Differences in age distribution.

<p>Dot density diagram representing differences in age distribution between the successive periods of trapping. The eye lens weight (mg) was used as age estimator. Symbols correspond to the season of trapping (red squares  =  Autumn, blue circles  =  Spring).</p

Relationship between overall shape of the tooth and local variations in tooth dimensions at the intraspecific (A) and interspecific (B) scale.

<p>The second synthetic shape axis PC2 is taken as an estimator of the <i>simplex-complex</i> variation. It is compared to a combination of the inter-triangles distances (D1+D2)−D3: the smaller (D1+D2), the shorter the spacing between the first triangles; the higher D3, the longer the posterior part of the tooth. Both mechanisms can contribute to the formation of the additional triangle typical of <i>complex</i> teeth, leading to a correlation between PC2 and (D1+D2)−D3. (A) Variation within the bank vole <i>M. glareolus</i>. (B) To include variation at a higher evolutionary scale, specimens of <i>M. rufocanus</i> (<i>simplex</i> UM3) and of the <i>M. rutilus</i> (<i>complex</i> UM3) have been added to the intra-specific variation of the bank vole. The shape axis PC2 was recalculated on the basis of the new dataset.</p

Examples of extreme morphologies of bank vole third upper molars in occlusal view.

<p>Measurements collected for this study are also presented. (A) A <i>simplex</i> molar characterised by three lingual triangles. (B) A <i>complex</i> tooth with four lingual triangles. Univariate measurements are: D1, the distance from the tips of the first to the second triangle; D2, the distance from the tips of the second to the third triangle; D3, the distance from the tip of the third triangle to the posterior end of the tooth; Infra-occlusal length, the total length of the tooth measured two millimetres under the occlusal surface on the labial side of the tooth; the last re-entrant angle, angle measuring the degree of indentation of the posterior part of the tooth. The overall shape of the tooth is quantified by the 2D outline of the occlusal surface, schematically represented here for each of the tooth. The starting point (black dot) is located at the most re-entrant point between the first and second anterior labial triangles.</p

Shape variation of the third upper molar in the bank vole.

<p>(A) Shape variation of the third upper molar in the bank vole, represented on the first two principal axes of a PCA on the Fourier coefficients of the molar outline. Each grey dot corresponds to a specimen; the mean (+/− the confidence interval) of the four successive periods of trapping have been superimposed to the total variation (red squares  =  Autumn, blue circles  =  Spring). (B) Reconstructed outlines visualising shape variations along the first and second axes.</p

Schematic representation of the evo-devo model proposed to explain the polymorphism in the UM3 shape.

<p>The formation of each triangle is controlled by a signalling centre (colour-filled circle) surrounded by an inhibitory field (black circle); the subsequent triangle can only develop outside this inhibitory field. (A) Intra-population variation in the bank vole is not related to a change in the spacing of the triangles (hypothesized as related to a change in the dimension of the inhibitory field during the tooth development), but to the termination of the process towards the posterior end of the tooth: an additional triangle will form if enough space is available. (B) In contrast, differences between species such as <i>M. rufocanus</i> and <i>M. rutilus</i> are related to a change in the spacing of the triangles.</p

Details of the vegetation indices calculated from the Sentinel-2 and Landsat data.

Details of the vegetation indices calculated from the Sentinel-2 and Landsat data.</p

Random forest predicted abundance for the Narati study area.

(a) A. uralensis, (b) M. obscurus, (c) M. centralis, (d) S. tianshanica and (e) S. asper using trapline data, and (f) E. tancrei, and (g) M. baibacina using transect data.</p

Top five EO-derived variables identified by the boruta feature selection analysis as important for each small mammal species for Sary Mogul.

Top five EO-derived variables identified by the boruta feature selection analysis as important for each small mammal species for Sary Mogul.</p

Remote sensing variables identified by the boruta feature selection analysis as important for each small mammal species for Sary Mogul.

Remote sensing variables identified by the boruta feature selection analysis as important for each small mammal species for Sary Mogul.</p

Random forest predicted abundance for the Sary Mogul study area.

(a) C. migratorius and (b) M. gregalis using the trapline survey data, and (c) E. tancrei and (d) M. gregalis using the transect survey data.</p