Interactions of large felids with their prey and humans in the Yucatán Peninsula of Mexico and Belize

Tropical-forest biodiversity is currently undergoing an unprecedented mass extinction caused by human exploitation of natural resources, and fragmentation and loss of forest habitat in conversion to human uses. Felids (wild cats) are particularly vulnerable because of their requirements for contiguous tracts of forest. This thesis addresses the status and value to human wellbeing of natural capital associated with felids that have biotic boundaries extending beyond the boundaries of areas designated for their protection. The principal aim is to evaluate locally viable conservation options for minimising human-wildlife conflict, in relation to populations of jaguars and pumas and their prey that occupy discontinuous areas of protected forest interspersed with farmland. Chapter 1 introduces the general context and background to this issue. Chapter 2 uses empirical data from systematic surveys by camera-trapping and scat sampling to estimate the availability of prey to jaguars and pumas in and between two small private nature reserves in the Northern Yucatán Peninsula. The chapter delivers the first sex-specific estimate of jaguar abundance in the area. It evaluates presence and abundance of potential prey for jaguars and pumas, and associations between daily activity patterns of jaguars and pumas with their prey. It quantifies jaguar and puma diets, and assesses prey exploitation and niche overlap. Chapter 3 uses questionnaire surveys to evaluate human-wildlife interactions between Maya communities and large felids. It includes a first assessment of perceptions about wildlife, hunting and wild meat consumption in the Northern Yucatán Peninsula. The chapter delivers an evaluation of livestock management practices, wild-meat consumption, hunting habits and experiences of human-wildlife conflict. Chapter 4 addresses the need to monitor cryptic sources of human exploitation of natural forest resources in the Yucatán Peninsula. The chapter describes the development and testing of a probabilistic method for near-optimal placement of acoustic loggers to detect and localise gunshots. Field tests in Mexico and Belize demonstrate for the first time the potential for flooding large areas of forest with small and low-cost acoustic devices to monitor rates of hunting activity. Chapter 5 delivers a synthesis of general conclusions from the study. Within the Northern Yucatán Peninsula, jaguars and pumas were found to have largely overlapping resource niches and activity patterns, consistent with a lack of options for niche separation in this heavily human modified and disturbed habitat. There was little evidence of declines in their populations with respect to earlier studies, despite ongoing habitat fragmentation. The viability of these large felids depends entirely on their ability to sustain access to prey in unprotected forests between nature reserves, as well as effective protection of prey in the reserves. Maya communities report a generally reducing availability of game – which are also prey to large felids – in the unprotected forests. They also report attacks by large felids on their livestock which, although infrequent, have potential to inflict severe economic injury. Hunters attributed a lack of game to overhunting in unprotected forests, and expressed a desire for support on this issue. The recent development of low-cost and power-efficient acoustic loggers opens up new potential for rural communities to monitor rates of hunting and logging, as a first step to policing their own natural resources

Knowledge of wildlife, hunting, and human-felid interactions in Maya Forest communities of the Northern Yucatan Peninsula, Mexico

Human-wildlife impacts threaten large-felid persistence in the northern Yucatán Peninsula, triggered largely by livestock depredation. We aimed to explore knowledge and attitudes about local wildlife in relation to husbandry practices, hunting habits, and human-wildlife interactions, in three Maya Forest communities. A questionnaire survey of 30 long-established smallholdings, where livelihood depended on a private fenced plot and surrounding communal forest, found wide knowledge of local wildlife, perception biases for abundances of game species, and preference for living amongst wild herbivores over carnivores. Interviewees had concerns about perceived year-on-year decreases in local wildlife, attributed to regular subsistence hunting by their communities. The few interviewees reporting large-felid attacks on their livestock subsequently altered management practices to prevent further attacks. The region suffers from a poverty trap of subsistence hunting by smallholders needing protein supplement potentially exacerbating depredation on the livestock that sustain their economies by large felids deprived of their natural pre

Ecology of large felids and their prey in small reserves of the Yucatán Peninsula of Mexico

Jaguars and pumas are top-predator species in the Neotropics that are threatened by habitat destruction, illegal poaching of their body parts and their favored prey, and by the human-wildlife conflicts that arise when predators attack livestock. Much of the remaining felid habitat in the Americas is in protected nature reserves that are too small and isolated to support local populations. Surrounding forests therefore play a vital role in felid conservation. Successful long-term conservation of these two felids requires evidence-based knowledge of their biological and ecological requirements. We studied population distributions of jaguars and pumas and their prey in and between two small, private reserves of the Northern Yucatán Peninsula, Mexico, with areas of 25 and 43 km2. During 2 years of camera trapping (2015 and 2016), we detected 21 jaguars, from which we estimated an average space requirement of 28-45 km2/individual. Dietary niche overlap exceeded random expectation. The most frequently occurring prey items in jaguar and puma diets were collared peccary and deer. Jaguar also favored nine-banded armadillos and white-nosed coati, while puma favored canids. Both felids avoided ocellated turkey. Overall, diet of jaguars was less species-rich, but similar in niche breadth, to that of pumas. A fluid use of space by both species, in 2015 tending toward mutual attraction and in 2016 toward partial exclusion of pumas by jaguars, combined with the high dietary overlap, is consistent with a dominance hierarchy facilitating coexistence. Jaguars and pumas favor the same prey as the people in local communities who hunt, which likely will intensify human-wildlife impacts when prey become scarce. We conclude that even small reserves play an important role in increasing the continuity of habitat for prey and large felids, whose generalist habits suppress interspecific competition for increasingly limiting prey that are largely shared between them and humans.</p

Automated detection of gunshots in tropical forests using convolutional neural networks

Unsustainable hunting is one of the leading drivers of global biodiversity loss, yet very few direct measures exist due to the difficulty in monitoring this cryptic activity. Where guns are commonly used for hunting, such as in the tropical forests of the Americas and Africa, acoustic detection can potentially provide a solution to this monitoring challenge. The emergence of low cost autonomous recording units (ARUs) brings into reach the ability to monitor hunting pressure over wide spatial and temporal scales. However, ARUs produce immense amounts of data, and long term and large-scale monitoring is not possible without efficient automated sound classification techniques. We tested the effectiveness of a sequential two-stage detection pipeline for detecting gunshots from acoustic data collected in the tropical forests of Belize. The pipeline involved an on-board detection algorithm which was developed and tested in a prior study, followed by a spectrogram based convolutional neural network (CNN), which was developed in this manuscript. As gunshots are rare events, we focussed on developing a classification pipeline that maximises recall at the cost of increased false positives, with the aim of using the classifier to assist human annotation of files. We trained the CNN on annotated data collected across two study sites in Belize, comprising 597 gunshots and 28,195 background sounds. Predictions from the annotated validation dataset comprising 150 gunshots and 7044 background sounds collected from the same sites yielded a recall of 0.95 and precision of 0.85. The combined recall of the two-step pipeline was estimated at 0.80. We subsequently applied the CNN to an un-annotated dataset of over 160,000 files collected in a spatially distinct study site to test for generalisability and precision under a more realistic monitoring scenario. Our model was able to generalise to this dataset, and classified gunshots with 0.57 precision and estimated 80% recall, producing a substantially more manageable dataset for human verification. Using a classifier-guided listening approach such as ours can make wide scale monitoring of threats such as hunting a feasible option for conservation management