We propose that, on the whole, web-invading aggressive mimicry favours exceptionally learn more cognitive predatory strategies. There are opportunities for assessing this hypothesis because, although Portia is the most
thoroughly studied web-invading aggressive mimic, there are other salticids (Su et al., 2007; Harland et al., 2012), some non-salticid spiders (Jackson, 1992; Herberstein & Wignall, 2011; Jakob, Skow & Long, 2011; Nelson & Jackson, 2011) and even some insects (Wignall & Taylor, 2009, 2010, 2011; Soley, Jackson & Taylor, 2011; Soley & Taylor, 2012) that practise this basic style of predation. Our limited understanding of these other species suggests that our hypothesis about the importance of web-invading strategies will be corroborated. However, even if we succeed in identifying the sources of natural selection that favour the strikingly flexible, cognitive strategies of web-invading aggressive mimics, another important issue remains unresolved. Regardless of the animal’s needs, we can expect that constraints related to the animal’s nervous system will impose limitations. Our commonsense may especially predispose us to expect severe size constraints on the computational
Selleckchem BGB324 power of animal brains. Compared with the much larger vertebrate animals used more often in cognitive research, we might expect much less capacity for orchestrating flexible, cognitive strategies by Portia and other spiders, as well as insects. However, what counts is the evidence (Eberhard, 2011; Eberhard & Wcislo, 2012), not our intuition. Among insects, findings from research on honeybees suggest that size constraints may be considerably less severe than many people would expect (Srinivasan,
2010). Among spiders, it is especially the findings from research on Portia that suggests the severity of size constraints has been overestimated (Harland & Jackson, 2004). Honeybees are not predators and, for this reason, we might expect the selection pressures responsible for honeybee behaviour to be rather different from those acting on Portia and other aggressive mimics. Yet Portia’s predatory strategy appears to be among the most flexible Cediranib (AZD2171) described for any predators of any size. That so much of this flexibility is expressed in the context of aggressive mimicry suggests that aggressive mimicry is, in general, particularly conducive to the evolution of interesting expression of animal cognition. We gratefully acknowledge the support of grants from the Foundation for Research, Science and Technology (UOCX0903), the Royal Society of New Zealand [Marsden Fund (M1096, M1079) and James Cook Fellowship (E5097)], the National Geographic Society (8676-09, 6705-00) and the US National Institutes of Health (R01-AI077722). “
“We investigated the effects of climatic variables on the flight activity of bats at the entrance of a hibernaculum (Kateřinská cave, Moravian Karst, CZ). Activity was recorded automatically using a double infrared-light logging system.