Sometimes tool use is not the key: no evidence for cognitive adaptive specializations in tool-using woodpecker finches

One contribution of 15 to a theme issue 'Innovation in animals and humans: understanding the origins and development of novel and creative behaviour'. Several studies on cognition, molecular phylogenetics and taxonomic diversity independently suggest that Darwin's finches are part of a larger clade of speciose, flexible birds, the family Thraupidae, a member of the New World nine-primaried oscine superfamily Emberizoidea. Here, we first present a new, previously unpublished, dataset of feeding innovations covering the Neotropical region and compare the stem clades of Darwin's finches to other neotropical clades at the levels of the subfamily, family and superfamily/order. Both in terms of raw frequency as well as rates corrected for research effort and phylogeny, the family Thraupidae and superfamily Emberizoidea show high levels of innovation, supporting the idea that adaptive radiations are favoured when the ancestral stem species were flexible. Second, we discuss examples of innovation and problem-solving in two opportunistic and tame Emberizoid species, the Barbados bullfinch Loxigilla barbadensis and the Carib grackle Quiscalus lugubris fortirostris in Barbados. We review studies on these two species and argue that a comparison of L. barbadensis with its closest, but very shy and conservative local relative, the black-faced grassquit Tiaris bicolor, might provide key insights into the evolutionary divergence of cognition. A nested phylogeny of flexible new world birdsThe superfamily Emberizoidea, also known as New World nine-primaried oscines [1], includes the families Emberizidae, Icteridae, Parulidae and Cardinalidae, as well as Thraupidae, whose most famous members are Darwin's finches. The superfamily accounts for almost 8% of all birds (832 species, [2]) and has evolved a broad range of morphologies and feeding adaptations that have allowed it to radiate throughout the New World, parts of the Old World (buntings) and to colonize outlying islands in the Pacific (Galápagos finches, Cocos finch) and Atlantic oceans (Tristan da Cunha finches, Gough finch) [3]. The diversification rate of the superfamily, based on statistical comparisons [4] and molecular estimates of divergence time from common ancestors [1], is higher than that of other clades, with the families Icteridae (grackles, cowbirds and New World blackbirds) and Thraupidae (collectively referred to as tanagers) contributing most of the effect.The family Thraupidae in particular has a 40% higher diversification rate than its most closely related clades, five times higher than that of the Neoaves mean and an order of magnitude higher than the vertebrate average [1]. Recent revisions of Thraupidae molecular phylogeny [5] have led to the incorporation into this family of many species previously classified [6] as Emberizidae. This includes Darwin's finches, as well as several Caribbean bullfinch and grassquit genera, plus the bananaquit Coereba flaveola that had earlier been considered the sole member of the Coeribidae. This revision makes tanagers th...

Section: A Review Of Innovativeness and Problemsolving In Loxigilla Bmentioning

confidence: 99%

Feeding innovations in a nested phylogeny of Neotropical passerines

Lefebvre¹,

Ducatez²,

Audet³

2016

“…While primates have formed a significant focus of research into tool use, the same effect of more frequent and diverse tool use in captivity has been noted in animals as varied as elephants [31], keas [32], small tree finches [33], rooks [34], cockatoos [35], rodents such as degus [36] and naked mole rats [37] and even gastropods [38]. The examples listed here are illustrative rather than exhaustive-of the 418 instances of animal tool use tabulated by Bentley-Condit & Smith [4], 120 or 28.7% were found in captivity alone.…”

Section: 'Captivity Bias' In Animal Tool Use (A) Animal Tool Use In Cmentioning

confidence: 99%

“…Where changes are observed in hominin behaviours that may be expected to influence tool use, such as ranging or diet, without accompanying changes in stone tool forms, we may therefore hypothesise that either (i) additional (non-lithic) tools were being incorporated into the toolkit, or (ii) existing tools were being sequentially combined for greater energy returns or to open up new extraction niches. Further, the captivity bias effect suggests that hominin groups, even if members of the same species, will show widely varying levels of tool use as a result of both cultural and stochastic processes [33]. Cognition is irrelevant to these processes.…”

Section: Hominins As Tool-using Animalsmentioning

confidence: 99%

‘Captivity bias’ in animal tool use and its implications for the evolution of hominin technology

Haslam

2013

Animals in captive or laboratory settings may outperform wild animals of the same species in both frequency and diversity of tool use, a phenomenon here termed ‘captivity bias’. Although speculative at this stage, a logical conclusion from this concept is that animals whose tool-use behaviour is observed solely under natural conditions may be judged cognitively or physically inferior than if they had also been tested or observed under controlled captive conditions. In turn, this situation creates a potential problem for studies of the behaviour of extinct members of the human family tree—the hominins—as hominin cognitive abilities are often judged on material evidence of tool-use behaviour left in the archaeological record. In this review, potential factors contributing to captivity bias in primates (including increased contact between individuals engaged in tool use, guidance or shaping of tool-use behaviour by other tool-users and increased free time and energy) are identified and assessed for their possible effects on the behaviour of the Late Pleistocene hominin Homo floresiensis . The captivity bias concept provides one way to uncouple hominin tool use from cognition, by considering hominins as subject to the same adaptive influences as other tool-using animals.

“…This distinguishes innovativeness from more specialized cognitive abilities like food hoarding or song learning, which are easier to understand as a result of exposure to consistent selection pressures. Indeed, experimental work has failed to identify any cognitive specialization associated with enhanced innovative abilities [10,11]. Instead, some animals seem to possess from the start the machinery needed to invent sophisticated behaviours even when these are rarely used in the wild [12].…”

Section: Introductionmentioning

confidence: 99%

The life-history basis of behavioural innovations

Sol¹,

Sayol

Ducatez

et al. 2016

114

125

One contribution of 15 to a theme issue 'Innovation in animals and humans: understanding the origins and development of novel and creative behaviour'. The evolutionary origin of innovativeness remains puzzling because innovating means responding to novel or unusual problems and hence is unlikely to be selected by itself. A plausible alternative is considering innovativeness as a co-opted product of traits that have evolved for other functions yet together predispose individuals to solve problems by adopting novel behaviours. However, this raises the question of why these adaptations should evolve together in an animal. Here, we develop the argument that the adaptations enabling animals to innovate evolve together because they are jointly part of a life-history strategy for coping with environmental changes. In support of this claim, we present comparative evidence showing that in birds, (i) innovative propensity is linked to life histories that prioritize future over current reproduction, (ii) the link is in part explained by differences in brain size, and (iii) innovative propensity and life-history traits may evolve together in generalist species that frequently expose themselves to novel or unusual conditions. Combined with previous evidence, these findings suggest that innovativeness is not a specialized adaptation but more likely part of a broader general adaptive system to cope with changes in the environment.