Stable isotopes reveal seasonal dietary responses to agroforestry in a venomous mammal, the Hispaniolan solenodon (Solenodon paradoxus)

While trends in tropical deforestation are alarming, conservation biologists are increasingly recognizing the potential for species survival in human-modified landscapes. Identifying the factors underlying such persistence, however, requires basic ecological knowledge of a species' resource use. Here, we generate such data to guide conservation of an understudied venomous mammal, the Hispaniolan solenodon (Solenodon paradoxus), that occupies a mosaic landscape of agriculture and forest fragments in the western Dominican Republic. Using feces collected in both wet and dry seasons, we found significant differences in the stable isotope values of carbon (delta C-13) between pasture (-24.63 +/- 2.31 parts per thousand, Las Mercedes) and agroforestry (-28.07 +/- 2.10 parts per thousand, Mencia). Solenodon populations in agricultural areas occupied wider isotopic niche spaces, which may be explained by more diverse resource within these patches or individuals combining resources across habitats. We detected elevated delta N-15 values in the dry season of pasture areas (8.22 +/- 2.30 parts per thousand) as compared to the wet season (5.26 +/- 2.44 parts per thousand) and overall narrower isotopic niche widths in the dry season, suggestive of the impacts of aridity on foraging behavior. Our work highlights the importance of considering a more nuanced view of variations in 'modified' or agricultural landscapes as compared with strictly protected national parks. We suggest that seasonal differences in foraging should be considered as they intersect with landscape modification by landowners for maintaining resources for focal consumers. This work adds to a growing body of literature highlighting that fecal stable isotopes are a non-invasive and cost-effective monitoring tool that is particularly well-suited for cryptic small mammal species, ensuring actionable and evidenced-based conservation practices in the tropic's rapidly changing landscapes.

Automated summary

This study investigates the impact of an agricultural and forest mosaic landscape on the survival of the Hispaniolan solenodon. The researchers found that solenodon populations in agricultural areas occupied wider isotopic niche spaces and had seasonal differences in foraging behavior influenced by aridity. This highlights the need for a nuanced understanding of modified landscapes for effective conservation practices.