Mural Dissections of Brain-Supplying Arteries in a Chimpanzee (Pan troglodytes)

We describe the pathologic features of mural arterial dissection involving brain-supplying arteries in a 31-y-old female chimpanzee (Pan troglodytes). Several hours after examination for a possible respiratory tract infection, the chimpanzee became unresponsive, developed seizures, and died within 18 h. At necropsy, the occipital cortex of the brain had a small area of congestion, and the cerebellar cortex contained a small necrotic area. Histologic evaluation confirmed the cortical lesions and revealed an additional necrotic area in the medulla oblongata characterized by mural dissection of the brain-supplying vertebral and basilar arteries and subsequent branches. Lesions in the cortices and medulla were within areas supplied by the vertebrobasilar system. Dissection of brain-supplying arteries has been described in humans but not previously in chimpanzees (or any other NHP), suggesting that these species might be useful in understanding this condition in humans. In addition, the lesion should be added to the NHP clinician''s and pathologist''s differential diagnosis list for similar presentations in this species.Mural dissection of brain-supplying arteries is a well-recognized clinical problem in humans.² In fact, these dissections are a common lesion of these arteries, second only to atherosclerotic changes. Dissections of these arteries can cause pain and lead to tissue ischemia and infarction (stroke).²In our experience, the blood supply to the brain is similar between chimpanzees and humans. However, mural dissection of brain-supplying arteries in NHP species had not been described previously, and the apparent absence of information on this topic might reflect a low rate of occurrence for the condition or indicate that the condition has gone unrecognized. Regardless of the cause, similar vascular mural dissection in NHP might be expected to cause significant clinical problems for the affected animal, as well as diagnostic and management challenges for veterinary clinicians and pathologists.Here we describe the first documented occurrence of mural arterial dissection involving brain-supplying arteries in an adult chimpanzee. The objectives of this report are to make the laboratory animal community aware of this condition and to suggest that chimpanzees might help to increase our understanding of this condition in humans.     

Obstructive Uropathy Secondary to Uterine Leiomyoma in a Chimpanzee (Pan troglodytes)

Complications due to uterine leiomyomata in chimpanzees have rarely been documented. Here we describe a female chimpanzee that developed severe hydronephrosis in the right kidney due to leiomyoma. Because hysterectomy did not alleviate the hydronephrosis, nephrectomy was elected. After these procedures, the chimpanzee is doing well. Leiomyomata screening programs with treatment algorithms are a useful component of a comprehensive chimpanzee program.The prevalence rates for the occurrence of uterine leiomyomata, or fibroids, in female captive chimpanzees are reported to be similar to those for humans.¹⁶ However, in contrast to humans, complications secondary to uterine leiomyomata in chimpanzees have been documented infrequently. Here we present a case of obstructive uropathy due to uterine leiomyoma that resulted in severe hydronephrosis and surgical removal of a kidney in a female chimpanzee.     

Intergroup Competition Enhances Chimpanzee (Pan troglodytes verus) In-group Cohesion

International Journal of Primatology - In-group cohesion is an essential component of successful intergroup competition in both human and nonhuman animals, likely facilitating group members access...     

Visual Search for Human Gaze Direction by a Chimpanzee (Pan troglodytes)

Background

Humans detect faces with direct gazes among those with averted gazes more efficiently than they detect faces with averted gazes among those with direct gazes. We examined whether this “stare-in-the-crowd” effect occurs in chimpanzees (Pan troglodytes), whose eye morphology differs from that of humans (i.e., low-contrast eyes, dark sclera).

Methodology/Principal Findings

An adult female chimpanzee was trained to search for an odd-item target (front view of a human face) among distractors that differed from the target only with respect to the direction of the eye gaze. During visual-search testing, she performed more efficiently when the target was a direct-gaze face than when it was an averted-gaze face. This direct-gaze superiority was maintained when the faces were inverted and when parts of the face were scrambled. Subsequent tests revealed that gaze perception in the chimpanzee was controlled by the contrast between iris and sclera, as in humans, but that the chimpanzee attended only to the position of the iris in the eye, irrespective of head direction.

Conclusion/Significance

These results suggest that the chimpanzee can discriminate among human gaze directions and are more sensitive to direct gazes. However, limitations in the perception of human gaze by the chimpanzee are suggested by her inability to completely transfer her performance to faces showing a three-quarter view.     

Classifying Chimpanzee (Pan troglodytes) Landscapes Across Large-Scale Environmental Gradients in Africa

International Journal of Primatology - Primates are sometimes categorized in terms of their habitat. Although such categorization can be oversimplistic, there are scientific benefits from the...     

Chimpanzee (Pan troglodytes) responses to caregiver use of chimpanzee behaviors

The relationships between captive primates and their caregivers are critical ones and can affect animal welfare. Friendly relationships can improve quality of life; adversely, agonistic relationships can decrease quality of life. Caregivers in and of themselves should not be stressful to their charges, instead the caregivers' behaviors and the nature of their interactions with captive primates is likely the basis for the stress. One method to promote positive relationships in the captive environment is for caregivers to employ species‐specific behaviors in their interactions with their charges. This study tested the effect of caregivers' use of these behaviors with chimpanzees at The Zoo Northwest Florida in Gulf Breeze. The chimpanzee participants were three males. Data collection occurred during typical interactions between the human participants and the chimpanzees. Some days the caregiver presented chimpanzee behaviors and vocalizations (CB—Chimpanzee Behavior Condition) in the data collection interactions with the chimpanzees. On other days the caregiver presented human behaviors and used speech (HB—Human Behavior Condition) in the interactions with the chimpanzees. The interactions were videotaped. Data coders recorded the behavioral contexts for each chimpanzee as they occurred on the videotape and the time that each context began. Overall they engaged in significantly more friendly behaviors such as play in CB than in HB. They were significantly less interactive in HB than CB. Caregivers should understand and employ species‐specific interactions with chimpanzees to promote friendly interactions and animal welfare. Zoo Biol 27:345–359, 2008. © 2008 Wiley‐Liss, Inc.     

Chimpanzee (Pan troglodytes) birth patterns and human presence in zoological settings

In response to work demonstrating a negative correlation between human staff activity and parturition in laboratory-managed primates, this study examined the distribution of 231 captive chimpanzee (Pan troglodytes) births that occurred in accredited American zoological institutions by the day of the week on which the birth was discovered. We hypothesized that if chimpanzee parturition patterns displayed sensitivity to human presence, then fewer births per day would be reported during the weekend period, when the visitor density was high, as compared with the lower density working week. Analyses indicated that chimpanzee births were randomly distributed throughout the week. In the context of the questionable sensitivity of primate parturition to external influence, results suggest that variations in human presence do not affect the fine-level timing of birth in chimpanzees managed in a zoological setting.     

Evidence of Hypertrophic Pulmonary Osteoarthropathy in a Chimpanzee,Pan troglodytes

Dissection of a chimpanzee has revealed the association of an intrathoracic disease (probably coccidioidomycosis) with periosteal lesions that are restricted almost entirely to the appendicular skeleton and are distributed with bilateral symmetry. These pathological conditions are compatible with a diagnosis of hypertrophic pulmonary osteoarthropathy.     

圈养条件下黑猩猩月经、排卵和妊娠周期

排卵期和妊娠期与月经周期紧密相关,监测月经周期对圈养黑猩猩（Pan troglodytes）的繁殖有着重要意义。本研究对上海动物园饲养的8只雌性黑猩猩2002年以来的月经周期记录进行统计分析,并对2只成年雌性黑猩猩共60 d尿液中促黄体生成素进行检测。黑猩猩月经周期平均为（33.5 ± 5.3）d,经期平均为（1.6 ± 1.1）d,妊娠期平均为（226.9 ± 17.3）d,产单胎和双胎有极显著差异;促黄体生成素在发情高峰期出现了峰值。     

The Ontogeny of Vocal Sequences: Insights from a Newborn Wild Chimpanzee (Pan troglodytes schweinfurthii)

International Journal of Primatology - Observations of early vocal behaviours in non-human primates (hereafter primates) are important for direct comparisons between human and primate vocal...     

基于正交试验设计开展的黑猩猩食物丰容效果研究

基于正交试验设计,对上海动物园8头黑猩猩(Pan troglodytes)进行食物丰容(木丝、麻袋和竹筒)对取食行为影响的研究,利用正交试验设计试验因素和水平,采用所有事件取样法记录丰容前后黑猩猩取食行为的持续时间。结果表明,通过正交试验设计,能够有效对不同的试验方案进行排序。本研究中,对黑猩猩取食行为影响的主次顺序依次为木丝>麻袋>竹筒;不同食物丰容方式对成年雄性取食行为影响不显著,所有成年雌性丰容后取食行为增加,且取食占比比雄性高,幼年个体在丰容后取食行为占比降低。3种丰容方式对成年雄性和幼年个体的取食行为都没有显著影响。对4头成年雌性黑猩猩的最优丰容组合为木丝和麻袋(有无竹筒都可),对1头亚成年雌性黑猩猩的最优组合为木丝(有无竹筒和麻袋都可)。木丝对成年雌性取食行为的影响极显著(P <0.01),竹筒对每个个体行为影响均不显著(P> 0.05),麻袋对部分个体影响不显著(P> 0.05)。     

Chimpanzee (Pan troglodytes verus) Density and Environmental Gradients at Their Biogeographical Range Edge

International Journal of Primatology - Identifying ecological gradients at the range edge of a species is an essential step in revealing the underlying mechanisms and constraints that limit the...     

Sex Bias and Social Influences on Savanna Chimpanzee (Pan troglodytes verus) Nest Building Behavior

International Journal of Primatology - Many primates show sex differences in behavior, particularly social behavior, but also tool use for extractive foraging. All great apes learn to build a...     

Food Supply and Chimpanzee (Pan troglodytes schweinfurthii) Party Size in the Budongo Forest Reserve,Uganda

A central issue in socioecology is the nature of the relationship between an organism's environment and its social structure. In chimpanzees, the fission-fusion social system is thought to minimize feeding competition for primary dietary components: ephemeral, dispersed patches of ripe fruit. Intragroup feeding competition is thought to force individuals into small parties. Informal observations in the Sonso region of the Budongo forest had suggested that in this habitat, food supply was such that feeding competition was less important in determining grouping patterns than elsewhere. We used data collected on food supply and party sizes over a 4-year period to investigate this suggestion. In accord with theoretical expectation, sizes of foraging parties fluctuated with the size of food patches. However, party sizes showed either negative or no relationship with habitat-wide measures of food abundance. Likewise party sizes showed little relationship to overall measures of food dispersion. For important dietary items, both fruit and leaves had patchy distributions, though the degree of clumping was not strong, and fruit was not more clumped than leaves. Generally, abundant food appeared to be less patchy, and chimpanzees appeared to use more patches as food became more abundant rather than forming larger parties. We suggest that both dispersal and abundance need to be considered when investigating the impact of food supply on grouping patterns, and that the importance of food as a factor in determining chimpanzee grouping patterns declines with increasing levels of abundance.     

Mothers Frequent Caves: Lactation Affects Chimpanzee (Pan troglodytes verus) Cave Use in Southeastern Senegal

International Journal of Primatology - Caves play an important ecological role for nonhuman primates in Africa and Asia. Savanna chimpanzees (Pan troglodytes verus) living in the Mandingue plateau...     

Acute appendicitis in a chimpanzee (Pan troglodytes)

BACKGROUND: A 7-year old, female chimpanzee (Pan troglodytes) developed acute abdominal pain and anorexia. An irregular, mineral opacity was identified in the caudal right quadrant of the abdomen on radiographs and computed tomography scan, which appeared to be in the region of the cecal appendage. RESULTS AND CONCLUSIONS: A diagnosis of acute appendicitis was made based on clinical signs, abnormal haematology findings, and consultation with a human radiologist. Exploratory laparotomy was performed and the cecal appendage was removed. On histologic examination, the mucosal epithelium contained eosinophilic and neutrophilic inflammation. The inflammation extended through the tunica muscularis to the serosal surface and adjacent mesentery. The histologic findings were consistent with acute appendicitis in humans. The chimpanzee recovered well from surgery with immediate improvement in clinical signs and no post-operative complications.     

Chimpanzee (Pan troglodytes schweinfurthii) Group Sleep and Pathogen-Vector Avoidance: Experimental Support for the Encounter-Dilution Effect

International Journal of Primatology - Sleep is essential for survival, yet it represents a time of extreme vulnerability, including through exposure to parasites and pathogens transmitted by...