Chaînes opératoires and resource-exploitation strategies in chimpanzee (Pan troglodytes) nut cracking

Journal of Human Evolution, V. 55, pp. 148-163

Human and climatic change impact modelling on the habitat suitability for the chimpanzee (Pan troglodytes ellioti) – Case study: The proposed Mount Cameroon National Park

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

Phylogeography, conservation genetics and parasitology of chimpanzees (Pan troglodytes versus) in Guinea-Bissau, West Africa

Tese de doutoramento em Antropologia, especialidade em Antropologia Biológica e Etnoecologia

Conducta instrumental del chimpace (Pan troglodytes) en su habitat natural

La constatación del uso sistemático de instrumentos por los chimpancés en su habitat natural ha planteado el problema de la aplicación del término cultura a un primate no humano. Una de las características de la cultura es la aparición de variantes conductuales en grupos separados. El propósito de este trabajo es revisar, con los datos disponibles en la actualidad, la hipótesis formulada por Sabater Pi (1974b) de que existen tres zonas culturales en los chimpancés e intentar identificar el origen ecológico y/o social de estas diferencias.

Relation between the level of self-mutilation and theconcentration of fecal metabolites of glucocorticoids incaptive chimpanzees (Pan troglodytes)

The influence of stress in an environment, according with the behavioral and endocrine variables of primates, are increasingly being studied by a diversity of authors, and have shown that abnormal behaviors associated with increased glucocorticoids may be directly related with the impairment of their well-being. In this work were used 22 adult chimpanzees (Pan troglodytes), 11 males and 11 females, kept in captivity in three different institutions. All animals had their behavior registered by focal session using a 30 seconds sample interval, during six months, totaling 4,800 registries per each animal. During this period, fecal samples were collected 3 times a week for the extraction and measurement of the concentration of fecal metabolites of glucocorticoid by radioimmunoassay. Of the total observed, stereotypical behaviors represented 13,45±2.76%, and among them, self-mutilation represented 38.28±3.98 %. The animals were classified into three different scores, according with the percentage of body surface with alopecia due to self-mutilation. It was found a positive correlation of high intensity between the scores of alopecia due to the observed mutilation and the average concentrations of fecal metabolites of glucocorticoids. This result strongly suggests that this measurement of self-mutilation in a chimpanzee can be used as an important auxiliary tool to evaluate de conditions of adaptation of an animal in captivity, functioning as a direct indicator of the presence of chronic stress.

Estudio de las regiones intergénicas del Locus GH-PL en el chimpancé (Pan troglodytes)

Tesis (Maestría en Ciencias con Especialidad en Biología Molecular e Ingeniería Genética) UANL

Relation between the level of self-mutilation and the concentration of fecal metabolites of glucocorticoids in captive chimpanzees (Pan troglodytes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Swimming and diving behavior in apes (Pan troglodytes and Pongo pygmaeus): first documented report

Extant hominoids, including humans, are well known for their inability to swim instinctively. We report swimming and diving in two captive apes using visual observation and video recording. One common chimpanzee and one orangutan swam repeatedly at the water surface over a distance of 2-6 m; both individuals submerged repeatedly. We show that apes are able to overcome their negative buoyancy by deliberate swimming, using movements which deviate from the doggy-paddle pattern observed in other primates. We suggest that apes' poor swimming ability is due to behavioral, anatomical, and neuromotor changes related to an adaptation to arboreal life in their early phylogeny. This strong adaptive focus on arboreal life led to decreased opportunities to interact with water bodies and consequently to a reduction of selective pressure to maintain innate swimming behavior. As the doggy paddle is associated with quadrupedal walking, a deviation from terrestrial locomotion might have interfered with the fixed rhythmic action patterns responsible for innate swimming.

Anaesthesia with medetomidine-ketamine-isoflurane with and without midazolam, in eight captive Chimpanzees (Pan troglodytes) premedicated with oral zuclopenthixol

In 8 captive adult chimpanzees of various ages premedicated with oral zuclopenthixol anaesthesia was induced intramuscularly with a combination of medetomidine and ketamine (40 or 50 µg/kg and 5 mg/kg, IM, respectively), with and without midazolam (0.05 mg/kg), and maintained with isoflurane in oxygen. At the end of the procedure, sedation was reversed with atipamezole (0.25 mg/kg, IM) and sarmazenil (0.005 mg/kg, IM) when midazolam had been administered. Oral zuclopenthixol resulted in tranquillization of the whole group and only one animal required a second dart injection to achieve adequately deep anaesthesia. Effective and reliable anaesthesia was achieved in all apes; the depth of hypnosis was stable and sudden arousal did not occur. Physiological parameters remained within normal ranges in the majority of the animals; however, manageable anaesthesia-related complications, namely apnoea after darting, hypotension, hypoventilation, hypoxemia and prolonged recovery, occurred in 6 out of 8 animals. The use of monitoring devices was essential to guarantee adequate management of these complications.

Imitation recognition in a captive chimpanzee (pan troglodytes)

This study investigated the ability of a captive chimpanzee (Pan troglodytes) to recognise when he is being imitated. In the experimental condition of test 1a, an experimenter imitated the postures and behaviours of the chimpanzee as they were being displayed. In three control conditions the same experimenter exhibited (1) actions that were contingent on, but different from, the actions of the chimpanzee, (2) actions that were not contingent on, and different from, the actions of the chimpanzee, or (3) no action at all. The chimpanzee showed more "testing" sequences (i.e., systematically varying his actions while oriented to the imitating experimenter) and more repetitive behaviour when lie was being imitated, than when he was not. This finding was replicated 4 months later in test 1b. When the experimenter repeated the same actions she displayed in the experimental condition of test 1a back to the chimpanzee in test 2, these actions now did not elicit those same testing sequences or repetitive behaviours. However, a live imitation condition did. Together these results provide the first evidence of imitation recognition in a nonhuman animal.

Do chimpanzees (Pan troglodytes) understand single invisible displacement?

Previous research suggests that chimpanzees understand single invisible displacement. However, this Piagetian task may be solvable through the use of simple search strategies rather than through mentally representing the past trajectory of an object. Four control conditions were thus administered to two chimpanzees in order to separate associative search strategies from performance based on mental representation. Strategies involving experimenter cue-use, search at the last or first box visited by the displacement device, and search at boxes adjacent to the displacement device were systematically controlled for. Chimpanzees showed no indications of utilizing these simple strategies, suggesting that their capacity to mentally represent single invisible displacements is comparable to that of 18-24-month-old children.

Do chimpanzees (Pan troglodytes) and 2-year-old children (Homo sapiens) understand double invisible displacement?

Chimpanzees (Pan troglodytes) and young children (Homo sapiens) have difficulty with double invisible displacements in which an object is hidden in two nonadjacent boxes in a linear array. Experiment 1 eliminated the possibility that chimpanzees' previous poor performance was due to the hiding direction of the displacement device. As in Call (2001), subjects failed double nonadjacent displacements, showing a tendency to select adjacent boxes. In Experiments 2 and 3, chimpanzees and 24-month-old children were tested on a new adaptation of the task in which four hiding boxes were presented in a diamond-shaped array on a vertical plane. Both species performed above chance on double invisible displacements using this format, suggesting that previous poor performance was due to a response bias or inhibition problem rather than a fundamental limitation in representational capacity.

Parámetros clínicos de chimpancé ("Pan troglodytes") en programas de rehabilitación y reintroducción en su medio natural

Genéticamente, los chimpancés y los bonobos son los parientes vivos más cercanos a los seres humanos, que comparten un ancestro común que vivió hace unos seis millones de años. Los chimpancés se consideran en peligro de extinción por la IUCN y numerosos programas de conservación en África trabajan hacia la protección de la especie y su hábitat. Amenazado por la caza furtiva y la destrucción del hábitat, las cifras de población de chimpancés salvajes siguen disminuyendo. Como consecuencia, un importante flujo de chimpancés en vivo que son víctimas de la caza furtiva son enviados a centros de rehabilitación en África donde viven en semilibertad y en ocasiones son reintroducidos en el medio natural. Un objetivo primordial en estos centros de rescate y rehabilitación es proporcionar a los primates en cautividad con altos estándares de bienestar. La realización de tratamientos médicos adecuados y una gestión cuidadosa contribuye a su buen estado de salud, que a su vez permite a estos centros para garantizar el bienestar óptimo chimpancé. A un nivel veterinaria, la implementación de un tratamiento rápido y efectivo para una enfermedad requiere las herramientas de diagnóstico adecuadas, así como los valores de referencia correctos correspondientes a la especie. El objetivo de la presente tesis es establecer rangos de referencia de los diferentes parámetros clínicos para el chimpancé común (Pan troglodytes), que viven en semi-libertad en su hábitat natural. A fin de establecer valores de referencia, hemos utilizado los datos obtenidos durante los controles de rutina del brezo en chimpancés realizados durante diez años, en Tchimpounga Centro de Rehabilitación de chimpancé. Todos los chimpancés en el Centro de Rehabilitación Tchimpounga someten a controles de salud a su llegada al centro y en adelante cada tres años. Los análisis se llevan a cabo para asegurar la buena salud de la comunidad, y mejorar el control de la transmisión de enfermedades infecciosas, como la tuberculosis. Los análisis incluyen la recogida de sangre de la muestra, electrocardiogramas, radiografías de tórax, ecografía abdominal y pruebas serológicas y bacteriológicas. Estos análisis requieren la inmovilización química del individuo. A su vez, otros controles de salud que no requieren inmovilización química se realizan a diario en el centro por personal cualificado. Estos incluyen el análisis de las heces y la orina, y la exploración física general. La exploración global incluye tomar la temperatura corporal diaria de los chimpancés menores de 10 años en virtud de condicionamiento positivo...

Cultural innovation and transmission of tool use in wild chimpanzees:evidence from field experiments

Animal Cognition, V.6, pp. 213-223