Evaluating ring‐tailed lemurs (Lemur catta) from southwestern Madagascar for a genetic population bottleneck

Abstract

In light of historical and recent anthropogenic influences on Malagasy primate populations, in this study ring-tailed lemur (Lemur catta) samples from two sites in southwestern Madagascar, Beza Mahafaly Special Reserve (BMSR) and Tsimanampetsotsa National Park (TNP), were evaluated for the genetic signature of a population bottleneck. A total of 45 individuals (20 from BMSR and 25 from TNP) were genotyped at seven microsatellite loci. Three methods were used to evaluate these populations for evidence of a historical bottleneck: M-ratio, mode-shift, and heterozygosity excess tests. Three mutation models were used for heterozygosity excess tests: the stepwise mutation model (SMM), two-phase model (TPM), and infinite allele model (IAM). M-ratio estimations indicated a potential bottleneck in both populations under some conditions. Although mode-shift tests did not strongly indicate a population bottleneck in the recent historical past when samples from all individuals were included, a female-only analysis indicated a potential bottleneck in TNP. Heterozygosity excess was indicated under two of the three mutation models (IAM and TPM), with TNP showing stronger evidence of heterozygosity excess than BMSR. Taken together, these results suggest that a bottleneck may have occurred among L. catta in southwestern Madagascar in the recent past. Given knowledge of how current major stochastic climatic events and human-induced change can negatively impact extant lemur populations, it is reasonable that comparable events in the historical past could have caused a population bottleneck. This evaluation additionally functions to highlight the continuing environmental and anthropogenic challenges faced by lemurs in southwestern Madagascar.

Genetic Diversity of the Ring-Tailed Lemur (Lemur catta) in South-Central Madagascar

“…When compared to L. catta populations within the markedly larger Bezà Mahafaly Special Reserve (BMSR) (600 ha) and Tsimanampesotse National Park (TNP) (48,000 ha) in southwestern Madagascar, similar average H O levels (0.82 and 0.82) were found [Parga et al, 2012]. However, in contrast, the 'mean numbers of alleles per locus' were greater across all loci for L. catta populations within the BMSR (MNA = 9.5) and TNP (MNA = 9.8) [Parga et al, 2012].…”

“…For our comparisons with Parga et al [2012], we only included the markers that were identical to our sample.…”

“…It should be noted that Parga et al [2012] had a larger sample size (BMST = 20, TNP = 25) and utilized 8 mi crosatellite loci for their analyses. For our comparisons with Parga et al [2012], we only included the markers that were identical to our sample.…”

Seasonal Feeding Ecology of Ring-Tailed Lemurs: A Comparison of Spiny and Gallery Forest Habitats

“…trees, shrubs, caves), in addition to sufficient food resources, although they can cope with variations in macronutrient (crude protein) and fiber (ADF) content within their foods. Long-term viability of ring-tailed lemurs in extremely isolated or altered habitats is not yet known, but populations are likely to be more affected by genetic bottlenecks [Parga et al, 2012] and inability to disperse across discontinuous habitat than by diet, given their ability to exploit similar plant parts, yet persist on differing macronutrient contents.…”

Genetic Evidence for Male and Female Dispersal in Wild Lemur catta

“…We studied L. catta in 2 areas of southwestern Madagascar: Bezà Mahafaly Special Reserve (BMSR) and Tsimanampesotse National Park (TNP) [Parga et al, 2012]. TNP is located approximately 135 km southwest of BMSR [Cuozzo et al, 2008].…”