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Landscape genetics of the nonnative red fox of California

View Article: PubMed Central - PubMed

ABSTRACT

Invasive mammalian carnivores contribute disproportionately to declines in global biodiversity. In California, nonnative red foxes (Vulpes vulpes) have significantly impacted endangered ground‐nesting birds and native canids. These foxes derive primarily from captive‐reared animals associated with the fur‐farming industry. Over the past five decades, the cumulative area occupied by nonnative red fox increased to cover much of central and southern California. We used a landscape‐genetic approach involving mitochondrial DNA (mtDNA) sequences and 13 microsatellites of 402 nonnative red foxes removed in predator control programs to investigate source populations, contemporary connectivity, and metapopulation dynamics. Both markers indicated high population structuring consistent with origins from multiple introductions and low subsequent gene flow. Landscape‐genetic modeling indicated that population connectivity was especially low among coastal sampling sites surrounded by mountainous wildlands but somewhat higher through topographically flat, urban and agricultural landscapes. The genetic composition of populations tended to be stable for multiple generations, indicating a degree of demographic resilience to predator removal programs. However, in two sites where intensive predator control reduced fox abundance, we observed increases in immigration, suggesting potential for recolonization to counter eradication attempts. These findings, along with continued genetic monitoring, can help guide localized management of foxes by identifying points of introductions and routes of spread and evaluating the relative importance of reproduction and immigration in maintaining populations. More generally, the study illustrates the utility of a landscape‐genetic approach for understanding invasion dynamics and metapopulation structure of one of the world's most destructive invasive mammals, the red fox.

No MeSH data available.


Related in: MedlinePlus

Genotypic assignments with bar graphs indicating the ancestry fraction (q) apportioned to individual genotypes of nonnative red foxes from California, showing 221 individuals with high assignment to a single cluster (qmax > 75%, top) and 160 admixed individuals (qmax < 75%, bottom) in 1 of K = 8 clusters according to admixture analysis in program Structure. Clusters indicated by light and dark shades of the same colors indicate those clustered together at K = 6 and 7 (green) or K = 6 (blue).
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ece32229-fig-0006: Genotypic assignments with bar graphs indicating the ancestry fraction (q) apportioned to individual genotypes of nonnative red foxes from California, showing 221 individuals with high assignment to a single cluster (qmax > 75%, top) and 160 admixed individuals (qmax < 75%, bottom) in 1 of K = 8 clusters according to admixture analysis in program Structure. Clusters indicated by light and dark shades of the same colors indicate those clustered together at K = 6 and 7 (green) or K = 6 (blue).

Mentions: At K = 8, most sampling sites were characterized by at least one cluster representative of the home population (Fig. 6). In some cases, these home clusters also predominated in adjacent sampling sites, suggesting they reflected the same population: (1) the South and West SF Bay, (2) Presidio and Half Moon Bay, and (3) SB and SO. In the first two cases, mtDNA haplotype frequencies supported subsuming of the sites in a single population, but SB and SO did not share any mtDNA haplotypes, suggesting these were distinct populations, at least maternally, despite clustering together with microsatellites (Table 1).


Landscape genetics of the nonnative red fox of California
Genotypic assignments with bar graphs indicating the ancestry fraction (q) apportioned to individual genotypes of nonnative red foxes from California, showing 221 individuals with high assignment to a single cluster (qmax > 75%, top) and 160 admixed individuals (qmax < 75%, bottom) in 1 of K = 8 clusters according to admixture analysis in program Structure. Clusters indicated by light and dark shades of the same colors indicate those clustered together at K = 6 and 7 (green) or K = 6 (blue).
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4979706&req=5

ece32229-fig-0006: Genotypic assignments with bar graphs indicating the ancestry fraction (q) apportioned to individual genotypes of nonnative red foxes from California, showing 221 individuals with high assignment to a single cluster (qmax > 75%, top) and 160 admixed individuals (qmax < 75%, bottom) in 1 of K = 8 clusters according to admixture analysis in program Structure. Clusters indicated by light and dark shades of the same colors indicate those clustered together at K = 6 and 7 (green) or K = 6 (blue).
Mentions: At K = 8, most sampling sites were characterized by at least one cluster representative of the home population (Fig. 6). In some cases, these home clusters also predominated in adjacent sampling sites, suggesting they reflected the same population: (1) the South and West SF Bay, (2) Presidio and Half Moon Bay, and (3) SB and SO. In the first two cases, mtDNA haplotype frequencies supported subsuming of the sites in a single population, but SB and SO did not share any mtDNA haplotypes, suggesting these were distinct populations, at least maternally, despite clustering together with microsatellites (Table 1).

View Article: PubMed Central - PubMed

ABSTRACT

Invasive mammalian carnivores contribute disproportionately to declines in global biodiversity. In California, nonnative red foxes (Vulpes vulpes) have significantly impacted endangered ground&#8208;nesting birds and native canids. These foxes derive primarily from captive&#8208;reared animals associated with the fur&#8208;farming industry. Over the past five decades, the cumulative area occupied by nonnative red fox increased to cover much of central and southern California. We used a landscape&#8208;genetic approach involving mitochondrial DNA (mtDNA) sequences and 13 microsatellites of 402 nonnative red foxes removed in predator control programs to investigate source populations, contemporary connectivity, and metapopulation dynamics. Both markers indicated high population structuring consistent with origins from multiple introductions and low subsequent gene flow. Landscape&#8208;genetic modeling indicated that population connectivity was especially low among coastal sampling sites surrounded by mountainous wildlands but somewhat higher through topographically flat, urban and agricultural landscapes. The genetic composition of populations tended to be stable for multiple generations, indicating a degree of demographic resilience to predator removal programs. However, in two sites where intensive predator control reduced fox abundance, we observed increases in immigration, suggesting potential for recolonization to counter eradication attempts. These findings, along with continued genetic monitoring, can help guide localized management of foxes by identifying points of introductions and routes of spread and evaluating the relative importance of reproduction and immigration in maintaining populations. More generally, the study illustrates the utility of a landscape&#8208;genetic approach for understanding invasion dynamics and metapopulation structure of one of the world's most destructive invasive mammals, the red fox.

No MeSH data available.


Related in: MedlinePlus