in 1950) while the latest egg 
date was Aug. 10, 1951. On this date at Cobb Island, Va., nests with 
eggs were found. One nest contained 9 eggs that were only one-third 
developed, while the eggs in two nests (both 5 eggs) were hatching. 
The earliest fully-developed immature birds recorded were taken in the 
banding traps on July 19, 1951, while the latest small newly~hatched 
juveniles were taken on Aug. 16, 1951 (Aug. 20 in 1950). The proportions 
of the different size groups of immatures during the trapping period are 
shown in the following table: 
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