swamps, all but the mangrove cuckoo have 

 expanded their range in peninsular Florida 

 by using non-mangrove habitat. In this 

 vein it is interesting to note that many 

 species of rare and/or irregular occur- 

 rence in south Florida are of West Indian 

 origin and use mangroves to a considerable 

 extent. These include the Bahama pintail, 

 masked duck, Caribbean coot, loggerhead 

 kingbird, thick-billed vireo, and stripe- 

 headed tanager (Robertson and Kushlan 

 1974). 



Twenty-four of the species in this 

 guild are permanent residents, 27 are win- 

 ter, and 6 are summer residents. Fourteen 

 species are seen only during migrations. 



9.8 ASSOCIATIONS BETWEEN 

 COMMUNITY TYPES AND BIRDS 



MANGROVE 



Estimating the degree of use of 

 mangrove swamps by birds as we have done 

 (Appendix D) is open to criticism because 

 of the paucity of information upon which 

 to base judgements. Estimating which 

 mangrove community types (see section 1, 

 Figure 4) are used by which birds is open 

 to even more severe criticism. For this 

 reason the following comments should be 

 regarded as general and preliminary. 



In terms of utilization by avifauna, 

 the scrub mangrove swamps are probably the 

 least utilized mangrove community type. 

 Because the canopy is poorly developed, 

 most of the arboreal species are absent, 

 although Emlen (1977) recorded the red- 

 winged blackbird, hairy woodpecker, north- 

 ern waterthrush, yellow-rumped warbler, 

 common yel 1 owth roat , orange-crowned 

 warbler, palm warbler, yellow warbler, 

 mourning dove, and gray kingbird in scrub 

 mangroves on Grand Bahama Island. Of 25 

 different habitats surveyed by Emlen 

 (1977), the yellow warbler and gray 

 kingbird were found in the scrub mangroves 

 only. Aerially-searching and wading birds 

 might use scrub mangroves if fishes are 

 present. 



Overwash mangrove islands are 

 utilized in a variety of ways by all of 

 the bird guilds. Most of the wading birds 



plus the magnificent f ri gatebi rd, the 

 anhinga, the cormorant, and the brown 

 pelican use overwash islands for nesting 

 (Kushlan and White 1977a). Wading and 

 aerially-searching birds commonly feed in 

 close proximity to overwash islands. A 

 variety of migrating arboreal and probing 

 species use the islands for feeding and 

 roosting. Yellow and palm warblers are 

 common around mangrove islands in Florida 

 Bay as are the black-bellied plover, ruddy 

 turnstone, willet, dunlin, and short- 

 billed dowitcher. Rafts of ducks are 

 common near the inshore islands and birds 

 of prey such as the osprey, the bald 

 eagle, and both vultures use mangrove 

 islands for roosting and nesting. 



Fringe and riverine mangrove com- 

 munities are important feeding areas for 

 wading and probing birds. Floating and 

 diving and aerially-searching birds use 

 the lakes and waterways adjacent to these 

 mangrove communities for feeding. Many of 

 the wading birds nest in fringe and 

 riverine forests. For example, when the 

 wood ibis nests in coastal areas, it uses 

 these mangrove communities almost exclu- 

 sively (Kushlan, personal communication). 

 Most of the arboreal birds and birds of 

 prey associated with mangroves are found 

 in these two types of communities. This 

 is not surprising since the tree canopy is 

 extremely wel 1 -devel oped and offers 

 roosting, feeding and nesting opportuni- 

 ties. 



Hammock and basin mangrove communi- 

 ties are so diverse in size, location, and 

 proximity to other communities that it is 

 difficult to make many general statements 

 about their avifauna. Since there often 

 is little standing water in hammock 

 forests, wading and diving birds probably 

 are not common. Proximity to terrestrial 

 communities in some cases may increase the 

 diversity of arboreal species in both 

 hammock and basin forests; proximity to 

 open areas may increase the likelihood of 

 bi rds of prey. 



It seems safe to conclude that each 

 of the six mangrove community types has 

 some value to the avifauna. This value 

 differs according to community type and 



70 



