Spatio-temporal partitioning facilitates mesocarnivore sympatry in the Stara Planina Mountains, Bulgaria

Limited spatiotemporal niche partitioning among mesocarnivores in Gorongosa National Park, Mozambique

Competition drives community composition and structure in many ecosystems. Spatial and temporal niche partitioning, in which competing species divide the environment in space or time, are mechanisms that may allow for coexistence among ecologically similar species. Such division of resources may be especially important for carnivores in African savannas, which support diverse carnivore assemblages. We used camera traps to explore patterns of spatial and temporal niche partitioning among four mesocarnivore species in Mozambique's Gorongosa National Park: large-spotted genet (Genetta maculata), African civet (Civettictis civetta), honey badger (Mellivora capensis) and marsh mongoose (Atilax paludinosus). We applied a multispecies occupancy model to evaluate spatial partitioning among mesocarnivores and to quantify the environmental factors that affect species-specific habitat use, including relative lion (Panthera leo) activity. We also analyzed the temporal activity overlap of the four focal species. We identified species-specific habitat covariates that influenced detection probabilities but found no evidence of spatial or temporal partitioning among mesocarnivores in the study system. Indeed, we found some evidence for spatial co-occurrence between two of our focal species: African civet and marsh mongoose. There may be limited competition among mesocarnivores in this system, perhaps due to niche and diet differentiation among these species and an abundance of resources. While we found limited evidence that lion activity impacts mesocarnivores, ongoing monitoring of intraguild interactions is vital as apex predator populations recover in the system. This study adds to a growing understanding of African mesocarnivore ecology and highlights the importance of understanding these dynamics for effective multispecies conservation and restoration.

Differentiation of activity rhythms and space use between two competing water shrew species in a laboratory experiment

Hypotheses about the differentiation of activity rhythms and space use between two competing species of water shrews, Neomys anomalus [AA] and N. fodiens [FF], were verified in a laboratory experiment. The animals were kept together for 2 months in an enclosure (195 × 145 cm) and their activity was video recorded using the time-lapse mode. Changes in activity rhythms, distances kept between active animals, and frequency of interspecific conflicts were compared between the early (first 24 h) and late (last 24 h, after 2 months) phases of the animals’ coexistence in the mixed group. In both phases, the activity of both species was relatively evenly distributed over 24 h, with breaks in activity nearly every 1 h. During the early phase, both species were equally and simultaneously active, whereas in the late phase, as predicted, the activity of FF was lower than that of AA, and asynchronous. In the late phase, pairs of different species (F-A) were rarely active simultaneously and kept long inter-individual distances. Consequently, the number of conflicts decreased. The results suggest that, over time, water shrews can develop mechanisms diminishing interference competition, which are based on shifts in activity rhythms, maintaining distance between individuals, and the rare usage of the same shelters and feeding sites.

Temporal Response of Mesocarnivores to Human Activity and Infrastructure in Taihang Mountains, Central North China: Shifts in Activity Patterns and Their Overlap

Mesocarnivores play essential roles in terrestrial ecosystems, but anthropocentric disturbances have profoundly transformed their intraguild interactions worldwide. In this study, we explored how a guild of four mesocarnivores (red fox Vulpes vulpes, leopard cat Prionailurus bengalensis, Asian badger Meles leucurus, and hog badger Arctonyx collaris) partition their temporal niche in the temperate montane forests in North China under different human influences. We conducted a systemic camera-trapping survey on the study species in the central Taihang Mountains from 2016 to 2020. With an extensive survey effort of 111,063 camera-days from 187 camera stations, we obtained 10,035 independent detections of the four mesocarnivores and examined the activity patterns of each species under different levels of human disturbance and their overlaps. The results showed that, while the leopard cat and the badgers shifted their activity towards nocturnality, the red fox showed no significant change. The leopard cat's degree of nocturnality varied between growing and non-growing seasons, likely a response to avoid humans and other competitors. However, the activity overlaps between species pairs demonstrated no statistically significant difference, indicating a long-developed coexistence mechanism that is homogenous across the landscape. Demonstrating how mesocarnivores shift activity patterns in response to human risks while partitioning resources, this study enhances our understanding of mesocarnivore behavioral changes and interspecific interactions at human-nature interfaces.

Spatiotemporal overlap between Siberian roe deer (Capreolus pygargus tianschanicus) and sympatric mammalian species on Jeju Island, South Korea

Analysis of spatiotemporal partitioning is pivotal to shed light on interspecific coexistence. Most research efforts have involved large-sized carnivores and their prey species, whereas little attention has been given to ungulate in the predator-free ecosystems. We assessed seasonal activity patterns and spatiotemporal overlap among the Siberian roe deer (Capreolus pygargus tianschanicus) and its sympatric species through camera-trapping from October 2017 and September 2020 in Jeju Island, South Korea. Trap events when compared seasonally, roe deer show higher activity in summer (34.9%), a pronounced low in winter (14.1%), and a moderate in autumn (23.8%) and in spring (26.9%). Roe deer exhibited bimodal activity patterns and had the highest spatiotemporal overlap and composite score with sika deer (Cervus nippon). Our results are among the few available data on the interaction of sympatric species and suggest strong overlapping with sika deer. This study provides important insight into species coexistence in predator-free habitats, which would be important for management initiatives.

A comparison of summer insectivory among four sympatric mesocarnivores on Izushima, a small island in northern Japan

Limited resources intensify interspecific competition and constrain the survival and distribution of species. A restricted, spatially isolated, small island can also pronounce this effect, as predicted in the island biogeography. This study compared the summer diets of sympatric carnivores, red foxes, raccoon dogs, Japanese martens, and Japanese weasels on the small island Izushima and evaluated niche partitioning, especially focusing on their insectivory. The results showed that insects were the main summer food source for all four species, with a significant overlap in their diets. However, in-depth investigation on insectivory down to the level of species and genera revealed that the species differences were more pronounced. Raccoon dogs frequently fed on ground-dwelling beetles, and Japanese martens fed on several arboreal beetles, while red foxes were less dependent on insects and more biased toward larger prey such as mammals and birds, and Japanese weasels foraged more on smaller prey, thereby reflecting niche partitioning between these species owing to differences in foraging ecology under the constrains of their body sizes.

Evaluating the temporal and spatio-temporal niche partitioning between carnivores by different analytical method in northeastern Japan

Temporal and spatio-temporal niche partitioning is an important strategy for carnivore coexistence. Camera-trap data has been analyzed through several methods to assess the temporal and spatio-temporal niche partitioning. However, different analytical approaches used to may evaluate niche partitioning detect different results. In this study, we evaluated the temporal or spatio-temporal partitioning among sympatric medium-sized carnivores, red foxes, raccoon dogs, and Japanese martens, based on three analytical methods-the temporal overlap, temporal co-occurrence, and time-to-encounter analysis-to evaluate. From May to October 2019 and 2020, we obtained the activity of the target species using camera-traps in northeastern Japan. We analyzed the data with the coefficient of temporal overlap, probabilistic co-occurrence analysis, checkerboard score, and multi-response permutation procedures. The results of the assessment of the niche partitioning differed depending on the analytical methods based on temporal and spatio-temporal partitioning. Therefore, we conclude that the choice of analytical approach is important for evaluating the temporal and spatio-temporal niche partitioning.

Habitat Selection and Activity Patterns of Japanese Serows and Sika Deer with Currently Sympatric Distributions

Simple Summary

Investigating the interspecific interactions between species provides a suitable model for understanding the mechanisms of coexistence between sympatric species. We assessed the spatial and temporal partitioning of spaces between Japanese serows (Capricornis crispus) and sika deer (Cervus nippon), which are usually allopatric, in an area with early-stage invasion of sika deer into Japanese serow habitat. The habitat selection and activity patterns of the two species were evaluated using camera traps. Both species were recorded in >25% of the same camera sites and showed similar selection tendencies for water resources. The Japanese serows selected steep slopes, whereas the sika deer selected areas distant from human settlements, resulting in low spatial overlap. Additionally, the Japanese serows were more active during the daytime, whereas the sika deer were active at the crepuscule. The observed spatial and temporal partitioning likely reduces their encounter rates, thereby minimizing possible interference competition. However, spatial and temporal overlaps between the two species are likely to increase as the density of sika deer increases, potentially resulting in a decline in the density of Japanese serows with smaller body sizes. Trapping for deer management should be focused on areas with gentle slopes, away from valleys and human settlements, to reduce the unintentional capture of Japanese serows.

Abstract

The Japanese serow (Capricornis crispus) and sika deer (Cervus nippon) in Japan are usually allopatric. However, a recent expansion in the distribution range of sika deer, combined with an increase in abundance, has resulted in an overlap of the distribution ranges of the two species. We examined the habitat selection and activity patterns of Japanese serows and sika deer using camera traps placed at 83 sites within a 210 km² study area, where the distribution range of these two species has recently overlapped. Although both species were photographed throughout the study area, we observed a low spatial overlap between them. The Japanese serows selected steep slopes, and the sika deer selected areas far away from human settlements. In addition, the Japanese serows and sika deer exhibited temporal partitioning with diurnal and crepuscular activity patterns, respectively. The observed partitioning could be explained by differences in their species-specific habitat selections, rather than competition, because the photographic capture rate of the Japanese serows was not affected by that of the sika deer and vice versa. These partitioning behaviors are likely to reduce the rate of encounters between the two ungulates, which enables their coexistence considering the sika deer density remains low.

The finely defined shift work schedule of dung beetles and their eye morphology

In nature, nothing is wasted, not even waste. Dung, composed of metabolic trash and leftovers of food, is a high-quality resource and the object of fierce competition. Over 800 dung beetle species (Scarabaeinae) compete in the South African dung habitat and more than 100 species can colonize a single dung pat. To coexist in the same space, using the same food, beetles divide the day between them. However, detailed diel activity periods and associated morphological adaptations have been largely overlooked in these dung-loving insects. To address this, we used a high-frequency trapping design to establish the diel activity period of 44 dung beetle species in their South Africa communities. This allowed us to conclude that the dung beetles show a highly refined temporal partitioning strategy, with differences in peak of activity even within the diurnal, crepuscular, and nocturnal guilds, independent of nesting behavior and taxonomic classification. We further analyzed differences in eye and body size of our 44 model species and describe their variability in external eye morphology. In general, nocturnal species are bigger than crepuscular and diurnal species, and as expected, the absolute and relative eye size is greatest in nocturnal species, followed by crepuscular and then diurnal species. A more surprising finding was that corneal structure (smooth or facetted) is influenced by the activity period of the species, appearing flat in the nocturnal species and highly curved in the diurnal species. The role of the canthus-a cuticular structure that partially or completely divides the dung beetle eye into dorsal and ventral parts-remains a mystery, but the large number of species investigated in this study nevertheless allowed us to reject any correlation between its presence and the nesting behavior or time of activity of the beetles.

Spatiotemporal Overlap between the European Brown Hare and Its Potential Predators and Competitors

Analysis of spatiotemporal partitioning is pivotal to shed light on interspecific coexistence. Most research effort has involved large-sized carnivores and their prey, whereas little attention has been devoted to lagomorphs. We assessed spatiotemporal overlap among the European brown hare Lepus europaeus and its potential competitors and predators through camera-trapping in an area in Central Italy. We estimated the interspecific patterns of the spatiotemporal activity rhythms of brown hares, its potential predators (the red fox Vulpes vulpes, the pine marten Martes martes, the domestic cat Felis catus, and the domestic dog Canis familiaris), and a competitor, the roe deer Capreolus capreolus. Brown hare activity was studied in natural conditions as well as in a fenced area that excluded terrestrial predators and competitors. Free-ranging hares developed a more nocturnal behavior to avoid diurnal predators (i.e., domestic carnivores and martens). Although high temporal overlap was observed between free-ranging brown hares and both red foxes (82%) and roe deer (81%), hares avoided fox by being more active on darkest nights, as well as avoided roe deer through spatial partitioning. We suggest that hares may adapt their spatiotemporal behavior to avoid potential predators and competitors.