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Few mammalian species produce vocalizations that are as richly structured as bird songs, and this greatly restricts the capacity for information transfer. Syntactically complex mammalian vocalizations have been previously studied only in primates, cetaceans and bats. We provide evidence of complex syntactic vocalizations in a small social mammal: the rock hyrax (Procavia capensis: Hyracoidea). We adopted three algorithms, commonly used in genetic sequence analysis and information theory, to examine the order of syllables in hyrax calls. Syntactic dialects exist, and the syntax of hyrax calls is significantly different between different regions in Israel. Call syntax difference is positively correlated to geographical distance over short distances. No correlation is found over long distances, which may reflect limited dispersal movement. These findings indicate that rich syntactic structure is more common in the vocalizations of mammalian taxa than previously thought and suggest the possibility of vocal production learning in the hyrax.

Amphibians are among the most threatened taxonomic groups worldwide. A fundamental step in species conservation is identifying the habitat requirements of the target species. However, this determination can often be problematic in endangered species because, by definition, they often only occupy a very limited number of sites. Moreover, when found, they are often in low abundance, and thus their detectability is low, yielding false “absence” data. Maximum entropy niche modeling provides a tool using only the presence data to predict potential habitat distributions of endangered species whose distributions have become highly limited. We provide two examples in the current study for the fire salamander, Salamandra infraimmaculata , and the green toad, Bufo viridis . S. infraimmaculata  is considered endangered in Israel and near endangered worldwide. B. viridis is classified as locally endangered in Israel. Soil type was the most important predictor of the distribution of S. infraimmaculata and, to a lesser extent, also predicted the distribution of B. viridis . In addition, S. infraimmaculata larvae were also associated with high elevation areas. B. viridis was negatively associated with distance to urban areas and low solar radiation level. The potential distribution maps determined for S. infraimmaculata and B. viridis can help in planning future wetland use management around its existing populations, discovering new populations, identifying top-priority survey sites, or set priorities to restore its natural habitat for more effective conservation.

In ephemeral streams, floods can temporarily connect isolated pools and provide otherwise spatially restricted organisms with the option to stay in or leave a pool. A field survey of the middle-eastern fire salamander (Salamandra infraimmaculata) larvae demonstrated that 18% disappeared from pools during high-discharge events, and ∼2% were found subsequently in downstream pools. We conducted indoor experiments to test whether larvae alter drift rate in response to different velocities and perceived risk of predation. We manipulated flow velocities within the range of natural ephemeral streams during floods. Anesthetized larvae (passive drifters) drifted out of a central pool faster than conscious larvae at low velocities but not at high velocities, suggesting that conscious larvae actively resisted hydraulic pressures. Drift of small larvae out of a pool in the presence of a caged, larger cannibalistic conspecific was faster than in the absence of a predator, indicating that the larvae perceived and attempted to avoid the predator. Our findings confirm that larval drift that occurs from normally isolated temporary pools in ephemeral streams, is in part behaviorally controlled, and can be mediated by predation risk. We suggest that larval drift can serve as a dispersal pathway for amphibians and may be of particular importance at local spatial scales when the terrestrial habitat surrounding breeding sites is fragmented and movement of terrestrial stages is restricted.

We explored how inter- and intra-specific competition among larvae of two temporary-pool mosquito species, Culiseta longiareolata and Ochlerotatus caspius, affect larval developmental strategy and life history traits. Given that their larvae have similar feeding habits, we expected negative reciprocal inter-specific interactions. In a microcosm experiment, we found sex-specific responses of larval survival and development to both intra- and inter-specific larval competition. C. longiareolata was the superior competitor, reducing adult size and modifying larval developmental time of O. caspius. We observed two distinct waves of adult emergence in O. caspius, with clear sex-specific responses to its inter-specific competitor. In males, this pattern was not affected by C. longiareolata, but in females, the timing and average body size of the second wave strongly varied with C. longiareolata density. Specifically, in the absence of C. longiareolata, the second wave immediately followed the first wave. However, as C. longiareolata abundance increased, the second wave was progressively delayed and the resulting females tended to be larger. This study improves our understanding of the way intra- and inter-specific competition combine to influence the life histories of species making up temporary pond communities. It also provides strong evidence that not all individuals of a cohort employ the same strategies in response to competition.

Natural selection should favor females that avoid ovipositing where risk of predation is high for their progeny. Despite the large consequences of such oviposition behavior for individual fitness, population dynamics, and community structure, relatively few studies have tested for this behavior. Moreover, these studies have rarely assessed the mode of detection of predators, compared responses in prey species that vary in vulnerability to predators, or tested for the behavior in natural habitats. In an outdoor artificial pool experiment, we tested the oviposition responses of two dipteran species, Culiseta longiareolata (mosquito) and Chironomus riparius (midge), to the hemipteran predator, Notonecta maculata. Both dipteran species have similar life history characteristics, but Culiseta longiareolata larvae are highly vulnerable to predation by Notonecta, while Chironomus riparius larvae are not. As their vulnerabilities would suggest, Culiseta longiareolata, but not Chironomus riparius, strongly avoided ovipositing in pools containing Notonecta. An experiment in natural rock pools assessing oviposition by Culiseta longiareolata in response to Notonecta maculata yielded an oviposition pattern highly consistent with that of the artificial pool experiment. We also demonstrated that the cue for oviposition avoidance by Culiseta longiareolata was a predator-released chemical: Notonecta water (without Notonecta replenishment) repelled oviposition for 8 days. Oviposition avoidance and mode of detection of the predator have important implications for how to assess the true impact of predators and for the use of commercially kairomones for mosqutio control

Heterogeneity–diversity relationship (HDR) is commonly shown to be positive in accordance with classic niche processes. However, recent soil‐based studies have often found neutral and even negative HDRs. Some of the suggested reasons for this discrepancy include the lack of resemblance between manipulated substrate and natural settings, the treated areas not being large enough to contain species' root span, and finally limited‐sized plots may not sustain focal species’ populations over time. Vegetated green roofs are a growing phenomenon in many cities that could be an ideal testing ground for this problem. Recent studies have focused on the ability of these roofs to sustain stable and diverse plant communities and substrate heterogeneity that would increase niches on the roof has been proposed as a method to attain this goal. We constructed an experimental design using green roof experimental modules (4 m2) where we manipulated mineral and organic substrate component heterogeneity in different subplots (0.25 m2) within the experimental module while maintaining the total sum of mineral and organic components. A local annual plant community was seeded in the modules and monitored over three growing seasons. We found that plant diversity and biomass were not affected by experimentally created substrate heterogeneity. In addition, we found that different treatments, as well as specific subplot substrates, had an effect on plant community assemblages during the first year but not during the second and third years. Substrate heterogeneity levels were mostly unchanged over time. The inability to retain plant community composition over the years despite the maintenance of substrate differences supports the hypothesis that maintenance of diversity is constrained at these spatial scales by unfavorable dispersal and increased stochastic events as opposed to predictions of classic niche processes. The unique negative/neutral heterogeneity–diversity relationships that are found in plant‐soil study are displayed in our green roof study. Our findings allow to examine some of the existing theory and suggest towards the population viability theory.

Understanding constraints on phenotypic plasticity is central to explaining its evolution and the evolution of phenotypes in general, yet there is an ongoing debate on the classification and relationships among types of constraints. Since plasticity is often a developmental process, studies that consider the ontogeny of traits and their developmental mechanisms are beneficial. We manipulated the timing and reliability of cues perceived by fire salamander larvae for the future desiccation of their ephemeral pools to determine whether flexibility in developmental rates is constrained to early ontogeny. We hypothesized that higher rates of development, and particularly compensation for contradictory cues, would incur greater endogenous costs. We found that larvae respond early in ontogeny to dried conspecifics as a cue for future desiccation, but can fully compensate for this response in case more reliable but contradictory cues are later perceived. Patterns of mortality suggested that endogenous costs may depend on instantaneous rates of development, and revealed asymmetrical costs of compensatory development between false positive and false negative early information. Based on the results, we suggest a simple model of costs of development that implies a tradeoff between production costs of plasticity and phenotype-environment mismatch costs, which may potentially underlie the phenomenon of ontogenetic windows constraining plasticity.

Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern fire salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

Priority effects, i.e., effects of an early cohort on the performance of a later cohort, are generally studied between, and not within, species. The paucity of intraspecific assessments does not reflect a lack of ecological importance, but the technical problem associated with differentiating between conspecific cohorts. Here, we examine priority and density-dependent effects on larval Salamandra salamandra infraimmaculata. Larvae deposited by their mother early in the season have increased risk of desiccation, as rains at the beginning of the season are less frequent and unpredictable. However, breeding later may incur a high cost through conspecific priority effects, including cannibalism and competition. In an outdoor artificial pool experiment, we established densities of 0, 1, 2, 4 or 6 newly born larvae per pool (∼30 1), and 40 days later, added a second cohort of three newly born larvae to each pool. We differentiated between cohorts using natural individual-specific markings. For the early cohort, increasing density decreased survival and size at metamorphosis, and increased time to metamorphosis. For the late cohort, survival was 100% in pools without early-cohort larvae, but ranged between 13 and 33% in the presence of early-cohort larvae. Time to metamorphosis was significantly longer in the presence of low vs high densities of early-cohort larvae. Results suggest that early-cohort larvae are mainly subjected to exploitative competition and cannibalism mediated by food limitation, and that late-cohort larvae are subjected to cannibalism and interference due to size asymmetry between cohorts. The strong priority effects suggest that Salamandra females could increase their fitness by adjusting the number of larvae they deposit in specific pools to avoid cannibalism and intraspecific competition.

For a vector species, understanding their egg raft predation (consumption) or destruction is essential for both ecological and human health reasons since it directly influences its fitness. In a mesocosm experiment, we assessed differences in Culiseta longiareolata egg raft predation/destruction by three aquatic predators Notonecta maculata (backswimmers), Sympetrum fonscolombii (dragonflies) and Ommatotriton vittatus (newts), both in the presence and absence of an alternate prey (Culex larve). Egg raft predation and destruction significantly differed between predators types, and strongly influenced by the presence of alternate prey. Backswimmers attacked and destroyed (broke down) all egg rafts until they disintegrated and sank in water regardless of whether an alternative prey was present. Egg raft predation by dragonflies was common in the absence of alternative prey, but rare when alternative prey was present. Predation by newts was rare regardless of whether there was an alternative prey. The number of alternate prey consumed also significantly differed between predators (P < 0.001) with backswimmers being the most effective predator. Relatively few studies have tested for egg raft predation/destruction. Hence it is crucial that we conduct similar trials in other landscapes since such predators can prove to be key agents for the biological control of mosquitoes.