Temporal activity patterns suggesting niche partitioning of sympatric carnivores in Borneo, Malaysia

To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed temporal activity patterns of the sympatric carnivore species using 37,379 photos collected for more than 3 years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each time period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felid, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species with similar morphology and ecology did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least 2 or 3 years is necessary to understand animals’ temporal activity patterns, especially for sun bears and civets, by camera-trapping and to establish effective protection measures.

Quantitative Research Methods of Linguistic Niche and Cultural Sustainability

Building Sustainable Cities and Human Communities is one of the 17 Sustainable Development Goals of the United Nations. And the sustainability of culture plays an important role in the sustainable development of cities and human communities. Language is an important carrier of culture, and the sustainability of language is the key factor in the sustainability of culture. How to measure the sustainability of language and its niche is key to achieving sustainable cities and communities. This paper systematically summarized the concept of niche and the theory of ecolinguistics as a theoretical basis for the quantitative study of the linguistic niche, and at the same time, the methods of niche measurement were summarized to provide mathematical support for the quantitative study of the linguistic niche. The Shannon-Wiener index and Pianka index were used to quantitatively study a particular linguistic niche for the first time, based on the use of Hmong and Mandarin in Jianhe County, Guizhou Province, China. The results showed that in the temporal dimension, the niche overlap indexes of Hmong and Mandarin were all above 0.9 in the sample villages, but in the spatial dimension, the niche overlap indexes of both languages were between 0.5 and 0.6. The spatial niche separation moderated the high temporal niche overlap, which made the two languages’ spatio-temporal niche overlap moderate. The quantitative study of a linguistic niche proved helpful in quantifying the level of sustainable development of language and culture, thus providing timely, accurate, and dynamic reference data to inform macro-control policies on the sustainable development of cities and human communities.

Temporal Activity Patterns of Sympatric Bornean Carnivore Species: Implications for Niche Partitioning and Conservation

To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed their temporal activity patterns using 37,379 photos collected for more than three years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felids, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least three years is necessary to understand animals’ temporal activity patterns by camera-trapping and to avoid diverting conservationists away from effective protection measures.

Temporal niche partitioning as a novel mechanism promoting co-existence of sympatric predators in marine systems

Niche partitioning of time, space or resources is considered the key to allowing the coexistence of competitor species, and particularly guilds of predators. However, the extent to which these processes occur in marine systems is poorly understood due to the difficulty in studying fine-scale movements and activity patterns in mobile underwater species. Here, we used acceleration data-loggers to investigate temporal partitioning in a guild of marine predators. Six species of co-occurring large coastal sharks demonstrated distinct diel patterns of activity, providing evidence of strong temporal partitioning of foraging times. This is the first instance of diel temporal niche partitioning described in a marine predator guild, and is probably driven by a combination of physiological constraints in diel timing of activity (e.g. sensory adaptations) and interference competition (hierarchical predation within the guild), which may force less dominant predators to suboptimal foraging times to avoid agonistic interactions. Temporal partitioning is often thought to be rare compared to other partitioning mechanisms, but the occurrence of temporal partitioning here and similar characteristics in many other marine ecosystems (multiple predators simultaneously present in the same space with dietary overlap) introduces the question of whether this is a common mechanism of resource division in marine systems.

Bird activity patterns in the understorey of an evergreen forest in Oaxaca, Mexico

Activity patterns of species are related to their physiology, their behaviour and the environment and can change in response to different factors, such as interactions between species. Bird species, typical of the understorey, show morphological and ecological similarities and must thus have some mechanism of ecological separation, such as temporal niche partitioning. The objective of this study was to provide information about activity patterns and activity overlap of bird species typical of the understorey. We expected temporal niche partitioning between ecologically-similar species. We placed camera traps in 29 sampling points in a high evergreen forest in the southeast of Mexico between 2011 and 2013. All species were mainly diurnal and, contrary to what we expected, there was temporal partitioning between tinamids, but not in galliforms and columbiforms. The degree of activity overlap might reflect a solitary or group lifestyle of the three sets of species, as well as shared behavioural preferences and similar adaptations. These results contribute to our knowledge of the basic biology and behavioural ecology of birds of the understorey.

Circadian activity patterns of mammalian predators and prey in Costa Rica

Temporal niche shifts can shape predator–prey interactions by enabling predator avoidance, enhancing feeding success, and reducing competition among predators. Using a community-based conservation approach, we investigated temporal niche partitioning of mammalian predators and prey across 12 long-term camera trap surveys in the Pacific slope and Talamanca Cordillera of Costa Rica. Temporal overlap and segregation were investigated between predator–prey and predator–predator pairs using overlap analysis, circular statistics, and relative abundance after accounting for differences in habitat, season, and human impact among sites. We made the assumption that predators select abundant prey and adjust their activity to maximize their temporal overlap, thus we predicted that abundant prey with high overlap would be preferred prey species for that predator. We also predicted that similar-sized pairs of predator species with the greatest potential for competitive interactions would have the highest temporal segregation. Our results supported the existence of temporal niche separation among the eight species of predators—the smaller Leopardus felids (ocelot, margay, oncilla) were primarily nocturnal, the largest felids (jaguar and puma) and coyote were cathemeral, and the smaller jaguarundi and tayra were mostly diurnal. Most prey species (67%) were primarily nocturnal versus diurnal or cathemeral (33%). Hierarchical clustering identified relationships among species with the most similar activity patterns. We discuss the primary prey and competitor species predicted for each of the eight predators. Contrary to our prediction, the activity pattern of similar-sized intraguild competitors overlapped more than dissimilar-sized competitors, suggesting that similar-sized predators are hunting the same prey at the same time. From this we conclude that prey availability is more important than competition in determining circadian activity patterns of Neotropical predators. Our results indicate the presence of a delicate balance of tropical food webs that may be disrupted by overhunting, leading to a depauperate community consisting of ubiquitous generalists and endangered specialists. With Central America a hotspot for hunting-induced “empty forests,” community-based conservation approaches may offer the best road to reduce illegal hunting and maintain the biodiversity and community structure of tropical forest systems.