Plant Species with Potential as Food,Nesting Material,or Tools at a Chimpanzee Refuge Site in Caddo Parish,Louisiana

Surplus chimpanzees live in research laboratories where they will likely remain for the rest of their lives. An alternative to laboratory housing is an outdoor enclosure in a warm climate. Before construction, researchers should conduct a vegetation survey because chimpanzees use vegetation daily. Chimp Haven, Inc. is developing a chimpanzee sanctuary in Caddo Parish, Louisiana, and we conducted a vegetation survey at the site to 1) characterize the abundance and structure of vegetation; 2) identify plants with utility as food, nesting material, or tools; 3) determine the abundance and distribution of useful vegetation; and 4) identify any possibly hazardous vegetation. We established 48 plots, quantified the woody vegetation, and identified potentially useful and hazardous plant species from the published literature. Vegetation at the site was secondary growth from logging of loblolly pine (Pinus taeda), the most abundant tree. Other abundant trees included oak (Quercus spp.), elm (Ulmus spp.), sweetgum (Liquidambar styraciflua), and maple (Acer spp.). Small plants (1–9.9 m tall) constituted 95% of all vegetation. Forty-one of 64 plant species have edible vegetative parts, while 35 species have edible reproductive parts. We identified 55 potential nesting trees by size (dbh ≥ 25 cm) and 4 species used as tools by captive great apes. Useful vegetation was concentrated in areas with topographic relief or in a floodplain, while flat areas with fields had less. We recommend that the floodplain be cropped for fruit and browse and enclosures encompass areas with relief and fields, creating a diverse habitat.     

Disappearance rate of chimpanzee scats: Implications for census work on Pan troglodytes

Scat (faeces) decay rate estimates are used to calculate animal species abundance and density. For African great apes, this has been measured only for Gorilla; chimpanzee scats are assumed to decay at a faster rate due to lower fibre content. We provide the first systematic measure of scat decay rate duration for Pan troglodytes schweinfurthii, in Kanyawara, Kibale National Park, Uganda. We used two methods: (1) multiple visits to obtain prospective decay rates (PDR) (N = 96 scats) and (2) a novel approach of time‐lapse photography (TLP) (N = 17 scats). Most of the visited scats (67%) decayed in ≤24 hr, and median decay rate duration from photographic documentation was 18 hr. Using regression analyses, we tested 11 covariables to determine predictors for decay rate duration. Greater volume of scat and reduced levels of diurnal dung beetle activity were positively associated with longer decay rate duration. Given a high prevalence of dung beetle activity (88% of scats), particularly within 3 hr post‐defaecation, we suggest the use of the alternative term, disappearance rate of scats. With a rapid disappearance rate, scat count surveys of unhabituated chimpanzees are challenging; further work is then needed for Pan spp. to determine spatial and temporal differences at intra‐ and inter‐species level.     

Sir2 blocks extreme life-span extension

Sir2 is a conserved deacetylase that modulates life span in yeast, worms, and flies and stress response in mammals. In yeast, Sir2 is required for maintaining replicative life span, and increasing Sir2 dosage can delay replicative aging. We address the role of Sir2 in regulating chronological life span in yeast. Lack of Sir2 along with calorie restriction and/or mutations in the yeast AKT homolog, Sch9, or Ras pathways causes a dramatic chronological life-span extension. Inactivation of Sir2 causes uptake and catabolism of ethanol and upregulation of many stress-resistance and sporulation genes. These changes while sufficient to extend chronological life span in wild-type yeast require severe calorie restriction or additional mutations to extend life span of sir2Delta mutants. Our results demonstrate that effects of SIR2 on chronological life span are opposite to replicatve life span and suggest that the relevant activities of Sir2-like deacetylases may also be complex in higher eukaryotes.     

Limiting the metabolic burden of recombinant protein expression during selection yields pools with higher expression levels

In order to avoid the metabolic burden of protein expression during cell growth, and to avoid potential toxicity of recombinant proteins, microbial expression systems typically utilize regulated expression vectors. In contrast, constitutive expression vectors have usually been utilized for isolation of protein expressing mammalian cell lines. In mammalian systems, inducible expression vectors are typically utilized for only those proteins that are toxic when overexpressed. We developed a tetracycline regulated expression system in CHO cells, and show that cell pools selected in the uninduced state recover faster than those selected in the induced state even though the proteins showed no apparent toxicity or expression instability. Furthermore, cell pools selected in the uninduced state had higher expression levels when protein expression was turned on only in production cultures compared to pools that were selected and maintained in the induced state through production. We show a titer improvement of greater than twofold for an Fc-fusion protein and greater than 50% improvement for a recombinant antibody. The improvement is primarily due to an increase in specific productivity. Recombinant protein mRNA levels correlate strongly with protein expression levels and are highest in those cultures selected in the uninduced state and only induced during production. These data are consistent with a model where CHO cell lines with constitutive expression select for subclones with lower expression levels.     

Cumulative culture in nonhumans: overlooked findings from Japanese monkeys?

Cumulative culture, generally known as the increasing complexity or efficiency of cultural behaviors additively transmitted over successive generations, has been emphasized as a hallmark of human evolution. Recently, reviews of candidates for cumulative culture in nonhuman species have claimed that only humans have cumulative culture. Here, we aim to scrutinize this claim, using current criteria for cumulative culture to re-evaluate overlooked qualitative but longitudinal data from a nonhuman primate, the Japanese monkey (Macaca fuscata). We review over 60 years of Japanese ethnography of Koshima monkeys, which indicate that food-washing behaviors (e.g., of sweet potato tubers and wheat grains) seem to have increased in complexity and efficiency over time. Our reassessment of the Koshima ethnography is preliminary and nonquantitative, but it raises the possibility that cumulative culture, at least in a simple form, occurs spontaneously and adaptively in other primates and nonhumans in nature.     

Cladistic analyses of behavioural variation in wild Pan troglodytes: exploring the chimpanzee culture hypothesis

Long-term field studies have revealed considerable behavioural differences among groups of wild Pan troglodytes. Here, we report three sets of cladistic analyses that were designed to shed light on issues relating to this interpopulation variation that are of particular relevance to palaeoanthropology.In the first set of analyses, we focused on the proximate cause of the variation. Some researchers have argued that it is cultural, while others have suggested that it is the result of genetic differences. Because the eastern and western subspecies of P. troglodytes are well differentiated genetically while groups within the subspecies are not, we reasoned that if the genetic hypothesis is correct, the phylogenetic signal should be stronger when data from the eastern and western subspecies are analysed together compared to when data from only the eastern subspecies are analysed. Using randomisation procedures, we found that the phylogenetic signal was substantially stronger with in a single subspecies rather than with two. The results of the first sets of analyses, therefore, were inconsistent with the predictions of the genetic hypothesis.The other two sets of analyses built on the results of the first and assumed that the intergroup behavioural variation is cultural in nature. Recent work has shown that, contrary to what anthropologists and archaeologists have long believed, vertical intergroup transmission is often more important than horizontal intergroup transmission in human cultural evolution. In the second set of analyses, we sought to determine how important vertical transmission has been in the evolution of chimpanzee cultural diversity. The first analysis we carried out indicated that the intergroup similarities and differences in behaviour are consistent with the divergence of the western and eastern subspecies, which is what would be expected if vertical intergroup transmission has been the dominant process. In the second analysis, we found that the chimpanzee cultural data are not only comparable to a series of modern human cultural data sets in terms of how tree-like they are, but are also comparable to a series of genetic, anatomical, and behavioural data sets that can be assumed to have been produced by a branching process. Again, this is what would be expected if vertical inter-group transmission has been the dominant process in chimpanzee cultural evolution.Human culture has long been considered to be adaptive, but recent studies have suggested that this needs to be demonstrated rather than assumed. With this in mind, in the third set of analyses we investigated whether chimpanzee culture is adaptive. We found the hypothesis that chimpanzee culture is adaptive was supported by an analysis of data from the Eastern African subspecies, but not by an analysis of data from the eastern and western subspecies.The results of our analyses have implications for the number of subspecies in Pan troglodytes, the relationship between hominin taxa and Palaeolithic industries, and the evolution of hominin cognition and behaviour.     

Differential vulnerability of lambs to coyote predation

Coyote-lamb interactions in 65-ha pastures were observed during a study of Komondor dogs guarding sheep. Vulnerability of lambs to coyote predation was related to total time lambs were exposed to coyotes in the enclosures and total time present in the flock. Lambs were most vulnerable during the first two weeks of exposure (P < 0.001, X² = 49.3), and were somewhat less vulnerable in the next 4 weeks of exposure. If the lambs survived 6 weeks of exposure, their chances of succumbing to predation were small. Lambs were most vulnerable if they were added to an established flock. Orphan lambs were more vulnerable than ewe-reared lambs. Even though the coyotes in this study were persistent in attacking lambs, their success was limited for at least 3 reasons. First, the lambs sometimes refused to run from the coyotes. In addition, they occasionally actively defended themselves by foot-stomping, butting and approaching the coyote. Finally, no lambs were killed while in close proximity to a guardian dog. Based on this study, predation might best be reduced by minimizing introductions of new lambs, and especially orphan lambs, to established flocks, and by using a guardian dog, if possible.