Wildlife conservation -- Florida

Invasion of exotic species is a global threat to native species, biological diversity, and ecological restoration projects. Pomacea maculata is a macrophyte herbivore often misidentified with one of the world’s most invasive and destructive exotic snail, Pomacea canaliculata, but has a broader geographical distribution and climate tolerance, and greater egg production. This research examines whether the exotic P. maculata and native Pomacea paludosa occupy identical vegetation communities, mechanisms of interference competition, grazing impact differences on Vallisneria americana and to develop an exploratory agent based model. This model uses historical and present data to project how differences between species in life history and grazing patterns can potentially impact South Florida ecosystems. This model examined how P. maculate invasion of South Florida could affect two of the Central Everglades Planning Project’s main environmental restoration goals: function of key vegetative communities and
conservation of endangered or threatened species.

This investigation compared statistical parameters for the blood serum chemistries
of free ranging Osprey nestlings from Florida Bay and an Osprey population from Lake
Istokpoga, in Central Florida (Chapter 1). Florida Bay Ospreys showed higher mean rank
values for alanine aminotransferase (H=6.79, P=.009), alkaline phosphatase (H=6.48,
P=.011), and sodium (H=5.7, P=.017), and Central Florida had higher mean rank values
potassium (H=13.19, P=.000) and carbon dioxide (H=6.23, P=.013). Serum chemistries
values were also compared between free-ranging Bald Eagle and Osprey nestling in
Florida Bay estuary in southern Florida (Chapter 2). There were significant differences
between serum values of Bald Eagle and Osprey nestlings. Bald Eagle serum values were
higher for total protein (H=17.833, P=.00002), Albumin (H=7.449, P=.006), Aspartate
aminotransferase (H=113.153, P =.0001), and Calcium (H=7.148, P = 008). Osprey serum values were higher for alanine aminotransferase (H=11.824, P = 0.0005), alkaline phosphatase (H=105.5, P =.0001), creatine kinase (H=13.465, P = 0.0002), carbon dioxide (H=4.443, P = 0.035) and cholinesterase (H=99.3, P=.0001). Sixteen nestling Bald Eagles were fitted with satellite platform transmitter terminal (PTT) or VHF radio transmitter package for a duration of six years (Chapter 3)= to identify their movement and dispersal. One of the 15 eagles migrated to North Carolina, whereas the other 14 (93%) confined their movements to Florida. Tracking duration per individual ranged from 82 to 1,531 days. We estimated first-year survival as 52% and 67% for the period from 1.5 to 3 years. Diamondback Terrapins (Chapter 4) were evaluated by an integrated assessment of physical, chemical, and physiological parameters. Extreme site fidelity of the turtles to mangrove habitat was evident along with a strong female biased sex ratio. There was a significant difference in the total number of individuals collected at the two sites (P =. 01) despite the total size and shorelines of the two sites being very nearly the same. Total recapture rate was 70% for combined population (TLK = 80% and CKW = 48%). We provide blood serum values and microbial cultures as baselines from these turtles in the wild.

The red imported fire ant, Solenopsis invicta, is a South American native
introduced in Alabama in the early 20th century. This predatory species has rapidly
spread throughout the southeastern US and parts of the West Indies, inflicting great
ecological and economic damage. For example, Solenopsis invicta is known to attack the
eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests
attacking hatchlings and diminishing their chance for survival. My thesis research aimed
to survey the distribution of ants on sea turtle nesting beaches in South Florida and St.
Croix, USVI, and to evaluate the possible threat of Solenopsis invicta and other predatory
ants to sea turtle hatchlings.

Juvenile green turtle (Chelonia mydas) abundance differs among nearshore reefs,
but why some sites are preferred over others is unknown. My study had two objectives:
to quantify differences in abundance over time (one year) and to determine what
ecological factors were correlated with those differences. I conducted quarterly surveys
on reefs in Palm Beach and Broward Counties and compared reef sites with respect to (i)
water depth, (ii) algal abundance and composition, and (iii) changes in reef area (caused
by sand covering) through time (11 years). Turtles were most abundant on shallow reefs
exposed to high light levels that remained stable (uncovered by sand) for long periods of
time. These reefs had the highest diversity of algal species, in part because cropping by
the turtles prevented any one species from becoming dominant. My results suggest that
both physical and biological factors make some reefs more attractive to turtles than
others