Dispersal: from “neutral” to a state- and context-dependent view

Abstract

last sentence, « Our findings show that reduced resource competition might facilitate female philopatry and that prior knowledge of an area does not appear to be a prerequisite for male great-tailed grackles to establish breeding territories”: The beginning of the sentence needs to be reformulated, as this study was not designed to assess the effect of resource competition on dispersal. Main hypothesis: “Based on the argument that males are expected to be philopatric when they defend resources beneficial to females”: In the paragraph describing the species behavior it is suggested that only some males defend territories. So it is surprising for the reader that the formulation of the main hypothesis relies on the idea that males defend resources. It is only when reading the alternative hypotheses that the reader understands that the different hypotheses are based on different aspects of the species behaviour. I suggest slightly reformulating the main hypothesis to make clear that it really means “given that some males defend resources, in which case males are expected to be philopatric and females to disperse to avoid mating with relatives, (...)”. Alternative hypothesis 2: “The polygamous mating system of great-tailed grackles, where females might be able to choose among potential males, might reduce a female’s risk of mating with their father or brother.” This argument is valid only if females can discriminate relatives from non relatives. Has this been demonstrated in this species? l.108: IN the methods below. l.119-124: It is currently difficult to distinguish the parameters from Thrasher et al. 2018 and those specific to the study presented in this ms, because of missing brackets and long sentences with semi-columns. Some rewording would help. Results, l.159-164: It would be informative to add an estimate of the total size of the population, if it is know. That would allow to assess how representative the genetic sample is. Results, l.161-164: How was the probability of identity of siblings estimated? (And heterozygosity compared to expected in a population with random mating? – Do the authors simply mean HW equilibrium, here (but they would have forgotten other conditions of HW equilibrium))? This piece of information is missing from the method section.