Award details

22 UKRI-SBE: Primate natal coats: Form and function

Reference	BB/X011097/1
Principal Investigator / Supervisor	Dr William Allen
Co-Investigators / Co-Supervisors
Institution	Swansea University
Department	College of Science
Funding type	Research
Value (£)	260,100
Status	Current
Type	Research Grant
Start date	01/02/2023
End date	31/01/2027
Duration	48 months

Abstract

Primates are exceptional among mammals in exhibiting spectacular and diverse coloration patterns on faces, genitals and other body parts linked to socio-sexual signaling and speciation processes. A major open question remains involving the perceptual form of primate natal coat colors, and their function(s). Many primate species exhibit colors as infants that to human perception contrast starkly with adult and typical background coloration. For example, in Hatinh langur (Trachypithecus hatinhensis) adults are black while infants are bright orange. Primate ontogenetic color change (OCC) is set apart from most other examples of OCC that result from changes in camouflage strategy or the acquisition of secondary sexual characteristics. In this project we have two main objectives: Objective 1: Investigate the form of primate natal coat coloration. Perceptual modelling will establish the conspicuousness of natal coat colors against adult phenotypes and natural backgrounds as perceived by different potential receivers, including dichromatic carnivore predators, di- and trichromatic conspecifics, and tetrachromatic raptor predators. To achieve this, we will to create a new database of standardized images of infant coloration taken at globally distributed zoos and wildlife sanctuaries throughout the period of OCC. We will report the perceptual form of OCC at a scale and level of detail unprecedented for any taxa. Objective 2: Investigate the function of primate natal coat coloration. We will assess evidence for six outstanding functional hypotheses against a non-adaptive hypothesis: i) anti-predator aposematism; ii) anti-infanticide aposematism; iii) infant tracking; iv) Paternity cloak; v) Alloparental care and vi) Maternal care. Our approach uses a powerful combination of phylogenetic comparative analyses to test cross-species predictions at macroevolutionary scales combined with rigorous looking-time experiments using perceptually manipulated images.

Summary

The color of infants in many primate species contrasts starkly with adult and background color. This is counterintuitive - why make the most vulnerable members of a group conspicuous to threats? This project will investigate the form, and function of infant coloration in primates, giving insight into the role of infants in the social systems of primates - our direct evolutionary lineage. Many ideas for the function of infant conspicuousness have been proposed but not rigorously investigated. These include the color warning potentially infanticidal out-group males or predators that the infant will be defended by the group, confusing the paternity of infants to prevent infanticide, helping caregivers keep track of the infant, and facilitating the care of infants by mothers and non-mothers. This project will test these multiple hypotheses by objectively measuring the color of many individuals from many primate species throughout infancy, conducting comparative analyses of infant coloration across species, and behavioral experiments to find out how mothers, fathers and non-fathers respond to different colored infants. Color will be measured using calibrated and standardized digital photography at zoos, sanctuaries and research centers globally, with local researchers taking photos of infants throughout the period of development. These will then be processed using visual-system dependent methods to get a 'receiver-eye-view' of primate infant appearance. Comparative analyses across primate species will test the predictions made by each of the functional hypotheses about how infant color should relate to species' behavior, ecology and social system. For example, the paternity confusion hypothesis would predict that infants should be more conspicuous in species where paternity certainty is low. The experimental tests of function involve showing multiple species of captive primate images that have been manipulated to different infant and juvenile colors and measuring the interest of different receivers to different manipulations. The various hypotheses make unique predictions about who should be interested in what image properties, testing the function of primate infant conspicuousness with powerful experiments for the first time.

Committee	Not funded via Committee
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

I accept the terms and conditions of use (opens in new window)

export PDF file

back to list new search