Synanthropes are known for their remarkable adaptability to coexist with humans, yet increased visibility exposes them to significant threats, such as hunting or conflict over resources. Moore et al.'s review 'The rise of hyperabundant native generalists threatens both humans and nature' (https://doi.org/10.1111/brv.12985) explores distribution patterns and impacts of macaques and pigs in anthropogenic environments. Our critical evaluation of this study revealed several substantial issues: the pooling of data from species that are ecologically and behaviourally distinct, an error in data acquisition, potential biases in statistical analyses, and critical misrepresentations of threats to and from wildlife in human-impacted habitats. Additionally, we highlight the lack of evidence supporting the authors' core assertion of hyperabundance of the study species. While Moore et al. compare species densities and abundance across various habitat types, their analyses did not demonstrate population increases over time. On the contrary, our re-analysis of their data sets showed a decreasing population trend in Macaca nemestrina and the absence of M. fascicularis from 44% of surveyed habitats characterized by medium to high forest integrity. Further, our findings emphasize the importance of intact forests for predicting a high relative abundance of macaques and pigs. Overall, we recommend a more careful interpretation of the data, as misrepresentations of abundance data can result in negative or sensational discourses about overabundance, which may threaten the conservation of species that often thrive in anthropogenic landscapes.
In 2022, long-tailed macaques (Macaca fascicularis), a once ubiquitous primate species, was elevated to Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. In 2023, recognizing that the long-tailed macaque is threatened by multiple factors: (1) declining native habitats across Southeast Asia; (2) overutilization for scientific, commercial, and recreational purposes; (3) inadequate regulatory mechanisms; and (4) culling due to human-macaque conflicts, a petition for rulemaking was submitted to the United States Fish and Wildlife Service to add the species to the US Endangered Species Act, the nation's most effective law to protect at risk species. The long-tailed macaque remains unprotected across much of its geographical range despite the documented continual decline of the species and related sub-species and the recent IUCN reassessment. This commentary presents a review of the factors that have contributed to the dramatic decline of this keystone species and makes a case for raising the level of protection they receive.
Accurately estimating population sizes for free-ranging animals through noninvasive methods, such as camera trap images, remains particularly limited by small datasets. To overcome this, we developed a flexible model for estimating upper limit populations and exemplified it by studying a group-living synanthrope, the long-tailed macaque (Macaca fascicularis). Habitat preference maps, based on environmental and GPS data, were generated with a maximum entropy model and combined with data obtained from camera traps, line transect distance sampling, and direct sightings to produce an expected number of individuals. The mapping between habitat preference and number of individuals was optimized through a tunable parameter ρ (inquisitiveness) that accounts for repeated observations of individuals. Benchmarking against published data highlights the high accuracy of the model. Overall, this approach combines citizen science with scientific observations and reveals the long-tailed macaque populations to be (up to 80%) smaller than expected. The model's flexibility makes it suitable for many species, providing a scalable, noninvasive tool for wildlife conservation.