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Migratory animals spend different periods of their lives in widely separated and ecologically different locations; their experiences from one activity/period/site (e.g., foraging) can dramatically affect their success during another (e.g., breeding). Carry-over effects reflect the influence of foraging quality on reproductive behaviors of migratory species, such as nesting loggerhead sea turtle ( Caretta caretta), which vary greatly in body size and reproductive parameters. We investigated carry-over effects on 330 loggerheads nesting at the Archie Carr National Wildlife Refuge (Melbourne Beach, Florida), one of the largest aggregations in the Western Hemisphere, using telemetry, stable isotope analysis and reproductive parameters. We assigned foraging locations used during the non-breeding period with discriminant function analysis and determined the relative contributions to different foraging regions from 2007 to 2012. Foraging regions significantly influenced female body size and fecundity. Loggerheads foraging southeast of the nesting beach in the vicinity of the Bahamas and Florida Keys laid larger clutches and had a shorter breeding frequency. On average, 47 % (±3 % SE) of the females foraged year-round in this area, while 33 % (±4 % SE) resided on the Southwest Florida continental shelf south of Tampa Bay and 18 % (±2 % SE) undertook seasonal migrations and foraged north of Cape Hatteras, North Carolina. Relative contributions to the foraging areas did not change over the 6-year period. The northern foraging area consistently contributed the fewest females despite being the most productive oceanographic region suggesting a trade-off between foraging area productivity and distance to the nesting beach. We reaffirm that the isotopic approach can be used to interpret trends in abundance at nesting beaches and demographic parameters affecting those trends. Understanding geospatial linkages and relative importance of foraging areas is critical to fostering appropriate management and conservation strategies for migratory species. [ABSTRACT FROM AUTHOR]

In the United States, raccoons Procyon lotor are often removed from sea turtle nesting beaches to decrease egg mortality. However, raccoons also consume ghost crabs Ocypode quadrata, another common egg predator. Reducing predator populations can benefit secondary predators, inflating total predation pressure and leading to a decline in prey species. We used track and burrow counts to compare raccoon and ghost crab abundance at four beaches in Florida, USA, that differ in management activity and determined predation rates on loggerhead Caretta caretta nests by each predator. Mean raccoon abundance (range 0.12–0.46 tracks plot−1 night−1) and ghost crab density (0.09–0.19 burrows m−2) were inversely correlated. Ghost crabs were largest at the site with the fewest raccoons. The stable nitrogen isotope ratios of ghost crabs (mean 9.8‰) were positively correlated with body mass, indicating larger ghost crabs feed at a higher trophic level and suggesting large ghost crabs may consume more loggerhead eggs. The highest rates of egg predation by both predators (31%) occurred where raccoon abundance was lowest and ghost crab abundance was highest, suggesting ghost crab burrows may facilitate predation by raccoons. Our data suggest that predation by raccoons limits ghost crabs and that removing raccoons can increase ghost crab abundance and sea turtle egg mortality. Although predator removal can be effective when nest predation rates are quite high, maintaining moderate raccoon densities may be important for controlling ghost crabs. These results highlight the importance of understanding food web connectivity in developing management strategies to achieve conservation goals, especially when the species of concern are threatened or facing extinction. [Copyright &y& Elsevier]

Predator removal can be an effective strategy for reducing mortality rates of prey species. Because removal programs must continue indefinitely to remain effective, trapping creates a source-sink dynamic that can alter predator spatial distribution and demography. We investigated the intraspecific effects of predator removal by comparing 2 Florida, USA, raccoon (Procyon lotor) populations that are managed to decrease sea turtle egg mortality. Long-term removal created an extremely male-biased population (>10:1), but the proportion of juveniles did not differ between sites. Stable isotope analyses indicate that raccoons on the removal beach originated from inland habitats. Our results suggest that adult males dominate the recolonization of removal areas and the presence of juveniles on the beach is due to predispersal behavior. Because raccoons are highly omnivorous and mobile, intensive management at a small scale may have broader impacts across the landscape that predator-removal programs should consider. [ABSTRACT FROM AUTHOR]

Abstract: Debate about the relative merits of single-species management versus more comprehensive approaches has intensified in recent years. In east-central Florida, USA, land managers use prescribed burns and mechanical cutting to manage and restore scrub habitat to benefit the imperiled Florida Scrub-Jay (Aphelocoma coerulescens). However, these land-management techniques may affect non-target taxa, especially the threatened southeastern beach mouse (Peromyscus polionotus niveiventris). We evaluated the collateral effects of single-species land management by trapping P. p. niveiventris and other small rodents in eighteen land-management compartments at Cape Canaveral Air Force Station, Florida during 2004–2005. Compartments were managed using either prescribed burns (N =5), mechanical cutting (N =6), checkerboarding (cut and uncut lanes alternating and overlapping, followed by a prescribed burn, N =4) or left unburned and uncut for >50year (N =3). P. p. niveiventris was significantly more abundant in compartments managed with prescribed burns (mean±SE: 4.2±0.7 individuals/transect) than those managed with cutting alone (1.0±0.3) or not managed for >50y (0.2±0.1 individuals/transect). In contrast, the cotton mouse (Peromyscus gossypinus) tended to be more abundant in compartments managed with mechanical cutting alone (2.6±0.4 individuals/transect) compared to the other three management strategies (prescribed burns; 1.5±0.4; checkerboarding, 1.1±0.3; not managed, 1.6±0.4 individuals/transect) but these differences were not statistically significant. Abundances of P. p. niveiventris and Florida Scrub-Jay breeding groups were positively correlated (r =0.655), suggesting that both listed species benefit from similar management techniques. Thus, the mosaic of burned and cut patches used to improve habitat for the Florida Scrub-Jay also benefits an endemic, non-target species. Single-species management may benefit multiple species when restoration improves their shared habitat, which in this case is an endangered, fire-dependent ecosystem: Florida scrub. [Copyright &y& Elsevier]