Avoiding predators at night: antipredator strategies in red-tailed sportive lemurs (Lepilemur ruficaudatus)

2007 ◽  
Vol 69 (6) ◽  
pp. 611-624 ◽  
Author(s):  
Claudia Fichtel
Author(s):  
Sonja Drack ◽  
Sylvia Ortmann ◽  
Nathalie Bührmann ◽  
Jutta Schmid ◽  
Ruth D. Heldmaier ◽  
...  

2020 ◽  
Vol 287 (1929) ◽  
pp. 20201011
Author(s):  
Iliana Medina ◽  
Regina Vega-Trejo ◽  
Thomas Wallenius ◽  
Damien Esquerré ◽  
Constanza León ◽  
...  

Many organisms use different antipredator strategies throughout their life, but little is known about the reasons or implications of such changes. For years, it has been suggested that selection by predators should favour uniformity in local warning signals. If this is the case, we would expect high resemblance in colour across life stages in aposematic animals where young and adults share similar morphology and habitat. In this study, we used shield bugs (Hemiptera: Pentatomoidea) to test whether colour and colour diversity evolve similarly at different life stages. Since many of these bugs are considered to be aposematic, we also combined multi-species analyses with predation experiments on the cotton harlequin bug to test whether there is evidence of selection for uniformity in colour across life stages. Overall, we show that the diversity of colours used by both life stages is comparable, but adults are more cryptic than nymphs. We also demonstrate that nymphs and adults of the same species do not tend to look alike. Experiments on our model system suggest that predators can generalise among life stages that look different, and exhibit strong neophobia. Altogether, our results show no evidence of selection favouring colour similarity between adults and nymphs in this speciose clade.


2019 ◽  
Vol 374 (1783) ◽  
pp. 20190069 ◽  
Author(s):  
Carita Lindstedt ◽  
Liam Murphy ◽  
Johanna Mappes

Antipredator strategies of the pupal stage in insects have received little attention in comparison to larval or adult stages. This is despite the fact that predation risk can be high during the pupal stage, making it a critical stage for subsequent fitness. The immobile pupae are not, however, defenceless; a wide range of antipredator strategies have evolved against invertebrate and vertebrate predators. The most common strategy seems to be ‘avoiding encounters with predators' by actively hiding in vegetation and soil or via cryptic coloration and masquerade. Pupae have also evolved behavioural and secondary defences such as defensive toxins, physical defences or deimatic movements and sounds. Interestingly, warning coloration used to advertise unprofitability has evolved very rarely, even though the pupal stage often contains defensive toxins in chemically defended species. In some species, pupae gain protection from conspecifics or mimic chemical and auditory signals and thereby manipulate other species to protect them. Our literature survey highlights the importance of studying selection pressures across an individual's life stages to predict how ontogenetic variation in selective environments shapes individual fitness and population dynamics in insects. Finally, we also suggest interesting avenues for future research to pursue. This article is part of the theme issue ‘The evolution of complete metamorphosis’.


1985 ◽  
Vol 63 (6) ◽  
pp. 1324-1329 ◽  
Author(s):  
A. T. Bergerud

A small herd of 15–31 caribou (Rangifer tarandus) inhabited a shoreline strip of habitat along Lake Superior from 1972 to 1983. By remaining near the shoreline, they were spaced away from the major distributions of wolves (Canis lupus) and lynx (Lynx canadensis) that hunted mainly inland for moose (Alces alces) and snowshoe hares (Lepus americanus), respectively. Lake Superior also provided a means of escape from wolves, and offshore islands constituted safe parturition sites. The persistence of this herd is consistent with the hypothesis that viable caribou populations cannot survive on ranges frequented by high numbers of wolves (maintained mainly by moose prey) unless there are special habitat features providing escape for cows with young calves.


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