Geology topics

Research about Key Largo

Source-linked reports with geographic coverage including Key Largo.

3 recordsLinked to original sources

USGS2023

Survey optimization for invasive Burmese pythons informed by camera traps

The Burmese python ( Python bivittatus ) is an invasive predator responsible for broad mammal declines in South Florida, United States. Despite their large size, pythons remain cryptic and require multifaceted approaches for detection. We evaluated a novel technique by deploying camera traps at known locations of radiotagged pythons in the Florida Keys. We estimated daily detection probabilities of snakes and plotted diel activity patterns. Our results suggest camera traps can effectively survey pythons but seasonality and camera trigger mechanisms affect utility. Pythons were most detectable with time-lapse camera traps and more detectable in winter. The diel activity pattern of pythons peaked midday through early afternoon, indicating an optimal survey time for other search methods. Artificial intelligence can alleviate photo volume, so we recommend a combination of motion detection and time-lapse with shorter time (1 min) intervals for python-specific surveys and where camera traps are deployed to monitor mammals to improve passive python detection.

Florida↗

USGS2016

Evaluating nest supplementation as a recovery strategy for the endangered rodents of the Florida Keys

The Key Largo woodrat ( Neotoma floridana smalli ) and Key Largo cotton mouse ( Peromyscus gossypinus allapaticola ) are federally endangered subspecies endemic to the tropical hardwood hammocks of Key Largo, Florida. Woodrats are considered generalists in habitat and diet, yet a steady decline in natural stick nests and capture rates over the past several decades suggests that they are limited by the availability of nesting habitat due to habitat loss and fragmentation. The more specialized Key Largo cotton mouse appears to rely on old growth hammock, a habitat type that is rare following past land clearing. In 2004, the U.S. Fish and Wildlife Service started building supplemental nest structures to restore habitat quality and connectivity for these endangered rodents, but nest use requires evaluation. We used camera traps and occupancy models to evaluate the factors influencing woodrat and cotton mouse use of the supplemental nests. We detected woodrats at 65 and cotton mice at 175 of 284 sampled nest structures, with co-occurrence at 38 nests. Woodrat nest use followed a gradient from low nest use in the north to high nest use in the south, which might relate to the proximity of free-ranging domestic cat ( Felis catus ) colonies in residential developments. Cotton mouse nest use, however, was related positively to mature hammock and related negatively to disturbed areas (e.g. scarified lands). The two species occurred independently of each other. Stick-stacking behavior was observed at supplemental nests and, although it was correlated with detection of woodrats, it was not a strong predictor of their occurrence. We suggest that nest supplementation can be an important tool for species recovery as habitat quality continues to improve with succession.

Florida↗

USGS1996

Decadal-scale changes in benthic foraminiferal assemblages off Key Largo, Florida

Assemblages of foraminiferal tests in sediments sampled off Key Largo, Florida, in 1982, 1991, and 1992 were significantly different from assemblages sampled along the same traverses in 1959–1961. Larger, algal symbiont-bearing taxa, primarily Soritidae, comprised 50–80% of the specimens in samples collected in 1959–1961, whereas Miliolidae and Rotaliidae comprised 65-90% of the specimens collected in 1991 and 1992. Test abundance in 1992 samples ranged from 1.0 × 10 2 /g to 8.1 × 104/g; tests were least abundant in coarse, well-sorted sediments. The lack of test-density data for the 1959-1961 samples prevented assessment of whether densities of smaller foraminifera have increased, symbiotic foraminifera have decreased, or both. Between 1982 and 1992, densities of smaller foraminifera appear to have increased. Although the causes of these changes in foraminiferal assemblages are not known, possible factors include nutrient loading inshore, winnowing and transport of tests by storm activity, and disease. The shift in dominance from long-lived, algal symbiont-bearing taxa in 1959--1961 to small, fast-growing, heterotrophic taxa in 1992 is consistent with predictions of community response to gradually increasing nutrient flux into south Florida's coastal waters. This study indicates that published accounts of foraminiferal assemblages from sediments collected 30 or more years ago can be valuable resources in efforts to determine if biotic changes have occurred in coastal ecosystems. This study also indicates that family-level identifications may be sufficient to detect decadal-scale changes in foraminiferal assemblages in reef-tract sediments.

Florida↗