The Arabian Sea humpback whale (Megaptera novaeangliae; ASHW) is understood to be the only population of this species that does not undertake long-range seasonal migrations between high- and low-latitude waters. Until recently, understanding the movements and range of individual ASHWs has relied mainly on comparisons of dorsal fin and tail-fluke images archived in photo-identification catalogues and on observations made during small-vessel surveys off the coast of Oman since 2000. The ASHW population is classified as Endangered by the IUCN Red List of Threatened Species, with an estimated 82 individuals off Oman’s coast (95% CI: 60–111), and faces increasing anthropogenic threats throughout its known range. To better understand the spatial ecology of this population, 14 Argos-enabled satellite tags were attached to ASHW off the Arabian Sea coast of Oman between February 2014 and December 2017. Individuals were tracked for a total of 749 days (mean=53, SD = 42, range=18–163 days) producing 484 days of depth-use data (mean=44, SD = 26, range=15-87). Home ranges extended along the western Arabian Sea coastline of northern Yemen and southern Oman, with a core area in the Gulf of Masirah (Oman). Switching state-space models revealed predominant area restricted search behavior (associated with breeding and foraging behavior) over continental shelf areas, with transiting movements occurring further offshore. The widest-ranging individual (a female, tag longevity 120 days) completed a round trip across the Northwest Indian Ocean between the Gulf of Masirah and the Gulf of Mannar (India). The track of this animal, and others along the coast of Oman, revealed an overlapping relationship between ecological drivers related to habitat use, including foraging and breeding, with fishing and shipping activities. The findings demonstrate the unique ecology of ASHW compared to other humpback whale populations and underscores the need for national and international authorities to incorporate these results into management initiatives to safeguard this small and Endangered population.
Illegal and unsustainable wildlife hunting poses a serious threat to biodiversity in tropical forests, particularly within production landscapes where logging concessions operate. This study assesses the effectiveness of wildlife protection strategies implemented in FSC-certified industrial forest concessions managed by Pallisco in Cameroon, covering 3889 km2. Using a 13-year dataset of patrol effort, poaching incident reports, and wildlife encounter records, we show a significant decrease in poaching pressure that coincides with increased patrol effort, particularly after adopting SMART (Spatial Monitoring and Reporting Tools) protocols. Law enforcement patrol activity increased by 50% following SMART implementation, leading to fewer recorded poaching incidents and fewer hotspots. At the same time, encounter rates and spatial distribution for key large mammals, including forest elephant, chimpanzee, and western lowland gorilla, remained steady, indicating positive conservation outcomes with a reasonable budget of $23/km2/year. Our findings emphasize the importance of integrating spatial technology-driven monitoring with corporate engagement in sustainable forest management. We conclude that FSC certification combined with SMART-enhanced law enforcement can provide an efficient approach to balancing timber production and biodiversity conservation. Given the shared certification frameworks and management structures across the region, these results offer a model that could be expanded to other FSC and PAFC-certified concessions in the Congo Basin. We recommend expanding these strategies regionally and formalizing partnerships to strengthen anti-poaching efforts in production forest landscapes.
Lepanthes is a diverse Neotropical genus within the Orchidaceae and a significant component of Costa Rica's orchid flora. Despite extensive taxonomic studies, an ongoing need persists to explore and document the diversity of Lepanthes in unexplored regions of the country, such as the Cordillera Volcánica Central and Braulio Carrillo National Park. This study describes and illustrates a new species, Lepanthes zygicola, discovered on the Caribbean slope of Costa Rica within the ecotourism farm "Finca Jungla Paraíso," adjacent to Braulio Carrillo National Park. The new species exhibits distinct characteristics, including slightly convex, ovate leaves, shorter inflorescences remaining on the abaxial side of the leaf, larger pedicels, glabrous entire-margin sepals and pink-red proximal petals transitioning to amber distally, along with a ciliate lip apex. These features distinguish L. zygicola from its most similar species, L. ingramii and L. subdimidiata. The discovery of L. zygicola highlights the botanical richness of the Cordillera Volcánica Central and encourages further exploration in similar regions to unveil potentially undiscovered species. It also advocates for floristic and conservation initiatives to protect these unique orchid populations in their natural habitats, contributing to the broader understanding of orchid diversity in the country.
Camera-traps have become one of the most common tools for studying wildlife abundance and population density. Traditionally, absolute density could be estimated only for species with individual markings, using capture–recapture frameworks. Newer methods allow to estimate density of unmarked species, but these have yet to be thoroughly tested and compared against capture–recapture methods. To make this comparison requires an identifiable species, for which both types of frameworks can be used. Here, we estimate the population density of ocelots (Leopardus pardalis) in the Osa peninsula, Costa Rica, comparing methods for marked and unmarked species. We deployed camera-trap grids between 2017 and 2019, identified individuals and determined spatially resolved individual detection histories, station-specific detection frequencies and times to first detection. Estimates obtained with methods for unmarked species (Time-to-Event and Random Encounter Model) varied widely among surveys, from 11 to 169 individuals/100 km2, and were significantly different from spatial capture–recapture estimates (28.1 individuals/100 km2). Differences were largely driven by the non-random placement of cameras on human-made trails, which inflated the detection frequency. Maximizing the number of encounters benefits methods based on capture–recapture but is detrimental for methods based on random detections. Our results highlight the incompatibility between surveys designed for capture–recapture analyses, and those that assume random movement of animals. For recently developed unmarked species methods to be used for a larger and more diverse set of species, it is necessary to further test and define the requirements and factors that affect their calculations. This information will ultimately allow for a greater diversity of population and community studies.
Previous estimates of tropical forest carbon loss in the twenty-first century using satellite data typically focus on its magnitude, whereas regional loss trajectories and associated drivers are rarely reported. Here we used different high-resolution satellite datasets to show a doubling of gross tropical forest carbon loss worldwide from 0.97 ± 0.16 PgC yr−1 in 2001–2005 to 1.99 ± 0.13 PgC yr−1 in 2015–2019. This increase in carbon loss from forest conversion is higher than in bookkeeping models forced by land-use statistical data, which show no trend or a slight decline in land-use emissions in the early twenty-first century. Most (82%) of the forest carbon loss is at some stages associated with large-scale commodity or small-scale agriculture activities, particularly in Africa and Southeast Asia. We find that ~70% of former forest lands converted to agriculture in 2001–2019 remained so in 2020, confirming a dominant role of agriculture in long-term pan-tropical carbon reductions on formerly forested landscapes. The acceleration and high rate of forest carbon loss in the twenty-first century suggest that existing strategies to reduce forest loss are not successful; and this failure underscores the importance of monitoring deforestation trends following the new pledges made in Glasgow. Using different high-resolution satellite datasets, this study analyses gross forest carbon loss associated with forest removal over the tropics during the twenty-first century focusing on regional fluxes and trends, as well as drivers of loss, both aspects rarely studied in previous work.
