The sperm of aging male bustards retards their offspring's development.

9 pagesInternational audienceUnderstanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with maternal aging. Fitting with predictions on germline aging, the sperm of immature males produce the fastest growing offspring. Our findings thus indicate that any good genes benefit that might be offered by older 'proven' males will be eroded by aging of their germline DNA

Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?

International audienceSupportive breeding is one of the last resort conservation strategies to avoid species extinction. Management of captive populations is challenging because several harmful genetic processes need to be avoided. Several recommendations have been proposed to limit these deleterious effects, but empirical assessments of these strategies remain scarce. We investigated the outcome of a genetic management in a supportive breeding for the Houbara Bustard. At the phenotypic level, we found an increase over generations in the mean values of gamete production, body mass and courtship display rate. Using an animal model, we found that phenotypic changes reflected genetic changes as evidenced by an increase in breeding values for all traits. These changes resulted from selection acting on gamete production and to a lesser extent on courtship display. Selection decreased over years for female gametes, emphasizing the effort of managers to increase the contribution of poor breeders to offspring recruited in the captive breeding. Our results shed light on very fast genetic changes in an exemplary captive programme that follows worldwide used recommendations and emphasizes the need of more empirical evidence of the effects of genetic guidelines on the prevention of genetic changes in supportive breeding

Pre-but not post-meiotic senescence affects sperm quality and reproductive success in the North African houbara bustard

Age-dependent reduction in reproductive success can arise due to multiple factors including a deterioration of reproductive physiology. Senescing males have been shown to produce ejaculates with poor sperm quality, which impinges on male reproductive success. In addition to individual age, gamete age can also affect male reproductive success. Accordingly, variance in male reproductive success can be due to pre-meiotic (referring to individual age) and post-meiotic senescence (sperm age). Here, we tested whether male senescence and sperm cell aging have additive or interactive effects on male reproductive success in a bird with a promiscuous mating system, the North African houbara bustard. To assess the effect of pre-meiotic aging, we compared male reproductive success between two age classes (3-6- and 12–16-year-old). To infer the effect of post-meiotic aging, male ejaculates were collected at three-time intervals following a common initial collection (day 1, 5, and 10). Therefore, day 1 ejaculates are supposed to contain younger sperm than day 5 and 10 ejaculates. Following controlled artificial inseminations, reproductive success was assessed using three fitness-linked traits (hatching success, chick growth rate and survival). In addition to reproductive output, we also assessed whether pre- and post-meiotic aging affected a wide range of sperm and ejaculate traits. In agreement with previous reports, we found that males in the older age class produced less sperm with poorer motility compared to young individuals. However, contrary to the prediction, we found that ejaculates collected at day 5 and 10 tended to have better sperm traits such as motility and velocity. The results on sperm traits were generally mirrored in the effect on reproductive success since young males produced offspring that grew faster and had better survival during the first month of life, and eggs fertilized by sperm collected at day 5 had the highest hatching success. In any of the models, there was evidence for interactive effects of male and sperm age. Overall, these results confirm the role of pre-meiotic aging on male reproductive success. The lack of evidence for sperm aging could come from the experimental design but might also reflect the pattern of mating frequency in a species with a lek-based mating system

Immune-Mediated Change in the Expression of a Sexual Trait Predicts Offspring Survival in the Wild

BACKGROUND: The "good genes" theory of sexual selection postulates that females choose mates that will improve their offspring's fitness through the inheritance of paternal genes. In spite of the attention that this hypothesis has given rise to, the empirical evidence remains sparse, mostly because of the difficulties of controlling for the many environmental factors that may covary with both the paternal phenotype and offspring fitness. Here, we tested the hypothesis that offspring sired by males of a preferred phenotype should have better survival in an endangered bird, the houbara bustard (Chlamydotis undulata undulata). METHODOLOGY/PRINCIPAL FINDINGS: We tested if natural and experimentally-induced variation in courtship display (following an inflammatory challenge) predicts the survival of offspring. Chicks were produced by artificial insemination of females, ensuring that any effect on survival could only arise from the transfer of paternal genes. One hundred and twenty offspring were equipped with radio transmitters, and their survival monitored in the wild for a year. This allowed assessment of the potential benefits of paternal genes in a natural setting, where birds experience the whole range of environmental hazards. Although natural variation in sire courtship display did not predict offspring survival, sires that withstood the inflammatory insult and maintained their courtship activity sired offspring with the best survival upon release. CONCLUSIONS: This finding is relevant both to enlighten the debate on "good genes" sexual selection and the management of supportive breeding programs

La reproduction chez la caille des bles (Coturnix coturnix coturnix): etudes experimentales des cycles saisonniers et de la variabilite interindividuelle

SIGLEINIST T 75320 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Do peahens not prefer peacocks with more elaborate trains?

5 pagesInternational audienc

Multiple sexual advertisements honestly reflect health status in peacocks (Pavo cristatus)

The evolution of multiple sexual traits remains controversial and poorly understood in evolutionary biology. In many bird species, males exhibit complex courtships involving feather ornaments and behavioral display. Multiple traits may convey information on the genetic and phenotypic quality of males. In particular, fixed characters, such as feather ornaments (produced once a year during the annual molt in many bird species) might convey information about past male condition (at the time of trait development); whereas flexible traits such as behavioral displays should be sensitive to present condition. Here we show that both flexible behavioral displays and fixed feather ornaments of peacocks, used by females to choose a mate, honestly reflect health status. Correlative data showed that peacocks with high display rate (the number of behavioral displays per hour) and a large number of tail eyespots had low levels of circulating heterophils, suggesting better health status. Experimental activation of the immune system, through LPS injection, significantly reduced display rate compared to a control group. However, the sensitivity of a male display rate to the immune challenge was dependent on the number of tail eyespots: males with higher number of tail eyespots were better able to cope with the experimental immune challenge, and maintained their display rate at levels closer to the levels performed before the immune activation. These results are consistent with the idea that multiple signaling might enhance information reliability

Public Support for Biodiversity After a Zoo Visit: Environmental Concern, Conservation Knowledge, and Self-Efficacy

The biodiversity crisis is not salient to many people. A zoo visit not only provides the opportunity to learn about the issue, but also provides direct experiences with animals that may increase public engagement. The present study used a nonequivalent pretest–posttest design to assess the impact of a zoo visit on conservation knowledge and engagement by comparing 88 visitors entering a zoo in Paris and 84 visitors on their way out. Those who had completed their visit scored higher on conservation knowledge, general concern about threats to biodiversity, and perceived self‐efficacy to protect biodiversity. Notably, conservation knowledge was not highly correlated with the other dependent variables, but self‐efficacy was significantly correlated with environmental concern, behaviour, and behavioural intent. We conclude that a zoo visit does have a positive impact on knowledge and concern, and by affecting self‐efficacy, it has the potential to influence future behavior

Male health status, signalled by courtship display, reveals ejaculate quality and hatching success in a lekking species.

8 pagesInternational audienceSummary 1. The information content of secondary sexual traits and the benefits gathered by choosy females are at the heart of sexual selection theory. Indicator models of sexual selection assume that secondary sexual traits reflect the phenotypic/genetic quality of their bearers and that females gather benefits from choosing these high-quality males. 2. Here, we tested the idea that courtship display reflects the health status in a bird species with a lek-based mating system, the houbara bustard (Chlamydotis undulata undulata). A group of males was treated with the lipopolysaccharide (LPS) of the cell wall of the bacterium Escherichia coli during the seasonal peak of courtship display, while another group of males was injected with a phosphate-buffered saline solution (PBS) as a control. We then monitored the effect of the treatment on both courtship display and ejaculate quality. Finally, females were artificially inseminated with semen from LPS and PBS males, which allowed us to assess the effect of the immunological treatment on reproduction. 3. We found that the inflammatory challenge reduced courtship display and semen quality compared to controls. Interestingly, males that better resisted to the immune challenge in terms of courtship display also better resisted in terms of ejaculate quality. Early reproductive failure was increased when females were artificially inseminated with semen from immune-activated males. Failure of eggs laid by females inseminated with LPS semen was due to a reduced fertilization power of sperm of LPS males or to increased embryo mortality in the very early stage of embryo development. As a consequence, hatching rate was reduced for females inseminated with semen collected from LPS males. 4. These results show that by assessing male courtship display, females may gain insight into the current phenotypic/genetic quality of mates and gather fitness benefits in terms of reproductive success

Mise au point d'un protocole d'évaluation du stress chez les primates captifs et sauvages

Si le stress est un mécanisme adaptatif qui permet aux populations sauvages et captives de s'adapter à une situation donnée, il peut également s'avérer délétère : immunodépression, troubles reproducteurs, cardiovasculaires, digestifs, neurologiques, etc. Inhérent à la notion de bien-être animal, il s'agit toutefois d'un phénomène difficile à quantifier et à évaluer. A travers cette étude, nous avons cherché à définir un protocole de dosage du cortisol utilisable en routine chez de nombreuses espèces de primates, afin d'évaluer le bien-être des animaux en milieu captif et de tester les protocoles existants sur des échantillons prélevés en milieu sauvage. Les objectifs de l'étude sont les suivants : 1/ Mettre au point un protocole de récolte non invasif d'échantillons biologiques en captivité, 2/ Évaluer les variations physiologiques liées au cycle nycthéméral du cortisol, 3/ Comparer deux méthodes d'extraction du cortisol fécal, à savoir une méthode de terrain à une méthode de laboratoire, 4/ Tester la faisabilité de l'évaluation du stress chronique à travers le dosage du cortisol dans le poil. Cette étude préliminaire s'est déroulée en juillet et août 2014 au Muséum national d'Histoire naturelle. Nous avons travaillé sur les orangs-outans (OO) de Bornéo de la ménagerie du Jardin des Plantes (n=3) et sur deux groupes de babouins de Guinée mâles au Parc Zoologique de Paris (n=7+5). Le stress aigu a été étudié chez les OO par le prélèvement de fèces (n=30) en juillet associé à des prélèvements salivaires sur 12 jours en juillet, le matin (n=39) et le soir (n=41), puis pendant 16 jours en août seulement le matin (n=46). Deux mois après une coupe de poils sur l'avant-bras (4*4 cm) des 3 OO, des analyses de cortisol pilaire ont été faites sur la repousse pour évaluer le stress chronique. En milieu naturel, nous avons récolté des échantillons provenant de chimpanzés en Ouganda (2 lots de poils et 20 fèces), de bonobos en RDC (20 fèces) et de gorilles au Cameroun (2 lots de poils). Les dosages du cortisol dans ces différents matériaux biologiques ont été réalisés en duplicata par méthode ELISA. Les résultats des dosages du cortisol salivaire, pilaire ou fécal sont cohérents avec ceux de la bibliographie. Grâce à un travail d'habituation et de training, nous avons pu obtenir des poils facilement et avons pu mettre au point un système de récupération de la salive plusieurs fois par jour. La différence de concentration en cortisol salivaire entre le matin et le soir n'était pas significative, suggérant une absence de variations nycthémérales. Nous n'avons pas mis en évidence de différence significative dans les concentrations en cortisol fécal (n=30 fèces d'orangs-outans) entre les méthodes d'extraction de terrain et de laboratoire, validant la méthode de terrain pour les grands singes en milieu naturel. Les dosages du cortisol pilaire après 2 mois de repousse ont permis d'évaluer un stress chronique sur une période connue. Ces résultats préliminaires permettent de valider les protocoles employés et la mise en place d'études plus approfondies sur l'évaluation du stress par dosage de cortisol chez les primates en milieu naturel et en captivit