Assessing the value of Amazonian Protected Areas on Jaguar Distribution

The Amazon is the biggest biodiversity repository on Earth and the stronghold of multiple species. Since the beginning of the 21st century, the extent of natural areas converted for land use, particularly due to farming expansion, has been growing in both unprotected and protected lands. Due to their ecological role and requirements, apex predators can be useful proxies of ecosystem health. Jaguars are the terrestrial apex predators in the Amazon and this biome covers most of their current geographic range. The conservation of this species helps to prevent wide impacts on surrounding biodiversity that could reflect on regional ecological implications. Therefore, given the ongoing human alteration of the natural landscape, the value of many Amazonian protected areas (PAs) for jaguar conservation is currently unclear and an assessment of their effectiveness is necessary. For that reason, this thesis aimed at (1) comparing differences on jaguar ungulate prey species distributions occurring over the Amazon in the last decade (2010-2020), (2) identify the locations and PA management regimes that currently require more focus to efficiently contribute to jaguar conservation in the region, and (3) study the influence of the Amazonian landscape context in the co-occurrence of jaguars and pumas. Data from camera-trapping surveys, tracks and sightings were combined with remote sensing information to be incorporated in spatial modelling frameworks (e. g. Species Distribution Models and species co-occurrence models).

The results of the thesis suggest a drift on the distribution of jaguar ungulate prey from older PAs towards unprotected lands in the last decade because the elements important to the conservation of those species may be starting to fade out. This may be problematic for jaguars, since the distribution of ungulate prey was the major driver of the habitat suitability estimates for these felines. Those estimates were, in fact, the lowest in some areas in the central and southwestern locations of the Amazon biome, which highlights the need for strong conservation efforts to assure the prevalence of the species in those sections the region. The results also showed that, in certain protection categories (IUCN Category V and RAMSAR Sites), the overall jaguar habitat suitability projections were comparable to, or even lower than, those obtained in unprotected lands. This was presumably due to the level of anthropogenic interference and vague regulatory frameworks these two protection categories are associated with. However, human accessibility can substantially reduce those estimates in IUCN Category VI and Indigenous Lands. This means that the necessity to improve conservation effectiveness is required not only in unprotected lands, but also in the PAs within those management regimes. Lastly, the findings of this thesis also suggested that the chance of alteration of natural landscapes induces greater spatial co-occurrence between the two largest terrestrial predators in the Amazon. Jaguars are known to segregate pumas where both occur in sympatry. Because pumas can adapt to human disturbance better than jaguars, greater co-occurrence mediated by decreasing degree of protection and landscape preservation probably reflects a reduction of the jaguar top-down pressure on pumas. This may initially result in ecological disruption that is likely magnified where the human pressure increases beyond the tolerance capability of both big cat species, due to the complete absence of large-sized predator species able to conduct specific ecological functions.

Overall, this thesis underlines the existence of undisturbed areas as pivotal to the presence of jaguars. From this point of view, PAs play a central role in source-sink dynamics in the region, since they may contribute to rebuild populations of large felines in areas of more disturbance. Nevertheless, their efficient role as sources may be compromised by the extent of human impact PAs are exposed to and the extirpation of jaguars and their ungulate prey, or even substantial reductions of the habitat suitability for these species in those areas, will certainly reflect on their loss of conservation value. The integration of human dimensions and elements in some PAs (e. g. transport networks for support of local peoples) is therefore central in the design of future management plans for existing and new PAs.