摘要: Individual phenological life-history variations in the context of seasonal conditions are well documented in fishes and birds. However, amphibians, a group heavily affected by habitat loss and fragmentation, have received relatively little attention regarding research on life-history adaptations. Here we present 3 years of data on the timing of reproductive activity in a suburban European green toad (Bufotes viridis) population. We found annually consistent patterns of reproductive activity and investigated whether these were caused by allochrony or individual attributes. Body size (a proxy for age), body condition, and sex significantly affected the timing of reproductive activity. However, most individuals showed considerable overlap in their reproductive timeframe, refuting the existence of allochronic subpopulations. Our findings may indicate life-history adaptations in the direction of a faster lifestyle in response to hazardous environments. We propose to focus further research efforts on phenological variations in the context of environmental conditions, and that phenological variations should be considered more strongly in amphibian conservation efforts.

摘要: Understanding the genetic diversity-area relationship (GAR) is essential for comprehending how species adapt to environmental changes, as genetic diversity is an indicator of a species' adaptive potential. Variation in environmental adaptation capacity exists among species and animal taxa with different distribution areas, highlighting the importance of understanding the GAR. To obtain a more comprehensive understanding of the GAR in terrestrial vertebrates, we assessed both haplotype diversity-area and nucleotide diversity-area relationships using 25,453 cytochrome c oxidase subunit I (COI) sequences from 142 amphibian species, 574 bird species, and 342 mammal species. We found that both measures of genetic diversity increased with species range size across major animal groups. Nevertheless, the GAR did not differ among animal groups, while haplotype diversity performed better than nucleotide diversity in profiling the GAR, as indicated by higher R2 values. The difference in the modeling fit may stem from the distinct biological and mathematical significance of nucleotide diversity and haplotype diversity. These results suggest that the GAR follows similar rules among different animal taxa. Furthermore, haplotype diversity may serve as a more reliable indicator for assessing the potential effects of area size changes on animal populations and provide better guidance for conserving genetic diversity.

摘要: Artificial light at night (ALAN) is a common anthropogenic disturbance, which alters animal behavior. However, little is known about the impact of the spectral composition of ALAN and co-occurring predation risk on the behavior of aquatic organisms. We experimentally investigated how ALAN of different spectra (cool white LED and HPS light) affects the behavior and foraging of Gammarus jazdzewskii (Amphipoda) on chironomid prey, both as a single stressor and in combination with an olfactory predation cue. Gammarids exposed to ALAN in the absence of predation cues consumed less, compared with darkness, mainly due to their lower activity. Moreover, gammarids showed a stronger response to LED light, spending more time in the shelter and increasing prey handling time in this treatment. The addition of predation cues did not enhance the negative impact of ALAN on the foraging success. Gammarids maintained similar consumption levels as in the ALAN treatment without predation cues and in darkness with predation cues. However, gammarids in LED light altered their behavior in response to predation threat: they decreased prey handling time and consumed prey faster, which may have compensated for the higher food demand in stressful conditions. They also tended to exhibit risky behavior, leaving the shelter and moving towards the lit area, presumably to escape and avoid the combined effects of light and predation cues. Therefore, when assessing the effects of ALAN on organisms, light quality and co-occurring biotic factors should be considered, as predator pressure is common in natural environments.

摘要: Variation in the vocal behavior of nonhuman vertebrates includes graded transitions and more dramatic changes. Wapiti males produce a reproductive bugle that has a fundamental frequency that surpasses 2,000 Hz with evidence of biphonation and other nonlinear phenomena. Here, we analyze the acoustic structure of captive wapiti vocalizations to compare the male bugle with 3 categories of distress vocalizations: neonate distress (capture) calls, calf isolation calls, and adult female isolation calls. These 4 high-arousal call categories serve a common general function in recruiting conspecifics but occur in different behavioral contexts (capture, isolation, reproduction). Our goal was to distinguish characteristics that vary in graded steps that may correspond to an animal's age or size from characteristics that are unique to the bugle. Characteristics of the high and loud fundamental (G0) varied in an age/size-graded manner with a decrease in minimum G0, an increase in the maximum and range of G0, with no evidence of sex differences. The nonlinear phenomena of deterministic chaos, biphonation, and frequency jumps were present in all 4 call categories and became more common from the distress vocalizations of neonates to calves to adult females to the male bugle. Two temporal characteristics sharply distinguished the bugle from the 3 categories of distress vocalizations: these included a prolonged call duration and a maximum G0 that occurred much later in the call for the bugle than for distress vocalizations. Our results suggest that distress vocalizations of different age groups and the reproductive bugle of wapiti share a high G0, with age/size-graded changes in G0 and nonlinear phenomena, but differ sharply in temporal characteristics.

摘要: Portschinskia Semenov is a rare genus of bot flies whose larvae are obligate parasites of pikas and murine rodents, crucial for understanding the evolutionary biology of Oestridae. However, limited information on their adult biology and early immature stages has hindered the progress. Here, we provided the first documentation of adult oviposition, behavior, and morphology of newly hatched first instars of P. magnifica Pleske. Using confocal laser scanning microscopy and scanning electron microscopy, we characterized the ultrastructure of egg and first-instar larva, identifying key traits facilitating attachment. Eggs were deposited individually or in groups, and glued on non-host surfaces with white adhesive substances, without specialized attachment organ. Newly hatched first instars were circled with an anterior spinose band on each body segment except the anal division, awaited hosts in an upright position, and anchored to the egg shell by their anal division, likely supported by curved spines originating from the peritreme of the posterior spiracles. Evolutionary analyses of reproductive behavior across the 4 bot fly subfamilies reveal at least 3 times independent evolution of oviposition on non-host surfaces in Portschinskia or the Hypodermatinae clade as a sister group to Ochotonia, Gasterophilus pecorum (Fabricius) (Gasterophilinae), and Cuterebrinae. In contrast, species in the Oestrinae are larviparous, depositing first instars directly onto hosts. Our findings shed light on oviposition behavior and early immature morphology of the rare genus Portschinskia, offering insights into reproductive strategies and evolutionary adaptations of bot flies.

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摘要: Emitting alarm calls may be costly, but few studies have asked whether calling increases a caller's risk of predation and survival. Since observing animals calling and being killed is relatively rare, we capitalized on over 24,000 h of observations of marmot colonies and asked whether variation in the rate that yellow-bellied marmots (Marmota flaviventer) alarm called was associated with the probability of summer mortality, a proxy for predation. Using a generalized mixed model that controlled for factors that influenced the likelihood of survival, we found that marmots who called at higher rates were substantially more likely to die over the summer. Because virtually all summer mortality is due to predation, these results suggest that calling is indeed costly for marmots. Additionally, the results from a Cox survival analysis showed that marmots that called more lived significantly shorter lives. Prior studies have shown that marmots reduce the risk by emitting calls only when close to their burrows, but this newly quantified survival cost suggests a constraint on eliminating risks. Quantifying the cost of alarm calling using a similar approach in other systems will help us better understand its true costs, which is an essential value for theoretical models of calling and social behavior.

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摘要: Although mollusks represent Earth's second most diverse invertebrate group, their natural history and ecology are still scarcely known. The compilation of non-traditional data, such as those from citizen science, represents an alternative to fill these gaps, particularly on striking land snail species such as Macrocyclis peruvianus. Based on long-term citizen science, we aimed to update and describe some basic ecological aspects, such as the distribution and protected area types used by M. peruvianus. We performed pairwise comparisons to test potential changes in occurrence and occupancy among administrative regions, forest types, and protected area types using chi-squared tests. The citizen scientists were also asked to provide the number of M. peruvianus individuals observed and the tree species that dominated their habitat. Thus, we tested if the number of land snails found by citizen scientists could be related to forest and protected area types using a generalized linear mixed model. We expanded the northern distributional limit, with Nothofagus, evergreen, and mixed forests far the most frequented by M. peruvianus. Parallelly, the occurrence of M. peruvianus in official protected areas (65.73%) was significantly higher than in privately owned areas. Moreover, we did not find associations between forest and protected area types with the number of M. peruvianus recorded. Although citizen science is a helpful method for obtaining novel information regarding the ecology of neglected species such as M. peruvianus, it also introduces spatial and occurrence biases explained by the access and attractiveness of the officially protected areas compared to privately owned patches of native forest.

摘要: Dispersal is an important life history trait with significant consequences for spatially structured populations, as the exchange of individuals between habitat patches is crucial for maintaining metapopulation connectivity. In this study, we used a long-term data set (2005-2023) to describe dispersal patterns in a patchy population of the Western Yellow Wagtail Motacilla flava within a large (approximately 1,300 km2) study area in the boreal zone of European Russia. We quantified dispersal distances for birds that dispersed outside their natal or breeding habitat patches and applied a multistate capture-recapture approach to estimate natal and breeding dispersal probabilities. Of 395 adult wagtails and 1,610 nestlings ringed, 3% of birds ringed as adults and 3% of birds ringed as nestlings were resighted outside their natal or breeding patches. The probability of natal dispersal (0.29 +/- 0.05) was significantly higher than the probability of breeding dispersal (0.05 +/- 0.01). The median natal dispersal distances (2.8 km for males, 3.9 km for females) were the same as the median breeding dispersal distances (2.7 km for males, 3.9 km for females). We did not find a significant effect of the fledging date on either the natal dispersal distance or the natal dispersal probability. Similarly, we did not find a significant effect of the previous reproductive success on either the breeding dispersal distance or the breeding dispersal probability. Our results indicate that strong breeding site fidelity and short-distance natal dispersal are the dominant dispersal strategies in a patchy population of the western yellow wagtail.