Mean (+SE) brood mass at dispersal at first breeding, in relation to the duration of maternal care.

<p>Mean (+SE) brood mass at dispersal at first breeding, in relation to the duration of maternal care.</p

Mean (+SE) brood mass at dispersal at subsequent breeding bout, in relation to the duration of maternal care at first breeding.

<p>Mean (+SE) brood mass at dispersal at subsequent breeding bout, in relation to the duration of maternal care at first breeding.</p

Mean (+SE) lifespan of experimentally widowed females in relation to the time spent caring for their first brood.

<p>Mean (+SE) lifespan of experimentally widowed females in relation to the time spent caring for their first brood.</p

Mean (+SE) lifespan of females that cared for larvae until they dispersed, either when widowed before hatching or when partners were present throughout the first brood.

<p>Mean (+SE) lifespan of females that cared for larvae until they dispersed, either when widowed before hatching or when partners were present throughout the first brood.</p

Boncoraglio et al database Dryad file

Original data collected in the lab. File created with Excel 2003. No abbreviations used for column headings

Romano_et_al

Data on begging behaviour of nestling barn swallow. See README.txt for details

Aposematism in the burying beetle? Dual function of anal fluid in parental care and chemical defence

Burying beetles (Nicrophorus vespilloides) bear distinctive and variable orange-black patterning on their elytra and produce an anal exudate from their abdomen when threatened. During breeding, the anal exudates contribute to the antimicrobial defence of the breeding resource. We investigated whether the anal exudates also provide a responsive chemical defence, which is advertised to potential avian predators by the beetle’s orange and black elytral markings. We found that that the orange-black elytral markings of the burying beetle are highly conspicuous for avian predators against range of backgrounds, by using computer simulations. Using bioassays with wood ants, we also showed that the burying beetle’s anal exudates are aversive to potential predators. From these results, and other evidence in the literature, we conclude that the evidence for aposematism in the burying beetle is as strong as the evidence for many other classically aposematic species, such as defended Hymenopterans, ladybirds or poisonous frogs. Nevertheless, we also report unexpectedly high levels of individual variation in coloration and chemical defences, as well as sex differences. We suggest that this variation might be due partly to conflicting selection pressures, particularly on the dual function of the exudates, and partly to nutritional differences in the developmental environment. The ecology of the burying beetles (Nicrophorus spp.) differs markedly from better-studied aposematic insects. This genus thus offers new potential for understanding the evolution of aposematism in general.</p

Yearlings TSR in relation to older individuals TSR recorded in the same year in 67 years×colony events.

<p>Continuous lines are least squares regressions for the 14 colonies included in the sample. Three data points with sex ratio of older individuals = 1 are not represented to better visualize the other data points. The coordinates (<i>x</i>, <i>y</i>) of those points are in parentheses.</p

No evidence of a cleaning mutualism between burying beetles and their phoretic mite

Burying beetles (Nicrophorus vespilloides) breed on small vertebrate carcasses, which they shave and smear with antimicrobial exudates. Producing antimicrobials imposes a fitness cost on burying beetles, which rises with the potency of the antimicrobial defence. Burying beetles also carry phoretic mites (Poecilochirus carabi complex), which breed alongside them on the carcass. Here we test the novel hypothesis that P. carabi mites assist burying beetles in clearing the carcass of bacteria as a side-effect of grazing on the carrion. We manipulated the bacterial environment on carcasses and measured the effect on the beetle in the presence and absence of mites. With next-generation sequencing, we investigated how mites influence the bacterial communities on the carcass. We show that mites: 1)cause beetles to reduce the antibacterial activity of their exudates but 2) there are no consistent fitness benefits of breeding alongside mites. We also find that mites increase bacterial diversity and richness on the carcass, but do not reduce bacterial abundance. The current evidence does not support a cleaning mutualism between burying beetles and P. carabi mites, but more work is needed to understand the functional significance and fitness consequences for the beetle of mite-associated changes to the bacterial community on the carcass.</p

TSR of yearlings in the population in any (<i>t</i>+1)-th study year in relation to adult survival between year <i>t</i> and year <i>t</i>+1.

<p>The analysis was restricted to the years when more than 180 yearlings were sampled (see <i>Statistical analyses</i>).</p