Mammal responses to global changes in human activity vary by trophic group and landscape

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe

Fire-associated reptile mortality in Tembe Elephant Park, South Africa

BACKGROUND : Even though fire has been used extensively as part of conservation management in South Africa, its impact on the life history and mortality of fossorial reptiles is poorly documented. We conducted post-fire transects after three controlled burns during different seasons in Tembe Elephant Park, recorded 14 reptile species, and found fewer mortalities in winter compared to spring. RESULTS : Histopathological examinations of species were conducted from different microhabitats to elucidate the possible cause of death. The unburned condition of most mortality specimens prompted suspicion of particulate smoke inhalation as a possible cause of death. However, the relative absence of carbon-rich particulate matter and the occasional presence of pulmonary oedema suggested asphyxiation, heat-induced cardiac arrest, or gas intoxication as the most likely cause of death. The association of most specimens with microhabitats rich in leaf litter may indicate higher reptile densities in this habitat or increased mortalities due to smoldering detrital material, or both. Detrital combustion and smoldering may result in advective transportation of heated gasses into underlying soil layers, with subsequent increased mortalities. CONCLUSION : Even though burrowing could potentially offer protection from fire to fossorial vertebrates through vertical movements into deeper substrate, our results indicated that they are not necessarily protected from fire effects. We speculate that seasonal reproductive behavior may contribute to fire mortality. These observations may contribute to improved understanding and management of fire in areas where fossorial reptiles occur.ANTECEDENTES : Aunque el fuego ha sido extensivamente usado como parte del manejo conservativo en Sudáfrica, su impacto en la historia de vida y mortalidad de reptiles excavadores ha sido muy pobremente documentado. A través de transectas post-fuego ubicadas en tres quemas prescriptas hechas en diferentes estaciones en el Parque Nacional de Tempbe, registramos 14 especies de reptiles y encontramos menos mortalidad en quemas realizadas en invierno comparadas con quemas de primavera. RESULTADOS : Exámenes histopatológicos de las especies fueron realizados de diferentes micro-hábitats para elucidar posibles causas de mortalidad. La condición de no-quemado en la mortalidad de especímenes incitó a sospechar que la inhalación de partículas de humo podría ser una posible causa de su muerte. Sin embargo, la ausencia relativa de partículas de carbono enriquecido y la presencia ocasional de edemas de pulmón sugieren que la asfixia, el paro cardíaco como consecuencia del calor, o la intoxicación por gases serían las causas de muerte más probables. La asociación de la mayoría de los especímenes con micro-hábitats ricos en mantillo de hojas podría indicar una mayor densidad de reptiles en este hábitat, un incremento en la mortalidad debido a la combustión latente (sin llamas) del material del mantillo, o a ambos. La combustión lenta y sin llamas del mantillo puede resultar en el transporte advectivo de gases calientes hacia horizontes más bajos del suelo, con el consecuente incremento en la mortalidad. CONCLUSIONES : Aunque las cuevas usadas como refugio pueden potencialmente ofrecer protección al fuego a los vertebrados excavadores a través de movimientos verticales a sustratos más bajos, nuestros resultados muestran que no necesariamente los protegen de los efectos del fuego. Especulamos que el comportamiento reproductivo estacional puede contribuir a la mortalidad por fuego. Estas observaciones puedenhttps://fireecology.springeropen.comam2020Paraclinical Science

Neutralizing antibodies against Rift Valley fever virus in wild antelope in far northern KwaZulu-Natal, South Africa, indicate recent virus circulation

Rift Valley fever (RVF) is a zoonotic viral disease of domestic ruminants in Africa and the Arabian Peninsula caused by a mosquito-borne Phlebovirus. Outbreaks in livestock and humans occur after heavy rains favour breeding of vectors, and the virus is thought to survive dry seasons in the eggs of floodwater-breeding aedine mosquitoes. We recently found high seroconversion rates to RVF virus (RVFV) in cattle and goats, in the absence of outbreaks, in far northern KwaZulu-Natal (KZN), South Africa. Here, we report the prevalence of, and factors associated with, neutralizing antibodies to RVFV in 326 sera collected opportunistically from nyala (Tragelaphus angasii) and impala (Aepyceros melampus) culled during 2016-2018 in two nature reserves in the same area. The overall seroprevalence of RVFV, determined using the serum neutralization test, was 35.0% (114/326; 95%CI: 29.8%-40.4%) and tended to be higher in Ndumo Game Reserve (11/20; 55.0%; 95%CI: 31.5%-76.9%) than in Tembe Elephant Park (103/306; 33.6%; 95%CI: 28.4%-39.3%) (p = .087). The presence of antibodies in juveniles (6/21; 28.6%; 95%CI: 11.3%-52.2%) and sub-adults (13/65; 20.0%; 95%CI: 11.1%-37.8%) confirmed that infections had occurred at least until 2016, well after the 2008-2011 RVF outbreaks in South Africa. Odds of seropositivity was higher in adults than in sub-adults (OR = 3.98; 95%CI: 1.83-8.67; p = .001), in males than in females (OR = 2.66; 95%CI: 1.51-4.68; p = .001) and in animals collected <= 2 km from a swamp or floodplain compared with those collected further away (OR = 3.30; 95%CI: 1.70-6.38; p < .001). Under similar ecological conditions, domestic and wild ruminants may play a similar role in maintenance of RVFV circulation and either or both may serve as the mammalian host in a vector-host reservoir system. The study confirms the recent circulation of RVFV in the tropical coastal plain of northern KZN, providing the basis for investigation of factors affecting virus circulation and the role of wildlife in RVF epidemiology