Kiyonori Kumazaki

Paternity discrimination and inter-group relationships of chimpanzees at Bossou

A small group of wild chimpanzees at Bossou, southeastern Guinea, is semi-isolated, occupying a home-range which is several kilometers from those of other groups. The group has had only one adult male since 1985, raising the probability of inbreeding. Direct observation suggests that this male was the father of all infants born in the group since 1985. In 1991 individually identified samples of food wadges, hair, and feces were collected from most of the group members. These samples were analyzed using GT dinucleotide repeat polymorphisms to determine familial relationships. The genetic analysis revealed that the resident adult male was the probable father of only three out of the four infants analyzed. It is suspected that an adult male from a neighboring group was the father of the fourth infant, born in late 1986 or early 1987.

Yersinia pseudotuberculosis infection in breeding monkeys: detection and analysis of strain diversity by PCR

In the last three decades, several monkeys reared in outdoor/indoor–outdoor breeding colonies and cages of the Primate Research Institute, Kyoto University, died of yersiniosis caused by Yersinia pseudotuberculosis, necessitating introduction of a method to detect the bacteria rapidly and thus allow preventive measures to be undertaken. A rapid nested polymerase chain reaction (PCR) method for identification of Y. pseudotuberculosis in fecal samples and a random amplified polymorphic DNA (RAPD)‐PCR approach for distinguishing between bacterial strains were therefore developed. Yersinia pseudotuberculosis isolates from monkey specimens were found to be classifiable into several types. To determine the source of infection, hundreds of fecal samples of wild rats, pigeons, and sparrows were collected from around the breeding colonies and cages, and subjected to PCR analyses. Yersinia pseudotuberculosis was detected in 1.7% of the fecal samples of wild rats. The DNA fingerprints of the bacteria revealed by RAPD‐PCR were the same as that of one strain isolated from macaques, suggesting the wild rat to be a possible source of infection.

Tetraparesis resembling acute transverse myelitis in a captive chimpanzee (Pan troglodytes): long-term care and recovery.

Background  A 24‐year‐old, male chimpanzee (Pan troglodytes) developed acute tetraparesis. Magnetic resonance imaging showed a diffuse T2‐weighted hyperintensive lesion, indicating inflammation at the C1–2 level. All infective, autoimmune, and vascular investigations were unremarkable.

A horse's eye view: size and shape discrimination compared with other mammals.

Mammals have adapted to a variety of natural environments from underwater to aerial and these different adaptations have affected their specific perceptive and cognitive abilities. This study used a computer-controlled touchscreen system to examine the visual discrimination abilities of horses, particularly regarding size and shape, and compared the results with those from chimpanzee, human and dolphin studies. Horses were able to discriminate a difference of 14% in circle size but showed worse discrimination thresholds than chimpanzees and humans; these differences cannot be explained by visual acuity. Furthermore, the present findings indicate that all species use length cues rather than area cues to discriminate size. In terms of shape discrimination, horses exhibited perceptual similarities among shapes with curvatures, vertical/horizontal lines and diagonal lines, and the relative contributions of each feature to perceptual similarity in horses differed from those for chimpanzees, humans and dolphins. Horses pay more attention to local components than to global shapes.

ORIGINAL ARTICLE: Tetraparesis resembling acute transverse myelitis in a captive chimpanzee (Pan troglodytes): long-term care and recovery: Tetraparesis in a chimpanzee

Background  A 24‐year‐old, male chimpanzee (Pan troglodytes) developed acute tetraparesis. Magnetic resonance imaging showed a diffuse T2‐weighted hyperintensive lesion, indicating inflammation at the C1–2 level. All infective, autoimmune, and vascular investigations were unremarkable.

ORIGINAL ARTICLE: Tetraparesis resembling acute transverse myelitis in a captive chimpanzee (Pan troglodytes): long-term care and recovery

Background  A 24‐year‐old, male chimpanzee (Pan troglodytes) developed acute tetraparesis. Magnetic resonance imaging showed a diffuse T2‐weighted hyperintensive lesion, indicating inflammation at the C1–2 level. All infective, autoimmune, and vascular investigations were unremarkable.