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A literature review on macaque monkeys finds that peer rearing of young macaques and rearing of young macaques by mothers that are undergoing variable foraging conditions result in emotional and neurophysiological disturbance. Certain genotypes contribute to resilience to this disturbance. The findings have implications to child mental health and early social environment.

Total parental expenditure of mammals and birds has been predicted to increase with litter or brood size, but data from rodents provide little support for this prediction. We examined the effects of natural variation in litter size on parental nest attendance in pine (= woodland), prairie, and meadow voles housed in seminatural environments. In all 3 species, mothers spent less time in the nest with large litters than with small; time spent in the nest by fathers was unaffected by litter size. We suggest that failure to meet the prediction of increased parental expenditure with increased litter size reflects basic differences in the manner in which mammals and birds feed altricial young. Key words: litter size, maternal behavior, meadow vole, Microtus, parental care, paternal behavior, pine vole, prairie vole, woodland vole

In order to ascertain the typical pattern and amount of parental care in the social vole (Microtus socialis guentheri) as well as the individual investment of the female, male, or both parents simultaneously, we studied ten primiparous females and their mates. Results revealed that out of seven parental behaviors, only crouching was correlated with litter size, suggesting that parental care was relatively independent of litter size--that is, duration of time spent with the young, licking them, retrieving them to the nest, having them attached to the female's nipples, and searching for a nipple on the male were not correlated with litter size. Individual investment of caretakers also varied, with no typical proportion of shared nurturing by the female and male. Accordingly, overall parental investment varied greatly among different sets of parents without correlation to the relative contribution of the female, the male, or both. Finally, duration and frequency of most parental behaviors declined over the course of postnatal development. Altogether, these data suggest a surplus parental investment that was probably not required for survival of offspring but might have evolved either for other purposes such as the formation of social bonds or was selected for in captivity. Key words: crouching, kyphosis, licking, maternal behavior, Microtus socialis guentheri paternal behavior, parental investment, retrieving

The behavior of infants of the cotton-top tamarins (Saguinus oedipus) in normal and fearful situations show that their attachment is toward family member with whom they were previously associated. Data indicate father as the primary attachment figure in these cooperatively breeding monkeys.

Research reveals that aggressive behavior by mothers on female helpers is not correlated with group size, sex ratios, number of females in the group, or age of the helpers. However, data indicate that daughters benefit from reduced aggression during act of carrying infants.

Results show that size of dung beetle offspring is influenced by the amount of dung provided to the developing larvae. Data further suggest that such provisioning by parents affects the body and horn size.

A procedure to take into account the nongenetic relationship between maternal effects in adjacent generations is presented. It considers a correlation between maternal environments provided by a dam and its daughters (lambda). The dispersion structure of the maternal animal model was modified to include a correlation matrix (E) that relates the maternal permanent environmental effects. The structures of the E matrix and its inverse (E(super -1) are described. Both matrices are completely defined by the correlation coefficient (lambda). An algorithm to compute these matrices from pedigree information was also developed. Furthermore, a Bayesian analysis of this model including the (lambda) parameter was developed using Gibbs sampling, with Metropolis steps for the nonstandard conditional distributions. With simulated data, the proposed model reduced the bias in all estimates of dispersion parameters when an antagonism between the maternal effects received by a daughter and its future maternal environment existed. This model also provides an estimate of the environmental relationship between the maternal effects of dams and daughters by the (lambda) parameter. The same Bayesian analysis was also carried out with weaning weight data of the Bruna dels Pirineus breed. The posterior means (standard deviation) of (co)variance ratios were .214 (.081) for direct heritability (h(super 2)(sub d)), .107 (.033) for maternal heritability (h(super 2)(sub m)), .047 (.020) for the proportion of variance due to maternal environmental effects (C(super 2)(sub m)), and -.034 (.043) for the genetic correlation between direct and maternal effects (r(sub dm)). The posterior mean of (lambda) parameter was -.190, and 76% of its marginal posterior distribution took negative values. As occurred with simulated data, considering the maternal environmental correlation in the analysis implied higher h(super 2)(sub m)estimates, lower C(super 2)(sub m) and h(super 2)(sub d) estimates, and less negative values for the marginal posterior distribution of r(sub dm). These results were considered as evidence of the environmental antagonism between maternal effects provided by a dam and its daughters to weaning weight of their progeny in the Bruna dels Pirineus breed. Key Words: Maternal Effects, Bayesian Theory, Gibbs Sampling, Beef Cattle, Weaning Weight

Bart Kempenaers and Ben C. Sheldon, in an article published in a 1997 edition of 'Animal Behaviour,' erred in their assumption on the inappropriateness of non-experimental studies on the relationship between measures of paternal care and paternity in birds. They argued that descriptive studies provide inaccurate information confounded by other factors where causality cannot be inferred. However, descriptive studies may contain valuable information about the topic which may not be adequately addressed by the experimental approach.

Experiment 1 compared the responses of wild-caught adult and captive-born adult and juvenile kangaroo rats (Dipodomys heermanni arenae) to a live snake. Wild-caught adult rats were less active and monitored the snake more than during a control condition; captive-born juvenile rats did not behave differently during snake and control tests. Snake-naive adult rats behaved more like the wild-caught adult rats, but not on all measures. In Experiment 2, pups were tested at 25 and 50 days of age in 4 conditions: no-snake control, alone with the snake, with a sibling and the snake, and with the mother and the snake. Pups did not behave differently during control and snake tests, but during tests with the mother, pups faced the snake less and followed the mother. Younger pups were more often near the mother than a sibling and followed the mother more when the snake was present. Development of defensive behavior may depend on both predator experience and maternal influence.

The relationship between paternity and parenteral behavior in animals cannot be determined based on the genetic analysis of the males' paternity and parenteral contributions to the care of the offspring. Research on natural populations of birds also indicated the negative effects of paternal care which reduces survival, breeding and mating opportunities. Furthermore, variations of specific conditions between males also affect paternity and the extent of paternal care.

Group-living yellow-bellied marmots' alarm call is a form of direct parental care behavior which is maintained by its role in maximizing direct fitness. Adult female marmots with pups call at higher rates than other age or sex classes, after pups emerge. Variables associated with direct parental care explain variation in the seasonal rate, as compared to variables reflecting the potential magnitude of inclusive fitness benefits.

Various internal and external cues influence the maternal behavior of burrower bugs, Sehirus cinctus (Heteroptera: Cydnidae). Second-brood mothers exhibit decreased maternal responsiveness earlier than first-brood mothers as a result of differences in parity and age. Prior maternal experience fails to affect the duration of care. Physiological constraints lead to early termination of maternal care among second-brooders. Hatching event, appearance of nymphs and depletion of metabolic reserves lead to decreased responsiveness and termination of maternal care.

Sexual selection linked with female parental care is responsible for the divergence in color and pattern in Dendrobates pumilio, a dart-poison frog of Bocas del Toro in Panama. Such variations are absent in two other dart-poison frog species, Minyobates sp. and Phyllobates lugubris, due to lack of sexual selection in them. Divergence in mitochondrial DNA is similar in all the three species. Female choice for male ornamentation is strong in D. pumilio as the female provide more parental care than the males. The other two species show weak selection because the males provide more parental care.

Double clutching is rare in Majorcan midwife toad, Alytes muletensis, due to the time constraint in males obtaining a second clutch. Multiple clutching is a method of taking care of the offsprings of two or more females simultaneously. An increase in the time limit for second clutch increases the rate of double clutching. The female inter-clutch interval and the male brooding period play an important role in affecting the rate of double clutching.

Male bluethroat, a monogamous passerine, uses mate guarding as its main paternity guard, and this behavior is related to paternity. In the observed sample, 20% of all offspring are sired by extra-pair males. The extra-pair offsprings are clustered in certain groups where their number is almost 54%. There is a no intraspecific brood parasitism. Males with full paternity guard their mates intensely at the beginning of egg-laying, and follow the female. Male singing decreases during breeding season. There are more intrusions in territories with extra-pair offspring.

A study on the mating behavior of yellow warblers shows that females observe the behavioral features of males to assess potential parental contribution. Male chest stripping is found to be an unreliable indicator of paternal care. Paternal care also varies between individuals. Reductions in male help are not compensated for by the females, resulting in the reduction of nestling growth. Paternal care is important to female fitness as higher post-fledging survival of heavier nestlings is observed as paternal care increases.

A study on filial cannibalism among fish in the genus Poeciliopsis shows that neonates of P. lucida, a non-cannibalistic species, do not avoid their female parent. Neonates of cannibalistic form, P. monacha and the hybrid P. monacha-lucida, exhibit clear avoidance. Examinations show that avoidance behavior in the hybrid P. monacha-lucida is inherited from genetic variance that existed in their P. monacha sexual ancestors. Parental avoidance also increases with size at birth, showing an anti-cannibalistic strategy in nature.

An analysis of parental care in the orange-tufted sunbird revealed that males showed more mobbing efforts than their female partners and the nest guarding activity increased both in males and females with increased brood size. For provisioning at higher rates, males failed to guard nests. Visit rates decreased in experimental nests and larger broods as evidenced by the lower chick growth rates.

Spotted hyena litter-mates establish their hierarchial status from the first day of life and dominant male hyena litter-mates were as aggressive towards their siblings as their female litter-mates. Cubs of low-ranking mothers fought more than the cubs of high-ranking mothers. Cubs cooperated better for coalition formation with their litter mates than the hyenas of the other litters.

Squabs showed pecking and begging actions whereas retracting and pecking was shown by parent doves at 12-17 days in an analysis of the parent-squab activity during the transition phase from dependent to independent feeding in ring doves. Negative correlation between regurgitative feeding and squab pecking is observed. Influence of pecking by the parents in eliciting independent feeding behavior in squabs is frequently observed.

Fledgling periods are very important for avian brood parasites. One example, fledgling Great Spotted Cuckoos, generally form a group with other fledgling cuckoos. The size of the group ranges from one to five fledglings that have their origin from one to four various nests. A group of Black-billed magpies attend each group of fledgling cuckoos. The rate of feeding of the cuckoos is directly proportional to the number of cuckoos per group and the number of adult magpies attending the group. The flocking behavior apparently is good for the fledglings as each fledgling in larger group receives more food.

Research shows that the cost of reproduction for for females of the fish species Sarotherodon galileaus is very high, both in the cost of gamete production and the cost of care. Parental care for both sexes has costs to growth and increases the number of days until the next reproductory cycle. Subsequent fecundity is decreases by care in females, as evident in the correlation between female fecundity and body weight.

The impact of control of adult nutritional situations was calculated to examine parent offspring conflict in Oceanodroma leucorhoa employing ptilochronology, and the impact on offspring nutritional situation was calculated by examining chick growth. There was no difference between treatment and control parents in nutritional situation. Treatment chicks acquired mass more slowly and spent a greater part of nights without being fed by either parent. The storm-petrel parents seemingly shunted that cost to their offspring when confronted with an increased cost of parental care.

The results corroborate earlier observations that the typical ovid social system does not demonstrate strong post-weaning relation between mothers and daughters. Powerful relations between mothers and yearlings, mainly for mothers that have given birth to a new lamb but lost it, were discovered in bighorn sheep, Ovis canadensis, at high density. The most important quality of these ewes was that they had milk and did not need to have a new lamb. The mother-yearling relation seemed more powerful for female than male yearlings whereas maternal age had no impact.

A study of a large captive group of mother-infant dyads of Japanese macaques, Macaca fuscata, shows that the quality of mother-infant relationship is affected by mother's age and matriline size. Rejection is common among mothers belonging to large matrilines, with older mothers being less protective of their infants. Mother-infant relationship remains unaffected by infant sex, maternal dominance rank and the number of immature offsprings, but is limitedly influenced by maternal experience.

A study of the relationship between paternity and paternal behavior in an eastern population of red-winged blackbirds during the four seasons shows that paternity does not influence paternal behavior. This result is suggested by the male provisioning of individual broods identically, despite the paternity of males in that brood. The level of provisioning by males with low paternity over several nests is the same as that of males with high paternity.

Analysis of social factors affecting paternal responsiveness and suppression of infanticide in male meadow voles, Microtus pennsylvanicus, tested with unrelated pups shows that pup exposure enhances paternal responsiveness. Rearing of pups as neonates with their fathers increases the responsiveness of adult males to pups. Intense exposure to pups is associated with diminished aggression and increased paternal responsiveness. Copulation and female contact do not influence male responsiveness to pups.

The absence or presence of a female in her fertile period rather than the availability of unmated females influences the male parental care behavior of polygynous male red-winged blackbirds, Agelaius phoeniceus. Males feed nestlings only when additional females are not in their fertile period. Opportunity to attract additional mates has less effect on male parental behavior than paternity guarding.

Video-cameras monitoring the activities of the biparental catfish, Bagrus merdionalis, in feeding and protecting their young ones from predators show that the male and female individuals adopt division of labor and perform various activities. The males treat the young ones to benthic invertebrate food while the females provide trophic eggs to the young ones. During predatory attacks the females chase the attackers while the males stay with them. When the young ones start maturing the females provide sex-specific food such as eggs while the males develop burrows.

Examination of the effects of biparental care and age of stimulus pups on care-giving by male and female virgin mice, Mus musculus, reveals that biparental care improves male care toward newborns and sustains female care for mid-preweaning pups at the levels observed for newborns. Biparentally cared females extend the duration of pup retrieval beyond normal time period. The effect of biparental care on pup retrieval by virgin mice is attributed to the presence of younger siblings or male parent.

Studies of single parent brood-care behavior in the burying beetle, Nicrophorus orbicollis, reveal that loss of a mate is compensated by enhanced brood-care behavior by the survivor. Single males and female reveal higher frequency of regurgitation to larvae and carrion maintenance. This also results in lesser frequency of brood guarding and shorter duration of guarding.

Effects of nestling age and brood size on parental food delivery and brood attention time were studied in the Bachman's sparrow (Aimophila aestivalis) in central Arkansas from 1983-1985. Nestlings received an increase in food mass with age because both parents increased the size of foods they delivered and because females increased the number of feeding trips and food items delivered. Males delivered a greater percentage of lepidopteran larvae to 0-2 day-old nestlings than to older nestlings. Nestling attentive time for both parents decreased with nestling age. Nestlings of large broods received approximately the same food mass as small brood nestlings because both parents increased the number of feeding trips and food items delivered. Brood size had no effect on the types of foods fed to nestlings. Small brood nestlings received more attentive time than large brood nestlings. Although females spent more time at the nest than males, they delivered roughly the same amount of food.

We report here self-suckling in four wild female Barbary macaques (Macaca sylvanus), living in two troops (i.e. 'Flat face' and 'Large' troop) in the middie-Atlas Mountains, Morocco. The four females lost their infants due to predation or for unknown causes. Self-suckling was observed before and after the infants died in the four females living in the 'Flat face' troop. When the infants were still alive, self-suckling was of short duration and it was probably a method to improve milk flow when the infant switched from one nipple to the other. After the infants died, self-suckling lasted significantly longer and the females were apparently drinking their own milk. Self-suckling was never observed among the four lactating females in the 'Large' troop (including one monkey who lost her infant) and it could thus represent a cultural difference. Moreover, self-suckling after the death of an infant may be explained by the energetic and immunological benefits that a monkey may gain from drinking their own milk. Finally, self-suckling may have a stress-releasing effect on the mothers who have lost their infants. KEY WORDS culture; emotion; grief; lactation; maternal behavior; predation; prolactin; stress; animal tradition

Infanticide has recently been observed in several primate species while female counterstrategies are seemingly rare. The question of why mothers do not increase their resistance to infanticide is investigated using a haploid two-locus model. A hypothesis that mothers can recover lost offspring by gaining more grandchildren is rejected in most cases, and it is shown that costs and benefits for both males and females have the strongest influence on the evolution of infanticide and obedience to it. An estimation of parameters for a natural population of hanuman langurs suggests that infanticide is more advantageous than noninfanticide and the costs of resistance, compared to obedience, is higher than its benefits. Data from other studies on primate infanticide are discussed in the light of results of the model.

Studies of the webspinner Anisembia texana reveal that communal females produce, on an average, a larger number of eggs than solitary females. Under experimental conditions, maternal care accelerates nymphal growth. Females do not assist emerging nymphs and produce two types of silk for protecting the egg and defending territory against intruders, respectively.