137 research outputs found
The Taming of the Cat
This article discusses research into the evolution of domesticated cats, which is complicated by the fact that they do not appear to serve humans. Although several species are morphologically similar, genetic research focusing on mitochondrial DNA and genetic microsatellites found that domesticated cats descended from F. sylvestris lybica. Archaeological research indicating cats came to live with humans as the prevalence of house mice in agricultural settlements increased is noted. Insets: The House Cat\u27s Ancestor; Early Domestication; From Wild to Mild; The Truth about Cats and Dog
Maternal, social and abiotic environmental effects on growth vary across life stages in a cooperative mammal.
Resource availability plays a key role in driving variation in somatic growth and body condition, and the factors determining access to resources vary considerably across life stages. Parents and carers may exert important influences in early life, when individuals are nutritionally dependent, with abiotic environmental effects having stronger influences later in development as individuals forage independently. Most studies have measured specific factors influencing growth across development or have compared relative influences of different factors within specific life stages. Such studies may not capture whether early-life factors continue to have delayed effects at later stages, or whether social factors change when individuals become nutritionally independent and adults become competitors for, rather than providers of, food. Here, we examined variation in the influence of the abiotic, social and maternal environment on growth across life stages in a wild population of cooperatively breeding meerkats. Cooperatively breeding vertebrates are ideal for investigating environmental influences on growth. In addition to experiencing highly variable abiotic conditions, cooperative breeders are typified by heterogeneity both among breeders, with mothers varying in age and social status, and in the number of carers present. Recent rainfall had a consistently marked effect on growth across life stages, yet other seasonal terms only influenced growth during stages when individuals were growing fastest. Group size and maternal dominance status had positive effects on growth during the period of nutritional dependence on carers, but did not influence mass at emergence (at 1 month) or growth at independent stages (>4 months). Pups born to older mothers were lighter at 1 month of age and subsequently grew faster as subadults. Males grew faster than females during the juvenile and subadult stage only. Our findings demonstrate the complex ways in which the external environment influences development in a cooperative mammal. Individuals are most sensitive to social and maternal factors during the period of nutritional dependence on carers, whereas direct environmental effects are relatively more important later in development. Understanding the way in which environmental sensitivity varies across life stages is likely to be an important consideration in predicting trait responses to environmental change
Maternal, social and abiotic environment effects on growth vary across life stages in a cooperative mammal
1. Resource availability plays a key role in driving variation in somatic growth and body
condition, and the factors determining access to resources vary considerably across life
stages. Parents and carers may exert important influences in early life, when individuals are
nutritionally dependent, with abiotic environmental effects having stronger influences later
in development as individuals forage independently.
2. Most studies have measured specific factors influencing growth across development, or
have compared relative influences of different factors within specific life stages. Such
studies may not capture whether early-life factors continue have delayed effects at later
stages, or if social factors change when individuals become nutritionally independent and
adults become competitors for, rather than providers of, food.
3. Here, we examined variation in the influence of the abiotic, social and maternal
environment on growth across life stages in a wild population of cooperatively breeding
meerkats. Cooperatively breeding vertebrates are ideal for investigating environmental
influences on growth. In addition to experiencing highly variable abiotic conditions,
cooperative breeders are typified by heterogeneity both among breeders, with mothers
varying in age and social status, and in the number of carers present.4. Recent rainfall had a consistently marked effect on growth across life stages, yet other
seasonal terms only influenced growth during stages when individuals were growing fastest.
Group size and maternal dominance status had positive effects on growth during the period
of nutritional dependence on carers, yet did not influence mass at emergence (at one month)
or growth at independent stages (>4 months). Pups born to older mothers were lighter at one
month of age, and subsequently grew faster as subadults. Males grew faster than females
during the juvenile and subadult stage only.
5. Our findings demonstrate the complex ways in which the external environment influences development in a cooperative mammal. Individuals are most sensitive to social and maternal
factors during the period of nutritional dependence on carers whereas direct environmental
effects are relatively more important later in development. Understanding the way in which
environmental sensitivity varies across life stages is likely to be an important consideration
in predicting trait responses to environmental change.Natural Environment Research Council (grant number PFZC092 to THCB).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2656hb201
Cost of dispersal in a social mammal : body mass loss and increased stress
Dispersal is a key process influencing the dynamics of socially and spatially structured populations. Dispersal success is determined by the state of individuals at emigration and the costs incurred after emigration. However, quantification of such costs is often difficult, due to logistical constraints of following wide-ranging individuals. We investigated the effects of dispersal on individual body mass and stress hormone levels in a cooperative breeder, the meerkat (Suricata suricatta). We measured body mass and faecal glucocorticoid metabolite (fGCM) concentrations from 95 dispersing females in 65 coalitions through the entire dispersal process. Females that successfully settled lost body mass, while females that did not settle but returned to their natal group after a short period of time did not. Furthermore, dispersing females had higher fGCM levels than resident females, and this was especially pronounced during the later stages of dispersal. By adding information on the transient stage of dispersal and by comparing dispersers that successfully settled to dispersers that returned to their natal group, we expand on previous studies focusing on the earlier stages of dispersal. We propose that body mass and stress hormone levels are good indicators to investigate dispersal costs, as these traits often play an important role in mediating the effects of the environment on other life-history events and individual fitness.Analyses in this study and data collection at the Kalahari Meerkat Project (KMP) on dispersers were funded by the Swiss National Science Foundation Grant (CR32I3_159743) to A.O., and data collection on resident individuals and maintenance of facilities at the Kalahari Research Centre (KRC) were funded by the ERC Advanced Grants (294494 and 742808) to T.C.-B. and by the University of Zurich.http://royalsocietypublishing.org/journal/rspbhj2019Mammal Research Institut
Fitness benefits of prolonged post-reproductive lifespan in women
Most animals reproduce until they die, but in humans, females can survive long after ceasing reproduction. In theory, a prolonged post-reproductive lifespan will evolve when females can gain greater fitness by increasing the success of their offspring than by continuing to breed themselves. Although reproductive success is known to decline in old age, it is unknown whether women gain fitness by prolonging lifespan post-reproduction. Using complete multi-generational demographic records, we show that women with a prolonged post-reproductive lifespan have more grandchildren, and hence greater fitness, in pre-modern populations of both Finns and Canadians. This fitness benefit arises because post-reproductive mothers enhance the lifetime reproductive success of their offspring by allowing them to breed earlier, more frequently and more successfully. Finally, the fitness benefits of prolonged lifespan diminish as the reproductive output of offspring declines. This suggests that in female humans, selection for deferred ageing should wane when one's own offspring become post-reproductive and, correspondingly, we show that rates of female mortality accelerate as their offspring terminate reproduction
Breeding phenology and meteorological conditions affect carer provisioning rates and group-level coordination in cooperative chestnut-crowned babblers
Recent theoretical and empirical work suggests that coordinating offspring provisioning plays a significant role in stabilizing cooperative care systems, with benefits to developing young. However, a warming and increasingly extreme climate might be expected to make contributions to, and so coordination of, care more challenging, particularly in cooperative breeding systems comprising multiple carers of varying age and pairwise relatedness. Here we investigated the interplay between breeding phenology, meteorological conditions and carer number on the individual rates and group-level coordination of nestling care in the cooperatively breeding chestnut-crowned babbler (Pomatostomus ruficeps) in outback south-eastern Australia. From 3 months since the last meaningful rain event, dominant male breeders and—to a lesser extent—related helpers showed reductions in their provisioning rates and increases in their day-to-day variation. Further, on days with high mean wind speed, dominant males contributed less and helpers were less likely to visit the nest on such days. Helpers also showed reduced visitation rates on days with high mean temperature. Provisioning rates were independent of the number of carers, and increasing numbers of carers failed to mitigate the detrimental effects of challenging environment on patterns of provisioning. Those helpers that were unrelated to broods often failed to help on a given day and tended to help at a low rate when they did contribute, with socio-environmental predictors having limited explanatory power. Given the marked variation in individual contributions to offspring care and the variable explanatory power of the socio-environmental predictors tested, babblers unsurprisingly had low levels of nest visitation synchrony. Large groups visited the nest more asynchronously on days of high mean temperature, suggesting that meteorological impacts on individual provisioning have consequences for group-level coordination. Our study has implications for the consequences of climate change on patterns of provisioning, the minimal role of group size in buffering against these challenges and the stabilization of cooperative care
Inbreeding and inbreeding depression of early life traits in a cooperative mammal
Mating between relatives often results in negative fitness consequences or inbreeding
depression. However, the expression of inbreeding in populations of wild cooperative
mammals and the effects of environmental, maternal and social factors on inbreeding
depression in these systems are currently not well understood. This study uses pedigree-based
inbreeding coefficients from a long-term study of meerkats (Suricata suricatta) in South
Africa to reveal that 44% of the population have detectably non-zero (F>0) inbreeding
coefficients. 15% of these inbred individuals were the result of moderate inbreeding
(F≥0.125), although such inbreeding events almost solely occurred when mating individuals
had no prior experience of each other. Inbreeding depression was evident for a range of traits:
pup mass at emergence from the natal burrow, hind-foot length, growth until independence
and juvenile survival. However, we found no evidence of significant inbreeding depression
for skull and forearm length or for pup survival. This research provides a rare investigation
into inbreeding in a cooperative mammal, revealing high levels of inbreeding, considerable
negative consequences and complex interactions with the social environment.The Meerkat project is funded by the Natural Environment
Research Council and the Earthwatch Institute. JFN is funded by a NERC CASE studentship with the Institute of Zoology, London.http://www.wiley.com/bw/journal.asp?ref=0962-1083ab201
Inbreeding and inbreeding depression of early life traits in a cooperative mammal
Mating between relatives often results in negative fitness consequences or inbreeding
depression. However, the expression of inbreeding in populations of wild cooperative
mammals and the effects of environmental, maternal and social factors on inbreeding
depression in these systems are currently not well understood. This study uses pedigree-based
inbreeding coefficients from a long-term study of meerkats (Suricata suricatta) in South
Africa to reveal that 44% of the population have detectably non-zero (F>0) inbreeding
coefficients. 15% of these inbred individuals were the result of moderate inbreeding
(F≥0.125), although such inbreeding events almost solely occurred when mating individuals
had no prior experience of each other. Inbreeding depression was evident for a range of traits:
pup mass at emergence from the natal burrow, hind-foot length, growth until independence
and juvenile survival. However, we found no evidence of significant inbreeding depression
for skull and forearm length or for pup survival. This research provides a rare investigation
into inbreeding in a cooperative mammal, revealing high levels of inbreeding, considerable
negative consequences and complex interactions with the social environment.The Meerkat project is funded by the Natural Environment
Research Council and the Earthwatch Institute. JFN is funded by a NERC CASE studentship with the Institute of Zoology, London.http://www.wiley.com/bw/journal.asp?ref=0962-1083ab201
iCount: a human-factors engineered solution to vaginal swab retention – an early-stage innovation report
© 2024 The Authors. Published by BMJ. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1136/bmjinnov-2024-001248WHAT ARE THE NEW FINDINGS
Despite established policies and procedures when swab counting, issues such as distraction, confirmation bias, competing task priorities and changes in swab appearance contribute to swab miscounts and therefore swab retention.
Cases of count discrepancies/miscounts are under-reported, and their impact extends to patient’s health, clinician’s time and trust’s reputation and finances.
iCount is a low-cost device designed and developed with human factors-ergonomics principles. It is a docking system that behaves as a physical checklist when swab counting and facilitates conscious engagement using visual and tactile cues when counting.
Users believe iCount to be a viable alternative to manual two-person swab counting with greater time efficiency and perceived safety. This could be valuable in emergency maternity situations.
HOW MIGHT IT IMPACT ON HEALTHCARE IN THE FUTURE
iCount has the potential to reduce or prevent retained swabs after vaginal deliveries along with appropriate policies, training and teamwork.
Additional clinical research and widespread adoption would be needed to validate this effectively.This study was funded by Innovate UK10033555.Published onlin
Middleborns disadvantaged? testing birth-order effects on fitness in pre-industrial finns
Parental investment is a limited resource for which offspring compete in order to increase their own survival and reproductive success. However, parents might be selected to influence the outcome of sibling competition through differential investment. While evidence for this is widespread in egg-laying species, whether or not this may also be the case in viviparous species is more difficult to determine. We use pre-industrial Finns as our model system and an equal investment model as our null hypothesis, which predicts that (all else being equal) middleborns should be disadvantaged through competition. We found no overall evidence to suggest that middleborns in a family are disadvantaged in terms of their survival, age at first reproduction or lifetime reproductive success. However, when considering birth-order only among same-sexed siblings, first-, middle-and lastborn sons significantly differed in the number of offspring they were able to rear to adulthood, although there was no similar effect among females. Middleborn sons appeared to produce significantly less offspring than first-or lastborn sons, but they did not significantly differ from lastborn sons in the number of offspring reared to adulthood. Our results thus show that taking sex differences into account is important when modelling birth-order effects. We found clear evidence of firstborn sons being advantaged over other sons in the family, and over firstborn daughters. Therefore, our results suggest that parents invest differentially in their offspring in order to both preferentially favour particular offspring or reduce offspring inequalities arising from sibling competition
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