The bright incubate at night: sexual dichromatism and adaptive incubation division in an open-nesting shorebird

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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How do ecological and social environments reflect parental roles in birds? A comparative analysis

10.1101/2020.12.24.424295 ◽

2020 ◽

Author(s):

Xiaoyan Long ◽

Yang Liu ◽

András Liker ◽

Franz J. Weissing ◽

Jan Komdeur ◽

...

Keyword(s):

Parental Care ◽

Social Environment ◽

Evolutionary Biology ◽

Sex Roles ◽

Ecological Factors ◽

Food Type ◽

Social Environments ◽

Colonial Species ◽

Parental Roles ◽

Care Patterns

AbstractParental roles are highly diverse in animal taxa. Since caring is an important determinant of fitness, understanding the origin and maintenance of various parental care strategies is a key question in evolutionary biology. Here we investigate parental care patterns in birds, which exhibit a remarkable diversity of parental sex roles. By means of phylogenetically informed comparative analyses we investigate whether and how care provisioning is predicted by ecology and social environment. Making use of the most comprehensive dataset including 1101 species that represent 126 avian families, we show that sex differences in parental care are neither related to food type nor to nest type, two key ecological factors. However, we found an effect of the social environment, as males tend to care relatively more in in colonial species than in non-colonial species. Taken together, these results highlight the importance of social effects for evolution of diverse parental sex roles.

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Relationship between nest defence behaviours and reproductive benefits in Chinese alligators

Amphibia-Reptilia ◽

10.1163/15685381-00002990 ◽

2015 ◽

Vol 36 (2) ◽

pp. 141-147 ◽

Cited By ~ 2

Author(s):

Fang Zhang ◽

Kevin Messenger ◽

Yong Wang

Keyword(s):

Reproductive Success ◽

Parental Care ◽

Clutch Size ◽

Evolutionary Theory ◽

Fertility Rate ◽

Nest Defence ◽

Hatching Rate ◽

Fertility Rates ◽

The Relationship ◽

Hatching Rates

The evolutionary theory in parental care predicts that parents may defend more vigorously of nests with higher survival and reproductive benefits. Based on this prediction, we proposed that the occurrence of nest defence behaviours in Chinese alligators might be connected to reproductive benefits (clutch size, fertility rate, and hatching rate). In this study, we examined the relationship between the occurrence of nest defence behaviours and (1) the variations in clutch size, fertility rate, and hatching rate of wild Chinese alligators, and (2) the variations in clutch size and fertility rate of captive Chinese alligators in a semi-natural facility. Results showed that for the wild Chinese alligators, the fertility and hatching rates with nest defence behaviours were higher than those without nest defence behaviours. The results also showed that for the captive Chinese alligators, the fertility rates with nest defence behaviours were higher than those without nest defence behaviours. These results suggested that nest defence behaviours in Chinese alligators might be relative to reproductive benefits, thus likely to further improve the probability of the species’ reproductive success.

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Parental roles and mating system in the black-winged stilt

Canadian Journal of Zoology ◽

10.1139/z03-082 ◽

2003 ◽

Vol 81 (6) ◽

pp. 947-953 ◽

Cited By ~ 5

Author(s):

J J Cuervo

Keyword(s):

Reproductive Success ◽

Parental Care ◽

Mating System ◽

Parental Investment ◽

Mate Guarding ◽

Egg Laying ◽

Nest Building ◽

Fertile Period ◽

Parental Roles ◽

Males And Females

The breeding behaviour of black-winged stilts (Himantopus himantopus) was studied in southwestern Spain. In the prelaying period males devoted more time than females to agonistic encounters, locomotion, and nest building. During egg laying, males spent more time than females at the nest, mostly building the nest and covering the eggs, while females spent more time foraging than males. During late incubation, females spent significantly more time at the nest than males. These results suggest very similar parental investment by the sexes. During part of the female's fertile period, males stayed at the nest while females were foraging, which precluded efficient mate guarding. However, females were reluctant to engage in extra-pair copulations, being always very aggressive towards conspecifics except for their mates. Even in two cases of extra-pair copulation, the first described for this species, the female continuously attacked the intrusive male and did not cooperate in copulation. Male parental care seems to be essential for reproductive success and females are probably faithful in order to assure male parental investment. The need for parental care from both males and females would maintain social, and perhaps also genetic, monogamy in this species.

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Female ornamentation, incubation behavior, and reproductive success in a wild bird

Behavioral Ecology and Sociobiology ◽

10.1007/s00265-021-03033-0 ◽

2021 ◽

Vol 75 (6) ◽

Author(s):

Conor C. Taff ◽

Corey R. Freeman-Gallant

Keyword(s):

Reproductive Success ◽

Wild Bird ◽

Incubation Behavior ◽

Female Ornamentation

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What makes the psychosis ‘clinical high risk’ state risky: psychosis itself or the co-presence of a non-psychotic disorder?

Epidemiology and Psychiatric Sciences ◽

10.1017/s204579602100041x ◽

2021 ◽

Vol 30 ◽

Author(s):

Laila Hasmi ◽

Lotta-Katrin Pries ◽

Margreet ten Have ◽

Ron de Graaf ◽

Saskia van Dorsselaer ◽

...

Keyword(s):

High Risk ◽

Drug Use ◽

Psychotic Disorder ◽

Positive Family History ◽

Mental Health Service Use ◽

Psychotic Symptoms ◽

Polygenic Risk Score ◽

Clinical High Risk ◽

Drug Use Disorders ◽

Per Se

Abstract Aims Although attenuated psychotic symptoms in the psychosis clinical high-risk state (CHR-P) almost always occur in the context of a non-psychotic disorder (NPD), NPD is considered an undesired ‘comorbidity’ epiphenomenon rather than an integral part of CHR-P itself. Prospective work, however, indicates that much more of the clinical psychosis incidence is attributable to prior mood and drug use disorders than to psychosis clinical high-risk states per se. In order to examine this conundrum, we analysed to what degree the ‘risk’ in CHR-P is indexed by co-present NPD rather than attenuated psychosis per se. Methods We examined the incidence of early psychotic experiences (PE) with and without NPD (mood disorders, anxiety disorders, alcohol/drug use disorders), in a prospective general population cohort (n = 6123 at risk of incident PE at baseline). Four interview waves were conducted between 2007 and 2018 (NEMESIS-2). The incidence of PE, alone (PE-only) or with NPD (PE + NPD) was calculated, as were differential associations with schizophrenia polygenic risk score (PRS-Sz), environmental, demographical, clinical and cognitive factors. Results The incidence of PE + NPD (0.37%) was lower than the incidence of PE-only (1.04%), representing around a third of the total yearly incidence of PE. Incident PE + NPD was, in comparison with PE-only, differentially characterised by poor functioning, environmental risks, PRS-Sz, positive family history, prescription of antipsychotic medication and (mental) health service use. Conclusions The risk in ‘clinical high risk’ states is mediated not by attenuated psychosis per se but specifically the combination of attenuated psychosis and NPD. CHR-P/APS research should be reconceptualised from a focus on attenuated psychotic symptoms with exclusion of non-psychotic DSM-disorders, as the ‘pure' representation of a supposedly homotypic psychosis risk state, towards a focus on poor-outcome NPDs, characterised by a degree of psychosis admixture, on the pathway to psychotic disorder outcomes.

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Clutch quality is related to embryonic development duration, hatchling body size and telomere length in the spined toad (Bufo spinosus)

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blab035 ◽

2021 ◽

Vol 133 (1) ◽

pp. 135-142

Author(s):

Marion Cheron ◽

Frédéric Angelier ◽

Cécile Ribout ◽

François Brischoux

Keyword(s):

Reproductive Success ◽

Embryonic Development ◽

Parental Care ◽

Telomere Length ◽

Mate Selection ◽

Hatching Success ◽

Egg Quality ◽

Parental Quality ◽

Complex Interactions ◽

Development Duration

Abstract Reproductive success is often related to parental quality, a parameter expressed through various traits, such as site selection, mate selection and energetic investment in the eggs or progeny. Owing to the complex interactions between environmental and parental characteristics occurring at various stages of the reproductive event, it is often complicated to tease apart the relative contributions of these different factors to reproductive success. Study systems where these complex interactions are simplified (e.g. absence of parental care) can help us to understand how metrics of parental quality (e.g. gamete and egg quality) influence reproductive success. Using such a study system in a common garden experiment, we investigated the relationships between clutch hatching success (a proxy of clutch quality) and offspring quality in an amphibian species lacking post-oviposition parental care. We found a relationship between clutch quality and embryonic development duration and hatchling phenotype. We found that hatchling telomere length was linked to hatching success. These results suggest that clutch quality is linked to early life traits in larval amphibians and that deciphering the influence of parental traits on the patterns we detected is a promising avenue of research.

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Laboratory comparison of the relative success of Biomphalaria glabrata stocks which are susceptible and insusceptible to infection with Schistosoma mansoni

Parasitology ◽

10.1017/s0031182000050502 ◽

1983 ◽

Vol 86 (2) ◽

pp. 335-344 ◽

Cited By ~ 41

Author(s):

D. J. Minchella ◽

P. T. Loverde

Keyword(s):

Life Cycle ◽

Natural Selection ◽

Reproductive Success ◽

Natural Populations ◽

Biomphalaria Glabrata ◽

Selective Advantage ◽

Controlled Conditions ◽

Plausible Answer ◽

Major Objection ◽

Transmit Disease

SUMMARYA method of interrupting the life-cycle of the human blood fluke Schistosoma by increasing the proportion of genetically insusceptible intermediate host snails in natural populations was first proposed nearly 25 years ago. The method assumes that insusceptible snails will be at a selective advantage over susceptible snails when the schistosome parasite is present, and therefore natural selection will act to increase the proportion of alleles for insusceptibility. A major objection to the proposed technique is ‘If insusceptible snails are at a selective advantage, then why are they not predominant in natural populations that transmit disease?’ One explanation of this paradox is that insusceptibility may be associated with a disadvantageous character or a physiological defect. This study tests this hypothesis by measuring the relative reproductive success of susceptible and insusceptible snails under controlled conditions. Results indicate that insusceptible (unsuitable) snails are negatively affected in the presence of either susceptible snails or schistosome parasites. Furthermore, in the presence of both susceptible snails and schistosome parasites, insusceptible snails are selectively disadvantaged compared to susceptible snails. These results obtained under laboratory-controlled conditions suggest a plausible answer as to why insusceptible snails are not predominant in natural populations that transmit disease.

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Energy Expenditure in Reproductive Effort of Male and Female Killdeer (Charadrius vociferus)

The Auk ◽

10.1093/auk/105.3.553 ◽

1988 ◽

Vol 105 (3) ◽

pp. 553-564 ◽

Cited By ~ 20

Author(s):

Dianne H. Brunton

Keyword(s):

Reproductive Success ◽

Energy Expenditure ◽

Parental Care ◽

Breeding Season ◽

Reproductive Effort ◽

Mating Effort ◽

Parental Effort ◽

Nest Failure ◽

Male And Female ◽

Charadrius Vociferus

Abstract The reproductive investment strategies of the sexes during the breeding season are detailed for Killdeer (Charadrius vociferus), a monogamous plover. I measured the energy investments of the sexes in reproductive, mating, and parental effort. As predicted, males expend more mating effort than females; however, the sexes expend equal amounts of parental effort. Total energy expenditure in reproductive effort (mating and parental effort) during a successful nesting attempt was also equal for the sexes. However, early parental effort expenditures by females, early mating effort expenditures by males, and high rates of nest failure combine to result in female reproductive energy expenditures being significantly higher over the breeding season. This suggests that energy expenditure alone is not adequate for accurate comparisons of the relative investments of the sexes. Studies investigating male and female investments need to consider the degree and pattern of nest failures along with patterns of energy expenditure. The advantages to male and female Killdeer of sharing parental care is demonstrated using adult removal experiments. In general, a deserted parent expends more energy in parental effort than a bi-parental parent and has significantly lower reproductive success. However, males are able to hatch chicks, whereas females lose or abandon their nests within a few days of mate removal. Thus, monogamy in Killdeer appears to result from high nest failure rates, the necessity of two parents for any reproductive success, and the generalizable nature of Killdeer parental care.

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