Journal of Zoology最新文献

Species are the most commonly used unit of biogeography research, and in many conservation schemes. For many faunal groups, taxonomy is in a constant state of flux, with new species being described, and our concept of existing species regularly being refined. Using the most diverse lineage of Australian lizards (460+ species), the skinks (Family Scincidae), we quantified the impacts of taxonomic changes over time on our understanding of species richness, endemism and beta diversity. We generated surfaces of species richness, endemism and beta diversity from four editions (1975, 1988, 2000, 2014) of an authoritative field guide to understand how taxonomic shifts, and enhanced biogeographic knowledge, influenced the inferred biogeographic patterns in Australian skinks. The number of recognized Australian skink species has increased 2.3-fold since 1975. The Wet Tropics was the major hotspot for (mostly locally endemic) species additions. Hotspots of species richness and beta diversity remained broadly similar over time, but some important local hotspots shifted. Endemism hotspots were weakly associated with hotspots of species additions over time except in the Wet Tropics. The major shifts in biogeographic patterns, which were not associated with taxonomic changes, resulted from better knowledge of species distributions through time. We hypothesize that the effects of taxonomy on biogeographic patterns we found generalize across clades and regions—especially away from major research hotspots. We suggest an understanding of the impact of taxonomic changes on conservation priorities for particular regions and taxonomic groups is needed.

Urban habitats differ from natural environments, however some predatory species have become established in cities across the globe. The aim of our study was to compare the occurrence of the red fox and the stone marten in Warsaw during three time periods (1976–1978, 2005–2008, 2015–2021) and in different habitats. Generalized linear models were used to show factors affecting the density indices of these two species (i.e., frequency of occurrence of tracks of each species recorded during snow tracking on linear transects). The frequency of occurrence of tracks of these two species on transects increased over time and was explained by habitat type and distance from the city centre. The frequency of fox tracks was higher in more-natural habitats located far from the city centre. In the first period (1976–1978), this species was recorded only in forests and riparian areas. In the last period (2015–2021), its tracks were recorded frequently in built-up areas and cemeteries. From the beginning of the first period, the stone marten was recorded in a wider range of habitats than the fox and it colonized all habitat types in the subsequent periods, but a statistically significant increase was observed only for cemeteries. The frequency of occurrence of stone marten tracks was lower than that of red fox tracks in most natural and seminatural habitats (forests, parks, riparian areas). No relationship between the occurrence of the red fox and the stone marten was found. We speculate that the growth of the urban red fox numbers was driven by an increase in the national population as a result of anti-rabies vaccinations. In turn, the stone marten, being a synanthropic species, was present in the city centre from the beginning of the study, but it now occurs in a wider range of habitats.

Daily activity patterns of free-ranging wildlife affect a wide range of ecological and physiological processes and, in turn are affected by anthropogenic disturbances to the environment. However, obtaining a continuous record of activity without disturbing wild animals is logistically challenging. We used commercially available, multi-purpose light-level geolocator dataloggers to continuously record light environment and time spent out of water during 5-months (1 May to 9 September 2021) in an ectothermic freshwater turtle species, the northern map turtle (Graptemys geographica). We used these data to compare time of year and sex differences in thermoregulatory behavior in an ectothermic species in its natural habitat. We recorded >500 000 data points from 17 individual turtles (nine males and eight females). We found no differences in the mean light levels, or proportion of time spent out of the water, between males and females. However, there was a significant effect of both time of year and sex by time of year interaction in both light level, proportion of time spent dry, and number of state changes (i.e., shuttling behavior, wet to dry or dry to wet), suggesting that turtles alter their aerial basking behavior over the course of the season and that the changes in patterns of aerial basking behavior differ between the sexes throughout the year. In general, the proportion of time spent dry decreased over the active season, with an increase during the last week of June and the first week of July, while the number of state changes increased in females during late May/early June before decreasing, while males remained relatively constant. These changes may reflect the different energetic demands associated with reproduction between the two sexes. The overall downward trend in aerial basking likely reflects the role of increasing environmental temperatures, particularly water temperature, in the maintenance of body temperature in this largely aquatic species.

Coloration is crucial for ambush mesopredators' survival as they depend on it for camouflage to hunt and avoid predation. Furthermore, coloration is especially important in ectotherms as it is linked to two essential functions for survival: thermoregulation and crypsis. In a context of trade-offs between thermoregulation and crypsis, the comprehension of how ectotherms employ color to address conflicting demands of thermoregulation and crypsis is limited. This study investigated background matching and thermoregulation in western diamond-backed rattlesnakes (Crotalus atrox). Rattlesnakes were predicted to better match selected microhabitats in terms of color, luminance, and pattern than random microhabitats within their home range, and body temperature was predicted to influence their body coloration with higher temperatures favoring lighter colors. Pictures of 14 radiotracked western diamond-backed rattlesnakes were taken in situ with a full spectrum camera (UV/VIS) and body temperature was recovered from internal temperature-datalogging radiotransmitters. Crotalus atrox matched the color, luminance, and pattern of the background better than a randomly selected background, thus enhancing background matching. Additionally, rattlesnake coloration varied independently of temperature indicating that rattlesnakes are behaviorally modifying crypsis regardless of thermoregulation.

Understanding how fecal glucocorticoid (GC) concentration is associated with reproduction in wild animals allows us to associate physiological stress with the costs of reproduction. Glucocorticoids are among the main stress-related hormones, and their secretion is strongly associated with reproductive seasonality. Using non-invasive methods (thereby avoiding causing stress), we used fecal GC metabolites (FGC) to test the hypothesis that the reproductive phase (mating, non-mating, gestation, and lactation) influences stress levels of the seasonally reproductive Pampas Deer (Ozotoceros bezoarticus). Furthermore, we compared FGC between sexes and between males of different antler statuses (velvet, hard, cast). During 1 year, in the Pantanal of Brazil, we collected 621 fresh fecal samples (327 from females, 294 from males) from which we estimated FGC using enzyme immunoassay (EIA). FGC concentrations varied by reproductive phase and antler status. Agonistic and courtship interactions associated with mating (i.e., fights between males, attempts to mount females), suggest that they influence FGC concentrations most strongly in both sexes. Females also had greater FGC concentrations during lactation, suggesting that this phase and parental care are also associated with increased physiological stress. In males, the association of FGC concentrations with antler status may be, in part, associated with photoperiod and testosterone secretion, both of which can trigger reproductive and agonistic behaviors. Finally, reproductive synchrony of the sexes causes similar FGC over time and suggests that environmental factors contribute as well. We show that non-invasive monitoring of glucocorticoid metabolites levels is an effective tool for detecting changes in the physiological stress response in Pampas Deer, suggesting that this tool will be useful for detecting changes in physiological stress caused by human disturbance, such as cattle ranching in Pantanal and similar disturbances elsewhere.

Animal groups are often composed of individuals with differences in their phenotypes (e.g. body size, personality, or internal nutritional state). Such differences in phenotypes between group mates can have significant consequences for the collective movement and behavior of a group. Here, we examined the effects of nutritional state and ecological context on the individual- and group-level behaviors of groups of shoaling goldfish (Carassius auratus) across an open water environment, an environment with food, and an environment with food and refuge. Fish were randomly manipulated to be in one of three nutritional states (control: fasted for 24 h, fasting: fasted for 1 week, and digestion: 2 h after feeding) and comprised five group compositions: the all-control (6 control fish), all-fasting (6 fasted fish), all-digestion (6 digesting fish), mixed con–fas (3 control fish and 3 fasted fish), and mixed con–dig treatment (3 control fish and 3 digesting fish). We found that compared to the control and fasted treatments, the fish in the digestion treatment had lower individual swimming speeds and nearest neighbor distances. However, group polarization was lower in the fasted treatment than in both the control and digestion treatments. For the two mixed treatments, individual and collective behaviors of the fish seemed to be intermediate in comparison to those of either the fasted or digestion treatments. Moreover, group-level differences in collective behaviors were maintained across different contexts. All five treatments exhibited considerable context-associated changes in collective behaviors, but behavioral repeatability was dependent on the nutritional state of the group composition. Our results suggest that nutritional state and ecological context influence both individual and collective behaviors and that fasting and digestion exert opposite effects on collective behaviors across ecological contexts.

The freshwater snail Latia neritoides occurs in certain streams and lakes of New Zealand's North Island. It defends itself against predators with a unique mechanism – the release of sticky, glowing mucus. Two possible origins of this defence mucus had earlier been suggested: the foot and the pneumostome area. After examining the glandular system of the foot in a previous study, in the present study we examined the general morphology of L. neritoides, focusing on the mantle cavity. With the first complete 3D model of L. neritoides now available, it is possible to evaluate previous morphological studies and to give non-specialists a better understanding of the soft part anatomy of this fascinating gastropod. As a by-product of this, we also compared the capabilities of μ-CT and HREM on a methodological level. We characterized the two most common gland types in the mantel cavity (Lmcg1/Lmcg2) on the basis of their ultrastructure. They are present in large numbers and, therefore, regarded as likely candidates for being the producers of one or more components of the defence mucus. This notion was confirmed by histochemical analyses of Lmcg1 and Lmcg2 and other gland types in L. neritoides.

Juvenile situational experiences that animals are exposed to different environmental conditions have the potential to shape the developmental trajectory of individuals, influencing their personality traits, anxiety level, cognition, and memory. However, empirical evidence regarding these effects remains limited. In this study on male Brandt's voles (Lasiopodomys brandtii) undergoing weaning process, we examined the consequences of juvenile situational experiences on their behavioral development, involving daily exploration of newly introduced objects with a diverse array of materials, shapes, sizes, and colors. The results showed that (1) the situational experience improved spatial cognition and memory, as evidenced by significantly higher scores in both the recognition index during test period (RIB) and the discrimination index during test period (DI) compared to the control group; (2) no significant differences were observed in autonomic activity between the two groups, including total distance traveled, resting time, mean speed, maximum speed, and duration of slow and fast movements across the entire arena; (3) situational experience reduced anxiety levels, indicated by increased exploration of the center area, more transitions between zones, shorter latency to enter the center zone, prolonged resting time in the center area, and greater total time spent and distance moved in the center area; and (4) the situational experience group exhibited significantly higher individual personality scores compared to the control group. In conclusion, our results imply that juvenile situational experience exerts significant positive effects on spatial cognition and memory, anxious behavior, and personality development in L. brandtii. These insights offer novel perspectives on the long-term impacts of juvenile situational experiences on adulthood, with potential applications in addressing mental health and behavioral anomalies. Additionally, our study provides practical implications for animal management and environmental enrichment strategies.

Subterranean rodents of the genus Ctenomys typically occupy fragmented habitats, many currently altered by anthropogenic development. These changes affect functional connectivity among individuals, reducing gene flow levels. This study assessed the functional connectivity of two sympatric species of subterranean rodents, Ctenomys australis and Ctenomys talarum, examining the impact of landscape changes on their population genetic structure at a fine spatial scale. We conducted a spatially continuous sampling over 12 km of coastline in Southeastern Buenos Aires Province, Argentina, genotyping 91 and 106 individuals of C. australis and C. talarum, respectively, using 10–12 microsatellite loci. We applied various spatial layers characterizing both species' habitats to evaluate the landscape configuration's effect on individual gene flow. We employed Bayesian genetic clustering methods to infer population structure levels. Ctenomys talarum showed greater structure than C. australis. NDVI temporal variation was the main factor influencing C. australis' genetic structure, whereas suitable habitat, linked to the current landscape configuration, was the most significant factor in shaping C. talarum's genetic structure. Differences in dispersal capacity and habitat specificity appear to have influenced the population genetic structures of these species. The results indicated varying sensitivities to landscape changes; temporal landscape variations primarily impacted C. australis' genetic connectivity, whereas for C. talarum, the current landscape configuration was more influential.

Otherwise, apparently cryptic mammals often have conspicuous patches of colour on distal regions of their body, possibly for signalling. To investigate ideas about communication within sociosexual contexts, we used a comparative dataset for 2726 terrestrial mammals to match the coloration and patterning of distal body areas (head, chest, rump and tail) to activity cycle, group size, sexual size dimorphism, mating system and congener overlap at both Class and Order levels. Using phylogenetic controls, we uncovered repeated associations between white colour patches and nocturnality, conspicuous rump patches and sexual selection and multicoloured, complex patterning on distal regions of the body being associated with small group size. Overall, however, we found rather few associations between conspicuous coloration and behavioural, social and morphological variables, suggesting that visual signalling is not a key driver of communication in mammals, perhaps because the majority are nocturnal and solitary, and rely on olfactory signalling.