The current annual population growth rate of 3.2% in Africa will double the population by the year 2025. The majority of this population is below 15 years of age, and Africa concurrently also has the highest incidence of infertility in the world. Sexual behaviour, which has been poorly studied in Africa, has a direct impact on reproductive health [including fertility, infertility and sexually t...

The hairworm (Nematomorpha) Paragordius tricuspidatus has the ability to alter the behaviour of its terrestrial insect host (the cricket Nemobius sylvestris), making it jump into the water to reach its reproductive habitat. Because water is a limited and critical resource in the ecosystem, we predicted that hairworms should adaptively manipulate host behaviour to maximize parasite reproductive ...

Aggressive behaviour is linked to fitness, but it is metabolically costly. Changes in metabolic demand during the reproductive cycle could constrain activity and thereby modulate behavioural phenotypes. We predicted that increased metabolic demands in late pregnancy would lead to reduced aggression and a lower metabolic cost of behaviour in the mosquitofish Gambusia holbrooki. Contrary to our p...

This paper reflects partial results from a study about male reproductive attitudes and behaviour concerning the decision-making processes related to sexual intercourse, adoption of contraception, and prevention of STDs and HIV infection. The study also explores whether and in waht way both objective characteristics of the men and their (culturally grounded) perceptions impinge on their behaviou...

Maternal behaviour in golden hamsters has been the subject of several studies (ROWELL 1960, 1961 a, 1961 b; LOTT 1962; NOIROT & RICHARDS 1966; RICHARDS 1966 a, 1966 b). Most of these have investigated the response to the presentation of pups placed outside the nest by the experimenter, analysing the functional relations between test behaviour and such variables as reproductive stage, hormonal s...

While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (Lythrypnus dalli) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, repro...

The reproductive behaviour of couples with heterozygous beta thalassaemia, with at least one affected child, was investigated for the period 1955 to 1984 and was compared to the behaviour of control couples matched for age, age at marriage, and presence of at least one child. The comparisons were made as a function of knowledge of the risk and availability of prenatal diagnosis and abortion. It...

A gall-forming aphid has an extended post-reproductive life in which adults become transformed into glue-packed warriors able to defend their colony. These aphids thus provide a novel example of late-life, post-reproductive helping behaviour.