Reproductive Behaviour

Breast cancer is the most frequent neoplasm in Europe. According to the International Agency for Research on Cancer, there were an estimated 429,900 cases diagnosed in Europe in 2006, with an age-standardised incidence rate of 110 cases per 100,000 women. It is also the most frequent cancer in Spanish women, accounting for one forth of female cancer cases, and its incidence is increasing around 2-3% per year. Changes in reproductive behaviour and life style along with the introduction of hormone replacement therapy are partially responsible of this trend. Our country, with an estimated age-standardised incidence rate of 93.6 cases per 100,000 women-year in 2006, occupies an intermediate position between Western and Eastern European countries. This tumour also represents an important cause of female mortality. In 2005, it caused 5,703 deaths in Spanish women, with an agestandardised mortality rate of 18.6 per 100,000 women-year. However, since the 90’s, breast cancer mortality is dec...

Social facilitation of reproductive behaviour has been studied extensively in gulls and terns, but social facilitation of preening has been reported only anecdotally, and has not been previously quantified. We studied a common tern,Sterna hirundo, colony during the summers of 1996 and 1997 to test for socially facilitated preening. Scan sampling provided evidence of spatial and temporal synchrony of preening

This paper examines timing of puberty and mechanisms through which society prepares adolescents to understand and deal with it in Malawi. Data from a national representative survey of adolescents and in- depth interviews also conducted with adolescents are used. SPSS was used to analyse survey data while N6 was used to analyse qualitative data. Results show that the onset of

Due to their permeable skin few amphibians are able to tolerate dry or salty conditions, a characteristic that has prevented most species from colonising oceanic islands. The most diverse oceanic island amphibian fauna is found in the Seychelles, an archipelago of about 115 granitic and coralline islands in the Indian Ocean, some 1,600km east of mainland Africa, and northeast of

Bradypus variegatus is a member of the Order Pilosa, Family Bradypodidae, and is distributed in many subtropical and tropical countries in South and Central America. However, studies on this species in the wild are relatively limited and many aspects of its reproductive behaviour are unknown or unclear. The current report presents new observations of the reproductive behaviour of B. variegatus in its natural environment. These include details of both a male–female copulation and the simultaneous nurturing of two young sloths.

Autor w swoim artykule wychodzi od mesjańskich nadziei związanych z rodzeniem dzieci. Przeciwstawia entuzjastycznemu spodziewaniu się zbawienia związanego z urodzeniem dziecka koncepcję mesjanizmu pustynnego Derridy, czyli oczekiwania pozbawionego horyzontu oczekiwania. Następnie ukazuje dziecko, jako niosące wraz ze swoim pojawieniem się obietnicę śmierci, wykorzystuję grecki mit o Kronosie oraza filozoficzne rozważania Georgesa Bataille'a. W kolejnej części Autor koncentruje się na zjawisku utraconych wizji przyszłości, które nazywa obsoletami nowoczesności i stara się wyjaśnić współczesną niechęć do tworzenia idealnego świata jutra. Ostatnią część artykułu stanowi interpretacja "Huby" (2014) w reżyserii Anki i Wilhelma Sasnalów, która staje się w tym kontekście próbą powstrzymywania się od przymusu (re)produkcji.

Mating behaviour is an important component of species’ life histories. Knowledge of natural patterns of mating can lead also to more effective management strategies for populations of conservation concern. Despite a high conservation profile many aspects of the biology of the common dormouse (Muscardinus avellanarius) remain unknown, potentially limiting present conservation efforts. We determine the mating behaviour of M. avellanarius at two woodland sites in the UK: (1) Bontuchel (a natural population in Wales) and (2) Wych (a population in England that was established by reintroducing captive-bred animals) by genotyping mothers and litters at a panel of 10 microsatellite loci. Adult female body weight positively correlates with litter size and no apparent reproductive skew was evident. We found that multiple mating by female dormice is prevalent at both sites, with litters containing three or more offspring sired by multiple fathers; moreover, multiple mating is adopted by released animals even after a period of captive breeding where females are mated singly or as a breeding pair. We also present evidence for low proportion of fathers identified in our samples that probably related to unsampled individuals and/or larger than anticipated population sizes. This first report of mating behaviour in M. avellanarius highlights the role of genetic studies to uncover species’ reproductive behaviours and include these data for conservation management.

For as long as people have walked the Earth, their lives have been touched by animals. They have dominated and feared them, hunted, fished and farmed them, conferred supernatural powers upon them, treated them cruelly, with compassion and even religious respect. The very survival of ancient people depended upon a keen knowledge of wild animals, their habitat and behaviour patterns.

Modern crocodilians and birds are the only living representatives of the Archosauria, a group that also includes non-avian dinosaurs and pterosaurs. Modern crocodilians originated during the early Cretaceous period and dispersed globally. Examples of physiological similarities between living crocodilians and birds include similar amino acids in β-keratins among crocodiles, turtles and birds; oviduct homologies between crocodilians and birds; similar forelimb structures in crocodiles and other archosaurs and similarities in gene expression in limb development in alligators and chickens. While individual crocodilian species have adapted their behaviours to meet specific strategies for survival in specific habitats, core reproductive behaviours are universal among modern crocodilians and transcend speciation, morphology and geographic distribution. Hard-wired core behaviours include social signals that incorporate chemosensory, auditory and mechanoreception modalities; construction of a temperature-stabilising nest chamber to incubate eggs; and parental care of their young. Parental care may reflect a primitive character for archosaurs, including dinosaurs. Crocodilians use integumentary sense organs (ISOs) during courtship and in parental care, and similar structures may have had similar functions in dinosaurs. The presence of numerous foramina (possible ISOs) in the skulls of saurischians, along with the findings of fossilised nests with adults, may indicate similar complex behaviours, including parental care, in dinosaurs.

Reproductive health and behaviour of adolescents is an
increasingly important component for the healthy nation.
Adolescence, the second decade of life is a period when young
people acquire new capacities for progress with physical growth,
physiological and psychological change, the development of
secondary sexual characteristics and reproductive maturation.
Young people worldwide, however, face social, economic and
health challenges that were unimaginable.  Adolescence is,
therefore, considered as a phase rather than a fixed age group;
with physical, psychological, social and cultural dimensions.
Programmes that can provide information, ensure access to
services, and develop life skills are crucial to the future of this
population. This paper will explore the existing practices or
information on sexual and reproductive behaviour among
adolescent  girls’ of Meitei-Pangals in Imphal East, Manipur; in
relation with the knowledge and attitudes, socio-economic and
cultural factors operating within, as well as their perception and
awareness level pertaining to the health care services.

What differentiates human males from human females? Is it the number of sex chromosomes? Is it the possession of the appropriate sex organs? Is it the amount of testosterone or estrogen? By what non-arbitrary universal standard can we judge?
In this brief article, I argue for such a standard and that this standard entails there are two and only two biological sexes.  Please click on the above link for the published article currently tracking over 20,000 views.

After mating, females may experience a decline in sexual receptivity and attractiveness that may be associated with changes in the production and emission of sex pheromones. In some cases, these changes are produced by chemical substances or structures (e.g., mating plugs) produced by males as a strategy to avoid or reduce sperm competition. In scorpions, sex pheromones may be involved in finding potential mates and starting courtship. Here, we tested the hypothesis that the males of Urophonius brachycentrus, a species that produces a mating plug, use chemical communication (sex pheromones) to detect, localize, and discriminate females according to their mating status (virgin or inseminated), aided by chemical signaling. We also explored the effect of extracting of the mating plug on chemical communication and mating acceptance. We used Y‐maze olfactometers with different stimuli to analyze male choice and exploration time. To evaluate mating acceptance, we measured the attractiveness and receptivity of females of different mating status. We found that chemical communication occurs through volatile pheromones, but not contact pheromones. Males equally preferred sites with virgin or inseminated females with removed mating plug. In turn, females with these mating statuses were more attractive and receptive for males than inseminated females. This study suggests that the mating plug significantly affects female chemical attractiveness with an effect on volatile pheromones and decreasing sexual mating acceptance of females. The decline in the female's sexual receptivity is a complex process that may respond to several non‐exclusive mechanisms imposed by males and strategically modulated by females.

Sesamoids are skeletal elements rarely considered in studies of the vertebrate skeleton. In this work, we integrate ontogenetic data of anuran sesamoids in two species (Leptodactylus latinasus and Pleurodema cf. guayapae), the related structures (tendons, muscles, and joints) in L. latinasus, and a survey of sesamoid distribution in 185 anuran taxa. Our main goals are: (1) to contribute to the knowledge of the comparative anatomy of sesamoids in tetrapods; (2) to provide additional developmental evidence to interpret the ontogenetic pattern of sesamoids in anurans, as a key to elucidate that of tetrapods in general; (3) to provide data about tendon development in relation to sesamoid development in anurans for the first time; and (4) to propose a pattern of anuran sesamoid distribution. The homologies of sesamoids across tetrapods are discussed here. Observations were made in cleared and stained skeletal whole-mounts. Fifty-four sesamoids were found in anurans, thirty-seven of which occur in L. latinasus. The traditional point of view of embedded sesamoids always resulting from biomechanical stimuli of a previously existing tendon is not sustained by our data. Many sesamoids arise before the differentiation of a tendinous tissue. Our survey results in a data set where the two big anuran clades, Hyloides (12 families) and Ranoides (14 families), were represented. The matrix has 38% missing entries. Most of the surveyed sesamoids have multiple origins, with only three of them (about 19%) having one origin. Anat Rec 293:1646–1668, 2010. © 2010 Wiley-Liss, Inc.

Sand goby (Pomatoschistus minutus, Pallas) were exposed for seven months to ethynyl oestradiol (EE2) or a sewage effluent containing known xeno-oestrogens (alkylphenol polyethoxylates). Nominal exposure concentrations were 6 ng l -1 EE2, 0.3% v/v or 0.03% v/v sewage effluent. The fish were bred using within treatment crosses during the final weeks of the exposures. At the end of the breeding

Discoveries of how social behavior can influence the plasticity of gonadotropin-releasing hormone (GnRH) have revolutionized the field of behavioral neuroendocrinology by providing new insights into the neural mechanisms controlling behavior. In 2000, the neuropeptide gonadotropin inhibitory hormone (GnIH) was discovered and is changing the way we view how the brain mediates reproduction and associated behaviors. GnIH acts as a reproductive ‘pause button’, momentarily inhibiting the activity of the reproductive system. However, how GnIH fluctuates naturally in response to social environment is unknown. We examine how the outcome of competition for limited resources needed for reproduction is associated with GnIH. We experimentally manipulated nesting opportunities for pairs of European starlings (Sturnus vulgaris) and examined brain GnIH mRNA and peptide content, as well as GnRH content and plasma testosterone and corticosterone. By limiting the number of nest boxes per enclosure and thus the number of social pairing and nesting opportunities, we observed that birds which outcompeted others for nest boxes (‘winners’) had significantly fewer numbers of GnIH peptide-producing cells than those without nest boxes (‘losers’) and this relationship changed with breeding stage. GnRH content, testosterone and corticosterone did not vary with nest box ownership. Thus, while birds appeared reproductively capable across treatments, our data indicate that GnIH may serve as a modulator of reproductive behaviors in response to social environment. Additionally, we provide some evidence of the adaptive value of this mechanism.

This volume brings together current research on the behavior, ecology, reproduction, and life history – and the interrelations among these variables – of baboons of the genus Papio. Baboons, found throughout Africa and into Arabia, represent one of the best-known primate lineages, renowned for their ecological and behavioral flexibility and adaptability. These characteristics are intimately intertwined with features of baboon life history and reproduction. Contributors to this volume, representing several major, long-term research projects from throughout the African continent, explore reproductive behavior and strategies of adult male and female baboons in a variety of ways. In Part I, authors explore various aspects of baboon reproduction and social organization, focusing on issues such as infanticide, mating strategies and investment, hybridization and genetics in examining how adults go about mating and reproducing. In Part II, these aspects of life are juxtaposed with detailed examinations of life history and parental investment. Together, the chapters in this volume explore reproduction and parenting from a variety of angles and motivate research from both the parental and offspring perspectives and at a variety of taxonomic levels. Articulating studies of reproduction with those of life history conveys a richly detailed portrait of life phases with critical evolutionary consequences. These lines of inquiry together forge new ways to investigate the life periods that matter most in evolution.