Source: Ecology and Evolution
Institutions Involved: Department of Botany & Zoology, Stellenbosch University. Conservation Services, South African National Parks.
A South African study suggests low levels of hybridization
between African wildcats (Felis silvestris lybica) and domestic cats (F. s.
catus) in South Africa, according to a study by Johannes J. Le Roux at Stellenbosch
University and colleagues.
African wildcats have been living across the whole entire
African continent, sparing tropical forests and true deserts, yet very little
research has been completed previously comparing its genetic and hybridization
status with the common domestic cat. Overall, the populations of African
wildcats tested were found to be relatively pure; however, the most genetically
“impure” samples were found in areas where high human activity and pressure
were recorded. This alludes to the unfortunate universal trend of declining biodiversity,
despite global conservation efforts.
This study was funded by a British Ecological Society Overseas
Bursary Fund. 165 tissue and hair
samples were tested, including 116 African wildcats or their suspected hybrids,
and 49 domestic cats. In order to obtain these numbers, “Tissue and hair material
of African wildcats and domestic cats were obtained from various sources”, so
that there is both a historic and contemporary basis of comparison between the
African wildcats and the domestic cats. The study delineated specific
guidelines concerning the classification of the animals by phenotypic
characteristics: “African wildcats have distinctive coat-patterns,
characteristic long legs, and a prominent reddish tint behind the ears. Cats
with typical wildcat markings and coloration but with darker ears were
classified as putative hybrids. Additionally, the legs of hybrids cats are
visibly shorter than those of pure wildcats.”
The researches selected 13 unlinked microsatellite markers (repeating
sequences in 2-5 base pairs of DNA) previously characterized in domestic cats
for genetic comparison. Using assignment values and their respective standard
deviations, the researchers were able to class individual genotypes into purity
categories. Of African wildcats
collected outside protected areas (n = 68), seven individuals had admixed
hybrid genotypes, while two cats of these cats highly resembled the domestic
cat genome cluster. Mostly all of the wildcats from protected enclosures were
genetically pure.
Likewise, human activity proved to be detrimental to genetic purity. Levels
of genetic dispersion were significantly lower for African wildcats inside or very
proximate to protected areas (p-value 0.02169, which is statistically
significant at the 0.01 level). Also, there is a 0.026 p-value associated with distance
from the nearest town, which further strengthens the claim that human
population has a significant negative effect on the genetic purity of African
wildcats. Feral cat populations are still of considerable growing concern due
to their presence across the entire African wildcat range, particularly in
urban areas. Likewise, the purest populations were found inside protected
areas. This is in direct contrast to the formerly held belief that no protected
areas in South Africa were viable for maintaining genetic purity in African
wildcats. Overall, this study strengthens the prominent global conservation
efforts as necessitated to maintain genetic sanctity and biodiversity, which is
critical to a healthy ecosystem and continued sustainable development.
Citation: Le Roux, J. Foxcroft, L. Herbst, M. MacFadyen, S. Genetic analysis shows low levels of hybridization between African wildcats (Felis silvestris lybica) and domestic cats (F. s. catus) in South Africa. Ecology and Evolution 2015; 5(2):288-299
It is interesting, but not surprising, to see how indirect human involvement affects the offspring of the wildcats. Perhaps if pet owners responsibly spayed and neutered their pets, feral cat populations would not be a problem, and domestic cats would likely not encroach on wildcat territory.
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