Number of other bats (1, 2, 3. or 4) actually found near a focal bat or expected by chance, summarized over all roosts and tracking sessions.

<p>First cluster of bars on x-axis: Black bar: number of occasions another bat was found in the same time window (n = 141), dark grey bar: number of occasions where this other bat also had the same compass bearing (±3°; n = 80), light grey bar: the random number of occasions another bat would be expected in the same time window and with the same compass bearing (n = 37.01 range 21 to 52). Group foraging occurred significantly more often than expected by chance. Additional clusters of bars: actual numbers of occasions that 2, 3 or 4 other bats were near in time or in time and space and the corresponding random expectations. Error bars indicate the minimum and maximum found with randomization through bootstrapping. See text for details.</p

Map of the study area showing the Chagres river entering the Panama Canal and the village of Gamboa, the location of roosts where radio-tracked bats were caught as well as our main tracking points.

<p>Map of the study area showing the Chagres river entering the Panama Canal and the village of Gamboa, the location of roosts where radio-tracked bats were caught as well as our main tracking points.</p

Visualisation of the complexity of a random movement that would lead to a false conclusion of coordinated movement between two bats.

<p>X: point from which bearings are taken by the observer; t1:position of the two bats along the same axis from the observer at time interval 1; t2: position of the same two bats along a different axis from the observer at time interval 2. The bats appear together (i.e. the strongest signal from their transmitter comes from the same direction) to the observer although they are not. It is very unlikely that movements like this would lead to a high percentage of co-locations in the dataset.</p

Decision-making time and homing direction of experimental pigeon flocks.

Decision-making time and homing direction of experimental pigeon flocks. Homing direction is difference between the vanishing bearing and the correct direction

Network graph showing the example of the first <i>Molossus molossus</i> colony (roost A) we radiotracked.

<p>Thickness of lines between individuals (diamonds) illustrates the number of times these two bats were found together. Number of co-observations range from 2 (between bats nr. 3 and 4) to 18 (between bats 1 and 5). Individual nr. 2 was a male.</p

Relationship between pigeon flock size and the decision-making period (i.e. time taken to assume a straight homing direction).

<p>Note that <i>y</i> values are represented in a logarithmic scale. Shading represents regression 95% confidence intervals. Points represent individual observations.</p

MHC class II <i>DRB</i> alleles influencing ectoparasite infestation in <i>N. albiventris</i>.

<p>Estimated regression parameters of specific <i>Noal-DRB</i> alleles influencing tick (A, N = 131) and bat flies (B, N = 165) infestation validated by GLMM models with ΔQAIC<2 (Laplace approximation with month in years as random effects). Best model and, for simplicity, averaged parameters of models with ΔQAIC<2 are shown.</p><p>GLMM: generalized linear mixed model; QAIC: quasi Akaike information criterion where the log likelihood is divided by the estimated overdispersion scale parameter of the full model; t-value: estimated parameter divided by its standard error, indicates the likelihood that the estimated parameter is not zero.</p

Tick infestation in <i>N. albiventris</i>.

<p>Estimated regression parameters and standard errors of combined ecological host characteristics and specific MHC class II <i>DRB</i> alleles on tick infestation obtained by GLMM (Laplace approximation with month and year as random effects) and GEE (with autocorrelation factor of roost: correlation parameter α = 0.03±0.07, overdispersion scale parameter = 7.1). Averaged estimates of GLMM models with ΔQAIC<2 are shown (QAIC_best = 182.9, overdispersion parameter of the full GLMM model = 4.57). N = 122.</p>1<p>compared to animals of BCI,</p>2<p>compared to non-reproductive adult females,</p>3<p>compared to reproductively active males.</p

Allele frequencies of MHC class II <i>DRB</i> exon 2 influencing the ectoparasite infestation in <i>N. albiventris</i>.

<p>Distribution of <i>Noal-DRB</i> alleles influencing the ticks and bat flies infestation in reproductive males (black bars), subadults (grey bars) and non-reproductive males (white bars). ‘+’ indicates an association with an increased and ‘−’ with a decreased parasite load. Allele <i>Noal-DRB</i>*02 is significant accumulated in non-reproductive males and less frequent in subadults (χ² = 10.07, p = 0.006, df = 2, Bonferroni significant, power (1-β err prob) 100%). Contrarily, allele <i>Noal-DRB</i>*10 is less frequent in non-reproductive males and accumulated in subadults (χ² = 3.20, df = 1, p = 0.064, power 98%).</p

Homing directions assumed by pigeon flocks of different sizes.

<p>Correct homing direction was set to 0°. Points represent individual observations. Inner lines represent mean vector lengths for each flock size (0.80, 0.75, 0.71 and 0.60 for group sizes of 2, 5, 10 and 20 pigeons respectively). Colour codes are blue, red, green and orange for group sizes of 2, 5, 10 and 20 pigeons respectively.</p