Wildlife conservation

In examining the intentional relationship between the conservationist and the shark in South Florida, this thesis considers the latter as both a scarce natural resource - caught up in what Clifford Geertz citing Weber referred to as "webs of significance" (Geertz 1973:5) - and as a reflection of dynamic human conceptions of nature : a meta shark. This complex relationship is described by interpretations of conservation discourse recorded through ethnographic interviews that demonstrate how these perceptions have been influenced by factors such as personal experiences, film and text, and broad changes in the relationship between humans and nature since the early days of the environmental movement. By linking these perceptual changes with changes in American shark conservation policy, this work not only explains a relationship between culture, perception, and policy, but also celebrates the emergence of a multispecies marine community.

The bald eagle, Haliaeetus leucocephalus, population declined dramatically in the early 20th century reducing the population from tens of thousands of birds within the lower 48 states, to <450 pairs of birds, effectively inducing a population bottleneck. The overall population has recovered and was removed from the endangered species list in 2007. This study investigates whether such overall population statistics are appropriate descriptors for this widespread species. I investigated the genetic differentiation between three populations of bald eagles from Alaska, North Florida and Florida Bay using both mitochondrial and nuclear DNA loci to determine whether discrete subpopulations comprise the broad range. Significant FST values, for both mtDNA and microsatellites, were found between both Florida populations and Alaska, but not within Florida populations. Results indicate that there is strong population structure, rejecting the null hypothesis of a panmictic population. Future conservation efforts should focus on subpopulations rather than the overall population.

This study examines prevalence of antibiotic resistant bacteria in Amazon parrots in three different groups, one wild and two captive. Commensal bacteria were isolated from 24 parrots and screened for antibiotic resistance. Culture-based and molecular methods were used and a total of 546 isolates from the genus Staphylococcus and Rothia were obtained. Antibiotic resistance was found in all parrot groups in 161 isolates with 48 having multi-drug resistance. The highest frequency of resistance was found to Enrofloxacin and Amoxicillin/Clavulnate though all antibiotics tested were resisted by some bacterial isolates. Both captive groups exhibited more resistant individuals than the wild. This study concluded that antibiotic resistant commensal bacteria in Amazons are common; however, patterns found cannot be explained by antibiotic use. A high rate of multi-drug resistance was detected in more common mannitol non-fermenting Staphylococcus spp., and drug resistant detected in Rothia spp. may indicate a future role in disease.

Due to an emergency status dune restoration project following Subtropical Storm Andrea in 2007 on Singer Island, Florida, nests needed to be moved during early to mid-incubation. Nesting success was compared between those moved mid-incubation, moved within 12h to either a native sand incubation area or a renourished sand incubation area, and those left in-situ. Nests moved within 12h to the native sand had a significantly larger proportion of pipped hatchlings. Nests moved mid-incubation had a significantly lower proportion of hatched eggs as well as emergent hatchlings. The stage in which embryonic development was arrested corresponded to the stage the embryos were in during the time of movement; indicating movement was the cause of death. When comparing nests moved within the initial 2.5 weeks of development to those moved after 2.5 weeks of development, there was no significant difference in hatching success.

I examined the impact of the exotic, invasive plant Old World climbing fern, Lygodium microphyllum (Cav.) R. Brown, on tree island plant and ant communities in the northern Everglades. I selected 15 tree islands representing four groups: non-Lygodium islands, islands with low levels of Lygodium, islands with high levels of Lygodium, and disturbed islands impacted by people. I used a variety of diversity indices to compare plant and ant data among habitats. The ant communities studied included native and exotic species typical of south Florida. Tree island plant communities were consistent with descriptions from previous studies. Plant species richness decreased with the level of L. microphyllum in the ground and midstory layers. Abundance of native plants decreased with level of L. microphyllum in the ground, midstory, and overstory layers. Lygodium microphyllum did not affect ant communities suggesting that although it negatively impacts plant communities it can provide habitat for ants.

In the Eastern United States, the Florida coastline provides 85% of all nesting sites for the green (Chelonia mydas), leatherback (Dermochelys coriacea), and loggerhead (Caretta caretta) sea turtles. Palm Beach County beaches experience some of the highest nesting frequencies, but recreational use of the beaches has increased threats like raccoon predation. The Gumbo Limbo Nature Center (GLNC) in Boca Raton (founded in 1984) keeps records of nests and predators to the nests. I analyzed 4554 GLNC nest records from 2002-2007 to examine whether raccoon predation of turtle nests was most prevalent in areas of high human impact. I found that raccoon predation occurred at significantly higher rates in areas with public access to the beach than in areas without such access (high access: 50.8%, low access: 14.4%, overall: 36.4%). This suggests the necessity of increased protection of nests in areas of high access for the preservation of nesting populations.

Upper Respiratory Tract Disease (URTD) is a highly contagious illness, caused by the bacterium Mycoplasma agassazii. URTD has affected the gopher tortoise population in the Abacoa Greenway, and is believed to have a high mortality rate. In this study, 18 samples of tortoise blood were collected from this location. Fifteen of the 18 samples were collected from previously tested individuals. Comparisons between the previously tested tortoises were made. According to this study there is no documented mortality rate with URTD in Abacoa. Results show that four tortoises have continued to test positive for the antibodies for several years, suggesting a chronic state of the disease. Four other tortoises have gone from positive results to negative results indicating that their immune systems' production of antibodies has tapered off, suggesting the ability to recover from the disease.

The Gull-billed Tern is a globally distributed species. Distribution in the United States is limited, however, with the majority of breeding birds being found in Texas. The remainder can be found scattered throughout the southeastern states. Florida has a mere 1.6% of the breeding birds in the U.S. This study has accumulated all breeding records of the Gull-billed Tern in Florida since 1973, and distribution trends were analyzed. Since 1973 the population of these birds has fluctuated widely and experienced an alarming decline of about "95% between 1975 and 1999" (Smith, in press.). I determined that the current status of this bird in Florida mandates that further conservation efforts occur rapidly in order to protect its diminishing population. This study examines those conservation measures already in place, and those pending, such as my petition to list this species as "threatened" under the endangered species provisions of the Florida Wildlife Code (Chap. 39 F.A.C.).

In Florida, loggerhead sea turtle (Caretta caretta) nesting populations are in decline, and human presence on beaches during nesting season can create an array of problems for the sea turtles. Volunteers and workers from the Loggerhead Marinelife Center collected nesting data from 2001 to 2005 along a 9.7 km stretch of Jupiter and Juno Beach, in Palm Beach County, Florida. Using these data, I found that human presence appears to have a negative impact on false crawl rates. The rate of false crawl was significantly higher on weekends than on weekdays(χ2 = 6.3, p < 0.05), and in areas with continuous public access than in areas with no public access(χ2 = 69.0, p < 0.0001). However, there was no significant difference in the number of nests laid on weekends versus weekdays(χ2 = 0.6, p > 0.05), although there are still other, less obvious negative effects caused by false crawling, and even nesting, while humans are in the vicinity. Even though it is impractical to try to keep people off the beach at night, it is important to increase awareness of the negative impacts that human presence may have on sea turtle nesting in order to help reverse the decline in the population of loggerhead sea turtles.

Nearshore sabellariid worm rock reefs tracts along Florida's east cost provide developmental habitat for many juvenile green turtles.