After decades of near‐complete extirpation, the yellow‐and‐black‐striped Southern Corroboree Frog (Pseudophryne corroboree) is being reintroduced into field enclosures that exclude all but avian predators. The frog's long absence means avian attack risk to reintroduced individuals is unknown, so we asked: does corroboree frog coloration make them vulnerable to predators? First, using painted clay frog models and humans as proxy predators, we found that, surprisingly, striped models were as difficult to detect as control black models, and were far less detectable than yellow models. Second, to quantify attack probabilities, we deployed 2,304 models twice in the species' former range. Of our recovered models, 18% of the striped models were attacked by birds, suggesting they are a significant threat. In our second deployment, we saw a significant reduction in attacks on all model colors with only 10% of striped models attacked. If predators generalize their avoidance learning to real corroboree frogs, strategically timed model deployment near release sites may enhance the probability of survival of reintroduced frogs. Our study suggests that model deployment could be an effective low‐cost technique to increase the survival of reintroduced prey species, including, but not limited to, those potentially conspicuous to their natural enemies.

Many animals utilize self-built structures – so-called extended phenotypes – to enhance body functions, such as thermoregulation, prey capture or defence. Yet, it is unclear whether the evolution of animal constructions supplements or substitutes body functions. Here, using Austral brown spiders, we explored if the evolutionary loss and gain of silken webs as extended prey capture devices correlates with alterations in traits known to play an important role in predatory strikes - locomotor performance and leg spination. For this purpose, we combined the reconstruction of the phylogeny of the Austral marronoid clade of spiders based on UCE target sequence capture with the assembly of kinematic, morphological and ecological data. We found that in this group extreme locomotor performance, with running speeds of over 100 body lengths per second, evolved repeatedly – both in web builders and cursorial spiders. There was no correlation with running speed, and leg spination only poorly correlated, relative to the use of extended phenotypes, with all of these traits showing highly mosaic, independent evolutionary patterns. This indicates that the use of webs does not reduce the selective pressure on body functions involved in prey capture and defence per se.