Infant Chimpanzees Research Articles

Object permanence in child and chimpanzee

In a repeated-measures design, two infant chimpanzees and three human infants were tested in like manner using the Uzgiris and Hunt (1975) stepwise assessment instrument for the development of object permanence in human infants. Comparisons between chimpanzee and human subjects showed similarities in the number of steps achieved, in the order and rate of achieving the steps, and in the detailed characteristics of searching behavior. These results suggest that the course of development of the concept of object permanence, as described by Piaget, is a very general one.

Failure to detect infectious hepatitis B virus using high dose safety test for hepatitis B vaccine.

One hundred milliliters of an inactivated hepatitis B vaccine (20 microgram/ml) were inoculated intravenously into two colony-born infant chimpanzees. Immediately thereafter each received hepatitis B virus from a documented infectious inoculum intravenously at a separate site. Neither chimpanzee developed elevation of aminotransferase levels, hepatitis B surface antigen (HBsAg), or antibody to hepatitis B core antigen during six months of evaluation, the duration of the currently recommended safety test. Both chimpanzees developed antibody to HBsAg beginning 8 and 9 weeks, respectively, after inoculation. The administration of a large intravenous quantity of vaccine antigen thus appeared capable of masking or preventing infection by simultaneously administered hepatitis B virus. This study suggests that a chimpanzee safety test for hepatitis B vaccine should not employ large quantities of vaccine antigen, since such a safety test may fail to detect small amounts of residual infectious hepatitis B virus.

Transmission of human non-A, non-B hepatitis to chimpanzees following failure to transmit GB agent hepatitis.

Two colony-born infant chimpanzees were inoculated with documented infectious serum containing the GB agent. Serum aminotransferase levels remained within normal limits in weekly serum samples, and no abnormalities were detected in weekly liver biopsy specimens. Each of these chimpanzees was subsequently inoculated with serum containing an agent of human non-A, non-B hepatitis. Each developed non-A, non-B hepatitis characterized by elevation of serum aminotransferase levels and histopathologic changes in liver biopsy specimens. Thus, the chimpanzee appears not to be susceptible to the GB agent, and prior inoculation with this agent does not appear to confer immunity to subsequent infection with human non-A, non-B hepatitis.

Patterns of food sharing among mother and infant chimpanzees at Gombe National Park, Tanzania.

The patterns of food sharing among mother and infant chimpanzees at the Gombe National Park, Tanzania, are primarily influenced by the infants' ability to procure and process foods independently. Foods infants could find and process on their own were not shared by mothers as frequently as foods infants could not obtain independently. Temporal changes were observed in the patterns of interactions as infants matured. It is suggested that food sharing may be considered a behavioral strategy which facilitates the infant's transition from dependent suckling to independent foraging.

Map reading by chimpanzees.

Infant chimpanzees, after watching a small black-and-white closed-circuit television picture of a familiar caretaker walking out into an outdoor field and disappearing from sight, were more successful in finding the person than if they had been given no such cue; and their performance approximated that which obtained after they had seen the same scene normally, via direct perception.

Coxsackievirus in an Infant Chimpanzee

Coxsackie B viruses may cause a severe, often fatal, illness in newborn and infant human subjects. As recorded in this case, infant chimpanzees respond similarly to Coxsackie B-5 virus.

Experimental Infection of Chimpanzees with Hepatitis A Virus

The susceptibility of chimpanzees to viral hepatitis type A was examined with immine electron microscopy. Of four seronegative infant chimpanzees, two were inoculated with a hepatitis A acute-phase stool filtrate rich in 27 nm virus-like hepatitis A antigen (HA Ag) particles, and two were inoculated with an HA Ag-negative preinfection stool filtrate. One of each pair of chimpanzees was inoculated intravenously, the other orally. One month later both chimpanzees that had received the HA Ag-positive filtrate developed biochemical, histologic, and clinical evidence of acute viral hepatitis. HA Ag particle (27 nm) were detected in their stools by immune electron microscopy; particle shedding followed a pattern similar to that in human volunteers. Immune electron microscopy also showed that antibody HA Ag had developed in the convalescent-phase sera of the infected chimpanzees. Control animals remained free of illness at this time but did develop hepatitis three to five weeks after exposure to the two infected chimpanzee-. The infectious inoculum was titrated in two additional seronegative chimpanzees. It was concluded that hepatitis a can be successfully transmitted to seronegative chimpanzees. Moreover, these studies provide further evidence that the 27-nm virus-like HA Ag particle is the etiologic agent of viral hepatitis type A.

A case of the adoption of an infant chimpanzee by a suckling foster chimpanzee

Chimpanzees in captivity have grown up in a rather unnatural social environment and there frequently are problems when they have to nurse their own offspring. It is most remarkable that a chimpanzee mother in a captive colony, who had lost her child almost immediately after birth, adopted without problems a five-week-old infant, which had been reared by humans from the day of its birth. Successful adoption has not been reported for feral chimpanzees; similar cases in captivity are not known.

Gonadotropins in the infant chimpanzee: a sex difference.

SummarySerial circulating levels of FSH were higher in five female than in four male infant (0.4-2.0 years) chimpanzees. A rhythm in FSH levels was observed in the females with a periodicity of 8–25 days. There was no sex difference in mean LH levels. However, greater day-to-day variability was observed in the females.The animals used in the study were handled in accordance with the “Guide for Laboratory-Animal Facilities and Care” established by The National Academy of Science-National Research Council. This work was supported in part by M. R. C. Canada Grant MA-2997 and by N. I. H. Contract DRR-73-2100. The LER-907 human pituitary gonadotropin standard was a gift of the National Pituitary Agency. We thank Dr. F. S. Chebib for help with the statistical analyses and Mrs. R. Poturnak, Mrs. E. Dudeck, and Mr. D. Bookout for technical assistance.

: Ape and Child Series: Part III. Experiments upon a Human and a Chimpanzee Infant after Six Months in the Same Environment . W. N. Kellogg.

: Ape and Child Series: Part III. Experiments upon a Human and a Chimpanzee Infant after Six Months in the Same Environment . W. N. Kellogg.

: Ape and Child Series: Part IV. Some General Reactions of a Human and a Chimpanzee Infant after Six Months in the Same Environment . W. N. Kellogg.

: Ape and Child Series: Part IV. Some General Reactions of a Human and a Chimpanzee Infant after Six Months in the Same Environment . W. N. Kellogg.

: Ape and Child Series: Part I. Some Behavior Characteristics of a Human and Chimpanzee Infant in the Same Environment . W. N. Kellogg.

: Ape and Child Series: Part I. Some Behavior Characteristics of a Human and Chimpanzee Infant in the Same Environment . W. N. Kellogg.

: Ape and Child Series: Part V. Facial Expressions of a Human and a Chimpanzee Infant Following Taste Stimuli . W. N. Kellogg.

: Ape and Child Series: Part V. Facial Expressions of a Human and a Chimpanzee Infant Following Taste Stimuli . W. N. Kellogg.

: Ape and Child Series: Part II. Comparative Tests on a Human and a Chimpanzee Infant of Approximately the Same Age . W. N. Kellogg.

: Ape and Child Series: Part II. Comparative Tests on a Human and a Chimpanzee Infant of Approximately the Same Age . W. N. Kellogg.

Sleep ontogeny in the chimpanzee: From two months to forty-one months

Over a one year period, 14 and 24 h EEG records were obtained with scalp electrodes from 14 infant chimpanzees aged from 2 to 41 months, sleeping on a couch in a soundproof room. They started to crawl at 3 months, sit and stand at 4–5 months, walk at 6–7 months, climb at 8–9 months and run and swing around 15 months. They napped until 9–10 months. The EEG morphology changed constantly until 2–3 years. Each stage had its own individual evolution. The waking EEG was composed of low voltage fast activity. Alpha rhythm appeared at 3 months, increased in amplitude until 20 months and became well stabilized around 30–36 months. Drowsiness with EEG hypersynchrony was seen at 11 months, the hypersynchrony became maximal in amplitude and duration at 18 months and then decreased. Stage 1 increased with age in number of occurrences, duration and EEG frequency. Sharp wave activity was seen in the parieto-occipital areas after 2 months and then increased in incidence and amplitude until around 18 months after which it declined and was rarely seen again. In stage 2 spindles declined in amplitude, occurrence and frequency with age, unlike the V waves and K complexes which increased in occurrence and definition with age. Stage 3 had few spindles, but more K complexes. High voltage sharp waves at 4–5 c/sec occurred in bursts between 1 and 2 years and then disappeared. Slow waves in the delta band marked the pattern of stage 3 after 2 years. Stage 4 was not seen before 4–5 months. High voltage sharp waves were maximal in amplitude and occurrence around 18 months. Delta activity was synchronous and without overriding faster activity after 2 years. REM showed an increase in frequency of background activity with age but decrease in percentage along with decreases in centro-parietal spike activity. The EEG pattern tended to reach maturity around 3 years.

A Nonhuman Being Can Learn Language

man beings. After some centuries of active doubt, and many pronouncements that nonhuman beings are incapable of language, an infant chimpanzee has learned two-way communication. The experiment is as yet incomplete; in fact, the experimenters point out that the attempt to teach a primate language is as yet only in its pioneer stage. The results thus far reported, however, seem to demonstrate that one nonhuman being has now learned what we must call lan-

Sex difference in gonadotropins in the infant chimpanzee.

Serial circulating levels of FSH were higher in two female than in two male infant chimpanzees. There was no sex difference in LH levels. A rhythm in FSH levels was seen in both sexes. The cycle amplitude was greater in the females. The LH data were qualitatively similar to those for FSH.

Object relations and the origin of tools.

Both captive and wild chimpanzees can make and use crude tools. Evidence is cited that chimpanzee tool use depends as much on their faculty for manipulating and relating to objects as on their high intelligence. Even early in life, this faculty is clearly evident, and infant chimpanzees, raised in nurseries under conditions similar to those for human infants, develop transitional object relationships identical with those seen in human infants. It is hypothesized that, in the evolution of man, object manipulation and relationships preceded tool making and tool use as a transitional step. Gradually, protohominids learned to manipulate objects in order to interact or manipulate other objects. The use and modification of these primitive tools was learned by cohabitants through imitation, thus becoming part of the learned behavior and tradition of the protohominid culture.

Plasma testosterone concentration and binding in the chimpanzee; effect of age.

Plasma testosterone concentration was 4.7 ± 6.2 SD, 14.7 ± 1 1.8 SD, 263 ± 144 SD and 495 ± 143 SD ng/100 ml in infant, juvenile, adolescent, and adult chimpanzees, respectively, as measured by competitive protein binding. The water blank of the method was 4.0 ± 2.9 SD ng/100 ml and was not subtracted. Plasma testosterone binding affinity and capacity as measured in concomitant samples by a Sephadex, equilibrium dialysis method was significantly less (p < 0.001) in adult chimpanzees than in any of the other age groups. Both the range of plasma testosterone and the fall in testosterone binding are similar to corresponding measurements reported for human pre- and postpubertal subjects. Estimates of the percent of the total testosterone remaining unbound in prepubertal and postpubertal male chimpanzees are about twice the corresponding values reported for boys and men, respectively. Serum total proteins and globulin were greater in adult than in infant chimpanzees while serum albumin and the albumin/globulin...

Chimpanzee foetal haemoglobin: Structure and heterogeneity of the γ chain

The amino acid compositions of soluble tryptic and chymotryptic peptides of the γ chain of chimpanzee foetal haemoglobin have been determined. The peptides, accounting for all 146 residues of the γ chain, were found to be identical in composition to the corresponding human γ chain peptides. As in man, position γ136 can be occupied by glycine ( Gγ chain) as well as alanine ( Aγ chain). The ratio of Gγ to Aγ chains in the infant chimpanzee is approx. 2:1, and in the adult approx. 1:2.