Reproductive life history of South African cheetahs (Acynonyx jubatus jubatus) at the San Diego Zoo Wild Animal Park, 1970–2005
Abstract 10.1002/zoo.20097.abs We analyzed 35 years of data from a captive breeding program of cheetahs to determine basic reproductive life history characteristics of females. Breeding females ranged in age from 2.7–10.5 years. Sixteen females and over 13 males produced 129 cubs in 36 litters, with an average litter size of 3.6. Older females produced significantly […]
Reproductive biology of captive and free-ranging spider monkeys
Abstract 10.1002/zoo.1430090102.abs Records from 42 zoos and from long-term studies of wild populations were analysed to describe the reproductive biology of spider monkeys (Ateles spp.). Both data sets suggested that spider monkey females typically have their first infant between 7 and 8 years of age with an interbirth interval of approximately 32–36 months. Infant sex […]
Psychosocial maternal stress during pregnancy: Effects on reproduction for F0 and F1 generation laboratory rats
The impact of daily social maternal stress on reproduction parameters was studied in F0 and F1 generation female Long–Evans rats. Chronic maternal stress was induced in pregnant females (F0 females) by 2 h social confrontation with a dominant female throughout pregnancy. Social stress of F0 females was associated with lower maternal body mass investment in […]
Maternal Investment in Captive Giraffes
Sex-biased maternal investment involves differential allocation of resources to production and rearing of sons or daughters as a function of their anticipated reproductive output. We examined reproductive investment among captive giraffes (Giraffa camelopardalis) over a 21-year period to determine extent to which females invest differentially in offspring by sex. We found an unbiased sex ratio […]
Research in Zoos- from behaviour to sex ratio manipulation
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Macaque mothers’ preconception testosterone levels relate to dominance and to sex of offspring
There is increasing evidence to support hypotheses that suggest that mammalian females may have some influence over which sex of offspring they conceive. In the search for a mechanism by which this might occur, female testosterone has become a focus of interest. We investigated the relation between level of faecal testosterone in female Barbary macaques, […]
Behavioural plasticity may compensate for climate change in a long-lived reptile with temperature-dependent sex determination
How are organisms responding to climate change? The rapidity with which climate is changing suggests that, in species with long generation times, adaptive evolution may be too slow to keep pace with climate change, and that alternative mechanisms, such as behavioural plasticity, may be necessary for population persistence. Species with temperature-dependent sex determination may be […]
Variation in female mate choice and mating success is affected by sex ratio experienced during early life
Females vary in their mate choice and consequent fitness outcomes. Individual differences may be explained by conditions experienced early in life. We tested whether the sex ratio at which young pheasants, Phasianus colchicus, were reared affected their adult sexual behaviour. Females reared in equal sex ratios discriminated strongly between males of differing attractiveness in choice […]
Dense, small and male-biased cages exacerbate male–male competition and reduce female choosiness in Bicyclus anynana
Sexual selection is increasingly recognized to depend upon, and to fluctuate with, major ecological factors in natural environments. The operational sex ratio (OSR) and population density can affect the opportunity for, and strength of, sexual selection but their effects are rarely taken into account in laboratory behavioural studies. In Bicyclus anynana, a model butterfly for […]