Birds — Our Living Resources 



Moritz, a German naturalist, indicated that the 

 Puerto Rican parrot population had begun to 

 decline (Snyder et al. 1987). 



By 1900 the human population had doubled 

 to a million (Fig. 1 ). About 76'>( ol'the land area 

 of Pueilo Rico had been converted from forest 

 to agriculture (Snyder et al. 1987); less than \% 

 of the old-growth forest remained after more 

 than 400 years of European civilization. At this 

 time, the parrot population must have been low, 

 but no data exist. By 1937 U.S. Forest Service 

 (USFS) rangers estimated the Puerto Rican par- 

 rot population at about 2,000 birds (Wadsworth 

 1949). A few years later, panots were found 

 only in the Luquillo Mountains, formerly a for- 

 est reserve of the Spanish Crown and now man- 

 aged by the USFS. This area contained the last 

 forest habitat suitable for Puerto Rican paiTots. 



Population surveys of the Puerto Rican par- 

 rot were not conducted until the 1950's. Early 

 estimates of the parrot population in Puerto 

 Rico are based on few written records and gen- 

 eral observations (Snyder et al. 1987). knowl- 

 edge of the parrot's biology, and e.Ktrapolation 

 of population surveys conducted by 

 Rodriguez- Vidal (1959). During the I950"s, 

 Rodriguez- Vidal of the Puerto Rico Department 

 of Agriculture and Commerce conducted the 

 first extensive study of the Puerto Rican panot. 

 He reported a population of 200 Puerto Rican 

 parrots by the mid-1950"s (Fig. 2). About 20 

 years later the population had dwindled to 14 

 individuals that inhabited an isolated rain forest 

 of the Luquillo Mountains. 



Puerto Rican parrot (Amazoiui vil- 

 lata). 



In 1968 Kepler, U.S. Fish and Wildlife 

 Service (USFWS), organized parrot surveys by 

 placing observers at strategic sites, including 

 overlooks from prominent rocks, road-cuts, and 

 building roofs. Snyder et al. (1987) improved 

 the survey method in 1972 by constructing 10 

 treetop lookouts in areas of major parrot use. 

 Parrot surveys are conducted from these plat- 

 forms during the breeding season and pre- and 

 postbreeding season (Snyder et al. 1987). 

 Observers collect information on parrot num- 

 bers, directions, and their distance from the 

 platform by the time of day. By 1993 this tree- 

 top lookout system was expanded to 38 plat- 

 forms (Vilella and Garcia 1994). 



In 1968 implementation of the Puerto Rican 

 Parrot Recovery Plan began: it is a cooperative 

 effort of scientists and managers of the Puerto 

 Rico Department of Environmental and Natural 

 Resources, USFS (Caribbean National Forest 

 and International Institute of Tropical Forestry). 

 USFWS Puerto Rican Parrot Field Office, and 

 the National Biological Service. After the 

 recovery program began, the parrot population 

 increased to^47 bird's by 1989 (Wiley 1980; 

 Lindsey et al. 1989; Meyers et al. 1993); how- 

 ever, about 5Q'7( of the population was 

 destroyed by Humcane Hugo that same year. A 

 small population of 22-24 individuals remained 

 in late 1989 (Fig. 2). Since then, the population 

 recovered to 38^-39 by early 1994 (F.J. Vilella, 

 USFWS, personal communication). After the 

 hurricane, the number of successful nesting 

 pairs increased from a maximum of 5 to 6 pairs 

 from 1991 to 1993 (Meyers et al. 1993; Vilella 

 and Garcia 1994). 



Research and Management 



Puerto Rican parrots declined in relation to 

 the increasing human population (Fig. 1). 

 Conversion of forests to agriculture and loss of 

 forest habitat, on which the species depended 

 for food and nest cavities, was the primary 

 cause for decline. Shooting parrots for food or 

 protection of crops and capture for pets were 

 secondary causes for decline. The remnant par- 

 rot population in the Luquillo Mountains was 

 further stressed when trails and roads were cre- 

 ated and when human uses of the forest timber 

 were encouraged in the early 1900"s (Snyder et 

 al. 1987). Storms before the arrival of 

 Europeans probably had little effect on the par- 

 rot population because the population was more 

 widespread, and hurricanes tend to affect only a 

 small geographic area. Severe hurricanes in 

 1898, 1928. 1932. and 1989 reduced small, 

 now-isolated populations even further. The 

 apparent ability of the population to rebound 

 after these storms is suggested by increases in 

 the panot population and in nesting pairs after 



