Ecologists are increasing the use of remote technologies in their research, as these methods are less labor intensive than traditional methods and oftentimes minimize the number of human errors. Camera traps can be used to remotely measure abundance and community composition and offer the potential to measure some phenotypic traits, such as body size. We designed a camera-trap setup that enabled us to capture images of both large and small animals and used our camera-trap design to investigate the community composition of mammals and birds and to estimate the biomass of mammals along two transects in a conservation reserve in Missouri. One transect ran from the edge of an agricultural field to an upland forest, and the other transect ran from the edge of a wetland to an upland forest. Over the 4.5-wk study, our cameras recorded 2,245 images that comprised 483 individuals of 16 species of mammals and birds. Coyotes Canis latrans and nine-banded armadillos Dasypus novemcinctus were unique to the riparian transect, as were several bird species. Fewer species used the forest immediately adjacent to the agricultural field, but more species used the forest immediately adjacent to the wetland. Biomass estimates from our camera-trap images were similar to those of published accounts. This is the first study to use camera traps to successfully estimate biomass. We showed that the value and utility of camera traps in wildlife studies and monitoring can be expanded by 1) using multiple cameras at different heights from the ground so as to capture different-sized animals and 2) obtaining phenotypic information of the captured animals.

Animals must navigate a complex mosaic of habitat types, both natural and artificial. As artificial habitats (e.g., agricultural fields) become increasingly abundant in many landscapes, species will be affected differently, depending on their habitat preferences. We investigated the diversity, richness, abundance, and biomass of mammals and birds with remote camera traps that optimized the capture of both large and small animals. Camera traps allowed us to capture natural rates of mammals and birds, which is difficult to obtain using human observers who can affect the behavior of animals and are limited in their spatio-temporal scope and ability to assess nocturnal communities. Our camera trap arrays were established along two transects in a local conservation reserve; one transect ran from an agricultural field to an upland forest and another from a wetland to an upland forest. Over the 6-week study our cameras recorded 2,245 images, within which we observed 483 individuals comprising 16 species of mammals and birds. Our data showed that species composition and abundances were only marginally different between the two transects, with species common to both transects not exhibiting any statistical difference in abundances. Coyotes and armadillos were unique to the riparian transect, and many more bird species were present along the riparian transect than the agricultural transect. Diversity, richness, and total community biomass did not differ significantly between the two transects nor along each transect but there were non-significant trends in predicted directions. Our results revealed that fewer species use the forest immediately adjacent to the agricultural field, but more species use the wetland and the forest immediately adjacent to the wetland. Our results corroborate other studies revealing that certain species are more common in forested areas but also that some species thought to prefer forested areas may actually be more habitat generalists than previously thought.