A study led by the University of Alicante (UA) reveals that the degradation of tropical dry forests alters vertebrate scavenger communities. Published in the journal Biodiversity and Conservation, the research is one of the first quantitative evaluations of how scavenger communities function in the tropical dry forests of southern Ecuador, one of the most threatened ecosystems in the world.
The scientific team monitored 60 carcasses in various states of forest conservation using camera traps. In total, they recorded 13 vertebrate scavengers (six mammals, six birds and one reptile) with estimates suggesting the presence of at least 17 species.
Results show that better-preserved forests host more diverse scavenger communities, with up to 11 different species detected, including birds such as the king vulture (Sarcoramphus papa) and the white-tailed jay (Cyanocorax mystacalis). In contrast, in more degraded environments, the data indicates simplified communities dominated by species such as the Sechuran fox (Lycalopex sechurae), which was responsible for consuming almost half of the carcasses.
Furthermore, the article highlights that carcasses disappeared faster in degraded habitats than in well-preserved forests. “While it took more than three days for carcasses to be completely consumed in semi-natural areas, the process was reduced to just one or two days in degraded areas,” explains Adrian Orihuela-Torres, lead author of the study and researcher at the UA Department of Ecology.
According to the researchers, this result indicates that certain ecological functions can be maintained despite biodiversity loss, although they are supported by simpler and potentially less stable communities in the long term.
Vertebrate scavengers (birds, mammals and reptiles that consume dead animals) play a fundamental role in ecosystems by accelerating the decomposition of organic matter, recycling nutrients and reducing the spread of pathogens. However, the UA researcher points out that their ecological functioning has been little studied in Neotropical dry forests.
The role of well-preserved forests
The article emphasises that better-preserved forests act as a refuge for sensitive and threatened species, including several endemic to the Tumbesian region located in Ecuador and Peru. Additionally, and according to Orihuela-Torres, in these habitats, they have documented scavenging behaviour in mouse opossums of the genus Marmosa for the first time, expanding their knowledge of the feeding ecology of these small marsupials.
The authors warn that the apparent functional efficiency observed in degraded areas should not be interpreted as ecological resilience, but rather as an ecosystem reorganisation towards more homogeneous communities dominated by opportunistic species. “This phenomenon is associated with the historical loss of large predators and the human transformation of the landscape,” the UA researcher adds.
The results underline the importance of conserving well-structured forests not only to protect biodiversity but also to maintain the complexity and stability of the ecological processes that sustain ecosystems.
The working team, headed by Adrian Orihuela-Torres, included researchers from the Miguel Hernández University of Elche, the University of Granada and the Universidad Técnica Particular de Loja (Ecuador).