Can matrix structure affect animal navigation between fragments? A dispersal experiment using release platforms

The persistence of species in fragmented landscapes relies on landscape connectivity and individuals’ ability in dispersing among habitat patches. Accordingly, matrix structure can affect the orientation of dispersing individuals across the landscape. In this study, we measured the impact of matrix structure on the dispersal performance of the white-eared opossum (Didelphis albiventris). We released individuals in three types of matrix: bare field, corn crops, and soybean crops, with distances of 30, 50, and 100 m to the nearest habitat patch. To test if the release height would affect the individuals’ dispersal performance, we released animals from the ground and from 2-m-high platforms. We released and tracked 14 individuals in bare field on the ground; 30 in corn crops, 22 on the ground, and 8 on platforms; 17 on soybeans crop, 12 on the ground, and 5 on platforms. The type of matrix influenced the perceptual range. Perceptual range was 100 m in bare field, 50 m in corn field, and <30 m in soybean field. The platforms only increased the perceptual range of individuals in the corn field from 50 to 100 m. Visual and olfactory cues would cause this effect. We conclude that matrix structure affects dispersal performance, and that vertical elements of the matrix, such as scattered trees, may increase orientation in crop fields during inter-patch dispersal.