Figure - uploaded by Kanishka Ukuwela
Content may be subject to copyright.
Morphometric Measurements (mm) and the Sex of Nannophrys marmorata Specimens Observed from the VRR Sanctu- ary, Sri Lanka
Source publication
Nannophrys marmorata is a critically endangered species of frog known only from a few locations in the Knuckles Conservation Forest (KCF) in the Knuckles mountain range of Sri Lanka. Here, we report new localities outside its known range in the KCF and examine the distribution of N. marmorata providing the most extensive distribution map for this s...
Context in source publication
Similar publications
Groundwater-dependent vegetation (GDV) is threatened globally by groundwater abstraction. Water resource managers require maps showing its distribution and habitat preferences to make informed decisions on its protection. This study, conducted in the southeast Pilbara region of Western Australia, presents a novel approach based on metrics summarisi...
Citations
... Species in tropical montane regions may be especially vulnerable to climate change because they are expected to move upwards, since altitudinal migration changes environmental conditions much more frequently than latitudinal migration in the tropics (Freeman and Freeman, 2014), and there will be progressively less area to move into at the tops of mountains (Rahbek et al., 2019). Yet few studies have been conducted on Sri Lankan biodiversity using SDM (Bandara et al., 2022;Rupasinghe et al., 2021;Karunarathna et al., 2021;Ukuwela et al., 2020), and only a few of them have included future predictions (Amarasinghe et al., 2021;De Mel et al., 2023;Wijerathne et al., 2024). ...
Rapid climate change and ongoing habitat destruction pose a serious threat to global biodiversity. Understanding how species shift their geographical distributions in response to climate change is important for planning conservation actions for the biodiversity of isolated islands like Sri Lanka. Here, we used Maximum Entropy (MaxEnt) modeling to predict current and future (by 2100) distributions of 233 vertebrate endemics to Sri Lanka under three general circulation models of the atmosphere (GCMs) and three shared socioeconomic pathways (SSPs). We used six bioclimatic layers, together with land use, human population, elevation, and the distance to water, as environmental factors for SDMs. Resultant maps were used to calculate the area of habitat (AOH) of each species. Using general linear mixed models, we identified a significant influence of GCM, SSP, and current elevation on the change in AOH. The southwestern wet zone and the montane areas of Sri Lanka were found to be the most suitable regions for the species currently and in the future. However, all climate change scenarios indicated endemic species extinctions, which may be proportionally fewer for mammals and birds, but are expected to occur for all SSPs in amphibians and reptiles, ranging from 1.4%-22.5% of these taxa in SSP5. Also, species declines were specific and severe at higher elevations. Our study highlights the risk to montane endemic vertebrates, yet given the vulnerability of the wet zone to urbanization, even lowland endemic species face an uncertain future.
... The use of SDMs, however, has provided relevant bases for their conservation (de Magalhães et al., 2017;Mayani-Par as et al., 2019;Préau et al., 2018;Zellmer et al., 2020). Furthermore, SDMs have promoted the search and description of new populations (Groff et al., 2014;Loebmann et al., 2017;Ukuwela et al., 2020), allowing a better assessment of species conservation status (Cruz-Elizalde et al., 2020;Gascon et al., 2007). Therefore, it is not surprising that an increased number of studies using these tools are attempting to project the potential distribution of amphibian species (e.g., Zellmer et al., 2020). ...
Species Distribution Models have emerged in recent decades as a powerful tool for biodiversity research, as they allow, for example, assessing the status of species in their whole distributions. These models have been particularly helpful in demonstrating that amphibian populations are at high risk, with many declining and others already extinct. Here, we assessed the potential distribution of the helmeted water toad (Calyptocephalella gayi), an endemic Chilean amphibian considered a living fossil and cataloged as vulnerable, which requires significant conservation efforts. We modeled the species' potential distribution using the Maximum Entropy (Maxent) approach and determined the overlap with national protected areas. In addition, we conducted a geospatial risk analysis to estimate the threat level to which this toad is being subjected. The potential distribution of C. gayi ranges from 28 S to 44 S, mainly explained by altitude, mean diurnal temperature range, slope, and distance to water bodies. Protected areas only cover 3.55% of the species' potential geographic distribution, which is of concern, considering that the geospatial risk analysis showed that 60.61% of C. gayi's distribution is subjected to extreme and high risks. We discuss how these results are relevant to focusing and directing efficient protection and conservation efforts for this species shortly. K E Y W O R D S amphibian conservation, Calyptocephalella gayi, endemism, geospatial risk analysis
... Ample studies of species distribution modeling have been conducted on various aspects throughout the world such as the identification of conservation targets for robust conservation planning (Escalante et al., 2013;Johnson and Gillingham, 2005), estimation of current and future distribution of conservation-dependent and rare species (Abdelaal et al., 2019), and forecasting their future distribution ranges in response to climate change (Ding et al., 2021). But, there are only a few published studies in Sri Lanka that have focused on species distribution modeling (Amarasinghe et al., 2021;Bandara et al., 2022;Nekaris et al., 2015;Ukuwela et al., 2020) using MaxEnt approach (Phillips, 2010). ...
... Several applications of species distribution modeling for estimating the current and future distribution of species (Eneanya et al., 2018;Thuiller et al., 2004;Zhang et al., 2020), identifying potential threats, and recommending conservation management plans are widely used in avian conservation (Hitch and Leberg, 2007;Jiménez-Valverde et al., 2011;Maclean et al., 2008;Pattinson et al., 2022) and for researching on other species (Chen et al., 2011;Hughes, 2017;Perry et al., 2005) Ukuwela et al., 2020), despite significant progress in other tropical humid nations within, the Indo-Malayan region (Sourd and Gautier-Hion, 1986). The limited use of SDMs in Sri Lanka can be attributed to factors such as insufficient georeferenced data and biases in species occurrence records (Graham et al., 2008) which are freely available on websites, as well as the lack of open-access nationwide geospatial layers. ...
There is ample evidence for the impacts of recent climatic changes on ecology. Climate plays a
major role in the population dynamic of birds. Hornbills are confined to Asia and Africa with only
two species present in Sri Lanka. In this study, we utilized field observations and filtered e-bird
records to generate current and future climatic models for the two hornbill species in Sri Lanka
(Ocyceros gingalensis and Anthracoceros coronatus). Critical reduction of predicted ecological
niches was observed in Anthracoceros coronatus throughout the period considered (2000–2100).
Special conservation interventions are required for these two species. However, predicted suitable
ecological niches for the Ocyceros gingalensis show little reduction towards the wet zone of Sri
Lanka. This shift in species distribution boundaries coincides with periods of global warming
suggesting a possible connection. This study provides supporting evidence for the possible influence
of climate change on hornbill species distribution.
Bats perform critical ecosystem functions, including the pollination, seed dispersal, and regulation of invertebrate populations. Yet, bat populations are declining worldwide primarily due to habitat loss and other anthropogenic stressors. Thus, studies on bat ecology, particularly on environmental determinants of bat occupancy, are paramount to their conservation. High mobility, nocturnal behavior, and roosting site selection of bats make conventional surveys challenging. Moreover, little is known about geographic distribution, habitat suitability, and responses to climate change among tropical bat species. To bridge these research gaps, we applied ecological niche modeling to two Ceylonese bat species, Kerivoula malpasi and Kerivoula picta, to map their geographic distribution. Seasonal variations in temperature and precipitation were critical environmental predictors of bat distribution in general. Southwestern lowland forests contained the most optimal habitats for the relatively wide-ranging Kerivoula picta, while the central highlands provided the most suitable habitats for the narrow-ranging Kerivoula malpasi. No tangible changes in the highly suitable habitats were evident in response to projected climate change for either species. Yet, the optimal ranges of K. malpasi can become fragmented in the future, whereas the most optimal habitats for K. picta are likely to become spatially contiguous in the future. Habitat availability or fundamental niche alone is insufficient to reliably forecast species persistence, thus we caution against considering these two bat species as resilient to climate change. Our findings will enable the conservation authorities to initiate preemptive conservation strategies, such as the establishment of landscape-scale habitat connectivity and management of buffer zones around conservation lands. We also encourage conservation authorities to employ ecological niche models to map potential species distributions and to forecast range shifts due to climate change.
