The Important Bird Areas of Florida - National Audubon Society

The Important Bird Areas of Florida: 2000–2002 – Pranty – 2-Jul-02 43natural habitat within IBAs has allowed significant numbers of virtually all of Florida's native birdspecies to be protected within the state's IBAs, even if these species or groups are not mentionedspecifically in the IBA accounts.3. Some population data used in Tables 1 and 4 were gathered in the 1970s or 1980s and probably areoutdated. The 1983 statewide estimate of 1600 pairs of Ospreys, for example, likely is anunderestimate of current numbers. The increase in Bald Eagle nests in the past 20 years may supportthis belief. During 1980–1984, the mean number of eagle nests in the state was 362 (range of 340–378), but the number of nests in 2001 was 1102 +(Nesbitt 2001b). The elimination of DDT and otherorganochlorine pesticides presumably is responsible for this increase, and it seems likely thatFlorida’s Osprey population has rebounded similarly. The statewide estimate of Wilson's Plovers(>300 birds), a species never formally censused in the state, also seems to be an underestimate. Thedata in Table 1 perhaps can be used to prioritize the list of species for which current statewidepopulation data should be determined.4. Statewide populations of some colonial breeding species vary considerably from one year to the next,often due to weather-related events (e.g., during years of extreme drought, wading birds may leaveFlorida to nest farther north). As a result, the percentage of the statewide population occurring withinIBAs (Table 4, page 32) exceeded 100% for several species. For species whose breeding populationswere restricted to IBAs (e.g., most larids), we used IBA data to determine the statewide population.For other species (e.g., White Ibis), we used the most recent population data to determine thepercentage of the population found within IBAs, even if this figure is greater than 100%.5. Based upon data summarized in Table 4, it is clear that the IBA Program failed to adequately “cover”a few species. Of the 40 species or subspecies included in Table 4, IBAs account for less than half ofthe statewide populations for 14 species, and less than 25% for 4 species (Short-tailed Hawk, 6%;Crested Caracara, 23%; “Florida” Sandhill Crane, 7%, and Burrowing Owl, 0%). The lack ofsignificant populations of Burrowing Owls within IBAs can be explained by the tendency for owls touse human-modified habitats (which generally were ignored by the IBA selection process) andprobably insufficient surveys on some several large properties that likely support significantpopulations (e.g., Kissimmee Prairie Preserve State Park). The small percentage of the populations ofthe Short-tailed Hawks, Crested Caracaras, and “Florida” Sandhill Cranes within IBAs may alsoreflect insufficient data from large properties, but future IBA site-selection efforts in Florida shouldkeep these species in mind.6. Because site nominations were being received at a slow rate—far too slowly to finish the initial siteselection period on schedule, a “top-down” approach eventually was taken. Using this method, theFlorida IBA Coordinator nominated or “pre-nominated” dozens of sites, and then sought assistanceand review from others. For the same reason, a similar “top-down” approach was undertaken inCalifornia +(Cooper 2001) and Georgia (J. Wilson pers. comm.). It is hoped that participation in theFlorida IBA process will increase now that sites have been selected. Local individuals or groups canvolunteer to lead bird walks, assist with bird surveys, or update bird checklists, remove trash or exoticplants and replant native vegetation, lobby politicians to purchase private property adjacent to IBAs,or assist agency staff with site management or improvement in other ways.7. Some important contributors to the Florida IBA Program were not contacted until shortly before thefinal manuscript was prepared, which prevented these individuals from contributing significantly tothe program. It seems a certainty that other equally important individuals who could have improvedthis document never were aware of the IBA Program before or during manuscript preparation. It ishoped that these and other individuals will offer their assistance with future IBA site selection effortsin Florida.