Food hoarding and pilferage in rodents may be regulated by intense competition between sympatric species that have similar habitats, diets and activity, but studies exploring this remain rare. Here, we used semi-natural enclosures to investigate food-hoarding and cache pilferage interactions between sympatric Korean field mice (KFM) (Apodemus peninsulae) and Chinese white-bellied rats (CWR) (Niviventer confucianus). KFM and CWR have similar diets, habitat and nocturnal activity, but the smaller KFM larder and scatter hoards and larger CWR larder hoard only. We found that KFM harvest, larder-hoard and eat seeds at a greater intensity when CWR are present as an audience (present but cannot pilfer). KFM ate 11.5%, re-larder-hoarded 17.9% and re-scatter-hoarded 1.3% of their scatter-hoarded seeds, and ate 29.3% of their larder-hoarded seeds when CWR were present as pilferers. A total of 12.8% of the seeds scatter-hoarded and 50% of seeds directly put on the ground by KFM were pilfered by CWR. CWR did not alter hoarding intensity in the presence of KFM and their stores cannot be pilfered by KFM. These results indicate that large-sized rodent species (more dominant) significantly increase the hoarding intensity of small-sized species and show a unidirectional pilferage of seeds cached by small-sized species. The behavioural differences between these two species may reduce competition for resources and promote coexistence between sympatric rodents.
Background Pleistocene climate fluctuations have strongly modified species genetic diversity and distributions. The Chinese pangolin (Manis pentadactyla) has been recognized as a critically endangered animal due to heavy poaching and trafficking. However, the effect of Pleistocene climate fluctuations on the genetic diversity and spatial distribution of the Chinese pangolin remains largely unknown. Here, we combined whole genome sequencing data, analysis of complete mitochondrial genomes, and a large amount of occurrence data from field surveys to infer the ancestral demographic history and predict the past spatial dynamics of the Chinese pangolin in Guangdong Province, China. Results Our results indicated that there were two subpopulations, which showed similar trends of population size change in response to past climatic changes. We estimated a peak effective population size (Ne) during the last interglacial (LIG), followed by a marked decrease (~ 0.5 to fivefold change) until the last glacial maximum (LGM) and a rebound to a small peak population size during the Mid-Holocene (MH). The estimated time of the separation event between two subpopulations was approximately 3,000–2,500 years ago (ka). We estimated that the distribution of suitable areas shrank by 14.4% from the LIG to LGM, followed by an expansion of 31.4% from the LGM to MH and has been stable since then. In addition, we identified an elevational shift and suitable area decreased significantly during the LGM, but that the geographic extent of suitable areas in the western region increased from the LIG to present. The eastern region of Guangdong Province had the highest habitat suitability across all the climate scenarios. Conclusions Our results suggested that Pleistocene climate fluctuations played an important role in shaping patterns of genetic diversity and spatial distribution, and that human stressors likely contributed to the recent divergence of two Chinese pangolin subpopulations sampled here. We argue that a key protected area should be established in the eastern region of Guangdong Province. As such, this study provides a more thorough understanding of the impacts of Pleistocene climate fluctuations impacts on a mammalian species in southern China and suggests more robust management and conservation plans for this Critically Endangered species of special interest.
The flagship species conservation strategy is widely practiced in nature reserves. However, few studies have quantitatively explored whether the current functional zoning adequately conserves the habitats of other species. To examine this problem, we selected the Tangjiahe, Xuebaoding, and Wanglang national nature reserves in southwest China and tested the protective efficiency of the giant panda (Ailuropoda melanoleuca) reserves on a local herbivore-Sichuan takin (Budorcas taxicolor tibetana) in functional zoning. We predicted that the habitat distribution of the Sichuan takin with Maxent and habitat suitability would be classified as very low, low, moderately, or highly suitable. We calculated the percentage of each type of habitat class across the core, buffer, and experimental zones in these reserves and introduced an economic index present value index to further assess the efficacy of the functional zoning in conserving the habitat of Sichuan takin. Our findings indicate that suitable habitat distributions of Sichuan takin are multicore and influenced by diverse variables in different nature reserves. The percentage of moderately suitable and highly suitable habitat in the core zone is 69% and 54% in Tangjiahe, 76% and 75% in Wanglang, and 47% and 28% in Xuebaoding, respectively. The present value index of moderately and highly suitable habitat is 1.01 and 0.79 (Tangjiahe), 0.87 and 0.86 (Wanglang), 0.76 and 0.44 (Xuebaoding), respectively. The efficiency of functional zoning on Sichuan takin seems lower than imagined in giant panda reserves, and species that have important impacts on local ecosystem need further estimation and greater focus.
Anthropogenic and climatic factors affect the survival of animal species. Chinese pangolin is a critically endangered species, and identifying which variables lead to local extinction events is essential for conservation management. Local chronicles in China serve as long‐term monitoring data, providing a perspective to disentangle the roles of human impacts and climate changes in local extinctions. Therefore, we established generalized additive models to identify factors leading to local extinction with historical data from 1700–2000 AD in mainland China. Then we decreased the time scale and constructed extinction risk models using MaxEnt in a 30‐year transect (1970–2000 AD) to further assess extinction probability of extant Chinese pangolin populations. Lastly, we used principal component analysis to assess variation of related anthropogenic and climatic variables. Our results showed that the extinction probability increased with global warming and human population growth. An extinction risk assessment indicated that the population and distribution range of Chinese pangolins had been persistently shrinking in response to highly intensive human activities (main cause) and climate change. PCA results indicated that variability of climatic variables is greater than anthropogenic variables. Overall, the factors causing local extinctions are intensive human interference and drastic climatic fluctuations which induced by the effect of global warming. Approximately 28.10% of extant Chinese pangolins populations are confronted with a notable extinction risk (0.37 ≤ extinction probability≤0.93), specifically those in Southeast China, including Guangdong, Jiangxi, Zhejiang, Hunan and Fujian Provinces. To rescue this critically endangered species, we suggest strengthening field investigations, identifying the exact distribution range and population density of Chinese pangolins and further optimizing the network of nature reserves to improve conservation coverage on the landscape scale and alleviate human interference. Conservation practices that concentrate on the viability assessment of scattered populations could help to improve restoration strategies of the Chinese pangolin.
Anthropogenic and climatic factors affect the survival of animal species. Chinese pangolins are a critically endangered species, and identifying which variables lead to local extinction events is essential for conservation management. Local chronicles in China serve as long-term monitoring data, providing a perspective to disentangle the roles of human impacts and climate changes in local extinctions. Through a generalized additive model, extinction risk assessment model and principal component analysis, we combined information from local chronicles over a period of three hundred years (1700-2000) and reconstructed environmental data to determine the causes of local extinctions of the Chinese pangolin in China. Our results showed that the extinction probability increased with population growth and climate warming. An extinction risk assessment indicated that the population and distribution range of Chinese pangolins has been persistently shrinking in response to highly intensive human activities (main cause) and climate warming. Overall, the factors that cause local extinction, intensive human interference and drastic climatic fluctuations induced by global warming, might increase the local extinction rate of Chinese pangolins. Approximately 25% of extant Chinese pangolins are confronted with a notable extinction risk (0.36≤extinction probability≤0.93), specifically those distributed in Southeast China, including Guangdong, Jiangxi, Zhejiang, Hunan, Fujian, Jiangsu and Taiwan Provinces. To rescue this endangered species, we suggest strengthening field investigations, identifying the exact distribution range and population density of Chinese pangolins and further optimizing the network of nature reserves to improve conservation coverage on the territory scale. Conservation practices that concentrate on the viability assessment of scattered populations could lead to the successful restoration of the Chinese pangolin population.
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