Browsing by Subject "Wildlife management"

A vast range of theoretical and empirical studies now suggests that MPAs can conserve marine biodiversity and, under some circumstances, increase fishery yields. However, despite the importance of pelagic apex predators to ecosystem function, the effectiveness of spatial management for the conservation of pelagic apex predator species is still unknown. I used fishery-dependent logbook and observer datasets to assess fishing effort and both the catch and size of pelagic apex predator species around five different MPAs. The US Hawaii-based deep-set or Atlantic pelagic longline fisheries fish the waters around these MPAs; both of these fisheries have experienced multiple management measures over time to protect species and maximize fishery yield. The MPAs selected for this study range in size, age, level of protection, and reason for establishment. I found that only two MPAs of the five appeared to be benefitting the pelagic apex predator species that I selected: the DeSoto Canyon and East Florida Coast MPAs, both in the Atlantic Ocean. The size of yellowfin tuna around the DeSoto Canyon MPA borders has increased over time, as has fishing effort. In contrast, the size of swordfish has decreased near the boundary of the East Florida Coast MPA, although the catch of swordfish has increased. The increase in catch of smaller swordfish was not a surprise because the East Florida Coast MPA was established around an area that is a nursery habitat for swordfish. These results are promising for the use of static MPAs for the conservation of pelagic apex predators, but three of the MPAs in my study did not show any indication of increased fishing effort, increased catch, or changes in pelagic apex predator size near their boundaries over time. Therefore, the characteristics of the DeSoto Canyon and East Florida Coast MPAs may provide a template for how to best design new MPAs for pelagic apex predators. Both of these MPAs were established with the specific intent of reducing pelagic apex predator bycatch, in areas where there were historically high catch rates. Both areas are relatively large (> 85,000 km2) and are also closed year-round. In combination, these characteristics may provide protection for pelagic apex predators.

This dissertation research explores participatory sea turtle conservation monitoring through a comparison of two case studies, one in North Carolina (NC), USA and the other in Baja California Sur (BCS), Mexico. Participatory approaches in conservation management can supplement state capacity as well as strengthen the involvement of citizens in environmental governance and knowledge production. Despite scholarship challenging the validity of the categories of developing and developed nations, this categorical assumptions derived from this binary world divide continue to inform conservation, and theoretical vocabularies for local roles in conservation management. In developed nations, participatory conservation management is framed through the broader administrative rationalism discourse, and is identified as volunteer conservation or citizen science. In developing nations, participatory conservation management is approached through the discourse of biodiversity and the threats human society poses to it, and is identified through community-based processes of conservation stewardship. The two case studies analyzed in this dissertation serve to interrogate the ways in which these distinct discourses influence outcomes, and consider what may be obscured or overlooked due to discursive constraints.

Conducting ethnographic research in each case study site, I participated in and observed sea turtle conservation activities and conducted in-depth interviews with relevant sea turtle conservation actors as well as collected documents pertaining to the conservation programs. Sea turtle conservation monitors in NC and BCS perform functionally similar conservation tasks, and I collected data using similar techniques in order to maximize comparability. I compare the case studies, not to generalize to a population, but instead to speak to theoretical propositions and inform existing theory on participatory conservation monitoring.

Although participatory monitoring in NC and BCS does not result in a democratization of science, there are beneficial outcomes to participants in both places. NC sea turtle monitors are enabled to take ownership of sea turtle stewardship, and BCS sea turtle monitors are enabled to promote conservation and cultural change using the authority of science. These outcomes challenge assumptions about state capacity and local engagements with science in participatory conservation, and the disparate approaches to local roles in conservation in each `world.' The overall findings suggest that a multitude of factors are involved in the production of conservation program frameworks and participant outcomes, and more deeply interrogating the taken for granted assumptions behind conservation designs and implementation can offer stronger understandings of what participatory conservation management can (and cannot) achieve.

Few areas of the planet are untouched by human actions, be they marine or terrestrial. Marine habitats face disturbance from overexploitation of fisheries and pollution while terrestrial habitats face significant threat from land cover conversion and degradation. To address these threats, conservationists utilize a variety of population viability analyses to both assess and manage species’ health. The results of these analyses often play a key role in determining when intervention is necessary and which actions will be the most successful. Within this dissertation, I used several population modeling approaches to advance our understanding of changes in the landscape on the persistence of populations and by extension, species.

This dissertation may be broadly divided into two halves, the first assessing a single, local population and the second evaluating metapopulations. In Chapter 2, I combined telemetry data on sooty terns (Onychoprion fuscatus) with a long-term capture-mark-recapture dataset from the Dry Tortugas National Park to map the movements at sea for this species, calculate estimates of mortality, and investigate the impact of hurricanes on a migratory seabird. Included in the latter analysis is information on the locations of recovered bands from deceased individuals wrecked by tropical storms. I present the first known map of sooty tern migration in the Atlantic Ocean. The results indicate that the birds had minor overlaps with areas affected by the major 2010 oil spill and a major shrimp fishery. Indices of hurricane strength and occurrence are positively correlated with annual mortality and indices of numbers of wrecked birds. As climate change may lead to an increase in severity and frequency of major hurricanes, this may pose a long-term problem for this colony.

In the latter half of this dissertation, I utilized a variety of metapopulation analyses for conservation at multiple scales. As a landscape becomes increasingly fragmented through habitat loss, the individual patches become smaller and more isolated and thus less likely to sustain a local population. Metapopulation theory is appropriate for analyzing fragmented landscapes because it combines empirical landscapes features with species-specific information to produce direct information on population extinction risks. Combining a spatially explicit metapopulation model with empirical data on endemic species’ ranges and maps of habitat cover, I could calculate the metapopulation capacity— a measure of a landscape’s ability to sustain a metapopulation.

Mangroves provide an ideal, model landscape for my analysis in Chapter 3. Of conservation concern, one can easily delineate their patch boundaries. I calculated metapopulation capacity for 99 metapopulations from 32 different mangrove-endemic bird species globally in the years 2000 and 2015. Northern Australia and South East Asia have the highest richness of mangrove-endemic birds, with some hotspots also occurring in Guyana and French Guiana. The areas with the highest metapopulation loss are the Caribbean, the Pacific coast of Central America, Madagascar, Borneo, and isolated patches in Southeast Asia in Burma and Malaysia. Regions with the highest loss of habitat area are not necessarily those with the highest loss of metapopulation capacity. Often it is not a matter of how much, but how the habitat is lost since fragmentation of patches has a complicated relationship with extinction risk.

After analyzing the effects of habitat loss and fragmentation on a species’ risk of extinction, it is natural to examine the reverse, the restoration of habitat. In Chapter 4, I used metapopulation models to prioritize locations for potential habitat corridors. I compared these results to standard connectivity models that have grown in popularity to illustrate how together they provide a more complete set of recommendations for the recovery of species. For this chapter, I use the golden lion tamarin (Leontopithecus rosalia) as the focal species. Endemic to the highly fragmented Atlantic coastal forest of Brazil, the golden lion tamarins are a highly studied species of top conservation concern. I identified the best locations for habitat restoration to increase metapopulation capacity and how they compare with movement of individuals in the current landscape. I also evaluated how a previous corridor restoration ranked according to these methods and how it effects future conservation planning. While large, occupied patches are significant for both sets of models, metapopulation models also indicate the importance of nearby, medium-sized empty patches that if connected by a corridor would facilitate the growth and recovery of tamarin populations.

In summary, I applied a suite of population modeling techniques to an assortment of landscapes and species for conserving biodiversity. Despite the variety of models used, I illustrate the flexibility and utility of population ecology to conservation management.

Self-determined community hunting governance and management is increasingly promoted as a key pathway towards the equitable sustainability of wild food systems, vital to the well-being of Indigenous peoples and local communities and the conservation of biodiversity. Yet there is scant scientific research providing robust, quantitative evidence of a community approach. Here I present the creation and use of a novel community bushmeat monitoring program to address this need across twenty villages in northeastern Gabon. Paraecologists conducted standardized monitoring of bushmeat, and hundreds of hunters conducted GPS self-follows mapping village hunting catchments. I integrated these data to estimate the proportion of bushmeat sampled and make robust extrapolations of total offtake across space and time, estimating an annual offtake of ~30,000 animals of >56 species across all villages.

Such community- and landscape- level SES dynamics are the aggregate of individual motivation for the use of CPRs, which can be fluid, with the line between subsistence and commercial often unclear and in flux. I applied hierarchical Bayesian structural equation modelling to 910 hunts from 111 gun and trap hunters across nine villages. I first establish the human behaviour driving gun-hunting and trapping success and predict its effect on offtake across villages, and then linked fluid motivation of gun hunters to their behaviour, number of animals hunted, biomass yielded, and income earned. Gun hunts across villages yielded more animals during the night than the day, and when hunters brought high amounts of ammunition and walked far distances from villages. Gun hunts were less successful when coupled with trapping while per-hunt success of trapping itself was generally low and difficult to predict. Fluid gun hunters hunted fewer animals when motivated strictly by subsistence, despite no reduction in ammunition brought or distance walked, while offtake from strictly commercial versus mixed motivation was the same. Numbers of animals hunted, biomass, and income were tightly linked.

In ten villages, the project facilitated community exploration of self-determined bushmeat hunting management, which three villages established. I used the paraecology data to quantify changes in offtake in these three villages in relation to fourteen other villages over the same period, and enriched insight in changes in offtake with participatory data analyses, long-term community engagement, and a mixed quantitative-qualitative survey of hunters’ perceived quality of their governance. The three communities created from three to nine different management rules, including no-hunting reserves and limits on ammunition and traps. Different management strategies in two villages both caused reductions in offtake of „ 400 animals a year; scaling up to 10–30% of Gabon’s total ~2500 villages could reduce national offtake by ~100,000–300,00 animals a year, with widespread community reserves driving substantial growth of wildlife populations. Hunters generally perceived the governance of their hunting management as high quality, though perceptions of conformity to rules and overall success varied across villages and hunters. Hunters perceived a lack of state support in their management; research and policy both should pay further attention to the governance of hunting management and the enabling conditions needed to improve it across SESs.

Despite 21 years of protection, sideneck river-turtles (Podocnemis expansa, P. unifilis and P. vogli, arrau, terecay and galápago, respectively), an important food resource for riverine communities (ribereños) in the Middle Orinoco, have not recovered. To determine the most effective conservation alternative for recovery, we conducted semi-structured interviews of ribereños and determined their attitudes towards turtle conservation; we collected discarded turtle remains in riverine communities to estimate the level of turtle harvest; and constructed a population model to study the effect of reduced survival and future extraction on arrau turtle population growth. We found that ribereños blame continued commercial extraction for the lack of turtle population recovery. Ribereños have a desire to participate actively in conservation and, despite feeling alienated by governmental officials charged with protecting turtles, prefer to be included in conservation efforts. However, ribereños also fear retaliation from turtle poachers. We found widespread turtle harvest along the Middle Orinoco centered on juvenile arrau turtles, and adult female terecay and galápago turtles. In our population model, reducing harvest causes an increase in population growth. A 10% increase in survival causes rapid exponential growth in arrau turtles. The population continues to grow in over 70% of projected scenarios with limited harvest from a recovered stock. Due to the widespread distribution of turtles and their harvest, we recommend increasing ribereño participation in conservation activities, closing outsider (non-ribereño) access to the resource, increasing enforcement against illegal commercial harvest, instating possession limits for subsistence harvest, and promoting localized captive breeding of faster maturing terecay and galápago turtles to satisfy desire for turtle consumption.