Presentation_1_Older males whistle better: Age and body size are encoded in the mating calls of a nest-building amphibian (Anura: Leptodactylidae).PDF

Courtship acoustic displays in anuran amphibians are energetically costly and risky, but have a major role in mating success since they encode relevant information regarding the caller’s identity and status. Age and size are essential traits shaping fitness, reproductive success and life-history strategies, and thus are expected to also have a role in courtship displays. We tested this assumption in a species of nest-building frogs, Leptodactylus bufonius, in northern Argentina. We conducted the first detailed quantitative description of the males’ mating calls and assessed the effects of biological traits (i.e., body size parameters and individual age) and local climate (i.e., air temperature and humidity) on the main acoustic features of these calls (i.e., call duration, inter-call duration, dominant frequency, and dominant frequency modulation). The calls were short (mean ± SE, 0.163 ± 0.004 s), whistle-like, single notes with harmonic structure. The dominant frequency (1381.7 ± 16.2 Hz) decreased with arm length (χ2 = 5.244, df = 1, p = 0.022) and had an upward modulation (456.4 ± 11.0 Hz) which increased with age (χ2 = 4.7012, df = 1, p = 0.030). Call duration and dominant frequency were the most static parameters at intra-individual level, indicating their role in individual recognition. Temperature and humidity shaped the temporal acoustic parameters, and the dominant frequency. Our findings suggest that the acoustic features of the mating calls in amphibians could promote female mate choice in relation to both size and age and open up new questions for future research: are females more attracted to older males, and what are the specific costs and benefits? We suggest that mating calls may direct female preferences toward males of certain size and age classes, ultimately shaping the life-history strategies in a given population. Finally, we found discrepancies in the mating calls of L. bufonius recorded from Corrientes and those previously described from other populations, which suggests that multiple species may have been recorded under the same name.</p

Data_Sheet_1_Older males whistle better: Age and body size are encoded in the mating calls of a nest-building amphibian (Anura: Leptodactylidae).XLSX

Courtship acoustic displays in anuran amphibians are energetically costly and risky, but have a major role in mating success since they encode relevant information regarding the caller’s identity and status. Age and size are essential traits shaping fitness, reproductive success and life-history strategies, and thus are expected to also have a role in courtship displays. We tested this assumption in a species of nest-building frogs, Leptodactylus bufonius, in northern Argentina. We conducted the first detailed quantitative description of the males’ mating calls and assessed the effects of biological traits (i.e., body size parameters and individual age) and local climate (i.e., air temperature and humidity) on the main acoustic features of these calls (i.e., call duration, inter-call duration, dominant frequency, and dominant frequency modulation). The calls were short (mean ± SE, 0.163 ± 0.004 s), whistle-like, single notes with harmonic structure. The dominant frequency (1381.7 ± 16.2 Hz) decreased with arm length (χ2 = 5.244, df = 1, p = 0.022) and had an upward modulation (456.4 ± 11.0 Hz) which increased with age (χ2 = 4.7012, df = 1, p = 0.030). Call duration and dominant frequency were the most static parameters at intra-individual level, indicating their role in individual recognition. Temperature and humidity shaped the temporal acoustic parameters, and the dominant frequency. Our findings suggest that the acoustic features of the mating calls in amphibians could promote female mate choice in relation to both size and age and open up new questions for future research: are females more attracted to older males, and what are the specific costs and benefits? We suggest that mating calls may direct female preferences toward males of certain size and age classes, ultimately shaping the life-history strategies in a given population. Finally, we found discrepancies in the mating calls of L. bufonius recorded from Corrientes and those previously described from other populations, which suggests that multiple species may have been recorded under the same name.</p

Supplemental material 5_Response curves of environmental variables with highest contributions to the ecological niche model of the meadow lizard (Darevskia praticola)

<p>Response curves of three environmental variables with highest contributions to the ecological niche model of the meadow lizard (<i>Darevskia praticola</i>) shown separately for the low resolution (a) and the high resolution ecological niche models (b). The curves show the relationship between each environmental variable and predicted values of the habitat suitability.<br></p

Supplemental material 4_Jackknife evaluation results of the ecological niche models of the meadow lizard (Darevskia praticola)

<p>Jackknife evaluation results of the relative importance of predictor variables shown separately for the low resolution (a) and the high resolution ecological niche models (b) of the meadow lizard (<i>Darevskia praticola</i>). Values on the X axis represent regularized training gain of the model. Only those variables with non-zero gain (when used alone) are shown in the graph. A variable is considered to be more important if it has a higher gain when used alone in the model, but also if it decreases the gain when excluded from the analysis.<br></p

Distribution of the meadow lizard in Europe and its realized ecological niche model

<p>One of the most interesting but elusive members of the European herpetofauna is the meadow lizard (<i>Darevskia praticola</i>). It is a small, ground dwelling, predominantly forest living lacertid, for which many ecological and biological data are still missing. Moreover, at least for the western part of the species range (south-eastern Europe) its distribution and environmental associations are insufficiently known, likely due to difficulties in detection even with intensive field sampling. Here, we complemented the available literature records with our personal observations and explored the effects of environmental factors shaping the species ecological niche and distribution in Europe using the ecological niche modelling approach from Maxent software. The new records of the meadow lizard fill a gap in its known distribution. The most suitable habitats are in central and eastern Serbia, south-western Romania, and central, southern and south-western Bulgaria. Mean temperature of the coldest quarter, vegetation and slope had the strongest effect in defining the meadow lizard’s ecological niche. Niche suitability increased with the increase in forest cover and slope, while the temperature showed a bell-shaped response with a rather narrow tolerance range for temperature. Contrary to expectations, precipitation seemed to have no contribution to the species occurrence. Ecological niche model performance increased with a higher resolution of predictor variables despite the lower number of available occurrence records, although the slope variable had a greater predictive power when calculated at a lower resolution. Interestingly, high resolution vegetation variables (30 m) were able to show some level of habitat fragmentation, which likely resulted from deforestation. Overall, our results epitomize the effects of limited sampling on the biogeography inference of elusive species while having significant repercussions on conservation priorities and management of the species.</p

Supplemental material 1_Database of literature records and recent field observations of the meadow lizard (Darevskia praticola)

<p>Database table composed of available literature records and our personal observations of the meadow lizard (<i>Darevskia praticola</i>) in the western part of its range (i.e. the European lineage of the species). The database includes exact coordinates and their precision, locality name, date, legator for data coming from observations or collections, and bibliographic data for the literature references (given in original language of the publication).<br></p

Planning unit (PU) irreplaceability scores under (a) unconstrained PU availability scenario (all PUs available for selection), and (b) constrained PU availability scenario (all currently protected PUs are given a score of 1).

<p>For (a), areas in blue represent priority areas for reptile and amphibian conservation regardless of their protection status. When all current SCIs are considered highly irreplaceable (b), northwest Romania becomes a conservation priority. </p

Flowchart of stages of analysis and data inputs.

<p>Flowchart of stages of analysis and data inputs.</p

Supplemental material 2_Model selection procedure using ENMeval in Maxent

<p>Overview of the model selection procedure using ENMeval used to find the optimal values of Maxent feature classes and regularisation parameter. The best fitting models are arranged according to the AICc values and the final model is selected from the list of supported ones. The results are given only for the low resolution model, since we were unable to run the high resolution model due to the computer hardware constrains.<br></p

Representation of amphibian and reptile species in Romanian Natura 2000 sites under current and future climate conditions for limited- and no-dispersal scenarios (shown as percentage of planning units of species ranges in Sites of Community Importance).

<p>Representation of amphibian and reptile species in Romanian Natura 2000 sites under current and future climate conditions for limited- and no-dispersal scenarios (shown as percentage of planning units of species ranges in Sites of Community Importance).</p