Quantitative genetics in the monk parakeet (Myiopsitta monachus) from central Argentina: Estimation of heritability and maternal effects on external morphological traits.

Suzannah Rutherford,Enrique H Bucher,María C De Aranzamendi,Juan J Martínez

doi:10.1371/journal.pone.0201823

Abstract

The monk parakeet (Myiopsitta monachus) is a South American species unique among parrots; it builds communal stick nests that allow independence from tree or cliff cavities required by most parrots. As a very successful invasive species, it has expanded into several countries around the world. Questions remain around the factors that allowed this species to be such a successful invader in its native range as in other countries, and particularly the extent that evolutionary processes may be involved in adapting to new areas. Along with this line of analysis, we focused on assessing whether morphological characteristics are sufficiently heritable, and therefore responsive to selection. As the first step in this direction, we have estimated heritability of monk parakeet in six external morphological traits considered of potential adaptability value. Samples were obtained in the province of Córdoba in central Argentina. Data from seven microsatellites were used to determine the familial relationships among individuals. Heritabilities and genetic correlations were estimated by means of animal models. We found evidence for significant heritability in the six traits measured, particularly in weight, tarsus length and bill width. We also found evidence of maternal effects on morphological traits, particularly in the traits with lower heritability: wing length, bill length and tail length. Genetic correlations between traits were significant and associated with phenotypic correlations, suggesting that these traits are constrained in terms of evolutionary potential, whereas the amount of additive genetic variance in weight, tarsus length and bill width indicate that these traits could be responsive to selection.

Highlights

The monk parakeet (Myiopsitta monachus) is a South American species unique among parrots since it builds communal stick nests
We found significant genetic correlations between wing length and bill length, wing length and Morphological traits that cause variation in fitness have the potential to evolve over time if those traits are sufficiently heritable and responsive to selection [37]
Quantitative genetics in the monk parakeet evidence for significant heritability in the six traits measured and open the possibility of these traits being under natural selection pressure, during adaptation to new environments occupied by this species

Summary

Introduction

The monk parakeet (Myiopsitta monachus) is a South American species unique among parrots since it builds communal stick nests. Goncalves da Silva et al [19] did not find cases of EPP in any of the three studied populations of monk parakeets (one in the species’ native area in Argentina and two in invasive areas in the USA), but Martınez et al [20] found evidence of EPP (40% of breeding chambers) and intra-brood parasitism (3% of chambers) in a population from central Argentina Another non-genetic cause of resemblance between parents and offspring is the existence of maternal effects, when the phenotype of an individual is determined by its own genotype and the environmental conditions it experience during development and by the phenotype or environment of its mother [12]. Maternal and nest effects were considered to account for non-genetic resemblance between individuals

Material and methods

Results

Discussion

Conclusions