Variation in dog handling behaviour across types of substrates and baits.

<p>For substrates, Tukey contrasts for pairs of means were indicated by shared superscripts: ^a<i>P</i><0.001, ^b<i>P</i> = 0.023, ^c<i>P</i> = 0.084, ^d<i>P</i> = 0.002.</p

Performance of substrates and baits.

<p>The amount of saliva attached to substrates after being handled by dogs, DNA concentration in saliva extracts, identification success, and number of genotyping replicates needed for individual identification are shown (sample size in brackets). Individual identification is expressed as the proportion of dogs matching all ten loci with the reference genotype (either hair genotype or consensus genotype) and as the percentage of correct loci per dog. Values represent means ± SE (upper half of the table) and proportions (lower half).</p

Individual identification success across different classes of DNA concentration in saliva extracts.

<p>Individual identification success across different classes of DNA concentration in saliva extracts.</p

A: Porous substrates (cork, styrofoam, wood) in a bag after sterilization. B: Cork substrates covered with meat, ready for delivery.

<p>A: Porous substrates (cork, styrofoam, wood) in a bag after sterilization. B: Cork substrates covered with meat, ready for delivery.</p

Species identification success across different classes of DNA concentration in saliva extracts.

<p>Species identification success across different classes of DNA concentration in saliva extracts.</p

Effects included in minimal adequate Generalized Linear Mixed Models.

<p>Parameter estimates of fixed effects influencing the quantity of saliva attached to substrates, DNA concentration in saliva extracts (ng µl^-1), and dog identification success expressed as a perfect match for 10 loci are shown. Levels styrofoam (substrate), meat (bait), female (sex), and small (dog size) are included in the intercept. All models contain the random effects of dog identity nested within experimental session. Errors: normal (saliva score, DNA concentration), binomial (species and individual identification) and Poisson (number of genotyping attempts needed for a correct identification). S*B: substrate-bait interaction.</p

Minimal adequate binomial GLMMs for dog identification success expressed as the percentage of correct loci.

<p>Parameter estimates of fixed effects are shown. For the effects of substrate, bait, dog sex and dog size the levels styrofoam, meat, female, and small, respectively, are included in the intercept. All models contain the random effects of dog identity nested within experimental session.</p

Frequencies of dog individual identification across classes of the amount of saliva attached to the substrate.

<p>Successful identification means complete agreement with 10-loci genotypes obtained from hair samples.</p

Log-transformed DNA concentration (ng μl^-1) in saliva extracts.

<p>Means and 95% CI are shown for every combination of substrate and bait, once records >60 ng μl^-1 were excluded.</p

Amount of saliva attached to three types of substrate after dog handling.

<p>Bars indicate the distribution of substrates among classes of collected amount of saliva, from absence (class 1) to saturation (class 4). Data from all five experimental sessions are shown. Cork, <i>n</i> = 58; styrofoam, <i>n</i> = 54; wood, <i>n</i> = 58.</p