Doves under surveillanceWed 11 Jan, 2017
On the western coast of Barbados, doves go around with a ring on their leg. Not that they are particularly concerned about fashion; these attributes are in fact evidence of a major study focused on this population of tropical birds.
Since 2007, several researchers work on the field each spring and fall, almost daily, to study the Caribbean endemic Zenaida dove, Zenaida aurita. Hundreds of birds have been captured, measured, and blood sampled, and equipped with a unique combination of rings of different colors, before being released. Blood sampling, which consists in collecting only a few drops, is essential to distinguish males from females in this species, where there is almost no sexual dimorphism, and also serves to determine the genetic richness of individuals, or heterozygosity.
Many results have already emerged from this large study. For example, it revealed that the body size of individuals influences their lifestyle, as territorial or not, or that this size as well as the genetic richness of individuals can play a role in pairing patterns.
In the latest study, the team examined further the heterozygosity. For this, nearly 400 individuals had their genotype investigated at 11 different places, called microsatellite markers, revealing this genetic richness. By combining all the observations recorded for these individuals since their ringing, researchers were able to estimate the probability of their survival. Results show that the higher is the genetic richness of an individual, the higher is its probability of surviving from one year to another, and therefore the greater is its life expectancy, with a difference that is measured in years. Although the positive effect of the genetic richness have already been demonstrated in other species, this study is the first to provide evidence of this phenomenon in an endemic Caribbean species.
Cézilly, F., Quinard, A., Motreuil, S. & Pradel, R. 2015. Adult survival selection in relation to multilocus heterozygosity and body size in a tropical bird species, the Zenaida dove, Zenaida aurita. Oecologia, 180, 127-136.