| Popis: |
Background: The effective conservation of mammals on the brink of extinction requires an integrated socio-ecological approach, yet the knowledge of updated species distribution, population size, and life-history remain fundamental steppingstones in designing successful conservation plans. This study presents the first clarification on the population status of the critically endangered Western Derby eland (WDE) within its last stronghold, based on the first camera trap monitoring in the Niokolo Koba National Park (NKNP, Senegal). The spatiotemporal pattern of WDE behaviour, their population structure (based on individual recognition), age-specific survival rates, and population size estimate were investigated.Results: WDE were recorded during 49 events using dry season deployments (2017, 2018), during which they showed substantially lower occupancy (< 5% of protected area) in comparison to other ungulates in the park. WDE distribution, as of that of many other large mammal species, was strongly localised in the core area of NKNP. Based on the records, WDE were the most active during the hottest periods of the day. Group size ranged from 1 to 32 individuals (mean 7.6 ± SE 8.9), with mixed herds being larger and most frequent compared to others. The adult sex ratio was female-biased, and showed low annual adult male survival rates. The population consisted of a relatively high proportion of juveniles, whilst the proportion of adults did not exceed 40%. The estimated population density is 0.138 WDE/km2 (± 0.0102), with an estimated 195 WDE in NKNP.Conclusions: Findings highlighted that the WDE population has potential to expand in the NKNP, due to an underutilized capacity, and considering the population density. The age-specific vital rates indicate that adult males are the most vulnerable; which suggests either an increase in the large predators’ population, livestock encroachment pressure, and/or poaching. The occurrence of WDE indicated the key conservation area within the park, and together with their active behaviour during daylight periods, this enables the setting up of effective species protection. The findings imply that targeted monitoring with science-based interpretation may bring forward strong conservation solutions to the protected area management decision-makers. |
