Plumage Convergence in Picoides Woodpeckers Based on a Molecular Phylogeny, With Emphasis on Convergence in Downy and Hairy Woodpeckers

Abstract

Abstract. Adult and juvenile plumage characters were traced onto a well-resolved molecular based phylogeny for Picoides woodpeckers, and a simple phylogenetic test of homology, parallelism, and convergence of plumage characters was performed. Reconstruction of ancestral character states revealed multiple events of independent evolution of derived character states in most characters studied, and a concentrated changes test revealed that some plumage characters evolved in association with habitat type. For example, there was a statistically significant association between loss of dorsal barring and use of densely vegetated habitats among Picoides species. Two analyses indicated that convergence, as opposed to parallel evolution or shared ancestry, underlies the similarity in plumage patterns between the Downy (Picoides pubescens) and Hairy (P. villosus) Woodpeckers. Possible causal explanations for convergence in plumage patterns may include mimicry and interspecific territoriality.Key words: adaptation, character evolution, convergence, Picoides, plumage, woodpeckers. Convergencia en Plumaje en Pájaros Carpinteros del Género Picoides Basada en una FilogeniaMolecular, con É nfasis en la Convergéncia entre Picoides pubescens y P. villosusResumen. Se reconstruyó la evolución de caracteres del plumaje de individuos adultos y juveniles con base en una filogenia molecular bien resuelta de los pájaros carpinteros del género Picoides. El estudio provee una prueba filogenética sencilla de homología, paralelismo y convergencia para los caracteres de plumaje. Las reconstrucciones de estados de caracter ancestrales revelaron múltiples eventos de evolución independiente de estados de caracter derivados en casi todos los caracteres estudiados, y una prueba de cambios concentrados reveló que algunos caracteres del plumaje evolucionaron en asociación con el tipo de hábitat. Por ejemplo, existe una asociación estadísticamente significativa entre la pérdida de barras dorsales y el uso de ambientes con vegetación densa en las especies de Picoides. Dos análisis indicaron que la similitud en los patrones de plumaje entre Picoides pubescens y P. villosus puede explicarse por convergencia, no por evolución paralela o por ancestría común. Se discuten posibles explicaciones causales para la convergencia, como la imitación y la territorialidad interespecífica.

Phylogenetic relationships of the Helmeted Woodpecker (Dryocopus galeatus): A case of interspecific mimicry?

“…He concluded that these plumage similarities were evidence of recent shared ancestry, in that ''the complexity of these color patterns precludes any reasonable possibility of their arising independently in three pairs of genera; no known selection forces could explain such a pattern of convergence.'' Over the past decade, molecular phylogenetic analyses have confirmed that the inverse is the case, documenting convergent evolution of phenotypic traits in 11 picid genera, and now our data provide yet another example in which plumage convergence in the Helmeted Woodpecker has confounded phylogenetic relationships in the Malarpicini (Webb and Moore 2005, Weibel and Moore 2005, Benz et al 2006, Moore et al 2006, Fuchs et al 2008. Although some uncertainty remains with respect to branching patterns among primary Celeus clades, our mitochondrial and nuclear data strongly support inclusion of D. galeatus within the genus (Figures 3 and 5).…”

“…Recent progress in assembling the avian tree of life has shed light on numerous instances of nonaposematic plumage convergence in disparate taxonomic groups (Weckstein 2005, Weibel and Moore 2005, Tello et al 2009, Jønsson et al 2010. The highest incidence, and perhaps the most comprehensive examples, of this phenomenon occur within the woodpeckers (Picidae), which exhibit convergent evolution of elaborate plumage patterns in !11 genera (Webb and Moore 2005, Weibel and Moore 2005, Benz et al 2006, Moore et al 2006, Fuchs et al 2008.…”

“…The highest incidence, and perhaps the most comprehensive examples, of this phenomenon occur within the woodpeckers (Picidae), which exhibit convergent evolution of elaborate plumage patterns in !11 genera (Webb and Moore 2005, Weibel and Moore 2005, Benz et al 2006, Moore et al 2006, Fuchs et al 2008. Although interspecific visual mimicry has long been suspected in various cases of avian plumage convergence, the adaptive significance and underlying socio-ecological mechanisms that promote phenotypic similarity in the absence of aposematism have received little attention and remain poorly understood compared with other forms of mimicry (Wallace 1869, Cody 1969, Diamond 1982, Ruxton et al 2004, Rainey and Grether 2007.…”

“…Elaborating upon the classic hawk-dove game, they used a well-documented case of plumage convergence between 2 North American woodpeckers (Picoides villosus and P. pubescens; Weibel and Moore 2005) to estimate the coevolutionary fitness dynamics between model and mimic, thereby establishing the conditions that promote evolution of interspecific social-dominance mimicry (ISDM). Prum and Samuelson (2012) defined ISDM as a type of social parasitism in which a smaller subordinate species uses visual deception to minimize competitive interference with a dominant model taxon and gain access to enhanced feeding opportunities.…”

An augmented supermatrix phylogeny of the avian family Picidae reveals uncertainty deep in the family tree

“…51 Woodpeckers are well known as ecosystem engineers, excavating 52 tree cavities that are subsequently used by numerous other species 53 of animals (Aitken and Martin, 2007;Cockle et al, 2011;Martin 54 and Eadie, 1999). The group also includes striking examples of 55 visual mimicry and convergent evolution (Benz et al,in press;56 Cody, 1969;Lammertink et al, 2015;Moore et al, 2006;Prum, 57 2014; Prum and Samuelson, 2012;Weibel and Moore, 2005;58 Winkler et al, 2014). A comprehensive species-level phylogeny 59 of the family is needed in order to more fully understand their bio-60 geography, convergence, morphological evolution and the evolu-61 tion of foraging modes and cavity-excavating behavior.…”