Beilschmiedia osacola (Lauraceae) a new species from the Osa Peninsula, Costa Rica

We describe and illustrate a new species of Beilschmiedia, from the Osa Peninsula of Costa Rica. It is distinguished by its small flowers, which are turbinate to campanulate, with six fertile stamens and pubescent ovary, in addition it has alternate leaves along the twigs, with the lower leaf surface glabrous and not glaucous. In the field, it can be recognized by its stature, a very large tree, with the bark reddish, and peeling in large plates. Among described congeners it is superficially similar to B. hexanthera, from French Guiana, which also has six fertile stamens, and staminodes of whorl III columnar, but differs in having a pubescent ovary and larger, more branched inflorescences.

Unexpected Diversity in Regenerating Sites Stresses the Importance of Baselines: A Case Study With Bats (Order Chiroptera) on the Osa Peninsula, Costa Rica

Introduction: Background and Research Aims: Assessing biodiversity recovery is key to determine whether the objectives of habitat restoration for conservation are met. Many restoration initiatives use cross-sectional comparisons of wildlife communities to infer restoration impact instead of longitudinal assessments from a baseline state. Using an indicator of biodiversity in the neotropics— bats— we demonstrate how assessing community diversity and composition in an area targeted for restoration prior to implementation, and when compared to surrounding intact forest, provides the groundwork to track changes in the community post-restoration. Methods We assessed bat communities by 1) using mist-net surveys to identify species in the family Phyllostomidae (leaf-nosed bats), and 2) conducting acoustic surveys to identify non-phyllostomid species (aerial insectivores). Results For both groups, we found that areas targeted for restoration had similar diversity as the surrounding forest, but the two habitat types differed in community composition. Phyllostomids were captured at higher rates in forest, but aerial insectivores were detected at higher rates in restoration habitat. Conclusion Our baseline assessment revealed unexpected diversity in areas targeted for restoration. The presence of all trophic groups in restoration habitat suggests that bats provide key ecosystem services in the restoration process, such as through seed dispersal, pollination and insect pest control. Implications for Conservation: Conducting a baseline survey of bats in areas targeted for restoration demonstrated that the community was not species poor at the baseline and was different from the surrounding forest, allowing us to better track restoration success and the effects of different restoration treatments.

Spatial analysis on the occurrence of inshore and offshore bottlenose dolphins (Tursiops truncatus) in Osa Peninsula waters and Golfo Dulce, Costa Rica

The aim of this assessment is to advance our understanding in the spatial ecology of the resident inshore and offshore population of bottlenosedolphins in Golfo Dulce (GD) and Osa Peninsula Waters (OPW). Our approach used niche-based models (Phillips et al., 2006, Thorne et al., 2012,Friedlaender et al., 2011), which provided details of how dolphins use coastal and oceanic habitats, describing the factors that influence theirdistribution in the study area and identifying the critical habitats to be considered for management and conservation. Our analyses indicate severalimportant aspects of the distribution of these two ecotypes of bottlenose dolphins. As expected in the study area, these two ecological races occurin close proximity, but differ in the structural factors of the habitat they occupy. The inshore population uses areas close to the mouths of the riversas critical foraging habitats, being influenced by tidal cycles and seasonal changes in water temperature and salinity. The offshore population inoceanic habitats must rely on prey species found in rare but profitable patches, therefore pelagic dolphins in the open ocean would often need totravel long distances searching for these patches. Distribution models illustrating the difference in habitat use presented in this assessment are keyto effective management of the marine mammals’ diversity in Costa Rica.

Survey of medium-sized and large mammals of Piedras Blancas National Park, Costa Rica

Piedras Blancas National Park, in southern Costa Rica, is an important component of two biological corridors connecting the Osa Peninsula (Corcovado National Park) and La Amistad International Park. Understanding the mammal community composition of Piedras Blancas will provide baseline data to evaluate the success of conservation efforts. We used camera traps and opportunistic observations to describe the medium-sized and large mammals of the park. We deployed camera traps for 1,440 trap nights (2016-2018). We detected 19 mammal species from seven orders and 13 families. Five species are globally threatened: Leopardus wiedii (Schinz, 1821), Saimiri oerstedii (Linnaeus, 1758), Ateles geoffroyi (Kuhl, 1820), Alouatta palliata (Gray, 1849), and Tapirus bairdii (Gill, 1865). We did not detect two locally threatened species, Panthera onca (Linnaeus, 1758) and Tayassu pecari (Link, 1795). Our research highlights a need for critical conservation work within the proposed biological corridor to support Costa Rica’s most threatened wildlife.

The abundance of false killer whale, Pseudorca crassidens (Artiodactyla: Delphinidae) in coastal waters of Golfo Dulce and Osa Peninsula, Costa Rica

Introduction: False killer whale (Pseudorca crassidens) is a tropical and subtropical social species that live in groups with individuals of mixed ages and sex classes. False killer whales have been documented since the late 1990s in Southwestern Costa Rica. Objective: To estimate the abundance of false killer whales in Osa Peninsula waters. Methods: Cetacean surveys off the Osa Peninsula Waters (OPW), Costa Rica, yielded opportunistic encounters with false killer whales in Drake Bay and Caño Island (2001-2015) and observations during formal surveys in Golfo Dulce (2005-2015). Photo-identification data was analyzed using capture-mark-recapture models in the study area, through an open population (POPAN) framework, considering the effect of time on the parameters apparent survival and capture probability, producing an abundance estimate for a superpopulation in the entire study area. Results: False killer whale abundance in OPW is characterized by a small population size of no more than 100 individuals, complemented by a very low probability of encounter and a contrasting high apparent survival. Conclusions: This population estimate should be taken as conservative, however, the small population size of less than 100 individuals should be considered vulnerable, in contrast to the increasing anthropogenic impacts in the coastal seascape. We argue the potential occurrence of population units along the coastal seascape of the Pacific littoral and oceanic island-associated units at Isla del Coco.