Timing of breeding to an optimal season is a requirement for a successful reproductive outcome in seasonally breeding species. Photoperiodic signals are capable of modifying the reproductive behaviour and reproductive systems in several vertebrate species. The cichlid fish Cichlasoma dimerus shows highly organized breeding activities and different social status. The aim of this study is to test...

A key step in the evolution of sociality is the abandonment of independent breeding in favour of helping. In cooperatively breeding vertebrates and primitively eusocial insects, helpers are capable of leaving the group and reproducing independently, and yet many do not. A fundamental question therefore is why do helpers help? Helping behaviour may be explained by constraints on independent repr...

Parasites are ubiquitous components of the environment that contribute to behavioural and life-history variation among hosts. Although it is well known that host behaviour can affect parasite infection risk and that parasites can alter host behaviour, the potential for dynamic feedback between these processes is poorly characterized. Using Grant's gazelle (Nanger granti) as a model, we tested f...

Reproductive modes are diverse and unique in anurans. Selective pressures of evolution, ecology and environment are attributed to such diverse reproductive modes. Globally forty different reproductive modes in anurans have been described to date. The genus Nyctibatrachus has been recently revised and belongs to an ancient lineage of frog families in the Western Ghats of India. Species of this g...

Few studies have examined the underlying hormonal mechanisms that mediate reproductive cyclicity, male pregnancy and reproductive behaviour in syngnathids. Progress in these areas has been hampered by the small size of most species in the family and a lack of validated techniques for assessing endocrine function. Research on a relatively small number of species has suggested that androgens are ...

in A Week with Elephants (eds Daniel, J. C. and Datye, H. S.), Bombay Natural History Society and Oxford University Press, Bombay, 1995, pp. 532. 35. Poole, J. H., Coming of Age with Elephants, Hyperion Press, New York, 1996. 36. Vidya, T. N. C., Fernando, P., Melnick, D. J. and Sukumar, R., Molecular genetic structure and conservation of Asian elephant (Elephas maximus) populations across Indi...

From the community profiles conducted by nursing students in Mangaung, the following observation was prevalent: an increase in the prevalence of teenage pregnancy together with a high prevalence of HIV infection was demonstrated. The relationship between young people's reproductive behaviour and the prevalence of HIV is well documented. To address this problem, a community -based education prog...

Gynandromorphs, Courtship, D. melanogaster, Fate Maps, Oviposition Reproductive behaviour was studied in 192 gynandromorphs with female genitalia and reproduc­ tive system, produced by ring-X chromosome loss. Male and female behaviour patterns were frequently found to coexist in the same individuals, and male courtship behaviour, when it oc­ curred, retained its characteristic hierarchical orga...