Stark increase in potential sink habitat for giant anteaters In the Argentine Chaco due to land-use change

SEMPER-PASCUAL, ASUNCIÓN ; DECARRE, JULIETA ; BAUMANN, MATTHIAS ; DI BLANCO, YAMIL E.; CAMINO, MICAELA; GÓMEZ-VALENCIA, BIBIANA; KUEMMERLE, TOBIAS

Posadas

Conferencia; IUFRO Conference Posadas 2018 - Adaptive Management for Forested Lanscapes in Transformation; 2018

IUFRO, INTA, Ecología Misiones, Misiones Provincia

Land-use change threatens biodiversity globally, and understanding where and how land-use impacts species of conservation concern is therefore important. Local extinctions are preceded by population declines, and these declines can extend beyond the actual footprint of land use. Assessing the geography of abundance changes in relation to land-use change allows the development of effective strategies to avoid population losses, but this is rarely done. We developed and mapped indicators of population change for the threatened giant anteater (Myrmecophaga tridactyla) in the Argentine Dry Chaco, a global deforestation hotspot. Specifically, we used an occupancy framework and extensive camera-trap data to proxy abundance changes between 1985 and 2013. To do so, we fitted single-season occupancy models for 2013, and then tracked occupancy back in time by projecting our models to land-use maps from 1985 and 2000. As land-use variables were the only time-variant predictors in our models, we were able to assess both the direct and indirect effect of land use on occupancy. Our resultsshow that anteater occupancy decreased substantially since 1985, especially after 2000 when rapid agricultural expansion occurred (i.e., up to ~76% between 1985 and 2013). The area in which occupancy declined was much larger than the area affected by land-use change itself (e.g., ~160,000 km² of Ψ decrease vs. ~65,000 km² of forest loss) and declines extended far into seemingly untransformed habitat. The widespread areas of potential sink habitat we foundhighlight the urgent need for conservation planning and action to ensure a future for the anteater in the Argentine Chaco. More broadly, our study exemplifies how species may lose much of their high-quality habitat through direct and indirect effects of land-use change, and where pro-active (e.g., protecting remaining source habitat) and re-active (e.g., restoring sink habitat) conservation strategies could be spatially targeted to halt local extinctions.