Terrestrial mammal responses to oil palm dominated landscapes in Colombia

Global mismatches between threat mapping research effort and the potential of threat abatement actions to reduce extinction risk

Threat mapping is a necessary tool for identifying and abating direct threats to species in the ongoing extinction crisis. There are known gaps in the threat mapping literature for particular threats and geographic locations, and it remains unclear if the distribution of research effort is appropriately targeted relative to conservation need. We aimed to determine the drivers of threat mapping research effort and to quantify gaps that, if filled, could inform actions with the highest potential to reduce species' extinction risk. We used a negative binomial generalized linear model to analyze research effort as a function of threat abatement potential (quantified as the potential reduction in species extinction risk from abating threats), species richness, land area, and human pressure. The model showed that threat mapping research effort increased by 1.1 to 1.2 times per standardized unit change in threat abatement potential. However, species richness and land area were stronger predictors of research effort overall. The greatest areas of mismatch between research effort and threat abatement potential, receiving disproportionately low research effort, were related to the threats to species of agriculture, aquaculture, and biological resource use across the tropical regions of the Americas, Asia, and Madagascar. Conversely, the threat of linear infrastructure (e.g., roads and rails) across regions, the threat of biological resource use (e.g., hunting or collection) in sub-Saharan Africa, and overall threats in North America and Europe all received disproportionately high research effort. We discuss the range of methodological and sociopolitical factors that may be behind the overall trends and specific areas of mismatch we found. We urge a stronger emphasis on targeting research effort toward those threats and geographic locations where threat abatement activities could make the greatest contribution to reducing global species extinction risk.

Puma concolor potential distribution and connectivity in the Colombian Llanos

Understanding species distribution to target biodiversity conservation actions in countries with high biodiversity, scarce data availability and low study sites accessibility is very challenging. These issues limit management and conservation actions even on charismatic and potentially conflictive species like large carnivores. We developed a geographic assessment of the potential distribution, core patches and connectivity areas for Puma concolor in the Colombian Llanos (Orinoco region). To create this geographic representation, we used methodological approaches that work with scarce information and still provide a spatially-explicit distribution that could be used by stakeholders. Our results show the importance that the Llanos region has for the conservation of the species and the potential role that can have to ensure a resident long-term population. Based on our approach, more than 50,000 km2 (near to 30% of the study area) can be still considered as core habitats for the species, and most of them are still connected, with spatial gaps lower than the estimated dispersal distance of the species and several remaining steppingstones. Further research is required to validate our analysis and we expect our results can target research and conservation priorities within the region.

Integral analysis of environmental and economic performance of combined agricultural intensification & bioenergy production in the Orinoquia region

Agricultural intensification is a key strategy to help meet increasing demand for food and bioenergy. It has the potential to reduce direct and indirect land use change (LUC) and associated environmental impacts while contributing to a favorable economic performance of the agriculture sector. We conduct an integral analysis of environmental and economic impacts of LUC from projected agricultural intensification and bioenergy production in the Orinoquia region in 2030. We compare three agricultural intensification scenarios (low, medium, high) and a reference scenario, which assumes a business-as-usual development of agricultural production. The results show that with current inefficient management or with only very little intensification between 26% and 93% of the existing natural vegetation areas will be converted to agricultural land to meet increasing food demand. This results in the loss of biodiversity by 53% and increased water consumption by 111%. In the medium and high scenarios, the intensification allows meeting increased food demand within current agricultural lands and even generating surplus land which can be used to produce bioenergy crops. This results in the reduction of biodiversity loss by 8-13% with medium and high levels of intensification compared to the situation in 2018. Also, a positive economic performance is observed, stemming primarily from intensification of cattle production and additional energy crop production. Despite increasing irrigation efficiency in more intensive production systems, the water demand for perennial crops and cattle production over the dry season increases significantly, thus sustainable management practices that target efficient water use are needed. Agricultural productivity improvements, particularly for cattle production, are crucial for reducing the pressure on natural areas from increasing demand for both food products and bioenergy. This implies targeted investments in the agricultural sector and integrated planning of land use. Our results showed that production intensification in the Orinoquia region is a mechanism that could reduce the pressure on natural land and its associated environmental and economic impacts.

Long-Term Land-Use/Land-Cover Change Increased the Landscape Heterogeneity of a Fragmented Temperate Forest in Mexico

The temperate forests of northern Mexico possess a great diversity of unique and endemic species, with the greatest associations of pine-oak in the planet occurring within them. However, the ecosystems in this region had experienced an accelerated fragmentation process in the past decades. This study described and quantified the landscape fragmentation level of a degraded watershed located in this region. For that, data from the Landsat series from 1990, 2005 and 2017, classified with the Support Vector Machine method, were used. The landscape structure was analyzed based on six metrics applied at both, the landscape and class levels. Results show considerable gains in surface area for the land use land cover change (LULC) of secondary forest while the Primary Forest (PF) lost 18.1% of its area during 1990–2017. The PF increased its number of patches from 7075 to 12,318, increased its patch density (PD) from 53.51 to 58.46 # of patches/100 ha, and reduced its average patch size from 39.21 to 15.05 ha. This made the PF the most fragmented LULC from the 5 LULCs evaluated. In this study, strong fluctuations in edge density and PD were registered, which indicates the forests of northern Mexico have experienced a reduction in their productivity and have been subjected to a continuous degradation process due to disturbances such as fires, clandestine and non-properly controlled logging, among others.

Effects of oil palm and human presence on activity patterns of terrestrial mammals in the Colombian Llanos

The ability of animals to adjust their behaviour can influence how they respond to environmental changes and human presence. We quantified activity patterns of terrestrial mammals in oil palm plantations and native riparian forest in Colombia to determine if species exhibited behavioural changes depending on the type of habitat and the presence of humans. Despite the large sampling effort (12,403 camera-days), we were only able to examine the activity patterns of ten species in riparian forests and seven species in oil palm plantations, with four species (capybara, giant anteater, lesser anteater and common opossum) being represented by enough records (i.e. n > 20) in both oil palm and forest to allow robust comparisons. Only capybaras showed an apparent change in activity patterns between oil palm plantations and riparian forests, shifting from being crepuscular in forest to predominantly nocturnal inside oil palm plantations. Further, capybaras, giant anteaters and white-tailed deer appeared to modify their activities to avoid human presence inside oil palm plantations by increasing nocturnality (temporal overlap $$\widehat{\Delta }$$ Δ ^ ranged from 0.13 to 0.36), whereas jaguarundi had high overlap with human activities [$$\widehat{\Delta }$$ Δ ^ =0.85 (0.61–0.90)]. Species pair-wise analysis within oil palm revealed evidence for temporal segregation between species occupying the same trophic position (e.g. foxes and jaguarundi), whereas some predators and their prey (e.g. ocelots and armadillos) had high overlaps in temporal activity patterns as might be expected. Our findings shed light on the potential behavioural adaptation of mammals to anthropogenic landscapes, a feature not captured in traditional studies that focus on measures such as species richness or abundance.

Wildlife-Friendly Livestock Management Promotes Mammalian Biodiversity Recovery on a Semi-Arid Karoo Farm in South Africa

Agriculture is an essential production system used to feed the growing human population, but at the same time has become a major driver of biodiversity loss and environmental degradation. Employing production methods that restore degraded landscapes can have a positive impact on biodiversity, whilst improving food production. We assessed how mammalian biodiversity, specifically richness and their relative abundances varied on five Karoo farms in South Africa that had been amalgamated and subjected to a transition from traditional livestock grazing techniques (sporadic rotational grazing and lethal predator control) to wildlife-friendly non-lethal predator management, using human shepherding of livestock under a high-density short-duration grazing regime. We used camera trap data collected over a 4-year period, to measure mammalian species richness, distribution and relative abundance on the wildlife-friendly farm to investigate temporal changes throughout the conversion from traditional farming practices. In the last year of the study (2019) additional cameras were used to provide a spatial comparison of mammalian species on the wildlife-friendly farm to two neighboring farms, a traditional livestock farm using lethal predator controls, and a game farm. We found that mammalian species richness increased year on year resulting in a significant increase of 24% over the duration of the study. Herbivores showed an increase of 33% in the number of species detected over the years, while predator species increased by 8%. The relative abundance and distribution of most species also showed increases as the conversion process took place. For example, 73% of the herbivore species detected throughout the study increased in their relative abundance. Similarly, 67% of all species showed an increase in the number of sites occupied over the years. In the final year of the study the wildlife-friendly farm had more mammalian species compared to the game farm and traditional livestock farm, with the latter two sites having a similar number of species when compared to the commencement of the conversion of the wildlife-friendly site. These broad improvements in mammalian biodiversity demonstrate that livestock production can benefit local mammalian biodiversity through a combination of herder grazing management and wildlife-friendly farming.

Bat Assemblage in an Oil Palm Plantation from the Colombian Llanos Foothills

The surge of oil palm production in the Neotropics has become a major concern about the potential impacts on biodiversity. In the Colombian Orinoquia, which has shown a massive landscape transformation due to the growth of oil palm plantations, the effects of oil palm agriculture on bats in this region have not been studied up to date. To understand the impact of habitat conversion on bat diversity, we characterised bat assemblages in secondary forest and palm plantations in the Colombian Llanos foothills (Meta, Colombia). We captured 393 individuals (forest = 81, plantation = 312) of 18 species and 3 families. The forest cover presented three exclusive species while the plantation had five. Species diversity (q¹) and evenness (J′) were higher in the forest compared to the plantation. These differences derived from the increase in abundances of generalist species (Artibeus sp., Carollia spp.) in the plantation. Despite the habitat simplification caused by oil palm plantations, this monoculture provides a cover that is used by some bats, decreasing their risk of predation and allowing movement between patches of forest habitat as steppingstones. Maintaining forest cover in agricultural landscapes favours diversity by generating a “spillover effect” of the forest towards plantations, which in the case of some bats contributes to the reduction of species isolation and the maintenance of ecosystem services provided by them. It is important to improve management practices of oil palm plantations to minimise negative impacts on biodiversity, considering the expansion of this productive system and the scarcity of protected areas in this region.

Wetlands are keystone habitats for jaguars in an intercontinental biodiversity hotspot

Agricultural development was the major contributor to South America's designation as the continent with the highest rates of forest loss from 2000-2012. As the apex predator in the Neotropics, jaguars (Panthera onca) are dependent on forest cover but the species' response to habitat fragmentation in heterogeneous agricultural landscapes has not been a subject of extensive research. We used occupancy as a measure of jaguar habitat use in Colombia's middle Magdalena River valley which, as part of the intercontinental Tumbes-Chocó-Magdalena biodiversity hotspot, is exceedingly fragmented by expanding cattle pastures and oil palm plantations. We used single-season occupancy models to analyze 9 months of data (2015-2016) from 70 camera trap sites. Given the middle Magdalena's status as a "jaguar corridor" and our possible violation of the occupancy models' demographic closure assumption, we interpreted our results as "probability of habitat use (Ψ)" by jaguars. We measured the associations between jaguar presence and coverage of forest, oil palm, and wetlands in radii buffers of 1, 3, and 5 km around each camera trap. Our camera traps recorded 77 jaguar detections at 25 of the camera trap sites (36%) during 15,305 trap nights. The probability of detecting jaguars, given their presence at a site, was 0.28 (0.03 SE). In the top-ranked model, jaguar habitat use was positively influenced by wetland coverage (β = 7.16, 3.20 SE) and negatively influenced by cattle pastures (β = -1.40, 0.63 SE), both in the 3 km buffers. We conclude that wetlands may serve as keystone habitats for jaguars in landscapes fragmented by cattle ranches and oil palm plantations. Greater focus on wetland preservation could facilitate jaguar persistence in one of the most important yet vulnerable areas of their distribution.

Land management strategies can increase oil palm plantation use by some terrestrial mammals in Colombia

While the conservation role of remaining natural habitats in anthropogenic landscapes is clear, the degree to which agricultural matrices impose limitations to animal use is not well understood, but vital to assess species’ resilience to land use change. Using an occupancy framework, we evaluated how oil palm plantations affect the occurrence and habitat use of terrestrial mammals in the Colombian Llanos. Further, we evaluated the effect of undergrowth vegetation and proximity to forest on habitat use within plantations. Most species exhibited restricted distributions across the study area, especially in oil palm plantations. Habitat type strongly influenced habitat use of four of the 12 more widely distributed species with oil palm negatively affecting species such as capybara and naked-tailed armadillo. The remaining species showed no apparent effect of habitat type, but oil palm and forest use probabilities varied among species. Overall, generalist mesocarnivores, white-tailed deer, and giant anteater were more likely to use oil palm while the remaining species, including ocelot and lesser anteater, showed preferences for forest. Distance to nearest forest had mixed effects on species habitat use, while understory vegetation facilitated the presence of species using oil palm. Our findings suggest that allowing undergrowth vegetation inside plantations and maintaining nearby riparian corridors would increase the likelihood of terrestrial mammals’ occurrence within oil palm landscapes.