Detection of echinostomatid trematode eggs at the forest-oil palm interface in Sabah, Malaysia.

In this study, we report the occurrence of echinostomatid eggs in feces of wildlife, domestic animals and humans frequenting the forest­oil palm plantation interface in the Kinabatangan (Sabah, Malaysia), and discuss potential implications for public health. Using microscopy, we detected echinostomatid eggs in six host species, including Asian palm civets (Paradoxurus hermaphroditus [13/18]), leopard cats (Prionailurus bengalensis [3/4]), long-tailed macaques (Macaca fascicularis [1/10]), domestic dogs [3/5] and cats [1/1], and humans [7/9]. Molecular analysis revealed a close genetic proximity of civet echinostomatids to Artyfechinostomum malayanum, a zoonotic parasite of public health relevance. The intermediate hosts for A. malayanum have been reported in at least 3 districts in Sabah, suggesting that all the necessary elements required for the completion of the parasite's life cycle are present. Our findings point at the presence of zoonotic trematodes in an area with high human­wildlife interaction and highlight the potential public and animal health concern of zoonotic trematode infection in the context of Southeast Asia's rapidly changing ecosystems.

The fast-food effect: costs of being a generalist in a human-dominated landscape.

Agricultural expansion in Southeast Asia has converted most natural landscapes into mosaics of forest interspersed with plantations, dominated by the presence of generalist species that benefit from resource predictability. Dietary shifts, however, can result in metabolic alterations and the exposure of new parasites that can impact animal fitness and population survival. Our study focuses on the Asian water monitor lizard (Varanus salvator), one of the largest predators in the Asian wetlands, as a model species to understand the health consequences of living in a human-dominated landscape in Sabah, Malaysian Borneo. We evaluated the effects of dietary diversity on the metabolism of monitor lizards and the impact on the composition of their parasite communities in an oil palm-dominated landscape. Our results showed that (1) rodent-dominated diets were associated with high levels of lipids, proteins and electrolytes, akin to a fast-food-based diet of little representativeness of the full nutritional requirements, but highly available, and (2) lizards feeding on diverse diets hosted more diverse parasite communities, however, at overall lower parasite prevalence. Furthermore, we observed that the effect of diet on lipid concentration differed depending on the size of individual home ranges, suggesting that sedentarism plays an important role in the accumulation of cholesterol and triglycerides. Parasite communities were also affected by a homogeneous dietary behaviour, as well as by habitat type. Dietary diversity had a negative effect on both parasite richness and prevalence in plantations, but not in forested areas. Our study indicates that human-dominated landscapes can pose a negative effect on generalist species and hints to the unforeseen health consequences for more vulnerable taxa using the same landscapes. Thus, it highlights the potential role of such a widely distributed generalist as model species to monitor physiological effects in the ecosystem in an oil palm-dominated landscape.

A call to strengthen local governance for preventing and mitigating global crises.

Deforestation and land conversion have dramatic consequences to biodiversity and disease emergence, but they are also deep-rooted in historical forces involved in environmental injustice. Global guidelines tackling global crises approach the problem using top-down formulas that often fail to match local needs and priorities, and are rarely evaluated for local suitability, implications, and impacts. Motivated by the report of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) workshop, published in 2020, we reflect on how drivers of zoonotic disease emergence are linked to historical injustices and how global initiatives tackling global crises are prone to reproducing colonial structures. We provide examples of local governance strengthening through horizontal and interdisciplinary collaborations, and how the support of local solutions can build resilience against global crises.

Serological evidence of exposure of Bornean wild carnivores to feline-related viruses at the domestic animal-wildlife interface.

We conducted an exploratory serological survey to evaluate the exposure of Bornean wild carnivores to several viruses common to domestic felids, at interface areas between protected forest and industrial agriculture in the Kinabatangan floodplain (Sabah, Malaysia). Blood samples, collected from wild carnivores (n = 21) and domestic cats (n = 27), were tested for antibodies against feline coronavirus (FCoV), feline panleukopenia virus (FPLV), feline herpesvirus (FHV) and feline calicivirus (FCV), using commercial enzyme-linked immunosorbent assay (ELISA) test kits. Anti-FCoV antibodies were detected in most species, including one flat-headed cat (Prionailurus planiceps, [1/2]), leopard cats (Prionailurus bengalensis, [2/5]), Malay civets (Viverra tangalunga, [2/11]) and domestic cats (Felis catus, [2/27]). Anti-FCV antibodies were present in all domestic cats and one flat-headed cat, while anti-FPLV antibodies were identified in Sunda clouded leopards (Neofelis diardi, [2/2]), domestic cats [12/27] and Malay civets [2/11]. Anti-FHV antibodies were only detected in domestic cats [2/27]. Our findings indicate pathogen transmission risk between domestic and wild carnivore populations at the domestic animal-wildlife interface, emphasizing the concern for wildlife conservation for several endangered wild carnivores living in the area. Special consideration should be given to species that benefit from their association with humans and have the potential to carry pathogens between forest and plantations (e.g., Malay civets and leopard cats). Risk reduction strategies should be incorporated and supported as part of conservation actions in human-dominated landscapes.

The effect of oil palm-dominated landscapes on the home range and distribution of a generalist species, the Asian water monitor.

The Asian water monitor lizard, Varanus salvator, is one of the largest predators in Southeast Asia which persists in human-dominated landscapes and, as such, is a suitable model to understand the behavioral plasticity of generalists in anthropogenic landscapes. We used Local Convex Hull with adaptive algorithm to estimate the home range size of 14 GPS-tagged individuals, followed by a MAXENT approach and community prey composition to understand the habitat preferences within the landscape. We estimated larger home ranges in forest than in oil palm plantations, as well as a larger diversity and abundance of mammals. Core home ranges were always linked to water bodies. However, the use of underproductive oil palm, freshwater swamp forest, and degraded forest by monitor lizards were higher than other kind of vegetation. This suitable habitat is proportionally larger in forest (73.7%) than in oil palm plantations (39.6%). Generalized estimation equation models showed that, while full home range size was negatively associated with the abundance of mammals, core areas depicted a positive association with mammal abundance, as well as with the proportion of suitable habitat within the home range. Besides having smaller home ranges in oil palm plantations, our findings suggest that limited suitable habitat availability forces the Asian water monitor lizard's population to establish only one or very few core areas. Contrastingly, under the protection of forest, they have more core areas, widely dispersed within larger home ranges. We conclude that regardless the plasticity of the species, human-dominated landscapes are altering natural patterns of home range establishment in the monitor lizard's population, creating a potential ecological trap where conditions may not remain favorable for them in the long run. A deeper understanding of the ecological implications on the species and the prey community is advisable.

The critical role of natural forest as refugium for generalist species in oil palm-dominated landscapes.

In Borneo, oil palm plantations have replaced much of natural resources, where generalist species tend to be the principal beneficiaries, due to the abundant food provided by oil palm plantations. Here, we analyse the distribution of the Asian water monitor lizard (Varanus salvator) population within an oil palm-dominated landscape in the Kinabatangan floodplain, Malaysian Borneo. By using mark-recapture methods we estimated its population size, survival, and growth in forest and plantation habitats. We compared body measurements (i.e. body weight and body length) of individuals living in forest and oil palm habitats as proxy for the population's health status, and used general least squares estimation models to evaluate its response to highly fragmented landscapes in the absence of intensive hunting pressures. Contrary to previous studies, the abundance of lizards was higher in the forest than in oil palm plantations. Recruitment rates were also higher in the forest, suggesting that these areas may function as a source of new individuals into the landscape. While there were no morphometric differences among plantation sites, we found significant differences among forested areas, where larger lizards were found inhabiting forest adjacent to oil palm plantations. Although abundant in food resources, the limited availability of refugia in oil palm plantations may intensify intra-specific encounters and competition, altering the body size distribution in plantation populations, contrary to what happens in the forest. We conclude that large patches of forest, around and within oil palm plantations, are essential for the dynamics of the monitor lizard population in the Kinabatangan floodplain, as well as a potential source of individuals to the landscape. We recommend assessing this effect in other generalist species, as well as the impact on the prey communities, especially to reinforce the establishment of buffer zones and corridors as a conservation strategy within plantations.

Physiological implications of life at the forest interface of oil palm agriculture: blood profiles of wild Malay civets (Viverra tangalunga).

Agricultural development is a major threat to global biodiversity, and effective conservation actions are crucial. Physiological repercussions of life alongside human-modified landscapes can undermine adaptable species' health and population viability; however, baseline data are lacking for many wildlife species. We assessed the physiological status of a generalist carnivore, the Malay civet (Viverra tangalunga), persisting within an extensively human-modified system in Sabah, Malaysian Borneo. We characterized hematology and serum biochemistry panels from civets sampled across a mosaic landscape comprising tropical forest fragments and oil palm plantations. Intra-population variation in certain blood parameters were explained by expected biological drivers such as sex, age category and sampling season. Furthermore, we determined several erythrocyte measures, immune cell counts and dietary biochemistry markers significantly varied with proximity to oil palm plantation boundaries. These findings were supported by a case study, whereby blood profiles of GPS collared male civets were contrasted based on their exclusive use of forests or use of oil palm plantations. These data provide robust and valuable first insights into this species' physiological status and suggest agricultural landscapes are impacting the persisting population.

Chemical immobilization of free-ranging and captive Sunda clouded leopards (Neofelis diardi) with two anesthetic protocols: medetomidine-ketamine and tiletamine-zolazepam.

There is currently no available information regarding the veterinary management of Sunda clouded leopards (Neofelis diardi), either in captivity or in the wild. In this study, 12 Sunda clouded leopards were anesthetized between January 2008 and February 2014 for medical exams, and/or GPS-collaring. Seven wild-caught individuals were kept in captivity and 5 free-ranging animals were captured by cage traps. Two anesthesia combinations were used: medetomidine-ketamine (M-K) or tiletamine-zolazepam (T-Z). Atipamezole (0.2 mg/kg im) was used as an antagonist for medetomidine. Medetomidine (range: 0.039-0.054 mg/kg) and ketamine (range: 3-4.39 mg/kg) were administered during 5 immobilizations, resulting in median induction times of 7 min. After a median anesthesia time of 56 min, atipamezole was injected, observing effects of antagonism at a median time of 12 min. T-Z (range: 6.8-10.8 mg/kg) was administered on 7 occasions. Median induction times observed with this combination were shorter than with M-K (4 min vs 7 min; P=0.04), and anesthesia and recovery times were significantly longer (244 and 35 min vs 56 and 16 min, respectively; P=0.02). Lower heart rates were measured in the M-K group, while lower rectal temperatures were found in the T-Z group. Both combinations resulted in safe and reliable immobilizations, although given the favorable anesthesia and recovery times of M-K, we recommend this approach over T-Z for the veterinary handling of Sunda clouded leopards.

West Nile virus infection of birds, Mexico.

West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006-2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths.