|
Hauber, M. E., & Sherman, P. W. (2003). Designing and interpreting experimental tests of self-referent phenotype matching. Anim. Cogn., 6(1), 69–71.
|
Tiefenbacher, S., Lee, B., Meyer, J. S., & Spealman, R. D. (2003). Noninvasive technique for the repeated sampling of salivary free cortisol in awake, unrestrained squirrel monkeys. Am. J. Primatol., 60(2), 69–75.
Abstract: The use of noninvasive measures of hypothalamic-pituitary-adrenal (HPA) axis function is of growing interest among preclinical and clinical investigators. This report describes a method for the repeated assessment of salivary free cortisol in awake, unrestrained squirrel monkeys (Saimiri sciureus) based on a saliva sampling technique previously developed for rhesus monkeys. Individually housed adult male squirrel monkeys were trained to chew on dental rope attached to a pole, from which saliva was extracted by centrifugation and analyzed for cortisol by radioimmunoassay (RIA). Eight of nine monkeys readily acquired the task, reliably providing adequate saliva samples for the assay. Salivary free cortisol levels were examined in these subjects under basal conditions and in response to two types of neuroendocrine challenge. Levels of salivary free cortisol showed relatively low intra- and interindividual variability, with mean individual morning levels ranging between 17.1 and 37.9 µg/dl. Squirrel monkeys demonstrated a consistent daily rhythm in salivary free cortisol ranging from a high of 27.4 ± 5.2 µg/dl (mean ± SEM) at 12 P.M. to a low of 7.5 ± 1.6 µg/dl at 6 P.M.. Intravenous (IV) challenges with 1 µg/kg ACTH, or 10 and 50 µg/kg CRF resulted in significant increases in salivary free cortisol. The described sampling technique provides a reliable and sensitive means for repeated measurement of HPA activity in unrestrained, awake squirrel monkeys. In addition, our findings illustrate several features of HPA system rhythmicity and reactivity using salivary cortisol instead of blood plasma or serum. Am. J. Primatol. 60:69–75, 2003. © 2003 Wiley-Liss, Inc.
|
|
Bolhuis, J. J. (2003). Bird brains and behaviour: perception, cognition and production. Animal Biology, 53(2), 71–72.
|
|
Mateo, J. M., & Johnston, R. E. (2003). Kin recognition by self-referent phenotype matching: weighing the evidence. Anim. Cogn., 6(1), 73–76.
|
Maninger, N., Capitanio, J. P., Mendoza, S. P., & Mason, W. A. (2003). Personality influences tetanus-specific antibody response in adult male rhesus macaques after removal from natal group and housing relocation. Am. J. Primatol., 61(2), 73–83.
Abstract: Previous research has suggested that personality is related to immune function in macaques. Using a prospective design, we examined whether variation in the personality dimension “Sociability” in adult male rhesus macaques (Macaca mulatta) was related to the in vivo secondary antibody response to a tetanus toxoid booster immunization following removal from natal groups and relocation to individual housing. We also explored whether the timing of the immunization following relocation had an impact on the immune response. Blood was sampled at the time of booster immunization, at 14 and 28 days post-immunization, and approximately 9 months post-immunization. Plasma was assayed for tetanus-specific IgG by enzyme-linked immunoassay (ELISA). There was no difference between High- and Low-Sociable animals in antibody levels at the time of the booster immunization. Multivariate analysis of variance (MANOVA) revealed that High-Sociable animals had a significantly higher antibody response following relocation and immunization compared to Low-Sociable animals. There was no effect of timing of the immunization on the immune response. The results confirm that personality factors can affect animals' immune responses, and that the dimension Sociability may be influential in a male's response to social separation and relocation.
|
Vonk, J. (2003). Gorilla ( Gorilla gorilla gorilla) and orangutan ( Pongo abelii) understanding of first- and second-order relations. Anim. Cogn., 6(2), 77–86.
Abstract: Four orangutans and one gorilla matched images in a delayed matching-to-sample (DMTS) task based on the relationship between items depicted in those images, thus demonstrating understanding of both first- and second-order relations. Subjects matched items on the basis of identity, color, or shape (first-order relations, experiment 1) or same shape, same color between items (second-order relations, experiment 2). Four of the five subjects performed above chance on the second-order relations DMTS task within the first block of five sessions. High levels of performance on this task did not result from reliance on perceptual feature matching and thus indicate the capability for abstract relational concepts in two species of great ape.
|
|
de Waal, F. B. M. (2003). Animal communication: panel discussion. Ann N Y Acad Sci, 1000, 79–87.
|
|
Reader, S. M., & MacDonald, K. (2003). Environmental variability and primate behavioural flexibiity. In S. M. Reader, & K. L. Laland (Eds.), Animal Innovation (pp. 83–116). Oxford: Oxford University Press.
|
Neff, B. D., & Sherman, P. W. (2003). Nestling recognition via direct cues by parental male bluegill sunfish ( Lepomis macrochirus). Anim. Cogn., 6(2), 87–92.
Abstract: Parental care can be costly to a parent in terms of both time and energy invested in the young. In species with cuckoldry or brood parasitism not all of the young under a parent's care are necessarily offspring. In such cases, distinguishing between kin and non-kin, and investing only in the former (nepotism), can be advantageous. Bluegill sunfish ( Lepomis macrochirus) are characterized by paternal care and cuckoldry, and care-providing males appear to show nepotistic behaviours. Here, we investigated nestling recognition in bluegill, determining whether parental males can differentiate between young from their own nest (familiar and related) and young from non-neighbouring nests (unfamiliar and unrelated) using (1) visual and chemical cues, and (2) chemical cues only. In the first experiment, wild-caught parental males were presented with samples of eggs or fry (newly hatched eggs) collected from their own nest or a foreign nest and placed on opposite sides of an aquarium. The time these parental males spent associating with each sample, and their “pecking” behaviours (indicating cannibalism), were recorded. Parental males showed no preference between eggs from their own nest and eggs from a non-neighbouring nest, but they preferred to associate with fry from their own nest over foreign fry. There also was a positive relationship between male body size and the time spent associated with fry from their own nest. Parental males pecked at foreign fry more than 5 times as often as fry from their own nest, though this difference was not statistically significant. In the second experiment, fry that were collected from the nest of a wild-caught parental male or a non-neighbouring nest were placed in different containers and the water from each was dripped into opposite ends of an aquarium. The time the male spent on each side was recorded. In this case, parental males spent more time near the source of water conditioned by unrelated fry, but there was a positive relationship between male condition (fat reserves) and the time he spent near the source of water conditioned by fry from his own nest. Results confirm that chemicals cue nestling recognition by parental male bluegill.
|
Cameron, E. Z.,, Linklater, W. L.,, Stafford, K. J.,, & Minot, E. O.,. (2003). Social grouping and maternal behaviour in feral horses (Equus caballus): the influence of males on maternal protectiveness. Behav. Ecol. Sociobiol., 53(2), 92–101.
Abstract: The risk of infant injury or mortality influences maternal behaviour, particularly protectiveness. Mares are found in bands with a single stallion or bands with more than one stallion in which paternity is less certain. We investigated maternal behaviour in relation to band type. Mares in bands with more than one stallion were more protective of their foals, particularly when stallions and foals approached one another. The rate of aggression between the stallion and foal was a significant predictor of maternal protectiveness, and mare protectiveness was significantly correlated with reduced reproductive success in the subsequent year. Mares that changed band types with a foal at foot, or had their band type experimentally altered, were more protective of their foal in multi-stallion bands than they were in single-stallion bands. Equids are unusual amongst ungulates in that infanticide and feticide have been reported. Both occur where paternity has been uncertain, and equid social structure is similar to other species in which infanticide has been reported. Stallions benefit from infanticide as the mare has greater reproductive success in the subsequent year. Stallion aggression is a significant modifier of mare behaviour and maternal effort, probably due to the risk of infanticide.
|
