Avian predation intensity as a driver of clinal variation in colour morph frequency

Genevieve Matthews, Celine T. Goulet, Kaspar Delhey, Zak S. Atkins, Geoffrey M. While, Michael G. Gardner, David G. Chapple

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Phenotypic variation provides the framework for natural selection to work upon, enabling adaptive evolution. One of the most discernible manifestations of phenotypic variability is colour variation. When this variation is discrete, genetically based colour pattern morphs occur simultaneously within a population. Why and how colour polymorphisms are maintained is an evolutionary puzzle. Several evolutionary drivers have been hypothesized as influencing clinal patterns of morph frequency, with spatial variation in climate and predation being considered especially important. Despite this, no study has examined both of their roles simultaneously. The aims of this study were to: (a) examine the covariation of physiology, environmental variables and colouration at a local scale; and (b) determine if these factors and their interplay explain broad clinal variation in morph frequency. We used the lizard Liopholis whitii as a model system, as this species displays a discrete, heritable polymorphism for colour pattern (plain-backed, patterned morphs) whose morph frequency varies latitudinally. We measured reflectance, field activity temperatures and microhabitat structure to test for differences in crypsis, thermal biology and microhabitat selection of patterned and plain-backed morphs within a single population where colour morphs occur sympatrically. We then used data from the literature to perform a broad-scale analysis to identify whether these factors also explained the latitudinal variation of morph frequency in this species. At the local scale, plain-backed morphs were found to be less cryptic than patterned morphs while no other differences were detected in terms of thermal biology, dorsal reflectance and microhabitat use. At a broader scale, predation was the most influential factor mediating morph frequency across latitudes. However, the observed pattern of morph frequency is opposite to what the modelling results suggest in that the incidence of the least cryptic morph is highest where predation pressure is most severe. Clinal variation in the level of background matching between morphs or the potential reproductive advantage by the plain-backed morph may, instead, be driving the observed morph frequency. Together, these results provide key insights into the evolution of local adaptation as well as the ecological forces involved in driving the dynamics of colour polymorphism.

Original languageEnglish
Pages (from-to)1667-1684
Number of pages18
JournalJournal of Animal Ecology
Volume87
Issue number6
DOIs
Publication statusPublished - 1 Nov 2018

Keywords

  • climate
  • evolution
  • latitudinal cline
  • local adaptation
  • phenotypic variation
  • reflectance
  • spectrometry
  • thermal biology

Cite this

Matthews, G., Goulet, C. T., Delhey, K., Atkins, Z. S., While, G. M., Gardner, M. G., & Chapple, D. G. (2018). Avian predation intensity as a driver of clinal variation in colour morph frequency. Journal of Animal Ecology, 87(6), 1667-1684. https://doi.org/10.1111/1365-2656.12894
Matthews, Genevieve ; Goulet, Celine T. ; Delhey, Kaspar ; Atkins, Zak S. ; While, Geoffrey M. ; Gardner, Michael G. ; Chapple, David G. / Avian predation intensity as a driver of clinal variation in colour morph frequency. In: Journal of Animal Ecology. 2018 ; Vol. 87, No. 6. pp. 1667-1684.
@article{f3dc881b870e4ab0a9cccaee659e41c6,
title = "Avian predation intensity as a driver of clinal variation in colour morph frequency",
abstract = "Phenotypic variation provides the framework for natural selection to work upon, enabling adaptive evolution. One of the most discernible manifestations of phenotypic variability is colour variation. When this variation is discrete, genetically based colour pattern morphs occur simultaneously within a population. Why and how colour polymorphisms are maintained is an evolutionary puzzle. Several evolutionary drivers have been hypothesized as influencing clinal patterns of morph frequency, with spatial variation in climate and predation being considered especially important. Despite this, no study has examined both of their roles simultaneously. The aims of this study were to: (a) examine the covariation of physiology, environmental variables and colouration at a local scale; and (b) determine if these factors and their interplay explain broad clinal variation in morph frequency. We used the lizard Liopholis whitii as a model system, as this species displays a discrete, heritable polymorphism for colour pattern (plain-backed, patterned morphs) whose morph frequency varies latitudinally. We measured reflectance, field activity temperatures and microhabitat structure to test for differences in crypsis, thermal biology and microhabitat selection of patterned and plain-backed morphs within a single population where colour morphs occur sympatrically. We then used data from the literature to perform a broad-scale analysis to identify whether these factors also explained the latitudinal variation of morph frequency in this species. At the local scale, plain-backed morphs were found to be less cryptic than patterned morphs while no other differences were detected in terms of thermal biology, dorsal reflectance and microhabitat use. At a broader scale, predation was the most influential factor mediating morph frequency across latitudes. However, the observed pattern of morph frequency is opposite to what the modelling results suggest in that the incidence of the least cryptic morph is highest where predation pressure is most severe. Clinal variation in the level of background matching between morphs or the potential reproductive advantage by the plain-backed morph may, instead, be driving the observed morph frequency. Together, these results provide key insights into the evolution of local adaptation as well as the ecological forces involved in driving the dynamics of colour polymorphism.",
keywords = "climate, evolution, latitudinal cline, local adaptation, phenotypic variation, reflectance, spectrometry, thermal biology",
author = "Genevieve Matthews and Goulet, {Celine T.} and Kaspar Delhey and Atkins, {Zak S.} and While, {Geoffrey M.} and Gardner, {Michael G.} and Chapple, {David G.}",
year = "2018",
month = "11",
day = "1",
doi = "10.1111/1365-2656.12894",
language = "English",
volume = "87",
pages = "1667--1684",
journal = "Journal of Animal Ecology",
issn = "0021-8790",
publisher = "Blackwell Science Ltd Oxford BSL",
number = "6",

}

Matthews, G, Goulet, CT, Delhey, K, Atkins, ZS, While, GM, Gardner, MG & Chapple, DG 2018, 'Avian predation intensity as a driver of clinal variation in colour morph frequency', Journal of Animal Ecology, vol. 87, no. 6, pp. 1667-1684. https://doi.org/10.1111/1365-2656.12894

Avian predation intensity as a driver of clinal variation in colour morph frequency. / Matthews, Genevieve; Goulet, Celine T.; Delhey, Kaspar; Atkins, Zak S.; While, Geoffrey M.; Gardner, Michael G.; Chapple, David G.

In: Journal of Animal Ecology, Vol. 87, No. 6, 01.11.2018, p. 1667-1684.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Avian predation intensity as a driver of clinal variation in colour morph frequency

AU - Matthews, Genevieve

AU - Goulet, Celine T.

AU - Delhey, Kaspar

AU - Atkins, Zak S.

AU - While, Geoffrey M.

AU - Gardner, Michael G.

AU - Chapple, David G.

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Phenotypic variation provides the framework for natural selection to work upon, enabling adaptive evolution. One of the most discernible manifestations of phenotypic variability is colour variation. When this variation is discrete, genetically based colour pattern morphs occur simultaneously within a population. Why and how colour polymorphisms are maintained is an evolutionary puzzle. Several evolutionary drivers have been hypothesized as influencing clinal patterns of morph frequency, with spatial variation in climate and predation being considered especially important. Despite this, no study has examined both of their roles simultaneously. The aims of this study were to: (a) examine the covariation of physiology, environmental variables and colouration at a local scale; and (b) determine if these factors and their interplay explain broad clinal variation in morph frequency. We used the lizard Liopholis whitii as a model system, as this species displays a discrete, heritable polymorphism for colour pattern (plain-backed, patterned morphs) whose morph frequency varies latitudinally. We measured reflectance, field activity temperatures and microhabitat structure to test for differences in crypsis, thermal biology and microhabitat selection of patterned and plain-backed morphs within a single population where colour morphs occur sympatrically. We then used data from the literature to perform a broad-scale analysis to identify whether these factors also explained the latitudinal variation of morph frequency in this species. At the local scale, plain-backed morphs were found to be less cryptic than patterned morphs while no other differences were detected in terms of thermal biology, dorsal reflectance and microhabitat use. At a broader scale, predation was the most influential factor mediating morph frequency across latitudes. However, the observed pattern of morph frequency is opposite to what the modelling results suggest in that the incidence of the least cryptic morph is highest where predation pressure is most severe. Clinal variation in the level of background matching between morphs or the potential reproductive advantage by the plain-backed morph may, instead, be driving the observed morph frequency. Together, these results provide key insights into the evolution of local adaptation as well as the ecological forces involved in driving the dynamics of colour polymorphism.

AB - Phenotypic variation provides the framework for natural selection to work upon, enabling adaptive evolution. One of the most discernible manifestations of phenotypic variability is colour variation. When this variation is discrete, genetically based colour pattern morphs occur simultaneously within a population. Why and how colour polymorphisms are maintained is an evolutionary puzzle. Several evolutionary drivers have been hypothesized as influencing clinal patterns of morph frequency, with spatial variation in climate and predation being considered especially important. Despite this, no study has examined both of their roles simultaneously. The aims of this study were to: (a) examine the covariation of physiology, environmental variables and colouration at a local scale; and (b) determine if these factors and their interplay explain broad clinal variation in morph frequency. We used the lizard Liopholis whitii as a model system, as this species displays a discrete, heritable polymorphism for colour pattern (plain-backed, patterned morphs) whose morph frequency varies latitudinally. We measured reflectance, field activity temperatures and microhabitat structure to test for differences in crypsis, thermal biology and microhabitat selection of patterned and plain-backed morphs within a single population where colour morphs occur sympatrically. We then used data from the literature to perform a broad-scale analysis to identify whether these factors also explained the latitudinal variation of morph frequency in this species. At the local scale, plain-backed morphs were found to be less cryptic than patterned morphs while no other differences were detected in terms of thermal biology, dorsal reflectance and microhabitat use. At a broader scale, predation was the most influential factor mediating morph frequency across latitudes. However, the observed pattern of morph frequency is opposite to what the modelling results suggest in that the incidence of the least cryptic morph is highest where predation pressure is most severe. Clinal variation in the level of background matching between morphs or the potential reproductive advantage by the plain-backed morph may, instead, be driving the observed morph frequency. Together, these results provide key insights into the evolution of local adaptation as well as the ecological forces involved in driving the dynamics of colour polymorphism.

KW - climate

KW - evolution

KW - latitudinal cline

KW - local adaptation

KW - phenotypic variation

KW - reflectance

KW - spectrometry

KW - thermal biology

UR - http://www.scopus.com/inward/record.url?scp=85053024210&partnerID=8YFLogxK

U2 - 10.1111/1365-2656.12894

DO - 10.1111/1365-2656.12894

M3 - Article

VL - 87

SP - 1667

EP - 1684

JO - Journal of Animal Ecology

JF - Journal of Animal Ecology

SN - 0021-8790

IS - 6

ER -

Matthews G, Goulet CT, Delhey K, Atkins ZS, While GM, Gardner MG et al. Avian predation intensity as a driver of clinal variation in colour morph frequency. Journal of Animal Ecology. 2018 Nov 1;87(6):1667-1684. https://doi.org/10.1111/1365-2656.12894