Corticosterone shifts reproductive behaviour towards self-maintenance in the barn owl and is linked to melanin-based coloration in females.

Trade-offs between the benefits of current reproduction and the costs to future reproduction and survival are widely recognized. However, such trade-offs might only be detected when resources become limited to the point where investment in one activity jeopardizes investment in others. The resolution of the trade-off between reproduction and self-maintenance is mediated by hormones such as glucocorticoids which direct behaviour and physiology towards self-maintenance under stressful situations. We investigated this trade-off in male and female barn owls in relation to the degree of heritable melanin-based coloration, a trait that reflects the ability to cope with various sources of stress in nestlings. We increased circulating corticosterone in breeding adults by implanting a corticosterone-releasing-pellet, using birds implanted with a placebo-pellet as controls. In males, elevated corticosterone reduced the activity (i.e. reduced home-range size and distance covered within the home-range) independently of coloration, while we could not detect any effect on hunting efficiency. The effect of experimentally elevated corticosterone on female behaviour was correlated with their melanin-based coloration. Corticosterone (cort-) induced an increase in brooding behaviour in small-spotted females, while this hormone had no detectable effect in large-spotted females. Cort-females with small eumelanic spots showed the normal body-mass loss during the early nestling period, while large spotted cort-females did not lose body mass. This indicates that corticosterone induced a shift towards self-maintenance in males independently on their plumage, whereas in females this shift was observed only in large-spotted females.

Massive nest-box supplementation boosts fecundity, survival and even immigration without altering mating and reproductive behaviour in a rapidly recovered bird population.

Habitat restoration measures may result in artificially high breeding density, for instance when nest-boxes saturate the environment, which can negatively impact species' demography. Potential risks include changes in mating and reproductive behaviour such as increased extra-pair paternity, conspecific brood parasitism, and polygyny. Under particular cicumstances, these mechanisms may disrupt reproduction, with populations dragged into an extinction vortex. With the use of nuclear microsatellite markers, we investigated the occurrence of these potentially negative effects in a recovered population of a rare secondary cavity-nesting farmland bird of Central Europe, the hoopoe (Upupa epops). High intensity farming in the study area has resulted in a total eradication of cavity trees, depriving hoopoes from breeding sites. An intensive nest-box campaign rectified this problem, resulting in a spectacular population recovery within a few years only. There was some concern, however, that the new, high artificially-induced breeding density might alter hoopoe mating and reproductive behaviour. As the species underwent a serious demographic bottleneck in the 1970-1990s, we also used the microsatellite markers to reconstitute the demo-genetic history of the population, looking in particular for signs of genetic erosion. We found i) a low occurrence of extra-pair paternity, polygyny and conspecific brood parasitism, ii) a high level of neutral genetic diversity (mean number of alleles and expected heterozygosity per locus: 13.8 and 83%, respectively) and, iii) evidence for genetic connectivity through recent immigration of individuals from well differentiated populations. The recent increase in breeding density did thus not induce so far any noticeable detrimental changes in mating and reproductive behaviour. The demographic bottleneck undergone by the population in the 1970s-1990s was furthermore not accompanied by any significant drop in neutral genetic diversity. Finally, genetic data converged with a concomitant demographic study to evidence that immigration strongly contributed to local population recovery.

Reproductive dynamics of Sterna hirundinacea Lesson, 1831 in Ilha dos Cardos, Santa Catarina, Brazil

In this work, we intend to describe the reproductive dynamics of Sterna hirundinacea in an island fromSouth Brazil.We studied the reproductive biology of this species in its natural environment and provide data on their growth, survival, and reproductive success in Ilha dosCardos, SantaCatarina, South Brazil. Samplingswere carried out daily on the island throughout the reproductive seasons of 2003, 2005, and 2006 and the different stages of development of the chicks were characterized according to age, length of the beak, and plumage characteristics.We provide a basic equation Lm = 167.91 (1 – e −0.062t−(−0.23)) to determine the approximate age of individuals using their body mass. The main cause of chick mortality on the island was natural (63.17% in 2003, 81.41% in 2005, and 79.96% in 2006), whereas predation contributed to mortality in a proportion of 38.83% in 2003, 18.59% in 2005, and 20.04% in 2006.The absence in the area of the chicks’ main predator, Kelp gull (Larus dominicanus), the large number of chicks that reached the final stages of development, and their reproductive success demonstrate that Ilha dos Cardos is an important breeding site for the species in southern Brazil.

Comparison of the reproductive behavior between isolated Peckia chrysostoma (Wiedemann, 1830) and Adiscochaeta ingens (Walker, 1849) (Diptera: Sarcophagidae) females reared in laboratory

In both species, maintained under laboratory environmental conditions, anautogeny was comproved and all females that had free access to proteic source were fertiles. We obtained the following average values for Peckiachrysostoma: 59.7 ± 15.6 and 81.8 ± 15.4 days of longevity in the respective cases of free access and no access to proteic source, 21.4 ± 4.3 days of pre-larviposition period and 35.2 ± 16.5 days of larviposition period, 5.3 ± 1.8 larvipositions female with 7.0 ± 1.1 days of periodicity, 35.7 ± 6.1 larvae per larviposition leading to a total number of 183.8 ± 69.2 viable larvae per female and 94.8% ± 5.3% of productivity. The mean number of ovarioles per female was 56.4 ± 9.8, resulting in a reproductive potential of 63.3%. For Adiscochaeta ingens, the obtained average values were: 41.3 ± 6.3 and 52 ± 13.1 days of longevity in the respective cases of free access and no access to proteic source, 15.3 ± 1.7 days of pre-larviposition period and 21.5 ± 7.5 days of larviposition period, 3 ± 0.7 larvipositions per female with 10.4 ± 0.8 days of periodicity, 30.3 ± 8.2 larvae per larviposition leading to a total number of 78.5 ± 21.7 viable larvae per female and 90.1% ± 16% of productivity. The mean number of ovarioles per female was 54.6 ± 5.2, resulting in a reproductive potential of 55.5%. Within applied parameters, the values obtained for P. chrysostoma demonstrate its superior productivity in comparison with A. ingens

Male body size and breeding tubercles are both linked to intra-sexual dominance and reproductive success in the minnow

Male dominance hierarchies are usually linked to relative body size and to weapon size, that is, to determinants of fighting ability. Secondary sexual characters that are not directly used as weapons could still be linked to dominance if they reveal determination or overall health and vigour and hence, indirectly, fighting ability. We studied the mating behaviour of the minnow, Phoxinus phoxinus, a cyprinid fish in which males develop breeding tubercles during the spawning season. The function of these breeding tubercles is still not clear. Using microsatellite markers, we determined male reproductive success under controlled conditions. The minnows were territorial and quickly established a dominance hierarchy at the beginning of the spawning season. Dominance was strongly and positively linked to fertilization success. Although body size and number of breeding tubercles were not significantly correlated in our sample, both large males and males with many breeding tubercles were more dominant and achieved higher fertilization success than small males or males with few tubercles. We found multimale fertilization in most clutches, suggesting that sperm competition is important in this species. Females showed behaviour that may be linked to spawning decision, that is, male dominance might not be the only determinant of male reproductive success in minnows

NOTES on THE BIOLOGY and BEHAVIOUR of THE JEWEL WASP, AMPULEX COMPRESSA (FABRICIUS, 1781) (HYMENOPTERA; AMPULICIDAE), IN THE LABORATORY, INCLUDING FIRST RECORD of GREGARIOUS REPRODUCTION

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Reproductive parasitism: male and female responses to conspecific and heterospecific intrusions at spawning in a mouth-brooding cichlid Ophthalmotilapia ventralis

A rare form of alternative reproductive behaviour without simultaneous parasitic spawning was observed in Ophthalmotilapia ventralis, a lekking mouth-brooding cichlid from Lake Tanganyika. Floater males attempted to sneak opportunistically into the territory to actively court the female, while the owner (bourgeois male) defended the territory against other potential intruders. Floater males had more body fat than territory owners and generally higher condition factors. In field experiments, the response of bourgeois males and courted females was tested towards floaters and egg predators (a catfish Synodontis multipunctatus) present in the territories. Territory owners responded aggressively particularly to floaters, and female responsiveness to bourgeois male courtship tended to decline when floaters were present. The potential influence of reproductive parasitism on sexual selection in mouth-brooding cichlids is discussed.

Effect of mating history on gender preference in the hermaphroditic snail physa acuta

Several internally fertilizing hermaphroditic animals can only perform one sexual role at a time. In such species, two individuals that engage in a copulation may have different interests in acting as male or female. A gender choice must be made which, if both individuals have the same preference, may give rise to a severe sexual conflict. Here we tested the hypothesis that gender choice could be influenced by mating history, using the freshwater snail, Physa acuta. We recorded the copulatory behaviour of 240 pairs composed of a focal individual and a partner, each either short- or long-isolated. We found that the time to the first copulation was unaffected by isolation status, suggesting that first contacts in this species are random processes. In contrast, the duration of copulations and the frequency of rejection behaviours suggested that individual gender preference switches from male biased to female biased as isolation increases. In addition, snails rejected copulations more frequently when presented to a partner with the same isolation status. Reciprocity, measured as the rate of gender swapping between the first and second copulations, was high irrespective of gender status. We suggest possible evolutionary causes for this gender preference switch and discuss its potential importance in natural population as well as its consequences for the maintenance of hermaphroditism

Contribution to the conservation biology of the wood ant Formica lugubris (Hymenoptera, Formicidae) in Switzerland

Summary Among ants, wood ants are probably the most fascinating and studied species in temperate European forests. Unfortunately, due to several threats they are nowadays registered in red lists. Recent studies made in the Swiss Jura Mountains ended up in the description of a new sympatric sibling species of Formica lugubris (i.e. Formica paralugubris Seifert 1996). Because of this confusion the biology of F. lugubris is incomplete. Due to the extreme difficulties to distinguish morphologically F. lugubris from F. paralugubris we studied their cuticular hydrocarbons profiles. Irrespective of their geographic origin, we observed quantitative discrimination between species within each caste (workers, males and gynes =young alate female). Moreover, using a behavioural taxonomic approach (i.e. the pupa-carrying test) we showed that ants preferred conspecific worker pupae to those of the sibling species. These first results allowed us to consider the two species as two separate taxonomic units. To understand their coexistence, habitat distribution models were fitted with GIS predictors and factors known to influence wood ant distribution. In the Jura Mountains, although the two species share very similar habitats, they are spatially segregated. F. lugubris occurs more frequently at woodland borders than in forest interiors. We demonstrated with genetic and field data that Formica lugubris displays two different social forms in close proximity in alpine zone (e.g. unmanaged forests of the Swiss National Park). We discovered populations mostly monogynous to weakly polygynous (i.e. one to a few egg laying queens per colony) and monodomous (i.e. one nest per colony), and polygynous/polydomous populations (new nests being founded by colony budding). It is generally admitted that monogyne species disperse well in order to find suitable habitat to found new colonies whereas polygyne species have restricted dispersal and local mating within the nest. In order to compare reproductive strategies of F. lugubris and F. paralugubris (i.e. matings and dealation process) we conducted experiments with sexuals. F, lugubris gynes from monogynous/monodomous populations do not show a local strategy like the obligately polygynous F. paralugubris (i.e. early dealation even without mating, insemination without flight activity and low fat reserve). They always keep their wings, do not mate when not able to fly and have high amount of fat content revealing high survival capacities. On the other side, F, lugubris gynes from polygynous/polydomous populations have lower lipid reserves and displayed a reproductive behaviour close to the F. para lugubris one. After dispersal, wood ant gynes can either start new societies by temporary social parasitism of another species (i.e. subgenus Serviformica) or be adopted intraspecifically in an existing nest. In F. lugubris, we demonstrated that gynes from monogynous/monodomous colonies showed a high success for temporary social parasitism compare to the lower success of gynes from polygynous/polydomous colonies. However, physiological analyses suggested that only gynes from monogynous/ monodomous populations can efficiently disperse and found new nest by temporary social parasitism. Intraspecifically, gynes were accepted to a high degree in polygynous nest and in monogynous nests as long as these nests contained sexuals. In conclusion, Formica lugubris displays a social and dispersal polymorphism (mixed mating and founding system) representing a behavioural plasticity in relation to environmental and ecological conditions. Therefore, conservation measures directed toward this species should try to maintain a maximum of diversity at the habitat level. Résumé Les fourmis des bois sont probablement parmi les espèces de fourmis les plus fascinantes et les plus étudiées des forêts tempérées Européennes. Actuellement, du fait de différentes menaces, elles figurent malheureusement sur listes rouges. Plusieurs études menées au sein du Jura Suisse ont abouti à la description d'une nouvelle espèce jumelle et sympatrique de Formica lugubris (F. para- lugubris Seifert 1996). A cause de cette confusion la biologie de F lugubris est lacunaire. La distinction morphologique de F. lugubris et de F. para lugubris est si difficile que nous avons étudié leurs hydrocarbures cuticulaires. Indépendamment de l'origine géographique, nous avons observé une discrimination quantitative entre les espèces au sein de chaque caste (ouvrières, mâles et jeunes femelles ailées). De plus, à l'aide d'une approche taxonomique comportementale (le test de transport de cocons) nous avons montré que les fourmis préfèrent des cocons d'ouvrières conspécifiques à ceux de l'espèce jumelle. Ces premiers résultats nous permettent de considérer ces deux espèces comme deux unités taxonomiques distinctes et valables. Afin de comprendre leur coexistence, des modèles mathématiques ont été développés avec des données SIG et des facteurs écologiques influençant la répartition des fournis des bois. Dans le Jura, même si elles partagent des habitats fortement similaires, les deux espèces n'occupent pas les mêmes secteurs. F. lugubris est plus fréquente en lisière forestière plutôt qu'en pleine forêt. Nous avons démontré grâce à des données génétiques et de terrain que F. lugubris présente deux formes sociales au sein de la zone alpine (forêts protégées du Parc National Suisse). D'autre part, nous avons découvert des populations monogynes à faiblement polygynes (une à quelques reines pondeuses par colonie) et monodomes (colonies composées d'une seule fourmilière), et des populations polygynes/polydomes (les nouveaux nids étant produit par bourgeonnement). Généralement, les espèces monogynes dispersent sur de grandes distances et peuvent coloniser des habitats favorables à la fondation de nouvelles colonies alors que les espèces polygynes possèdent une dispersion limitée avec des accouplements à l'intérieur des nids. Afin de comparer les stratégies de reproduction de F. lugubris et de F. paralugubris (accouplements et perte des ailes) nous avons mené des expériences avec les sexués. Les jeunes femelles ailées de F. lugubris issues de populations monogynes/monodomes ne présentent pas de stratégie locale comparée à l'espèce obligatoirement polygyne F paralugubris (perte des ailes précoce même si il n'y a pas eu accouplement, insémination possible sans avoir volé activement et faibles réserves de graisse). Elles conservent toujours leurs ailes, ne s'accouplent pas lorsqu'elles sont empêchées de voler et possèdent de grandes quantités de graisse révélant de fortes capacités de survie. D'autre part, les jeunes femelles ailées de F. lugubris provenant de populations polygynes/polydomes ont peu de réserves lipidiques et ont un comportement de reproduction proche de celles de F. paralugubris. Après leur dispersion, les jeunes sexués femelles de fourmis des bois peuvent soit fonder une nouvelle société par parasitisme social temporaire d'un nid d'une autre espèce (sous-genre Serviformica) soit être adoptées dans un nid déjà existant de leur propre espèce. Chez F. lugubris, nous avons pu démontrer que les jeunes sexués femelles de colonies monogynes/monodomes présentent un succès élevé au parasitisme sociale temporaire en comparaison au plus faible succès obtenu avec des sexués provenant de colonies polygynes/polydomes. Cependant, les données physiologiques suggèrent que seules les jeunes sexués femelles de populations mono-gynes/monodomes peuvent disperser efficacement et fonder un nouveau nid par parasitisme social temporaire. Au niveau intraspécifique, les jeunes femelles sont acceptées à un taux élevé dans les nids polygynes mais aussi dans les nids monogynes tant que ces nids possèdent encore de jeunes sexués. En conclusion, F. lugubris est caractérisée par un polymorphisme dans ses structures sociales et ses stratégies de dispersion (système mixte d'accouplement et de fondation) ce qui représente une forte plasticité comportementale en relation avec les conditions environnementales et écologiques. Par conséquent, les mesures de conservation de cette espèce devraient s'attacher à maintenir un maximum de diversité au niveau des habitats.

Mating behaviours of the field cricket (Gryllus integer) at different levels of male density

The reproductive behaviour of the field cricket, Gryllus integer, was systematically observed in indoor arenas to determine the extent of female Choice and male-male competition at different sex ratios representing two male densities (12:6 and 6:6). The costs and benefits to males and females in those two densities were analyzed according to the theory of the evolution o£ leks. Observations were conducted during the dark hours when most calling occurred since hourly rates of courtship song and mating did not fluctuate significantly over a 24 h period. Female mating rates were not significantly different between densities, therefore males at high densities were not advantaged because of increased female tendencies to mate when social stimulation was increased. Mean rates of acoustical signalling (calling and courtin"g) did not differ significantly between densities. Mean rates of fighting by males at the high density were significantly greater than those of males at the low density. Mating benefits associated with callin~courting and fighting were measured. Mating rates did not vary with rates of calling at either density. Calling was not a prerequisite to mating. Courtship song preceded all matings. There was a significant power fit between male mating and courting rates, and male mating and fighting rates at the low, but not at the high, density. Density differences in the benefits associated with increased courting and fighting may relate, in part, to greater economic defensibility and monopoly of females due to reduced male competition at the low density. Dominant males may be preferentially chosen by females or better able to monopolize mating opportunities than subordinate males. Three criteria were used to determine whether dominant males were preferentially chosen by females. The number of matings by males who won fights (within 30 min of mating) was significantly greater than the number of matings by males who were defeated in such fights. Mating rates did not vary significantly with rates of winning at either density. There was a significant power fit between male mating rates and the percentage of fights a male won (irrespective of his fighting-frequency) at the low density. The mean duration a male guarded the female after mating did not vary significantly between densities. There was a significant linear relationship between the duration a spermatophore was retained and the duration a male guarded the female after mating. Courtship song apparently stimulated spermatophore removal. Male guarding involved inter-male aggression and reduced courtship attempts by other males. Males at the high density received no apparent reproductive benefits associated with increased social stimulation. Conclusive evidence for preferential choice of males by females, using the criteria examined here, is lacking. Males at the lower density had fewer competitors and could monopolize females more effectively.

Ecologia comportamental reprodutiva de Diastatops obscura Fabricius (Insecta, Odonata)

In this thesis I discuss the reproductive behaviour and ecology of the libellulid Diastatops obscura Fabricius, 1775, (Insecta: Odonata) in natural conditions. Populations of this species were studied on the middle stretch of the Pitimbu River, Parnamirim municipality, Rio Grande do Norte, Brazil, during four discontinuous periods between 2002 and 2004. The objectives include the description of strategies and behaviors of both sexes, with especial interest in the intra-male competition for territories and females, the mate selection by females and the importance of male body size and other secondary characters on their reproductive success; from an adaptationist point of view. It was observed that the behavior of males and females in the reproductive areas are interrelated : the males came earlier to compete for the best territories and the females waited the result of that competition to be fertilized by dominants males, which preferably occupied areas near the river margin. The reproductive success of males with territories on the margin, estimated by number of copulations, ovipositions and days acting as territorial, was better than obtained by more separated territorial males and by satellite males. The body size of males is an important factor for the copulation and oviposition taxes and for the number of territorial days, favoring the biggest individuals. I also discuss the apparently importance of wing brilliance and wing integrity on male reproductive success. On inter-sexual relationships, I proved that females of D. obscura participate in mate selection, rejecting non-territorial males or substituting their sperm for other of higher status

A histological study of the seminal vesicle of the armoured catfish Corydoras aeneus

Most species of Corydoras exhibited a reproductive behaviour called 'T-position', and exhibited an accessory gland in the male genital tract, called the seminal vesicle. It appeared that both the structure and the composition of the fluid varied considerably between the species investigated. Consequently, different opinions were proposed regarding the possible role of seminal vesicle on this particular reproductive behaviour. Male adults of Corydoras aeneus were collected, anaesthetized, and samples of seminal vesicle were fixed in Bouin's solution. The sections were stained with haematoxylin-eosin and periodic acid Schiff. The seminal vesicle showed a system of anastomosed secretory tubules, forming a vesicular collective network, which gave rise to the vesicular ducts. The latter fused with the testicular efferent ducts and formed the spermatic ducts. Considering this fusion, when the sperm cells reached the spermatic ducts, the fluid produced at the seminal vesicle covered them. Histochemical studies evidenced the presence of neutral and acid glycosaminoglycans in the seminal fluid. Considering the reproductive behaviour of C. aeneus, it is believed that the protection associated with the immobilization of the sperm cells assures the sperm integrity during the passage through female's intestine until fertilization.

The fitness of the Brazilian damsel Stegastes fuscus is increased by sharing the territory with the dusky grouper Epinephelus marginatus

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Population, social equity and changing production patterns

Includes bibliography