Length polymorphisms at two candidate genes explain variation of migratory behaviors in blackpoll warblers (Setophaga striata)

Abstract

Migratory behaviors such as the timing and duration of migration are genetically inherited and can be under strong natural selection, yet we still know very little about the specific genes or molecular pathways that control these behaviors. Studies in candidate genes Clock and Adcyap1 have revealed that both of these loci can be significantly correlated with migratory behaviors in birds, though observed relationships appear to vary across species. We investigated geographic genetic structure of Clock and Adcyap1 in four populations of blackpoll warblers ( Setophaga striata ), a Neotropical–Nearctic migrant that exhibits geographic variation in migratory timing and duration across its boreal breeding distribution. Further, we used data on migratory timing and duration, obtained from light‐level geolocator trackers to investigate candidate genotype–phenotype relationships at the individual level. While we found no geographic structure in either candidate gene, we did find evidence that candidate gene lengths are correlated with five of the six migratory traits. Maximum Clock allele length was significantly and negatively associated with spring arrival date. Minimum Adcyap1 allele length was significantly and negatively associated with spring departure date and positively associated with fall arrival date at the wintering grounds. Additionally, we found a significant interaction between Clock and Adcyap1 allele lengths on both spring and fall migratory duration. Adcyap1 heterozygotes also had significantly shorter migration duration in both spring and fall compared to homozygotes. Our results support the growing body of evidence that Clock and Adcyap1 allele lengths are correlated with migratory behaviors in birds.

Hybridization alters growth and migratory life‐history expression of native trout

“…Our findings of a genetic driver of migratory life history variation align with recent findings from salmonids (Hecht et al, 2013;Kelson et al, 2019;Pearse et al, 2019) and other vertebrate taxa (mammals -Berg et al, 2019;McDevitt et al, 2009;birds -Delmore et al, 2016;Ralston et al, 2019).…”

Shorebird’s Longer Migratory Distances are Associated with Larger ADCYAP1 Microsatellites and Greater Morphological Complexity of Hippocampal Astrocytes

“…Although the observed relationships between candidate genes CLOCK and ADCYAP1 and migratory behavior in birds appear to vary across species, previous studies revealed that both loci can be signi cantly correlated with a variety of distinct phenotypes in long distance migratory birds [2,81]. For example, in blackpoll warblers (Setophaga striata), a Neotropical-Nearctic migrant, minimum ADCYAP1 allele length was signi cantly and negatively associated with spring departure date and positively associated with fall arrival date at the wintering grounds [5]. Longer ADCYAP1 alleles seem to be associated with earlier spring arrival dates [6], earlier postnatal dispersal and plumage morph [82], greater migratory restlessness [1,4].…”

“…Speci c genes or gene regions, and polymorphisms at candidate genes, may explain phenotypic variance in many aspects of migratory behavior [2]. Previous studies have pointed out that ADCYAP1 and CLOCK gene expression are essential to the control of migratory behavior but there is controversy about whether allele size is associated with migratory activity, spring and fall migratory duration, and arrival and departure dates [1,[3][4][5]. In addition, it has been suggested that potential interaction between ADCYAP1, wing morphology and sex predict spring migration arrival in blackcap populations [6] and that both ADCYAP1 and CLOCK gene alleles increase in size with breeding latitude in trans-Saharan migratory birds [2,7].…”

Spring migration of Blackpoll Warblers across North America

“…Blackpoll Warblers are an excellent model species to explore strategies during spring migration because of their extensive breeding range spanning the continent in the boreal forest, their long-distance migration, and their clear sexual dichromatism. As a result of their breeding range, the distance traveled from their South American wintering grounds by Blackpoll Warblers breeding furthest west is twice that of those breeding in the eastern parts of their range (Morris et al 2016, DeLuca et al 2019. Despite these potentially interesting differences in migration patterns across the range of this species, the majority of studies have focused on a single site (e.g., Morris et al 1994, Dunn 2002, Bonter et al 2007, Holzschuh and Deutschlander 2016 until recently (DeLuca et al 2019).…”

“…As a result of their breeding range, the distance traveled from their South American wintering grounds by Blackpoll Warblers breeding furthest west is twice that of those breeding in the eastern parts of their range (Morris et al 2016, DeLuca et al 2019. Despite these potentially interesting differences in migration patterns across the range of this species, the majority of studies have focused on a single site (e.g., Morris et al 1994, Dunn 2002, Bonter et al 2007, Holzschuh and Deutschlander 2016 until recently (DeLuca et al 2019). Rosenberg et al (2016) have suggested that Blackpoll Warbler populations are declining at one of the highest rates of all North American birds.…”