Jumping spiders: An exceptional group for comparative cognition studies

Abstract

Several non-mutually exclusive hypotheses have been proposed to explain the evolution of cognition in animals. Broadly, these hypotheses fall under two categories: those that pertain to the selective pressures exerted either by sociality or by the ecological niche in which animals live. We review these ideas and then discuss why the highly visual jumping spiders (Salticidae) are excellent models for investigating how cognitive ability evolves. With few exceptions, these behaviorally complex spiders are non-social, making them ideal candidates to explore ideas pertaining to selection based on habitat complexity and selection based on predatory behavior (foraging niche hypotheses). With the exception of Antarctica, salticids are found in all habitats on Earth, ranging from very complex to barren and simple. While many species are generalist predators, a minority also have specialized predatory behavior and prey specialization on dangerous prey, which has been proposed as an explanation for advanced cognitive ability. As this large group has a diversity of habitats in which it lives, diverse predatory behavior, as well as some "social" species, we argue that salticids are ideal candidates for comparative studies to explore the myriad selection factors acting upon a group well known for their cognitive prowess, despite having miniature brains.

A road map of jumping spider behavior

“…Comparative studies suggest that salticid cognitive ability is graded (Tarsitano & Jackson 1992; Cross & Jackson 2016; Aguilar-Arguello et al 2019, 2020, 2021), with the genus Portia considered the salticid equivalent of Einstein. As Portia behavior has been reviewed elsewhere (e.g., Jackson & Cross 2011; Aguilar-Arguello & Nelson 2021), I will only lightly touch on Portia and more generally discuss other lesser-known salticids with comparable cognitive attributes.…”

“…Evolution .—Numerous hypotheses have been proposed to explain the evolution of advanced cognition in animals, but they broadly fall into two categories: those pertaining to sociality (i.e., sociality facilitates advanced cognition) and those pertaining to ecological drivers, including that selection for advanced cognition is increased in animals living in more complex environments or facing challenges in obtaining food (e.g., patchy spatiotemporal distribution, or hunting risky prey). Although there are some social salticids (see ‘Parental behavior’), little is known about them, so I will focus on ecological aspects of cognition (see Aguilar-Arguello & Nelson 2021).…”