Evaluation of Human Disturbance on the Activity of Medium–Large Mammals in Myanmar Tropical Forests

Abstract

The effects of human disturbance represent one of the major threats for wildlife conservation. Many studies have shown that wildlife avoids or reduces direct contact with human activities through changes in activity patterns, and by minimizing spatiotemporal overlap. In this study, we investigated the possible effects of human presence on the temporal activity of medium-to-large mammals using two areas in Myanmar that differ in the intensity of human disturbance. We monitored temporal segregation mechanisms using camera trapping data and with two statistical approaches: daily activity overlaps between humans and wildlife and circular statistics. We did not find a significant difference in overlapping activity between areas but, thanks to circular statistics, we found that some species show changes in activity patterns, suggesting temporal avoidance. We observed that the daily activity of five species differed between areas of Myanmar, likely adopting mechanisms to reduce overlap in areas highly frequented by humans. Interestingly, these species are all threatened by hunting or poaching activities, four of which have been described in literature as “cathemeral”, or species that are active through day and night. This study suggests that some species adapt their behavior, at least partially, to avoid human presence in habitats with higher anthropic occurrence and increase our knowledge on the status of medium–large mammals in a poorly studied country as Myanmar.

Camera Trapping to Assess Status and Composition of Mammal Communities in a Biodiversity Hotspot in Myanmar

“…A separate consideration concerns humans, whose presence was recorded by a considerably higher number of detections in the RYER (3109) compared to the HWS (96), with significantly higher occurrence and detectability values. This fact confirmed that the RYER is more disturbed, dealing with not only "chronic" disturbance effects like habitat degradation and fragmentation but also "acute" disturbance conditions due to the high rate of human presence in the forests that can affect species in many ways, as documented for this area with a significant effect on some species activity patterns [25]. As we said previously, we are aware that the two areas were distant from each other, meaning that some community patterns could be related to differences in geographical and landscape features and not only to human disturbances.…”

“…In this study, we analyzed the status of two mammal communities in two geographically distinct areas in Myanmar that are similar in climate, elevation, and habitat types but have sharp differences in their levels of habitat degradation and human disturbance. We used camera trap data to evaluate both biodiversity levels (estimated species richness) and some ecosystem functions such as trophic niches and body mass in two different contexts: a well-preserved and mostly untouched evergreen forest and a degraded and fragmented forest with a high level of human pressure [25]. It is important to increase our knowledge of the status of communities and species because no previous studies, with a structured monitoring scheme, have been done in these study areas.…”

“…The biodiversity of the two areas is known to be high and variegated [26,34] with many shared species, as well as some differences given by the geographical distance and landscape features. Both areas have been poorly studied: in particular, there have been few studies on the possible impacts of the constant and intense human presence in the RYER [25].…”

“…In this study, we focused on two poorly studied areas of Myanmar with two different conditions: one area in Sagaing (North Myanmar) is located inside a protected area (PA), with an efficient management regime and a well-preserved continuous evergreen forests. The other, in Rakhine (West Myanmar), is close to the border of a PA and located in a coastal area, with a strong presence of human activity in the surrounding forests [25]. Both areas support a rich biodiversity including key species for the maintenance of ecosystems like large herbivores such as the Asian elephant (Elephas maximus) or gaur (Bos gaurus), apex predators such as Indochinese tiger (Panthera tigris), two bear species (sun bear (Helarctos malayanus) and Asiatic black bear (Ursus thibetanus)), and two critically endangered pangolins species (Manis javanica and Manis pentadactyla) [26,27].…”

Behavioral states in space and time: understanding landscape use by an invasive mammal

“…Proclivity for exploratorytype activities (e.g., foraging) during the daylight hours was somewhat unexpected, though the exploratory behavioral state featured low movement potentially allowing individuals to remain active and undetected. Other studies reported diurnal activity in wild pigs, particularly in areas where animals are less likely to experience disturbance (Keuling et al 2008a, Podgórski et al 2013, Cremonesi et al 2021). Our study area was primarily forested with substantial understory cover, potentially limiting human disturbances and providing enough concealment to facilitate modest diurnal activity.…”