28 resultados para Parental care


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Nest visit synchrony, whereby adults coordinate their visits to the nest, has been documented in several species of cooperative breeders. Visit synchrony may reduce nest predation rate or sibling competition, or instead follow from synchronisation of other behaviours, such as foraging. However, nest visit synchrony has rarely been considered in species with bi-parental care, even though it could conceivably bring similar fitness benefits to that seen in cooperative breeders. In addition, in species with bi-parental care, we might expect nest visit synchrony to reflect the quality of the pair or the overall coordination of breeding activity between partners. Here, we tested whether nest visit synchrony occurs in a classic avian model for the study of bi-parental care, the zebra finch Taeniopygia guttata. We found that in the wild, both zebra finch parents visited the nest very infrequently during nestling provisioning, with only one visit per hour, and that nest visits were highly synchronised with parents visiting the nest together on 78% of the visits. In addition, we found that nest visit synchrony was correlated with hatching rate, brood size at hatching and the number of offspring in the nest a few days prior to fledging. Our results suggest that, while more work is required to understand the benefits of nest visit synchrony in this species, considering behavioural synchrony and cooperation between mated partners may offer new insight into the study of parental investment, including in species with bi-parental care.

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Although the costs of parental care are at the foundations of optimal-parental-investment theory, our understanding of the nature of the underlying costs is limited by the difficulty of measuring variation in foraging effort. We simultaneously measured parental provisioning and foraging behavior in a free-living population of Zebra Finches (Taeniopygia guttata) using an electronic monitoring system. We fitted 145 adults with a passive transponder tag and remotely recorded their visits to nest boxes and feeders continuously over a 2-month period. After validating the accuracy of this monitoring system, we studied how provisioning and foraging activities varied through time (day and breeding cycle) and influenced the benefits (food received by the offspring) and costs (interclutch interval) of parental care. The provisioning rates of wild Zebra Finches were surprisingly low, with an average of only one visit per hour throughout the day. This was significantly lower than those reported for this model species in captivity and for most other passerines in the wild. Nest visitation rate only partially explained the amount of food received by the young, with parental foraging activity, including the minimum distance covered on foraging trips, being better predictors. Parents that sustained higher foraging activity and covered more distance during the first breeding attempt took longer to renest. These results demonstrate that in some species matching foraging activity with offspring provisioning may provide a better estimate of the true investment that individuals commit to a reproductive attempt.

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The foraging benefits of coloniality, whereby colony members exchange information about food location, have been suggested as a primary factor influencing the evolution of coloniality. However, despite its longstanding popularity, this hypothesis has rarely been tested experimentally. Here, we conducted a field experiment in the wild Zebra Finch Taeniopygia guttata to test whether colonial birds are better at finding food than solitary individuals. We manipulated food patch location and directly measured foraging activity of many colonial and solitary parents at those patches using an electronic monitoring system. We provided nesting sites in excess to alleviate nest site competition and manipulated brood size to eliminate the possible correlation between brood size, nesting density, and individual quality (including foraging activity). We found that solitary birds found experimental food patches first, closely followed by colonial birds. Moreover, solitary parents adjusted the amount of food per nestling to experimental brood size, whereas colonial parents did not, although overall, nestlings were fed more per capita in colonial than in solitary nests. In addition, brood size and, to a lesser extent, nesting density negatively affected nestling growth. Therefore, with the effect of provisioning rate, sibling competition, and cost of coloniality combined, nestling mass was not affected by the brood manipulation in solitary nests, whereas nestlings were lighter in enlarged than in reduced broods in colonies. Our results therefore suggest that individuals settling in solitary nests were intrinsically better foragers and more optimal parents. While they do not invalidate the possibility of information transfer at colonies, our findings highlight the importance of considering settlement bias in future studies and add to the existing evidence that the effects of nesting density on fitness are both complex and multiple.

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Ornamentation of parents poses a high risk for offspring because it reduces cryptic nest defence. Over a century ago, Wallace proposed that sexual dichromatism enhances crypsis of open-nesting females although subsequent studies found that dichromatism per se is not necessarily adaptive. We tested whether reduced female ornamentation in a sexually dichromatic species reduces the risk of clutch depredation and leads to adaptive parental roles in the red-capped plover Charadrius ruficapillus, a species with biparental incubation. Males had significantly brighter and redder head coloration than females. During daytime, when visually foraging predators are active, colour-matched model males incurred a higher risk of clutch depredation than females, whereas at night there was no difference in depredation risk between sexes. In turn, red-capped plovers maintained a strongly diurnal/nocturnal division of parental care during incubation, with males attending the nest largely at night when visual predators were inactive and females incubating during the day. We found support for Wallace's conclusion that reduced female ornamentation provides a selective advantage when reproductive success is threatened by visually foraging predators. We conclude that predators may alter their prey's parental care patterns and therefore may affect parental cooperation during care.

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Parental care strategies have been widely investigated in shorebirds that undertake long-distance regular migrations. In contrast, virtually nothing is known of the parental care of nomadic, opportunistically breeding shorebirds, although the irregular and short-lived nature of their breeding potentially accentuates the trade-offs between investment in successive clutches and between the sexes. We investigated the incubation behaviour of the nomadic, opportunistically breeding Banded Stilt (Cladorhynchus leucocephalus). Seven nests, filmed continuously with day–night cameras over 2–7 days, revealed that both sexes contributed to incubation, with males apparently the sole carer during hatching and early brood-rearing; this is a possible adaptation, which enables females to quickly produce a second clutch if favourable conditions persist. All incubator changeovers occurred after dark; incubation shifts averaged 44.8 ± 10.9 (s.e.m.) h (n = 11, 17.5–139.6 h), the longest recorded for any shorebird. Incubation constancy averaged 96.5%; this high value is possibly an adaptation to high predation and the need for rapid embryonic development in the face of ephemeral resources for breeding. Long incubation shifts may be explained by extended foraging trips to distant areas of the partially inundated salt-lake surface, where food resources had been concentrated by wind-driven water movement.

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The Prevention of Organised Crime Act 121 of 1998 [POCA] embodies a serious attempt by the South African government to effectively police and curb organised crime, money laundering and criminal gang activities in South Africa. The Act provides inter alia for a range of crippling fines and for orders such as confiscation and forfeiture. Asset forfeiture and confiscation orders can affect the rights of third parties directly and indirectly in a number of ways. Young persons and children can beaffected indirectly because asset forfeiture and confiscation orders may violate the right to parental care of the dependent young persons and children of the person who is subject to the order. This brief article will investigate aspects of the protection afforded to the rights of children when such orders are made in terms of the provisions of the Prevention of Organised Crime Act.

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Life history theory suggests that species experiencing high extrinsic mortality rates allocate more resources toward reproduction relative to self-maintenance and reach maturity earlier ('fast pace of life') than those having greater life expectancy and reproducing at a lower rate ('slow pace of life'). Among birds, many studies have shown that tropical species have a slower pace of life than temperate-breeding species. The pace of life has been hypothesized to affect metabolism and, as predicted, tropical birds have lower basal metabolic rates (BMR) than temperate-breeding birds. However, many temperate-breeding Australian passerines belong to lineages that evolved in Australia and share 'slow' life-history traits that are typical of tropical birds. We obtained BMR from 30 of these 'old-endemics' and ten sympatric species of more recently arrived passerine lineages (derived from Afro-Asian origins or introduced by Europeans) with 'faster' life histories. The BMR of 'slow' temperate-breeding old-endemics was indistinguishable from that of new-arrivals and was not lower than the BMR of 'fast' temperate-breeding non-Australian passerines. Old-endemics had substantially smaller clutches and longer maximal life spans in the wild than new arrivals, but neither clutch size nor maximum life span was correlated with BMR. Our results suggest that low BMR in tropical birds is not functionally linked to their 'slow pace of life' and instead may be a consequence of differences in annual thermal conditions experienced by tropical versus temperate species.

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Sexual conflict over parental care relies on the fundamental assumption that parents do not share the cost of their partner's effort on future reproduction. However, this is unlikely to be true whenever partners breed together more than once. In that case, individuals should try to optimize the cost and benefits for the pair, rather than only for themselves. Here we seek to establish whether the synchronization of parents' provisioning visits to the nest could fulfill this function. We conducted a brood-size manipulation experiment on wild zebra finches to test whether nest visit synchrony was flexible and beneficial for nestlings' growth, while controlling for the confounding effects of pair "quality" and synchrony away from the nest during foraging. Using a network of readers to track parents at nests and feeding stations, we found that nest visit synchrony responded directly to the brood manipulation and increased with brood size. Synchrony at the nest and while foraging were correlated, but the latter better predicted nestling mass, possibly because it was associated with more regular provisioning patterns. Our findings suggest that parental coordination could indeed play an important role in partners' investment decisions, underpinning the evolution of the most prominent mating system in birds.

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Sexual segregation in habitat use is widely reported in many taxa and can profoundly influence the distribution and behaviour of animals. However, our knowledge of the mechanisms driving sexual segregation is still in its infancy (particularly in marine taxa) and the influence of extrinsic factors in mediating the expression of sex differences in foraging behaviour is underdeveloped. Here, we combine data from biologging tags, with stable isotope analysis of vibrissae, to assess sexual segregation in southern sea lions (SSL) (Otaria flavescens) breeding at the Falkland Islands in the South Atlantic. We found evidence to support segregation, most notably in δ13C and δ15N values. However, in spite of extreme sexual size dimorphism and differing constraints related to female-only parental care, adult male and adult female SSL overlapped considerably in isotopic niches and foraging area, and shared similar foraging trip characteristics (such as distance and duration). This is in contrast to SSL breeding in Argentina, where prior studies report sexual differences in foraging locations and foraging trip characteristics. We posit that sexual segregation in SSL is influenced by habitat availability (defined here as the width of the Patagonian Shelf) and individual foraging preferences, rather than commonly invoked individual-based limiting factors per se.

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Partnering early childhood education and care (ECEC) and the home together may be more effective in combating obesogenic risk factors in preschool children. Thus, an evaluation of ECEC obesity prevention interventions with a parental component was conducted, exploring parental engagement and its effect on obesity and healthy lifestyle outcomes. A search revealed 15 peer-reviewed papers. Some studies demonstrated positive weight changes, and secondary outcomes of changes in physical activity and healthy eating were reported in most studies; study quality ranged from fair to good. Four findings were linked to weight changes: (1) when educational material is consistent across settings; (2) capacity building of parents; (3) parents encouraging their children to drink water and (4) parental satisfaction and participation. A partnership between parents and ECEC may be a powerful force in the prevention of paediatric obesity. A better understanding of collaborative parental engagement is needed.

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This paper reviews current research regarding the impact of birth complications on parental decisionmaking, and the resulting effects on parent-infant and infant-marital relationships. It discusses the importance of informed decision-making on parental satisfaction of the birthing experience, and the benefits of certain strategies, such as kangaroo care, in the facilitation of greater levels of attachment and improved relationships. The paper concludes with suggestions for future research areas to focus on finding better ways to prepare and support parents in these situations, thus improving the quality of relationships between parents and with their child.

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The Out of School Hours Sports Program (OSHSP) aimed to provide structured sporting experiences and community links to local clubs for children in Out of School Hours Care (OSHC). The OSHSP involved 17 State Sporting Associations (SSAs), 71 OSHC Services and local club representatives. This study explored children's participation in sport in and outside the OSHSP and parental intention for participation in sport in and outside the OSHSP. Surveys were received from 211 children (76 girls and 125 boys; mean age = 7.9 years, S.D. = 1.7) and their parents/guardians (37.9% response rate). OSHC is characterised by freedom of choice of participation in activities by children. The OSHSP was used to provide an opportunity to choose to participate in a sport while attending OSHC. At the OSHC Services surveyed, between 7.1 and 100% of the children attending OSHC chose to participate in the OSHSP. Of those children who chose to participate, 85% were participating in a sport, usually a different sport to the one offered in the OSHSP. This participation was largely club-based (49.8%), most often once a week for training and competition (55.2%). Parental intentions for children's participation in the OSHSP sports varied with respect to the number of years attending the OSHSP, where children played and trained in their main sport, and how many times a week a child played and trained in their main sport. Older children tended to play and train for sport more times per week and had been attending the OSHC for more years than younger children.

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© 2015 American Psychological Association. Richard Warshak (2014) published a "consensus report" in this journal (Vol. 20, No. 1) documenting a policy position on infants and overnight care following parental separation. He asserts that "[t]here is no evidence to support postponing the introduction of regular and frequent involvement, including overnights, of both parents with their babies and toddlers" (p. 60). To support this assertion, Warshak presents a series of detailed concerns about an Australian study the authors conducted, some of which involve serious misrepresentations of our aims, methodology, and findings. In this reply, we clarify the purpose, context, and limitations of our study, and refute one of Warshak's central theses: that our study's design and results favor primary maternal care of young children and discourage overnights and shared parenting for fathers. We appraise the Warshak article, and consider whether other approaches to consensus statements and to policy dialogue might better serve families involved in the family law system, particularly when emotive debates such as the overnight care of young children cannot yet be resolved by science.