Publications by authors named "Jack D Lester"

Article Synopsis
  • Scientists study how animals change to survive in different places, which is really important for understanding biology.
  • They looked at chimpanzees, our closest relatives, who live in many types of environments like rainforests and savannahs.
  • By examining genetic information from wild chimpanzees, they discovered that some chimps have adapted to fight off malaria in similar ways to humans, showing how important genetic diversity is for endangered animals.
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Article Synopsis
  • This study provides the first comprehensive catalog of chimpanzee genetic diversity using non-invasive samples collected from 48 sites in Africa, focusing on chromosome 21.
  • The research reveals clear genetic differences among the four recognized chimpanzee subspecies and indicates unexpected local genetic exchanges, while also mapping patterns of population isolation, migration, and connectivity.
  • Unlike humans, chimpanzees lack a history of long-distance migrations, which may affect their cultural transmission, and the study introduces a precise geolocation method for identifying the origins of confiscated chimpanzees.
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Paleoclimate reconstructions have enhanced our understanding of how past climates have shaped present-day biodiversity. We hypothesize that the geographic extent of Pleistocene forest refugia and suitable habitat fluctuated significantly in time during the late Quaternary for chimpanzees (Pan troglodytes). Using bioclimatic variables representing monthly temperature and precipitation estimates, past human population density data, and an extensive database of georeferenced presence points, we built a model of changing habitat suitability for chimpanzees at fine spatio-temporal scales dating back to the Last Interglacial (120,000 BP).

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Understanding variation in host-associated microbial communities is important given the relevance of microbiomes to host physiology and health. Using 560 fecal samples collected from wild chimpanzees (Pan troglodytes) across their range, we assessed how geography, genetics, climate, vegetation, and diet relate to gut microbial community structure (prokaryotes, eukaryotic parasites) at multiple spatial scales. We observed a high degree of regional specificity in the microbiome composition, which was associated with host genetics, available plant foods, and potentially with cultural differences in tool use, which affect diet.

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Article Synopsis
  • Chimpanzees show diverse behaviors and inhabit various environments, but they are considered a discontinuous species with four subspecies separated by historical geography.
  • Genetic studies reveal that most of their genetic structure is influenced by distance rather than strict subspecies boundaries, indicating some geographic barriers were not effective in preventing gene flow.
  • Ongoing human impacts and habitat fragmentation threaten their genetic diversity, suggesting urgent conservation efforts are needed to maintain healthy populations.
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Social rank is positively correlated with reproductive success in numerous species, albeit demographic factors often influence those patterns. In multimale primate species, reproductive skew tends to decrease with increasing numbers of males and sexually receptive females. Alpha male chimpanzees (Pan troglodytes) often sire a disproportionate, though somewhat variable, percentage of offspring compared to other males.

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Although infanticide by wild adult male chimpanzees has been reported from multiple sites, affiliative infant carrying by males is rare. We observed infant carrying by an alpha male chimpanzee at Bulindi (Uganda) on two consecutive mornings and collected faecal samples from the newborn infant female, her mother and all candidate fathers to determine whether the alpha male was the infant's father using a likelihood-based method of paternity assignment. In contrast to previous observations of male care of orphans, in this case the mother was present during observations.

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Large-scale genomic studies of wild animal populations are often limited by access to high-quality DNA. Although noninvasive samples, such as faeces, can be readily collected, DNA from the sample producers is usually present in low quantities, fragmented, and contaminated by microorganism and dietary DNAs. Hybridization capture can help to overcome these impediments by increasing the proportion of subject DNA prior to high-throughput sequencing.

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Habitat fragmentation is a leading threat to global biodiversity. Dispersal plays a key role in gene flow and population viability, but the impact of fragmentation on dispersal patterns remains poorly understood. Among chimpanzees, males typically remain in their natal communities while females often disperse.

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As habitat loss and fragmentation place growing pressure on endangered nonhuman primate populations, researchers find increasing evidence for novel responses in behavior. In western Uganda between the Budongo and Bugoma Forests, chimpanzees () inhabit a mosaic landscape comprising forest fragments, human settlements, and agricultural land. We recorded nests and feeding evidence of unhabituated chimpanzees in this region over a 12-mo period.

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Background: As habitat degradation and fragmentation continue to impact wildlife populations around the world, it is critical to understand the behavioral flexibility of species in these environments. In Uganda, the mostly unprotected forest fragment landscape between the Budongo and Bugoma Forests is a potential corridor for chimpanzees, yet little is known about the status of chimpanzee populations in these fragments.

Results: From 2011 through 2013, we noninvasively collected 865 chimpanzee fecal samples across 633 km(2) and successfully genotyped 662 (77%) at up to 14 microsatellite loci.

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We sought evidence for a distinct diapause in adult overwintering mountain pine beetles (Dendroctonus ponderosae Hopkins) by measuring metabolic rate and supercooling ability of field collected beetles throughout the year. Metabolic rates measured at 0, 5, and 10°C declined significantly from October through November, then rose slowly, reaching levels as high as those recorded in October by late May. From December to February metabolic rates were not correlated with minimum weekly phloem temperatures (R(2)=0.

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