Since the early 1990s, morbidity and mortality in tortoise populations have been associated with a transmissible, mycoplasmal upper respiratory tract disease (URTD). Although the etiology, transmission, and diagnosis of URTD have been extensively studied, little is known about the dynamics of disease transmission in free-ranging tortoise populations. To understand the transmission dynamics of Mycoplasma agassizii, the primary etiological agent of URTD in wild tortoise populations, we studied 11 populations of free-ranging gopher tortoises (Gopherus polyphemus; n = 1667 individuals) over five years and determined their exposure to the pathogen by serology, by clinical signs, and by detection of the pathogen in nasal lavages. Adults tortoises (n = 759) were 11 times more likely to be seropositive than immature animals (n=242) (odds ratio = 10.6, 95% CI = 5.7-20, P < 0.0001). Nasal discharge was observed in only 1.4% (4/296) of immature tortoises as compared with 8.6% (120/1399) of adult tortoises. Nasal lavages from all juvenile tortoises (n=283) were negative by PCR for mycoplasmal pathogens associated with URTD. We tested for spatial segregation among tortoise burrows by size class and found no consistent evidence of clustering of either juveniles or adults. We suggest that the social behavior of tortoises plays a critical role in the spread of URTD in wild populations, with immature tortoises having minimal interactions with adult tortoises, thereby limiting their exposure to the pathogen. These findings may have broader implications for modeling horizontally transmitted diseases in other species with limited parental care and emphasize the importance of incorporating animal behavior parameters into disease transmission studies to better characterize the host-pathogen dynamics. Abstract. Since the early 1990s, morbidity and mortality in tortoise populations have been associated with a transmissible, mycoplasmal upper respiratory tract disease (URTD). Although the etiology, transmission, and diagnosis of URTD have been extensively studied, little is known about the dynamics of disease transmission in free-ranging tortoise populations. To understand the transmission dynamics of Mycoplasma agassizii, the primary etiological agent of URTD in wild tortoise populations, we studied 11 populations of free-ranging gopher tortoises (Gopherus polyphemus; n ¼ 1667 individuals) over five years and determined their exposure to the pathogen by serology, by clinical signs, and by detection of the pathogen in nasal lavages. Adults tortoises (n ¼ 759) were 11 times more likely to be seropositive than immature animals (n ¼ 242) (odds ratio ¼ 10.6, 95% CI ¼ 5.7-20, P , 0.0001). Nasal discharge was observed in only 1.4% (4/296) of immature tortoises as compared with 8.6% (120/1399) of adult tortoises. Nasal lavages from all juvenile tortoises (n ¼ 283) were negative by PCR for mycoplasmal pathogens associated with URTD. We tested for spatial segregation among tortoise burrows by size class and found no consistent evidenc...

Thirty-three black bears (Ursus americanus) were captured and 27 (11 F: 16 M) were radiocollared from 1983 to 1988 on 2 study areas in north-central Florida to study home-range characteristics, habitat use, and mortality. A total of 2,146 locations were recorded. Homerange sizes, calculated by the convex polygon method, averaged 170 ? 26 (SE) km2 for adult males (n = 12) and 28 ? 5 km2 for adult females (n = 8). Home-range sizes were smallest during winter and spring and largest during summer and fall for all bears. Home ranges of bears from all sex and age classes overlapped. Habitat preference of bears on the Ocala study area shifted from pine flatwoods in winter and spring to sand pine scrub in summer and fall. Bears on the Osceola study area preferred hardwood swamps throughout the year. Annual mortality rates were 0.16 for females and 0.12 for males. Major causes of death for tagged bears were hunting and collisions with motor vehicles. Int. Conf. Bear Res.and Manage. 9(1):349-356 Until the late 1800s, black bears occurred throughout the Florida mainland (Brady and Maehr 1985). The replacement of native forests with agricultural and urban development has resulted in forest fragmentation and bear populations that are geographically isolated. Bear populations in Florida are largely restricted to the expansive, undeveloped woodlands concentrated in and around Apalachicola, Osceola, and Ocala National Forests, and Big Cypress National Preserve. The black bear is listed by the State of Florida as a threatened species, except in 2 areas in northern Florida where it retains game status. Wise management of Florida's black bears requires information on the biological needs of the species. The gathering of this information was begun in the 1950s (Harlow 1961), but little else was done until the mid-1970s. Information has since been collected on distribution (Williams 1978, Brady and Maehr 1985), food habits (Maehr and Brady 1984), parasites (Conti et al. 1983), beeyard depredation and control (Maehr and Brady 1982, Wooding et al. 1988), roadkill mortality (Wooding and Brady 1987), home range (Mykytka and Pelton 1989, 1990), and winter denning (Wooding and Hardisky 1992). The purpose of this study was to investigate black bear home-range characteristics and habitat use in north-central Florida. In the process, we also gained some insight into mortality, density, and dispersal. This information is also reported here. J. Brady initiated this study in 1983 and, with D. Maehr's assistance, conducted the fieldwork through 1985. We thank J. Brady, P. Moler, and an anonymous reviewer for their helpful comments on earlier drafts of this manuscript.

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Demodicosis was diagnosed in five black bears (Ursus americanus) from north-central Florida. The first bear examined, a 5-yr-old male, had severe alopecia except for the dorsal neck, paws, and ears. The skin was characterized by moderate orthokeratotic hyperkeratosis, and mild to moderate follicular hyperkeratosis. Superficial dermatitis, follicular pustules, and epidermal pustules were present, but rare. Specimens of Demodex sp. were seen most commonly within hair follicles devoid of hair and at the infundibulum of sebaceous glands. Four additional bears from the same area also had some degree of alopecia and skin scrapings were positive for Demodex sp. This mite may be common, although its prevalence is not known.