Is camera trapping helping us to fill knowledge gaps related to the conservation of wild mammals?

• Camera trapping is an increasingly popular mammal monitoring technique. • We lack assessments on how the spatial distribution of camera trapping efforts responds to knowledge gaps. • There is a poor relationship between camera trapping studies and areas with high species richness and threat of mammals. • Coordinated efforts are needed to take full advantage of camera trapping to increase its impact on mammal conservation. The magnitude of human impact on biodiversity makes producing information on the conservation status of wildlife an urgent matter. Despite the increasingly widespread use of camera trapping for mammal monitoring, there are no assessments on how this tool helps fill specific knowledge gaps. We reviewed studies published between 2000 and 2018 in Mexico, a country with very high mammalian diversity, and analysed their spatial distribution. Specifically, we looked at how the number of studies at the level of the country's states related to a) each state's medium/large mammalian species richness and b) each state's proportion of mammalian species classified as threatened at the national and global level. Moreover, we assessed the occurrence of studies within protected areas, terrestrial ecoregions, and mammal geographic provinces. Finally, we recorded the proportion of studies focused on estimating mammal population density and community richness that incorporated measures of variability and completeness, respectively. Based on a compilation of 191 papers published in 48 journals, we found a weak relationship between the number of studies and mammalian species richness and no clear evidence of a relationship between the number of studies and the proportion of threatened species. The studies concentrated on a few mammalian species, protected areas, forested ecoregions, and mammal geographic provinces in the country's southern region. More than half of the studies that conducted population density estimations included measures of variability, but only one-third of the studies estimating species richness included completeness assessments. There is a need for more coordinated efforts to take full advantage of camera traps in order to produce more comprehensive and standardised surveys of the status of mammalian fauna at the country level. [ABSTRACT FROM AUTHOR]