Mexican wolf (Canis lupus baileyi) from camera trapping efforts. Credit: Zaira González
Large carnivores are crucial to ecosystem functioning, as they enhance the biodiversity of the native communities in which they live. However, most large carnivores are threatened with extinction resulting from human persecution, habitat encroachment, and the loss of habitat connectivity. One strategy to lessen negative consequences of habitat loss for large carnivores has been to promote landscape connectivity, a measurable feature of the landscape that serves as a proxy for population connectivity.
We conducted a recent study using multi-species analysis to identify suitable areas to facilitate landscape connectivity for puma (Puma concolor), black bear (Ursus americanus), and Mexican wolf (Canis lupus baileyi) across northwestern Mexico and the southwestern United States. The principal aim was to contribute to national and binational cooperative efforts towards conservation of these large carnivores, especially at present, when building a wall between the two countries is a real threat.
We performed a habitat suitability analysis for these three large carnivores by combining ecological niche modeling with anthropogenic variables to identify high-quality habitat patches to be connected. We also developed a connectivity analysis to identify smaller suitable habitat patches within connecting corridors to evaluate their contributions to connecting larger populations.
Mountain lion (Puma concolor) and black bear (Ursus americanus) from camera trapping efforts. Credits: Zaira González
The results show that there are numerous (at least 10) existing large, high-quality areas in Mexico and the United States that could connect individuals through smaller patches. Likewise, we identified pinch-point areas, patches, and links with high centrality, which indicate that several biological corridors promote connectivity among the most extensive suitable patches. The removal or degradation of high-centrality areas, as well as physical barriers within these areas, compromise the connectivity of the network.
Recent socio-political affairs seriously threaten habitat connectivity between the two countries. Currently, walls and fences built and being built along segments of the border between Mexico and the United States reduce landscape connectivity and wildlife dispersal. Barriers to control pedestrian transit are more impervious to species dispersal than barriers for vehicles, but the problem is not only physical barriers per se, but also increased human infrastructure, vehicle traffic, and human activity.
Regarding binational cooperation, the study may help to identify potential areas for further recovery actions in Mexico and the United States to maximize the probability of establishment and connectivity, both within and between the two countries. In this regard, decision-makers, academia, and civil society need to strengthen their bonds to reduce the pressure on these carnivores and help authorities improve binational plans and agreements to consolidate conservation actions and landscape connectivity between Mexico and the United States.
Resources
González-Saucedo, Z.Y., González-Bernal, A. and Martínez-Meyer, E. 2021. Identifying priority areas for landscape connectivity for three large carnivores in northwestern Mexico and southwestern United States. Landscape Ecology 36: 877-896.
Big cats and big connectivity (September 2018)
Conservation and connectivity across the border (November 2018)
