Genetic assessment reveals inbreeding, possible hybridization, and low levels of genetic structure in a declining goose population

Abstract

The population numbers of taiga bean goose (Anser fabalis fabalis) have halved during recent decades. Since this subspecies is hunted throughout most of its range, the decline is of management concern. Knowledge of the genetic population structure and diversity is important for guiding management and conservation efforts. Genetically unique subpopulations might be hunted to extinction if not managed separately, and any inbreeding depression or lack of genetic diversity may affect the ability to adapt to changing environments and increase extinction risk. We used microsatellite and mitochondrial DNA markers to study the genetic population structure and diversity among taiga bean geese breeding within the Central flyway management unit using noninvasively collected feathers. We found some genetic structuring with the maternally inherited mitochondrial DNA between four geographic regions (ɸ ST = 0.11-0.20) but none with the nuclear microsatellite markers (all pairwise F ST -values = 0.002-0.005).These results could be explained by female natal philopatry and male-biased dispersal, which completely homogenizes the nuclear genome. Therefore, the population could be managed as a single unit. Genetic diversity was still at a moderate level (average H E = 0.69) and there were no signs of past population size reductions, although significantly positive inbreeding coefficients in all sampling sites (F IS = 0.05-0.10) and high relatedness values (r = 0.60-0.86) between some individuals could indicate inbreeding. In addition, there was evidence of either incomplete lineage sorting or introgression from the pink-footed goose (Anser brachyrhynchus). The current population is not under threat by genetic impoverishment but monitoring in the future is desirable.

When and where to count? Implications of migratory connectivity and nonbreeding distribution to population censuses in a migratory bird population

“…As pair formation among waterfowl usually takes place during winter (Rohwer & Anderson, 1988), low migratory connectivity between breeding and wintering sites should lead to genetically mixed populations. Birds marked in Finland (breeding both in Finland and Russia) showed low connectivity (Figure 3), so our results are coherent with the recent study by Honka et al (2022), who found no genetic structure among the taiga bean geese sampled in Finland. The geese wintering in Denmark showed higher migratory connectivity (Figure 3), potentially leading to genetic differentiation between the birds wintering in Denmark and Sweden, although this has not been investigated to date.…”

When and where to count? Implications of migratory connectivity and non-breeding distribution to population censuses in a migratory bird population

“…As pair formation among waterfowl usually takes place during winter (Rohwer & Anderson, 1988), low migratory connectivity between breeding and wintering sites should lead to genetically mixed populations. Birds marked in Finland (breeding both in Finland and Russia) showed low connectivity (Figure 3), so our results are coherent with the recent study by Honka et al, (2022), who found no genetic structure among the taiga bean geese sampled in Finland. The geese wintering in Denmark showed higher migratory connectivity (Figure 3), potentially leading to genetic differentiation between the birds wintering in Denmark and Sweden.…”

Productive qualities of geese when crossing breeds and using hepatoprotective complex

“…The offspring obtained from crossing those breeds surpassed the parental breeds in productivity and viability. In addition, they indicate the influence of interbreeding on the exterior features of poultry, affecting its meat productivity (Honka et al, 2022; Ivanov et al, 2021; Lee, 2021). A group of scientists working with Lalev et al (2014), obtained similar results.…”