13 research outputs found
Scaling issues in the study of livestock depredation by carnivores
Context: Many studies have documented the magnitude and socioecological drivers of livestock depredation, yet few have assessed how observations of depredation might vary with spatiotemporal scale. Understanding scaling relationships may allow for more accurate aggregation of observations collected across diverse extents and resolutions to better inform management actions. Objectives: Herein we examine how reported metrics of livestock depredation varied by spatial and temporal scale (extent and resolution) after controlling for other drivers of differences among studies. Methods: From 213 published studies we extracted conflict metrics (i.e., number of animals killed, number of attack incidents, and percent annual loss of stock) and regressed each against spatiotemporal extent (i.e., size of study area, duration of study) and resolution (i.e., minimum mapping unit, frequency of observations) while controlling for potential biases. Results: The number of attacks or animals killed was positively related to spatial and temporal extent whereas percent annual loss of stock declined with extent. Further, the effects of scaling variables were modified through interactions with other factors (e.g., human density) known to influence human-carnivore conflict. The data available for spatiotemporal resolution were too sparse to draw conclusions. While scaling relationships were generally linear, they became increasingly noisy at broader extents. Conclusions: Consistent with other ecological investigations, the scale of observation influenced the observed outcomes in human-carnivore conflict metrics. Authors should report the spatiotemporal dimensions of their observations to improve robust inference in comparative studies. Enhanced understanding of scaling relationships in human-carnivore conflict metrics should improve strategic allocation of resources to better mitigate future conflict
Relative efforts of countries to conserve worldâs megafauna
Surprisingly little attention has been paid to variation among countries in contributions to conservation. As a first step, we developed a Megafauna Conservation Index (MCI) that assesses the spatial, ecological and financial contributions of 152 nations towards conservation of the worldâs terrestrial megafauna. We chose megafauna because they are particularly valuable in economic, ecological and societal terms, and are challenging and expensive to conserve. We categorised these 152 countries as being above- or below-average performers based on whether their contribution to megafauna conservation was higher or lower than the global mean; âmajorâ performers or underperformers were those whose contribution exceeded 1 SD over or under the mean, respectively. Ninety percent of countries in North/Central America and 70% of countries in Africa were classified as major or above-average performers, while approximately one-quarter of countries in Asia (25%) and Europe (21%) were identified as major underperformers. We present our index to emphasize the need for measuring conservation performance, to help nations identify how best they could improve their efforts, and to present a starting point for the development of more robust and inclusive measures (noting how the IUCN Red List evolved over time). Our analysis points to three approaches that countries could adopt to improve their contribution to global megafauna conservation, depending on their circumstances: 1) upgrading or expanding their domestic protected area networks, with a particular emphasis on conserving large carnivore and herbivore habitat, 2) increase funding for conservation at home or abroad, or 3) ârewildingâ their landscapes. Once revised and perfected, we recommend publishing regular conservation rankings in the popular media to recognise major-performers, foster healthy pride and competition among nations, and identify ways for governments to improve their performance
Savanna fire management can generate enough carbon revenue to help restore Africa's rangelands and fill protected area funding gaps
Many savanna-dependent species in Africa including large herbivores and apex predators are at increasing
risk of extinction. Achieving effective management of protected areas (PAs) in Africa where lions live will cost
an estimated US 59.6â655.9 million/year (at US 155.0 million/year to US 13/ton). We highlight variable but significant PCRs for savanna PAs from US$ 1.5â44.4
million/year per PA. We suggest investing in fire management programs to jump-start the United Nations
Decade of Ecological Restoration to help restore degraded African savannas and conserve imperiled
keystone herbivores and apex predators.https://www.cell.com/one-earth/homeam2022Zoology and Entomolog
Occupancy estimation of jaguar Panthera onca to assess the value of east-central Mexico as a jaguar corridor
The use of wildlife corridors to maintain landscape connectivity has become increasingly relevant to the conservation of wide-ranging species, including the jaguar Panthera onca. Jaguars are particularly threatened in Mexico, where corridor linkages are tenuous as a result of habitat fragmentation. Our study assessed a section of potential corridor south of the Sierra Madre Oriental in eastern Mexico. We conducted 245 interviews with local inhabitants in 140 36-km(2) sampling units over a 5-month period and compiled detection histories for jaguars and five prey species: collared peccary Pecari tajacu, red brocket deer Mazama americana, white-tailed deer Odocoileus virginianus, spotted paca Agouti paca, and nine-banded armadillo Dasypus novemcinctus. These detection histories were then analysed using site occupancy modelling. Each sampling unit was assigned a probability of habitat use based on (1) the two smaller prey species (paca and armadillo) and (2) at least two of the larger prey species (collared peccary and two deer species) using habitat in that unit. This probability estimate was considered a proxy for the prey base of each sampling unit and therefore the unit's suitability as a jaguar corridor. Although the prey base in some areas appears adequate to support a jaguar population, large-scale development projects and the paucity of jaguar sign are major obstacles to this region's potential as a jaguar corridor. Our results suggest that the eastern coast of Mexico may not be a priority area for range-wide jaguar conservation
Census and distribution of large carnivores in the Tsavo national parks, a critical east African wildlife corridor
Kenya's Tsavo National Parks are a critical conservation area and the only wilderness corridor through densely populated human-dominated landscapes stretching from the East African coast to Lake Victoria, separating extensive undeveloped grasslands south of the equator from the undeveloped semiarid bushlands to the north. At nearly 21,000 km(2), Tsavo is one of four lion strongholds in East Africa and part of Africa's most important populations of all other large African carnivores. To provide baseline data on the status of large carnivores, a track survey was undertaken in 2013. Lions and both hyaena species were widely distributed across both parks, while cheetahs and wild dogs were more patchily distributed. Spotted hyaenas were the most abundant, with an estimated population of 3,903 +/- 514 (95% CI), followed by lion (706 +/- 201), striped hyaena (679 +/- 144), leopard (452 +/- 98), cheetah (154 +/- 74) and wild dog (111 +/- 92). Tsavo's carnivores suffer from bushmeat poaching, illegal grazing and retaliatory killing, and increasing human numbers on its periphery. Given Tsavo's importance as a stronghold for lions and an ecological corridor, increased investment in effective protection is strongly recommended. Evaluating trends will require complementary techniques in light of intensive monitoring requirements
Forest cover mediates large and medium-sized mammal occurrence in a critical link of the Mesoamerican Biological Corridor.
Connectivity of natural areas through biological corridors is essential for ecosystem resilience and biodiversity conservation. However, robust assessments of biodiversity in corridor areas are often hindered by logistical constraints and the statistical challenges of modeling data from multiple species. Herein, we used a hierarchical community occupancy model in a Bayesian framework to evaluate the status of medium and large-sized mammals in a critical link of the Mesoamerican Biological Corridor (MBC) in Costa Rica. We used camera traps deployed from 2013-2017 to detect 18 medium (1-15 kg) and 6 large (>15 kg) mammal species in a portion of two Jaguar Conservation Units (JCUs) and the Corridor linking them. Camera traps operated for 16,904 trap nights across 209 stations, covering an area of 880 km2. Forest cover was the most important driver of medium and large-sized mammal habitat use, with forest specialists such as jaguars (Panthera onca) and pumas (Puma concolor) strongly associated with high forest cover, while habitat generalists such as coyotes (Canis latrans) and raccoons (Procyon lotor) were associated with low forest cover. Medium and large-sized mammal species richness was lower in the Corridor area ([Formula: see text] = 9.78±1.84) than in the portions evaluated of the two JCUs ([Formula: see text] = 11.50±1.52). Puma and jaguar habitat use probabilities were strongly correlated with large prey species richness (jaguar, r = 0.59, p<0.001; puma, r = 0.72, p<0.001), and correlated to a lesser extent with medium prey species richness (jaguar, r = 0.36, p = 0.003; puma, r = 0.23, p = 0.064). Low estimated jaguar habitat use probability in one JCU (Central Volcanic Cordillera: [Formula: see text] = 0.15±0.11) suggests that this is not the jaguar stronghold previously assumed. In addition, the western half of the Corridor has low richness of large mammals, making it necessary to take urgent actions to secure habitat connectivity for mammal populations
Data from: Robust inference on large-scale species habitat use with interview data: the status of jaguars outside protected areas in Central America
Evaluating range-wide habitat use by a target species requires information on species occurrence over broad geographic regions, a process made difficult by species rarity, large spatiotemporal sampling domains, and imperfect detection. We address these challenges in an assessment of habitat use for jaguars (Panthera onca) outside protected areas in Central America.
Occurrence records were acquired within 12 putative corridors using interviews with knowledgeable corridor residents. We developed a Bayesian hierarchical occupancy model to gain robust inference, allowing for heterogeneity introduced in the sampling process over space and time, using records of jaguar occurrence prone to false positives and false negatives.
Probability of false detection of jaguars increased with the number of interviews conducted per unit (from 5.42% to 7.74% given <4 and â„4 observers per unit). True probability of detection (mean=0.58) increased with the number of days interviewees spent in a survey unit per year. Failing to account for false positives biased predicted habitat use high (Ë1.8x), especially where occurrence records were sparse.
Probability of site use by jaguars increased with greater forest cover, prey richness, and distance from human settlements, and decreased with greater agricultural cover, elevation, and distance from protected areas. Site use probabilities averaged 0.15-0.97 by corridor, providing relatively fine-scale resolution of predicted jaguar occurrence consistent with known patterns of jaguar gene flow across Central America.
Model validation, accounting for both false positives and negatives in the observation process, indicated moderate correspondence between model-predicted observations and actual observations for withheld data (0.65, 95% CRI 0.59â0.71), with sensitivity and specificity rates of 0.69 (0.61 â 0.77) and 0.59 (0.50 â 0.68), respectively. These results demonstrate that reliable predictions can be achieved despite the complexity of large-scale, interview-based analyses of species occurrence.
Synthesis and applications. Our Bayesian hierarchical occupancy model accommodated heterogeneity caused by typical sampling inequities and idiosyncrasies associated with interview data, yielding robust estimates of jaguar habitat use. Our approach is applicable to any wide-ranging and readily identifiable species and has particular utility for rare species in human-dominated landscapes where traditional survey techniques (e.g., camera traps) may be impractical
More than $1 billion needed annually to secure Africaâs protected areas with lions
Protected areas (PAs) play an important role in conserving biodiversity and providing ecosystem services, yet their effectiveness is undermined by funding shortfalls. Using lions (Panthera leo) as a proxy for PA health, we assessed available funding relative to budget requirements for PAs in Africaâs savannahs. We compiled a dataset of 2015 funding for 282 state-owned PAs with lions. We applied three methods to estimate the minimum funding required for effective conservation of lions, and calculated deficits. We estimated minimum required funding as 1,271/km2 based on modeled costs of managing lions at â„50% carrying capacity across diverse conditions in 115 PAs; and 1.2 to 1,000 to 2,000/km2, yet received only 200/km2. Ninety-six percent of range countries had funding deficits in at least one PA, with 88 to 94% of PAs with lions funded insufficiently. In funding-deficit PAs, available funding satisfied just 10 to 20% of PA requirements on average, and deficits total 2.1 billion. African governments and the international community need to increase the funding available for management by three to six times if PAs are to effectively conserve lions and other species and provide vital ecological and economic benefits to neighboring communities.Panthera provided funding to support the study. J.R.B.M. was supported in part by National Science Foundation Coupled Human and Natural Systems Grant 115057. L.C. was funded by the US Agency for International Development.http://www.pnas.org2019-05-06hj2019Mammal Research InstituteZoology and Entomolog
Census and distribution of large carnivores in the Tsavo national parks, a critical east African wildlife corridor
Kenya's Tsavo National Parks are a critical conservation area and the only wilderness corridor through densely populated human-dominated landscapes stretching from the East African coast to Lake Victoria, separating extensive undeveloped grasslands south of the equator from the undeveloped semiarid bushlands to the north. At nearly 21,000 km(2), Tsavo is one of four lion strongholds in East Africa and part of Africa's most important populations of all other large African carnivores. To provide baseline data on the status of large carnivores, a track survey was undertaken in 2013. Lions and both hyaena species were widely distributed across both parks, while cheetahs and wild dogs were more patchily distributed. Spotted hyaenas were the most abundant, with an estimated population of 3,903 +/- 514 (95% CI), followed by lion (706 +/- 201), striped hyaena (679 +/- 144), leopard (452 +/- 98), cheetah (154 +/- 74) and wild dog (111 +/- 92). Tsavo's carnivores suffer from bushmeat poaching, illegal grazing and retaliatory killing, and increasing human numbers on its periphery. Given Tsavo's importance as a stronghold for lions and an ecological corridor, increased investment in effective protection is strongly recommended. Evaluating trends will require complementary techniques in light of intensive monitoring requirements