Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| nucleotide diversity in gorillas. | comparison of the levels of nucleotide diversity in humans and apes may provide valuable information for inferring the demographic history of these species, the effect of social structure on genetic diversity, patterns of past migration, and signatures of past selection events. previous dna sequence data from both the mitochondrial and the nuclear genomes suggested a much higher level of nucleotide diversity in the african apes than in humans. noting that the nuclear dna data from the apes were ... | 2004 | 15082556 |
| treatment of acute self-aggressive behaviour in a captive gorilla (gorilla gorilla gorilla). | 2004 | 15083975 | |
| fracture toughness of mountain gorilla (gorilla gorilla beringei) food plants. | mountain gorillas, the largest extant primates, subsist almost entirely on plant matter. moreover, their diet includes a substantial amount of structural material, such as bark and stems, which other primates tend to avoid. accordingly, the robust masticatory apparatus of gorillas may be adaptive to this presumably tough diet; however, quantitative information on this subject is lacking. in this study the fracture toughness of mountain gorilla foods was examined for the first time. samples of 44 ... | 2004 | 15085532 |
| dental topography and diets of australopithecus afarensis and early homo. | diet is key to understanding the paleoecology of early hominins. we know little about the diets of these fossil taxa, however, in part because of a limited fossil record, and in part because of limitations in methods available to infer their feeding adaptations. this paper applies a new method, dental topographic analysis, to the inference of diet from fossil hominin teeth. this approach uses laser scanning to generate digital 3d models of teeth and geographic information systems software to mea ... | 2004 | 15120268 |
| mitochondrial dna phylogeography of western lowland gorillas (gorilla gorilla gorilla). | the geographical distribution of genetic variation within western lowland gorillas (gorilla gorilla gorilla) was examined to clarify the population genetic structure and recent evolutionary history of this group. dna was amplified from shed hair collected from sites across the range of the three traditionally recognized gorilla subspecies: western lowland (g. g. gorilla), eastern lowland (g. g. graueri) and mountain (g. g. beringei) gorillas. nucleotide sequence variation was examined in the fir ... | 2004 | 15140097 |
| interlaminar astroglial processes in the cerebral cortex of great apes. | the present study was designed to document the architecture of neocortical astroglia in great apes, following glial fibrillary acidic protein immunohistochemistry. these anthropoid species were missing from previous phylogenetic descriptions of astroglia with interlaminar processes, a characteristic event of the cerebral cortex within the primate order. pongo pygmaeus (orangutan), gorilla gorilla (gorilla) and pan troglodytes (chimpanzee) brain samples showed the typical "palisade" of interlamin ... | 2004 | 15221474 |
| population and group structure of western lowland gorillas (gorilla gorilla gorilla) at lokoué, republic of congo. | during a 17-month study at the lokoué clearing in odzala national park, republic of congo, we identified 377 western lowland gorillas. this population included 31 solitary males, 37 breeding groups, and eight nonbreeding groups. its age- and sex-class structure was similar to those observed at two other clearings in the same forest block. however, the size of breeding groups varied with site (either clearing or forest sites). at lokoué, breeding groups (mean size: 8.2 gorillas; range: 3-15) incl ... | 2004 | 15258956 |
| nuclear integrations of mitochondrial dna in gorillas. | great ape systematics, particularly at the species level and below, is currently under debate, due in part to the recent influx of molecular data. the phylogenies of previously published mitochondrial control region (or d-loop) dna sequences in gorillas show deep splits within west african gorillas (gorilla gorilla gorilla), and very high levels of nucleotide diversity in this subspecies. here we demonstrate that several previously reported d-loop haplotypes from west african gorillas are in all ... | 2004 | 15258958 |
| brain structure variation in great apes, with attention to the mountain gorilla (gorilla beringei beringei). | this report presents data regarding the brain structure of mountain gorillas (gorilla beringei beringei) in comparison with other great apes. magnetic resonance (mr) images of three mountain gorilla brains were obtained with a 3t scanner, and the volume of major neuroanatomical structures (neocortical gray matter, hippocampus, thalamus, striatum, and cerebellum) was measured. these data were included with our existing database that includes 23 chimpanzees, three western lowland gorillas, and six ... | 2004 | 15258959 |
| 3d-kinematics of vertical climbing in hominoids. | vertical climbing has played an important role in theories about the evolution of habitual bipedalism in early hominids and of locomotor specialization in hominoids. however, empirical data on vertical climbing in nonhuman primates are scarce, especially regarding kinematics. in this paper, the kinematics of flexed-elbow vertical climbing of four hominoid species are reported: western lowland gorillas (gorilla gorilla gorilla), bonobos (pan paniscus), sumatran orangutans (pongo pygmaeus abelii), ... | 2005 | 15386239 |
| linear enamel hypoplasia in the great apes: analysis by genus and locality. | most studies report a high prevalence of linear enamel hypoplasia (leh) in the great apes relative to other nonhuman primates and some human populations. it is unclear if this difference is a direct result of poor health status for the great apes, or if it represents differential incidence due to a lower threshold (sensu goodman and rose, 1990 am. j. phys. anthropol. [suppl.] 33:59-110) for the occurrence of enamel hypoplasia among great apes. this study uses the smithsonian national museum of n ... | 2005 | 15386281 |
| home-range use and intergroup encounters in western gorillas (gorilla g. gorilla) at lossi forest, north congo. | i present data on home-range use and types of intergroup encounters for one group (apollo) of western gorillas (gorilla gorilla gorilla) from a new study site in the republic of congo. the total home-range size of the focal group, which i calculated by superimposing a 100 m x 100 m grid over the mapped daily path traveled, was 11 km2. the majority (73%) of the group's home range was used exclusively, although at the periphery it overlapped with the ranges of three other groups. most encounters ( ... | 2004 | 15470740 |
| impact of ecological and social factors on ranging in western gorillas. | we examined the influence of ecological (diet, swamp use, and rainfall) and social (intergroup interaction rate) factors on ranging behavior in one group of western gorillas (gorilla gorilla gorilla) during a 16-month study. relative to mountain gorillas, western gorillas live in habitats with reduced herb densities, more readily available fruit (from seasonal and rare fruit trees), and, at some sites, localized large open clearings (swamps and "bais"). ranging behavior reflects these ecological ... | 2004 | 15470743 |
| within-group social relationships among females and adult males in wild western lowland gorillas (gorilla gorilla gorilla). | within-group female relationships, and relationships between females and adult males have not been described for wild western lowland gorillas. new data are presented here from mbeli bai in the nouabale-ndoki national park, republic of congo. nine groups were observed over a continuous 2-year period, and affiliative and agonistic interactions, as well as time spent by females and adult males in proximity to each other were recorded. affiliative behavior was extremely rare in the bai, and measure ... | 2004 | 15470744 |
| effects of group dynamics and diet on the ranging patterns of a western gorilla group (gorilla gorilla gorilla) at bai hokou, central african republic. | this study describes how group dynamics and diet have influenced the ranging patterns of a western gorilla group at bai hokou, central african republic. the results are compared with those from an earlier study [cipolletta, international journal of primatology, 2003], when the same group was larger and undergoing the process of habituation to humans. data were obtained from maps of the gorillas' travel routes, direct observations, and analysis of fecal samples. through the years, the group has e ... | 2004 | 15470747 |
| social structure and life-history patterns in western gorillas (gorilla gorilla gorilla). | life-history traits and ecological conditions have an important influence on primate social systems. most of what we know about the life-history patterns and social structure of gorillas comes from studies of eastern gorillas (gorilla beringei sp.), which live under dramatically different ecological conditions compared to western gorillas (gorilla gorilla sp.). in this paper we present new data on western gorilla social structure and life histories from four study sites, and make comparisons wit ... | 2004 | 15470749 |
| natural simian foamy virus infection in wild-caught gorillas, mandrills and drills from cameroon and gabon. | a survey for the presence of simian foamy retroviruses (sfvs) was performed in 44 wild-caught apes and monkeys, including 27 gorillas, 11 mandrills and six drills, originating from south cameroon or gabon. combined serological and/or nested-pcr assays indicated sfv infection among five gorilla gorilla gorilla, seven mandrillus sphinx and two mandrillus leucophaeus. sequences of a 425 bp fragment of the integrase gene were obtained for 11 animals. phylogenetic studies indicated that strains from ... | 2004 | 15483245 |
| a case study of primiparous maternal and infant gorilla (gorilla gorilla gorilla) behavior. | a primiparous mother and her infant were subjects of a longitudinal behavioral study at lincoln park zoo in chicago, illinois. from november 1998 to november 1999, we collected a total of 100 hr of focal nonhuman animal instantaneous point sampling and all occurrence data on the mother and her infant. after 8 months, we introduced the 4-member focal group to an 8-member gorilla group, thus providing an opportunity to study the effect of the introduction on mother-infant behavior. overall, time t ... | 2004 | 15498722 |
| common aspects of human and primate seronegative arthritis. | a 27-year-old female lowland gorilla developed an asymmetric oligoarthritis 3 months post-partum. there was no evidence of an antecedent gastrointestinal or genitourinary infection. serum was negative for rheumatoid factor and antinuclear antibody. synovial fluid revealed 2000 white blood cells with negative cultures and polarized microscopy. studies on synoviocytes were the following: (1) facs analysis revealed surface expression of a b27-like epitope of the cells. (2) analysis of intracellular ... | 2004 | 15517649 |
| inter-group encounters in western lowland gorillas at a forest clearing. | 2004 | 15583421 | |
| species and sex identification of western lowland gorillas (gorilla gorilla gorilla), eastern lowland gorillas (gorilla beringei graueri) and humans. | methods for the identification of the sex and species of individuals from samples non-invasively taken from humans and gorillas were established. amplification of a segment of amelogenin (amg), which is an x-y homologous gene, using two pairs of primers from human amg, revealed both x- and y-specific bands. the possibility of sex identification was examined by typing the amg gene using hair and fecal samples from captive western lowland gorillas (gorilla gorilla gorilla) in japan and hair sample ... | 2005 | 15635453 |
| endoparasites of western lowland gorillas (gorilla gorilla gorilla) at bai hokou, central african republic. | a coprologic study of free-ranging western lowland gorillas (gorilla gorilla gorilla) at bai hokou, dzangha-ndoki national park, central african republic (2 degrees 51'34''n, 16 degrees 28'03''e) was conducted from october 1999 to november 2000. all 75 fecal samples examined were positive for endoparasites, and each contained at least two species. parasites present included two genera of amoebae, entodiniomorph ciliates, including prototapirella gorillae, troglodytella spp., and gorillophilus th ... | 2004 | 15650099 |
| cataract surgery with foldable intraocular lens implants in captive lowland gorillas (gorilla gorilla gorilla). | two juvenile, male, captive-born lowland gorillas (gorilla gorilla gorilla) with the same father but different mothers developed bilateral cataracts. the cataracts were surgically removed within 6 yr and 3 mo, respectively, of diagnosis, and foldable intraocular lenses were implanted. although vision was not restored in one eye with a mature, 6-yr-old cataract in gorilla a, surgical intervention on the other eye was performed before a complete cataract developed, and vision was fully restored. g ... | 2004 | 15732594 |
| osteocalcin protein sequences of neanderthals and modern primates. | we report here protein sequences of fossil hominids, from two neanderthals dating to approximately 75,000 years old from shanidar cave in iraq. these sequences, the oldest reported fossil primate protein sequences, are of bone osteocalcin, which was extracted and sequenced by using maldi-tof/tof mass spectrometry. through a combination of direct sequencing and peptide mass mapping, we determined that neanderthals have an osteocalcin amino acid sequence that is identical to that of modern humans. ... | 2005 | 15753298 |
| successful treatment of idiopathic dilated cardiomyopathy in an adult chimpanzee (pan troglodytes). | various congenital and acquired forms of heart disease have been reported in captive lowland gorillas, and heart disease is a major cause of morbidity and mortality in geriatric humans. however, the prevalence of heart disease is unknown in nonhuman great apes species. indeed, little is known about heart disease in chimpanzees, although the species has been used in research for decades. this report details the clinical presentation and diagnostics (thoracic radiography, electrocardiography, and ... | 2005 | 15766214 |
| use and manufacture of tools to extract food by captive gorilla gorilla gorilla: experimental approach. | 2005 | 15900106 | |
| a comparative analysis of temporomandibular joint morphology in the african apes. | a number of researchers have suggested a functional relationship between dietary variation and temporomandibular joint (tmj) morphology, yet few studies have evaluated tmj form in the african apes. in this study, i compare tmj morphology in adults and during ontogeny in gorilla (g.g. beringei, g.g. graueri, and g.g. gorilla) and pan (p. paniscus, p. troglodytes troglodytes, p.t. schweinfurthii, and p.t. verus). i test two hypotheses: first, compared to all other african apes, g.g. beringei exhib ... | 2005 | 15927660 |
| comparison of arthritis characteristics in lowland gorilla gorilla and mountain gorilla beringei. | gorilla gorilla and the less-studied g. beringei occupy very different, geographically separate habitats. we studied the occurrence of various forms of arthritis to examine possible nature/nurture causality. the macerated skeletons of 38 g. beringei and 99 g. gorilla individuals were examined macroscopically for the presence of articular and osseous pathologies. contrasting with only isolated osteoarthritis and infectious arthritis was the frequent occurrence of a form of erosive arthritis assoc ... | 2005 | 16015662 |
| flow cytometric sorting of fresh and frozen-thawed spermatozoa in the western lowland gorilla (gorilla gorilla gorilla). | we adapted flow cytometry technology for high-purity sorting of x chromosome-bearing spermatozoa in the western lowland gorilla (gorilla gorilla gorilla). our objectives were to develop methodologies for liquid storage of semen prior to sorting, sorting of liquid-stored and frozen-thawed spermatozoa, and assessment of sorting accuracy. in study 1, the in vitro sperm characteristics of gorilla ejaculates from one male were unchanged (p > 0.05) after 8 hr of liquid storage at 15 degrees c in a non ... | 2005 | 16104034 |
| relative numerousness judgment and summation in young and old western lowland gorillas. | the relationship between age, relative numerousness judgment, and summation was investigated in 11 western lowland gorillas (gorilla gorilla gorilla). experiments 1 and 2 evaluated the gorillas' ability to select the larger of 2 food quantities before and with training. the majority of gorillas did not reliably select the larger quantity in experiment 1 until receiving training to do so in experiment 2. experiment 3 evaluated their ability to select the larger of 2 pairs of quantities. all goril ... | 2005 | 16131257 |
| diet and seasonal changes in sympatric gorillas and chimpanzees at kahuzi-biega national park. | based on 8 years of observations of a group of western lowland gorillas (gorilla beringei graueri) and a unit-group of chimpanzees (pan troglodytes schweinfurthii) living sympatrically in the montane forest at kahuzi-biega national park, we compared their diet and analyzed dietary overlap between them in relation to fruit phenology. data on fruit consumption were collected mainly from fecal samples, and phenology of preferred ape fruits was estimated by monitoring. totals of 231 plant foods (116 ... | 2006 | 16142424 |
| alveolar echinococcosis in the zoological garden basle. | alveolar echinococcosis (ae) is a rare, but potentially severe zoonotic disease caused by echinococcus (e.) multilocularis. recent findings indicated an increasing importance of ae for non-human primates living in regions endemic for e. multilocularis. the death of five cynomolgus monkeys (macaca fascicularis) and a lowland gorilla (gorilla g. gorilla) due to ae raised concern about the incidence of this parasite in the basle zoo. consequently, a project was initiated to investigate the prevalen ... | 2005 | 16315852 |
| effects of selected behavioral enrichment devices on behavior of western lowland gorillas (gorilla gorilla gorilla). | environmental complexity plays an integral role in the activity and psychological well-being of primates. the experiment described in this article evaluates the effects of nonintrusive, inexpensive, and easily managed behavioral enrichment devices on the behavior of a group of captive western lowland gorillas. devices used included cardboard boxes containing food items, paper bags containing food items, burlap rags, and willow and maple browse. the enrichment devices increased foraging, social p ... | 1998 | 16363941 |
| structural variation of the monoamine oxidase a gene promoter repeat polymorphism in nonhuman primates. | by conferring allele-specific transcriptional activity on the monoamine oxidase a (maoa) gene in humans, length variation of a repetitive sequence [(variable number of tandem repeat (vntr)] in the maoa promoter influences a constellation of personality traits related to aggressive and antisocial behavior and increases the risk of neurodevelopmental and psychiatric disorders. here, we have analyzed the presence and variability of this maoa promoter repeat in several species of nonhuman primates. ... | 2006 | 16436187 |
| captive female gorilla agonistic relationships with clumped defendable food resources. | minimal feeding competition among female mountain gorillas (gorilla gorilla beringei) has resulted in egalitarian social relationships with poorly defined agonistic dominance hierarchies. thus, gorillas are generally viewed as non-competitive egalitarian folivores that have had little need to develop effective competitive strategies to access food resources. however, this generalization is inconsistent with more recent research indicating that most gorillas are frugivorous, feeding on patchily d ... | 2006 | 16467958 |
| living in nonbreeding groups: an alternative strategy for maturing gorillas. | the one-male reproductive strategy implies that maturing males are temporarily excluded from reproduction. in gorillas, these excluded males live either solitarily or in nonbreeding groups (nbgs) that are devoid of adult females. the dynamics of nbgs are not well known. in this study, which was conducted on a gorilla population (gorilla gorilla gorilla) of 377 individuals that visited the lokoué clearing in the republic of congo, we detail how the nbgs formed, and analyze their dynamics accordin ... | 2006 | 16477595 |
| food transfers in immature wild western lowland gorillas (gorilla gorilla gorilla). | the transfer of food items between individuals has been described in primates as serving an informative purpose in addition to supplementing the diet of immature individuals. this behaviour has yet to be described in western lowland gorillas (gorilla gorilla gorilla), and results are presented here of observations of food transfers in immature gorillas at mbeli bai, republic of congo. the frequency of food transfers decreased with increasing immature age, while the frequency of independent feedi ... | 2006 | 16596463 |
| how great apes perform on a modified trap-tube task. | to date, neither primates nor birds have shown clear evidence of causal knowledge when attempting to solve the trap tube task. one factor that may have contributed to mask the knowledge that subjects may have about the task is that subjects were only allowed to push the reward away from them, which is a particularly difficult action for primates in certain problem solving situations. we presented five orangutans (pongo pygmaeus), two chimpanzees (pan troglodytes), two bonobos (pan paniscus), and ... | 2006 | 16612632 |
| orangutan positional behavior and the nature of arboreal locomotion in hominoidea. | the asian apes, more than any other, are restricted to an arboreal habitat. they are consequently an important model in the interpretation of the morphological commonalities of the apes, which are locomotor features associated with arboreal living. this paper presents a detailed analysis of orangutan positional behavior for all age-sex categories and during a complete range of behavioral contexts, following standardized positional mode descriptions proposed by hunt et al. ([1996] primates 37:363 ... | 2006 | 16617429 |
| morphological analysis of the hindlimb in apes and humans. i. muscle architecture. | we present quantitative data on the hindlimb musculature of pan paniscus, gorilla gorilla gorilla, gorilla gorilla graueri, pongo pygmaeus abelii and hylobates lar and discuss the findings in relation to the locomotor habits of each. muscle mass and fascicle length data were obtained for all major hindlimb muscles. physiological cross-sectional area (pcsa) was estimated. data were normalized assuming geometric similarity to allow for comparison of animals of different size/species. muscle mass s ... | 2006 | 16761973 |
| pcdh11 is x/y homologous in homo sapiens but not in gorilla gorilla and pan troglodytes. | protocadherin x (pcdhx) and protocadherin y (pcdhy) are cell-surface adhesion molecules expressed predominantly in brain. the human pcdh11x/y gene pair is located in the non-pseudoautosomal x-y homologous region (xq21.3/yp11.2). the possible existence of pcdh11 gene dosage differences between human and non-human primates is of evolutionary significance with respect to species differences and escape from x inactivation, and has been repeatedly debated. previous investigations on the x/y homologou ... | 2006 | 16825765 |
| postconflict behavior in captive western lowland gorillas (gorilla gorilla gorilla). | postconflict (pc) behaviors, including reconciliation and consolation, have been observed in many primate and several nonprimate species. using the pc-matched control (mc) method, pc behavior was examined in two groups (n=13) of captive western lowland gorillas, a species for which no conflict resolution data have been published. analyses of 223 conflicts showed significantly more affiliation between former opponents after a conflict when compared to control periods, indicating reconciliation. r ... | 2006 | 16847973 |
| anthrax in western and central african great apes. | during the period of december 2004 to january 2005, bacillus anthracis killed three wild chimpanzees (pan troglodytes troglodytes) and one gorilla (gorilla gorilla gorilla) in a tropical forest in cameroon. while this is the second anthrax outbreak in wild chimpanzees, this is the first case of anthrax in gorillas ever reported. the number of great apes in central africa is dramatically declining and the populations are seriously threatened by diseases, mainly ebola. nevertheless, a considerable ... | 2006 | 16900500 |
| identification of the ancestral killer immunoglobulin-like receptor gene in primates. | killer immunoglobulin-like receptors (kir) are essential immuno-surveillance molecules. they are expressed on natural killer and t cells, and interact with human leukocyte antigens. kir genes are highly polymorphic and contribute vital variability to our immune system. numerous kir genes, belonging to five distinct lineages, have been identified in all primates examined thus far and shown to be rapidly evolving. since few kir remain orthologous between species, with only one of them, kir2dl4, sh ... | 2006 | 16911775 |
| evolution of an intronic microsatellite polymorphism in toll-like receptor 2 among primates. | nonhuman primates express varying responses to mycobacterium tuberculosis: new world monkeys appear to be resistant to tuberculosis (tb) while old world monkeys seem to be particularly susceptible. the aim of this study was to elucidate the presence of the regulatory guanine-thymine (gt) repeat polymorphisms in intron 2 of toll-like receptor 2 (tlr2) associated with the development of tb in humans and to determine any variations in these microsatellite polymorphisms in primates. we sequenced the ... | 2006 | 16912902 |
| impacts of roads and hunting on central african rainforest mammals. | road expansion and associated increases in bunting pressure are a rapidly growing threat to african tropical wildlife. in the rainforests of southern gabon, we compared abundances of larger (>1 kg) mammal species at varying distances from forest roads and between hunted and unhunted treatments (comparing a 130-km2 oil concession that was almost entirely protected from bunting with nearby areas outside the concession that had moderate hunting pressure). at each of 12 study sites that were evenly ... | 2006 | 16922241 |
| phylogeny of primate t lymphotropic virus type 1 (ptlv-1) including various new asian and african non-human primate strains. | to further unravel intra- and interspecies ptlv-1 evolution in asia and africa, we phylogenetically analysed 15 new stlv-1 ltr and env sequences discovered in eight different asian and african non-human primate species. we show that orang-utan stlv-1s form a tight, deeply branching monophyletic cluster between asian stlv-1 macaque species clades, suggesting natural cross-species transmission. novel viruses of macaca maura, macaca nigra and siamang cluster with other sulawesian stlv-1s, demonstra ... | 2007 | 16931175 |
| differential use of attentional and visual communicative signaling by orangutans (pongo pygmaeus) and gorillas (gorilla gorilla) in response to the attentional status of a human. | in this study we investigated the communicative abilities of 10 orangutans (pongo pygmaeus) and seven western lowland gorillas (gorilla gorilla gorilla), and particularly focused on their sensitivity to the attentional state of a human experimenter when choosing from a repertoire of both auditory and visual communication strategies. in experiment 1 a banana was placed in front of the subject's cage and a human experimenter was either present or absent. the subject's behavior was recorded for 60 ... | 2006 | 16967515 |
| bed and bed-site reuse by western lowland gorillas (gorilla g. gorilla) in moukalaba-doudou national park, gabon. | in this paper we describe bed (nest) and bed-site reuse by western lowland gorillas (gorilla g. gorilla) in moukalaba-doudou national park, south-eastern gabon. during an eight-month study 44 bed sites and 506 beds were found. among these, 38.6% of bed sites and 4.1% of beds were reused. we analyzed the monthly frequency of bed-site reuse in relation to rainfall, fruit abundance, and fruit consumption by the gorillas. the different frequency of bed-site reuse in the rainy and dry seasons was not ... | 2007 | 17106788 |
| another gorilla (gorilla gorilla gorilla) recognizes himself in a mirror. | various attempts have been made to explain why gorillas (gorilla gorilla gorilla) find it difficult to recognize their mirror image. one of the most oft-cited reasons is aversion to eye contact, which stops gorillas from looking into a mirror and thus prevents them from carrying out a suitable exploration that could lead to self-recognition. in the experimental design used here the subject was first habituated both to observers and to the mirror as an object before being exposed to the latter. t ... | 2007 | 17154375 |
| genetic analysis reveals population structure and recent migration within the highly fragmented range of the cross river gorilla (gorilla gorilla diehli). | recently developed methods of individual-based analysis of genetic data allow an unprecedented opportunity to understand the relationships among fragmented populations. by defining population structure and identifying migrant individuals, such analyses can provide a framework to aid in evaluating the threats posed by inbreeding and reduced genetic variability as a consequence of limited gene flow among fragments. here we investigate population structure in the critically endangered cross river g ... | 2007 | 17257109 |
| ophthalmic examination of the captive western lowland gorilla (gorilla gorilla gorilla). | this study examined the captive western lowland gorilla (gorilla gorilla gorilla) eye as compared and contrasted with the human eye. bilateral ophthalmic examinations of western lowland gorillas (n = 5) while under general anesthesia were performed opportunistically, including slit-lamp biomicroscopy, dilated fundus examination, cycloplegic retinoscopy, schiotz tonometry, corneal diameter and thickness measurements, a-scan and b-scan ultrasonography, keratometry, and cultures of the eyelid margi ... | 2005 | 17312760 |
| clostridium septicum myositis in a western lowland gorilla (gorilla gorilla gorilla). | a 10-yr-old male gorilla (gorilla gorilla gorilla) with a history of conspecific bite wounds was evaluated for acute onset of depression, anorexia, and right hemiparesis. the animal was immobilized for diagnostic examination and treatment for suspected toxic shock from a necrotizing, emphysematous wound infection, but was euthanized due to complications during recovery. gross and histopathologic examination revealed acute necrotizing myositis, fasciitis, cellulitis, and emphysema in the affected ... | 2005 | 17312773 |
| preliminary evaluation of blood lipid profiles in captive western lowland gorillas (gorilla gorilla gorilla). | published serum cholesterol values in captive western lowland gorillas (gorilla gorilla gorilla) are much higher than human ranges, with a national mean of 7.36 mmol/l (284 mg/dl, n = 863). complete blood lipid profiles were examined in 15 captive gorillas. high-density lipoprotein (hdl) was found to decrease more rapidly with age than total cholesterol, resulting in an increasing ratio of cholesterol hdl with age. the ratio of apolipoprotein b to apolipoprotein al also increased with age. estab ... | 2006 | 17312789 |
| resolution of a hyperprolactinemia in a western lowland gorilla (gorilla gorilla gorilla). | prolactin-secreting pituitary adenomas are one of the most common causes of infertility in women. prolactin plays an important role in lactation and is involved in producing some of the normal mammalian breeding and maternal behaviors. elevated serum prolactin concentrations can adversely affect the reproductive cycle in females by inhibiting the normal lutenizing hormone surge that stimulates ovulation. a 17-year-old western lowland gorilla (gorilla gorilla gorilla) presented with low fertility ... | 2006 | 17315448 |
| cholesterol values in free-ranging gorillas (gorilla gorilla gorilla and gorilla beringei) and bornean orangutans (pongo pygmaeus). | cholesterol concentrations in captive gorillas and orangutans vary widely within species and average approximately 244 mg/dl for gorillas and 169 mg/dl for orangutans as published previously. the international species inventory system reports higher concentrations of 275 and 199 mg/dl for gorillas and orangutans, respectively. it is unknown whether these values were typical, influenced by captive management, or both. to answer this question, banked serum samples from free-ranging mountain gorill ... | 2006 | 17319127 |
| retrospective evaluation of measles antibody titers in vaccinated captive gorillas (gorilla gorilla gorilla). | retrospective analyses of banked serum samples and medical records from captive western lowland gorillas (gorilla gorilla gorilla) at lincoln park zoo showed that vaccination of gorillas with a human vaccine induced antibody production. no significant relationship was found between the groups that received one, two, or three vaccinations and the probability of seroconversion. these data also suggested that antibodies in western lowland gorillas persist for at least 11 yr. this information is use ... | 2005 | 17323559 |
| spontaneous external endometriosis in a gorilla (gorilla gorilla). | the present report describes a case of external endometriosis in a 28 year old female gorilla (gorilla gorilla). microscopical examination of a pelvic mass observed at necropsy revealed ovarian tissue together with uterine glands and stroma, fibrous tissue and many siderophages. theories of pathogenesis of external endometriosis are briefly reviewed. | 1985 | 17422589 |
| influence of social and environmental factors on nesting behaviour in captive gorillas (gorilla gorilla gorilla). | field studies on gorilla sleeping sites usually emphasize environmental influences on nest site selection, as individual nesting behaviours are usually not observed directly. in captivity, nesting behaviour and influencing factors are often overlooked. in the present study, the sleeping sites of members of a captive group of 16-21 gorillas were analysed, based on 152 nights over a 5-year period. subadults tended to sleep apart from adults but clustered around the oldest blackback male. full sibl ... | 2007 | 17429209 |
| fine-tuning of social play in juvenile lowland gorillas (gorilla gorilla gorilla). | social play, which involves cooperation, communication, and learning, may represent a suitable field for the investigation of cognitive ability in a given species. we collected data on a captive group of gorillas in order to evaluate the potential cognitive skill of juveniles in fine-tuning play behavior. this study revealed that juvenile gorillas are able to "place" the play session in a proper spatial/temporal context, thus evaluating a complex net of factors (e.g., play partner, play roughnes ... | 2007 | 17455241 |
| rethinking incisor size and diet in anthropoids: diet, incisor wear and incisor breadth in the african apes. | in a seminal study hylander (1975) concluded that the length of the incisor row in catarrhines considered frugivores is longer relative to body mass than in those classified as folivores. assuming that large fruits require greater incisal processing than do leaves, stems, berries, and seeds, he argued that the larger incisors of frugivores increased their resistance to wear. the present analysis examines diet, incisor wear, and incisor crown breadth in cranial samples of western lowland gorillas ... | 2007 | 17455285 |
| fluorescent (f) bodies in the spermatozoa of man and the great apes. | mature spermatozoa of the chimpanzee (pan troglodytes), the gorilla (gorilla gorilla), and the orangutan (pongo pygmaeus) were stained with quinacrine dihydrochloride. fluorescent (f) bodies were visualized in the spermatozoa of the chimpanzee and gorilla but were absent in the orangutan, in which there is no brilliant fluorescence in any chromosome. the f bodies appeared to be randomly located in the sperm heads of these two species, as they usually are in human spermatozoa. however, the propor ... | 1976 | 17494623 |
| response of captive lowland gorillas (gorilla gorilla gorilla) to different housing conditions: testing the aggression-density and coping models. | several studies have suggested that primates react differently to spatial reduction. in this article, the authors tested some general hypotheses on primate response to spatial reduction by studying the apenheul lowland gorillas (gorilla gorilla gorilla; apeldoorn, the netherlands). the frequency of conflicts did not greatly change between the 2 housing settings, thus not supporting the density- aggression model. indoor, gorillas performed touching behavior more often and increased their level of ... | 2007 | 17516795 |
| sex-biased dispersal in western lowland gorillas (gorilla gorilla gorilla). | we explored two hypotheses related to potential differences between sexes in dispersal behaviour in western lowland gorillas (gorilla gorilla gorilla). direct observations suggest that immature females have more opportunities to move between breeding groups than immature males. the distribution of kin dyadic relationships within and between groups does not, however, support this hypothesis. at larger geographical scales, dispersal is likely to be easier for males than females because of the soli ... | 2007 | 17561888 |
| genetic diversity and phylogeographic clustering of sivcpzptt in wild chimpanzees in cameroon. | it is now well established that the clade of simian immunodeficiency viruses (sivs) infecting west central african chimpanzees (pan troglodytes troglodytes) and western gorillas (gorilla gorilla gorilla) comprises the progenitors of human immunodeficiency virus type 1 (hiv-1). in this study, we have greatly expanded our previous molecular epidemiological survey of sivcpz in wild chimpanzees in cameroon. the new results confirm a wide but uneven distribution of sivcpzptt in p. t. troglodytes thro ... | 2007 | 17651775 |
| resting heart rate and tympanic temperature in operant conditioned western lowland gorillas (gorilla gorilla gorilla). | the conscious, resting heart rate and body temperature of healthy western lowland gorillas (gorilla gorilla gorilla) is not reported in the literature. to obtain this information, two clinically healthy adult male western lowland gorillas in a training program were conditioned to allow auscultation and obtain tympanic temperatures. the mean heart rate was 73.8 +/- 8.96 beats per minute (n = 176), and it was lower than mean heart rate reported in studies on anesthetized gorillas. the mean tympani ... | 2007 | 17679523 |
| spontaneously occurring mother-infant swapping and the relationships of infants with their biological and foster mothers in a captive group of lowland gorillas (gorilla gorilla gorilla). | the present study describes spontaneously occurring infant-mother swapping and the relationships of infants with their biological and foster mothers after swapping in a captive social group of lowland gorillas (gorilla gorilla gorilla). after infant-swapping took place between a primiparous mother with a neonate and a multiparous mother with a 10-month-old infant, the mothers provided appropriate maternal care, including nursing, to their adopted infants, but the older infant still sought refuge ... | 2007 | 17683751 |
| selective logging, habitat quality and home range use by sympatric gorillas and chimpanzees: a case study from an active logging concession in southeast cameroon. | we examined range use by great apes during logging activities and investigated associations between local variations in ape abundance and changes in the structure of the habitat or in the availability of fruits after disturbances. we carried out two annual censuses of western lowland gorilla (g. g. gorilla) and chimpanzee populations (pan t. troglodytes) in an active logging concession in southeast cameroon. the results suggest that gorillas may adapt their range use to avoid most recently logge ... | 2008 | 17726332 |
| prevalence and genetic diversity of simian immunodeficiency virus infection in wild-living red colobus monkeys (piliocolobus badius badius) from the taï forest, côte d'ivoire sivwrc in wild-living western red colobus monkeys. | numerous african primates are infected with simian immunodeficiency viruses (sivs). it is now well established that the clade of sivs infecting west-central african chimpanzees (pan troglodytes troglodytes) and western gorillas (gorilla gorilla gorilla) represent the progenitors of human immunodeficiency virus type 1 (hiv-1), whereas hiv-2 results from different cross-species transmissions of sivsmm from sooty mangabeys (cercocebus atys atys). we present here the first molecular epidemiological ... | 2008 | 17916449 |
| comparative ocular anatomy of the western lowland gorilla. | to examine the lowland gorilla (gorilla gorilla gorilla) eye and determine similarities to and differences between the mountain gorilla (gorilla gorilla beringei) and the human eye. in addition, we compare our findings of g. g. gorilla to previous reports on the eye of this subspecies. | 2007 | 17970996 |
| gorillas are a host for dientamoeba fragilis: an update on the life cycle and host distribution. | dientamoeba fragilis is a gastrointestinal protozoan that has a worldwide distribution and is emergeing as a common cause of diarrhea. as d. fragilis has a propensity to cause chronic illness with symptoms similar to irritable bowel syndrome (ibs) it is not surprising that some patients with d. fragilis are misdiagnosed as having ibs. in contrast to most other pathogenic protozoa very little is known about its life cycle, epidemiology and mode of transmission. what role animal reservoirs play in ... | 2008 | 18022187 |
| influence of male morphology on male mating status and behavior during interunit encounters in western lowland gorillas. | the western lowland gorilla (gorilla gorilla gorilla) is one of the most sexually dimorphic primate species. mature males are twice the size of females and have grey fur on their backs and a fibrous, adipose crest on their heads. such traits are likely to have evolved by sexual selection, either because they confer advantages during male-male fights or because females prefer males with more dimorphic traits. we developed photogrammetric methods for distance collection of morphological data from ... | 2008 | 18044692 |
| the role of pleistocene refugia and rivers in shaping gorilla genetic diversity in central africa. | the role of pleistocene forest refugia and rivers in the evolutionary diversification of tropical biota has been the subject of considerable debate. a range-wide analysis of gorilla mitochondrial and nuclear variation was used to test the potential role of both refugia and rivers in shaping genetic diversity in current populations. results reveal strong patterns of regional differentiation that are consistent with refugial hypotheses for central africa. four major mitochondrial haplogroups are e ... | 2007 | 18077351 |
| comparing ape densities and habitats in northern congo: surveys of sympatric gorillas and chimpanzees in the odzala and ndoki regions. | the conservation status of western lowland gorillas and central chimpanzees in western equatorial africa remains largely speculative because many remote areas have never been surveyed and the impact of emergent diseases in the region has not been well documented. in this study, we compared ape densities and habitats in the lokoué study area in odzala national park and the goualougo triangle in nouabalé-ndoki national park in northern republic of congo. both of these sites have long been consider ... | 2008 | 18176937 |
| the behavior of two captive specimens of the lowland gorilla, gorilla gorilla gorilla (savage & wyman). | this report describes the behavior of two pre-adolescent lowland gorillas in the new york zoological park during the summer of 1948. oka, then an eight-year-old female, and makoko, a ten-year-old male, were observed in their regular living cages when alone and when placed together. a check-list was prepared and regular half-hour periods of observation were systematically made. significant behavioral items were compared for the sessions when the animals were alone and when they were together. com ... | 1949 | 18268801 |
| an experimental study of nettle feeding in captive gorillas. | mountain gorillas (gorilla beringei beringei) in karisoke, rwanda, feed on the stinging nettle laportea alatipes by means of elaborate processing skills. byrne [e.g. philosophical transactions of the royal society of london, series b, biological sciences 358:529-536, 2003] has claimed that individuals acquire these skills by means of the so-called program-level imitation, in which the overall sequence of problem-solving steps (not the precise actions) is reproduced. in this study we present west ... | 2008 | 18330896 |
| fatal ulcerative colitis in a western lowland gorilla (gorilla gorilla gorilla). | a captive western lowland gorilla (gorilla gorilla gorilla) presented with watery diarrhoea that progressed to become profuse and haemorrhagic. faecal analyses revealed balantidium (b.) coli trophozoites and salmonella-like bacteria. despite treatment the gorilla died on the 5th day after onset of symptoms. post-mortem examination revealed a severe erosive-ulcerative superficial and deep colitis. histological examination of post-mortem samples of the colon showed plentiful b. coli invading into ... | 2008 | 18466283 |
| color preferences in gorillas (gorilla gorilla gorilla) and chimpanzees (pan troglodytes). | color plays an important biological role in the lives of many animals, with some species exhibiting preferences for certain colors over others. this study explored the color preferences of two species of ape, which, like humans, possess trichromatic color vision. six western lowland gorillas, and six chimpanzees, housed in belfast zoological gardens, were exposed to three stimuli (cloths, boxes, sheets of acetate) in red, blue, and green. six stimuli of the same nature, in each of the three colo ... | 2008 | 18489237 |
| effects of habitat fragmentation, population size and demographic history on genetic diversity: the cross river gorilla in a comparative context. | in small and fragmented populations, genetic diversity may be reduced owing to increased levels of drift and inbreeding. this reduced diversity is often associated with decreased fitness and a higher threat of extinction. however, it is difficult to determine when a population has low diversity except in a comparative context. we assessed genetic variability in the critically endangered cross river gorilla (gorilla gorilla diehli), a small and fragmented population, using 11 autosomal microsatel ... | 2008 | 18521886 |
| perimenopause and menopause: documenting life changes in aging female gorillas. | as our closest living relatives, great apes likely experience physiological patterns associated with reproductive aging that are similar to humans. we present results from a nationwide zoo-based study on female western lowland gorillas during which we evaluated concentrations of progestogens via daily fecal sampling in 30 gorillas, 22 of whom were geriatric (>or=30). whereas control females cycled regularly, ca. 23% of geriatric females were acyclic (menopausal), and approximately 1/3 showed var ... | 2008 | 18523376 |
| prolactin levels in western lowland gorillas. | hyperprolactinemia is known to cause menstrual irregularity and infertility in humans. however, little is known about the role of prolactin in menstruation and fertility in western lowland gorillas. to create a database of prolactin values in gorillas, we have performed immunoassays on serum specimens dating back to 1983 from nine female gorillas at the brookfield zoo. we matched these samples with documented behavioral data to correlate menstrual timing. in addition, we ran other reproductive h ... | 2008 | 18523963 |
| hominoid seminal protein evolution and ancestral mating behavior. | hominoid mating systems show extensive variation among species. the degree of sexual dimorphism in body size and canine size varies among primates in accordance with their mating system, as does the testes size and the consistency of ejaculated semen, in response to differing levels of sperm competition. to investigate patterns of evolution at hominoid seminal proteins and to make inferences regarding the mating systems of extinct taxa, we sequenced the entire coding region of the prostate-speci ... | 2008 | 18561295 |
| peaceful post-conflict interactions between aggressors and bystanders in captive lowland gorillas (gorilla gorilla gorilla). | we observed a colony of lowland gorillas in order to assess the occurrence of peaceful post-conflict interactions between aggressors and bystanders (ppiab). we compared the dynamics of ppiab with those of peaceful post-conflict interactions between victims and bystanders (ppivb), which are directed toward victims. we confirmed the occurrence of ppiab (mean triadic contact tendency: 41.7%+/-16.2% sem) at frequencies comparable to ppivb. immature gorillas were responsible for most ppiab. ppiab occ ... | 2008 | 18615459 |
| western lowland gorillas (gorilla gorilla gorilla) change their activity patterns in response to frugivory. | the most important environmental factor explaining interspecies variation in ecology and sociality of the great apes is likely to be variation in resource availability. relatively little is known about the activity patterns of western lowland gorillas (gorilla gorilla gorilla), which inhabit a dramatically different environment from the well-studied mountain gorillas (g. beringei beringei). this study aims to provide a detailed quantification of western lowland gorillas' activity budgets using d ... | 2009 | 19021124 |
| origin and biology of simian immunodeficiency virus in wild-living western gorillas. | western lowland gorillas (gorilla gorilla gorilla) are infected with a simian immunodeficiency virus (sivgor) that is closely related to chimpanzee and human immunodeficiency viruses (sivcpz and hiv-1, respectively) in west central africa. although existing data suggest a chimpanzee origin for sivgor, a paucity of available sequences has precluded definitive conclusions. here, we report the molecular characterization of one partial (bq664) and three full-length (cp684, cp2135, and cp2139) sivgor ... | 2009 | 19073717 |
| chemical characterization of oligosaccharides in chimpanzee, bonobo, gorilla, orangutan, and siamang milk or colostrum. | neutral and acidic oligosaccharides were isolated from the milk or colostrum of four great ape species (chimpanzee (pan troglodytes), bonobo (pan paniscus), gorilla (gorilla gorilla), and orangutan (pongo pygmaeus)) and one lesser ape species (siamang (symphalangus syndactylus)), and their chemical structures were characterized by (1)h-nmr spectroscopy. oligosaccharides containing the type ii unit (gal(beta1-4)glcnac) were found exclusively (gorilla and siamang) or predominately (chimpanzee, bon ... | 2009 | 19164487 |
| milk composition of captive vervet monkey (chlorocebus pygerythrus) and rhesus macaque (macaca mulatta) with observations on gorilla (gorilla gorilla gorilla) and white handed gibbon (hylobates lar). | the nutrient content and fatty acid composition of vervet monkey milk has been determined and is compared with rhesus macaque, and two hominoid apes, the white handed gibbon and gorilla. with 15.7+/-4.1 g protein, 33.1+/-9.4 g fat, and 85.1+/-7.5 g lactose per kg milk, vervet monkey milk does not differ from that of rhesus macaque, and is within the range of other primates. small amounts (>1 g kg(-1)) of oligosaccharides, glucose, galactose and fucose were noted. in comparison, gorilla milk has ... | 2009 | 19168147 |
| superior olivary complex organization and cytoarchitecture may be correlated with function and catarrhine primate phylogeny. | in the mammalian auditory system, the medial nucleus of the trapezoid body and the lateral superior olive (mntb-lso system) contribute to binaural intensity processing and lateralization. localization precision varies with the sound frequencies. as recency of common ancestry with human beings increases, primates have improved low-frequency sensitivity and reduced sensitivity to higher frequencies. the medial part of the mntb is devoted to higher frequency processing. thus, its high-frequency-dep ... | 2009 | 19184100 |
| gestural communication of the gorilla (gorilla gorilla): repertoire, intentionality and possible origins. | social groups of gorillas were observed in three captive facilities and one african field site. cases of potential gesture use, totalling 9,540, were filtered by strict criteria for intentionality, giving a corpus of 5,250 instances of intentional gesture use. this indicated a repertoire of 102 gesture types. most repertoire differences between individuals and sites were explicable as a consequence of environmental affordances and sampling effects: overall gesture frequency was a good predictor ... | 2009 | 19184669 |
| estimation of african apes' body size from postcranial dimensions. | we examine how african apes' postcranial skeletal dimensions and their combinations are related to body size, as represented by trunk volume, within sex-specific samples of a total of 39 central chimpanzees (pan troglodytes troglodytes) and 34 western gorillas (gorilla gorilla gorilla). we examine this relationship by determining the strength of the correlation between selected skeletal dimensions and trunk volume. the findings indicate that sex should be taken into account when possible. most t ... | 2009 | 19221857 |
| hand-clapping as a communicative gesture by wild female swamp gorillas. | hand-clapping is a form of gestural communication commonly observed in captive great apes yet only isolated instances of this behaviour have been documented in the wild. nearly 20 years ago fay recorded the first observations of hand-clapping in western lowland gorillas (gorilla gorilla gorilla) in the central african republic. here we present observations of likouala swamp gorillas using hand-clapping as a form of gestural communication in previously undocumented contexts in the wild. we observ ... | 2009 | 19221858 |
| cervical necrotizing fasciitis and myositis in a western lowland gorilla (gorilla gorilla gorilla). | a 39-yr-old wild-caught, female western lowland gorilla (gorilla gorilla gorilla) died during an immobilization to assess swelling and apparent pain of the cervical region. necropsy revealed a fistulous tract containing plant material in the oropharynx, above the soft palate, communicating with a left-sided cervical necrotizing fasciitis and myositis. alpha-hemolytic streptococcus and prevotella sp. were isolated from the cervical lesion. this is a report of cervical necrotizing fasciitis in a w ... | 2009 | 19239573 |
| the occurrence and ape-to-ape transmission of the entodiniomorphid ciliate troglodytella abrassarti in captive gorillas. | entodiniomorphid ciliates are often present in the colons of wild apes. in captive apes the infection tends to gradually disappear, with the exception of troglodytella abrassarti. we used fecal examinations to screen the gorillas (gorilla gorilla gorilla) in european (czech republic, uk) and australian zoos to explore the ape-to-ape transmission pattern of t. abrassarti. gorillas from two out of three european zoos were positive for t. abrassarti, while gorillas from the australian zoo were nega ... | 2009 | 19335778 |
| assessment of reproductive behavior and hormonal cycles in geriatric western lowland gorillas. | the population of western lowland gorillas in north american zoos is aging and, as is the case with the aging human population, may have unique physical and social needs. we have documented previously that 25% of aging females (5/22) ceased to show reproductive cycles entirely, and could be defined as menopausal. approximately 32% of females showed somewhat irregular cycling patterns. we review our hormonal and behavioral findings on reproductive aging in gorillas; describe the range of cycling ... | 2007 | 19360566 |
| infant cradling in a captive mother gorilla. | the purpose of the study presented here was to investigate the handedness and cradling preferences of a mother gorilla (gorilla gorilla) from the metro toronto zoo. the study also examined preferences for handedness for each member of the captive group. observational data were collected using scan sampling at 60-sec intervals. handedness was determined with a coordinated bimanual tube test using peanut butter spread on the interior of a pvc tube. our findings were largely consistent with the lit ... | 2008 | 19360636 |
| behavioral response of captive western lowland gorillas (gorilla gorilla gorilla) to the death of silverbacks in multi-male groups. | in both free-ranging and captive western lowland gorillas, a silverback provides protection and leadership, mediating conflict within a group. in the wild, when a dominant silverback dies the group will disperse or transfer to a solitary male, unless a subsequent male is present to inherit the group. in captivity, studies have focused on groups containing one male and therefore it is unclear how gorillas respond to the death or removal of a silverback in multi-male groups. this study examined th ... | 2010 | 19367612 |
| sexual behavior in female western lowland gorillas (gorilla gorilla gorilla): evidence for sexual competition. | previous research in gorillas suggests that females engage in post-conception mating as a form of sexual competition designed to improve their own reproductive success. this study focused on sexual behaviors in a newly formed group of western lowland gorillas (gorilla gorilla gorilla) housed at zoo atlanta. all females engaged in mating outside their conceptive periods, although there was individual variation in the frequency of the behavior. an analysis of the presence/absence of sexual behavio ... | 2009 | 19399838 |
| logging concessions can extend the conservation estate for central african tropical forests. | the management of tropical forest in timber concessions has been proposed as a solution to prevent further biodiversity loss. the effectiveness of this strategy will likely depend on species-specific, population-level responses to logging. we conducted a survey (749 line transects over 3450 km) in logging concessions (1.2 million ha) in the northern republic of congo to examine the impact of logging on large mammal populations, including endangered species such as the elephant (loxodonta african ... | 2009 | 19453655 |
| dimensions of the foot muscles in the lowland gorilla. | we dissected the hindlimb of a female western lowland gorilla and determined the muscle dimensions (mass, fascicle length, and physiological cross-sectional area: pcsa). comparisons of the muscle parameters of the measured gorilla with corresponding reported human data demonstrated that the triceps surae muscles were larger and had more capacity to generate force than the other muscle groups in both species, but this tendency was more prominent in the human, probably as an adaptation to strong t ... | 2009 | 19578296 |
| why do gorillas make sequences of gestures? | great ape gestures have attracted considerable research interest in recent years, prompted by their flexible and intentional pattern of use; but almost all studies have focused on single gestures. here, we report the first quantitative analysis of sequential gesture use in western gorillas (gorilla gorilla gorilla), using data from three captive groups and one african study site. we found no evidence that gesture sequences were given for reasons of increased communicative efficiency over single ... | 2010 | 19649664 |