Signals of forest degradation in the demography of common Asian amphibians

Meta-analysis reveals impacts of disturbance on reptile and amphibian body condition

Ecosystem disturbance is increasing in extent, severity and frequency across the globe. To date, research has largely focussed on the impacts of disturbance on animal population size, extinction risk and species richness. However, individual responses, such as changes in body condition, can act as more sensitive metrics and may provide early warning signs of reduced fitness and population declines. We conducted the first global systematic review and meta-analysis investigating the impacts of ecosystem disturbance on reptile and amphibian body condition. We collated 384 effect sizes representing 137 species from 133 studies. We tested how disturbance type, species traits, biome and taxon moderate the impacts of disturbance on body condition. We found an overall negative effect of disturbance on herpetofauna body condition (Hedges' g = -0.37, 95% CI: -0.57, -0.18). Disturbance type was an influential predictor of body condition response and all disturbance types had a negative mean effect. Drought, invasive species and agriculture had the largest effects. The impact of disturbance varied in strength and direction across biomes, with the largest negative effects found within Mediterranean and temperate biomes. In contrast, taxon, body size, habitat specialisation and conservation status were not influential predictors of disturbance effects. Our findings reveal the widespread effects of disturbance on herpetofauna body condition and highlight the potential role of individual-level response metrics in enhancing wildlife monitoring. The use of individual response metrics alongside population and community metrics would deepen our understanding of disturbance impacts by revealing both early impacts and chronic effects within affected populations. This could enable early and more informed conservation management.

Land use land cover change and socio-economic activities in the Burunge Wildlife Management Area ecosystem during COVID-19

Land use land cover change (LULCC) is among the major factors affecting the natural environment worldwide. Studying LULCC is essential as it contributes to natural resource management, biodiversity conservation, and land use planning, especially during pandemics such as COVID-19. This study aimed at assessing the trend (1995-2021) and magnitude of LULCC in the Burunge WMA ecosystem before (2015-2018) and during COVID-19 (2018-2021). The data on LULCC were collected from the satellite imagery on the USGS website, whereas the data on perceptions of local communities on LULCC from Mwada, Kakoi and Maweni villages were collected through a household questionnaire survey (HQS) of 445 randomly sampled households, focused group discussions (FGDs) and key informant interviews (KIIs). Quantitative data were analyzed using MS Excel 2019, R software (2022.02.0 + 443) and ArcGIS (Version 10.8). Qualitative data were analyzed using content analysis techniques. The findings indicated a fluctuation in agriculture, forest, and water coverage. For instance, agriculture and settlements increased significantly by 23.91% in 2015-2021 and 5.71% in 1995-2005 respectively, whereas forested land showed a maximum increase of 7.33% in 1995-2005. However, there was a pronounced increase in agricultural lands (3.99%) during the COVID-19 phase as compared to the same time frame before the pandemic. Local communities pointed to agriculture and settlements as the major activities contributing to LULCC. The findings show significant LULCC in Burunge WMA which calls for special attention from responsible authorities and other stakeholders for the achievement of biodiversity conservation and the development of livelihoods in the area.

No room to roam: King Cobras reduce movement in agriculture

BACKGROUND

Studying animal movement provides insights into how animals react to land-use changes. As agriculture expands, we can use animal movement to examine how animals change their behaviour in response. Recent reviews show a tendency for mammalian species to reduce movements in response to increased human landscape modification, but reptile movements have not been as extensively studied.

METHODS

We examined movements of a large reptilian predator, the King Cobra (Ophiophagus hannah), in Northeast Thailand. We used a consistent regime of radio telemetry tracking to document movements across protected forest and adjacent agricultural areas. Using dynamic Brownian Bridge Movement Model derived motion variance, Integrated Step-Selection Functions, and metrics of site reuse, we examined how King Cobra movements changed in agricultural areas.

RESULTS

Motion variance values indicated that King Cobra movements increased in forested areas and tended to decrease in agricultural areas. Our Integrated Step-Selection Functions revealed that when moving in agricultural areas King Cobras restricted their movements to remain within vegetated semi-natural areas, often located along the banks of irrigation canals. Site reuse metrics of residency time and number of revisits appeared unaffected by distance to landscape features (forests, semi-natural areas, settlements, water bodies, and roads). Neither motion variance nor reuse metrics were consistently affected by the presence of threatening landscape features (e.g. roads, human settlements), suggesting that King Cobras will remain in close proximity to threats, provided habitat patches are available.

CONCLUSIONS

Although King Cobras displayed individual heterogeneity in their response to agricultural landscapes, the overall trend suggested reduced movements when faced with fragmented habitat patches embedded in an otherwise inhospitable land-use matrix. Movement reductions are consistent with findings for mammals and forest specialist species.