Data from: Seeing spots: measuring, quantifying heritability, and assessing fitness consequences of coat pattern traits in a wild population of giraffes (Giraffa camelopardalis)

Little is known about the heritability and fitness consequences of polymorphic variation in mammalian coat pattern traits in wild populations. Understanding the evolution of coat patterns requires reliably measuring traits, quantifying heritability of the traits, and identifying the fitness consequences of specific phenotypes. Giraffe coat markings are highly variable and it has been hypothesized that variation in coat patterns most likely affects fitness by camouflaging neonates against predators. We quantified spot pattern traits of wild Masai giraffes using image analysis software, determined whether spot pattern traits were heritable, and assessed whether variation in heritable spot pattern traits was related to fitness as measured by juvenile survival. The methods we described comprise a framework for objective quantification of mammalian coat pattern traits based on photographic coat pattern data, and spot trait measurements from individuals could be used as input to a cluster analysis for taxonomic or other group classifications. We demonstrated that characteristics of giraffe coat spot shape and color are heritable. We did not find evidence for fitness consequences of variation in spot traits on juvenile survival, suggesting that spot traits are currently not under strong directional or stabilizing selection for neonate camouflage in our study population. This may be due to either reduced predation pressure in the study area, or because spot variation may be more relevant to other components of fitness, such as adult survival or fecundity.