Management and husbandry of duikers at the Los Angeles Zoo

Abstract

The Los Angeles Zoo has maintained and managed six different species of forest duikers since 1975. Over the years we have achieved relative success with the majority of these species. The maintenance and breeding of duikers has proved to be difficult at best. The major problems that we have experienced concern diet, stress-related medical conditions, neonatal mortality, and postanesthetic pneumonia. As concentrate selectors, duikers have a diet relatively low in fiber, a well-developed ability to forage selectively, a rumen bypass that is functionally important, a rapid passage and high fermentation rate for starch, and frequently encountered toxins. From an examination of the captive diet of duikers it is evident that the domestic fruits fed to duikers in captivity are not well suited for them. Duikers are highly susceptible to the slightest amount of stress. The group size in which duikers are managed has proved to be critical in the successful management of these species. In our earlier years of duiker management we often kept five or more animals together in a single exhibit. This would at times result in stress-related jaw abscesses. Our group size has since been reduced to no more than three animals in any one exhibit. Since 1977, the Los Angeles Zoo has had 92 duiker births. The survival rate past 6 months of age has been 61%. Of the 36 neonatal deaths, 42% were stillborn or died within a few hours of birth. Hypothermia and maternal neglect have been linked to infant mortality. Duikers are also easily prone to capture myopathy and regurgitation during anesthesia or capture, which can often lead to aspiration pneumonia. If at all possible, the capture and restraint of a duiker should be avoided. However, there are times when the capture or restraint (chemically or manually) of a duiker is required.

Natural behavioural biology as a risk factor in carnivore welfare: How analysing species differences could help zoos improve enclosures

“…reviewed by Snyder et al, 1996;Barnes et al, 2002;Clubb andMason, 2002, 2004). Given that these animals receive veterinary care and are free from predation, drought and starvation, this is surprising and suggests a role of chronic, husbandry-related stress (see e.g.…”

Maternal deprivation and the development of stereotypic behaviour

“…Firstly, Nash et al (1999) found that mother-reared chimpanzees perform less stereotyped rocking and selfsucking; and secondly, Rybiski Tarou et al found no apparent effects of hand-rearing on stereotypic behaviours in zoo-housed prosimians (possibly due to the small number of handreared animals included in the sample population) (Rybiski-Tarou et al, 2005). Interestingly, in addition to these examples, Wielebnowski et al (2002) found that hand-reared clouded leopards (Neofelis nebulosa) show a trend to exhibiting lower corticosteroid levels than mother-reared individuals; and Barnes et al (2002) reported that hand-reared duikers tend to be calmer and less stress-prone than mother-reared individuals. Thus, as in wild-caught animals, rearing conditions that increase stereotypic behaviour do not necessarily lead to poorer welfare in adulthood.…”

Species differences in responses to captivity: stress, welfare and the comparative method

“…in zoos, for instance, are 'highly susceptible to stress' [15], vulnerable to opportunistic infections such as jaw abscesses [15], and commonly have infant mortality rates of 30-40% [16], which is higher than typical for ungulates in good conditions [12]. Giraffes (Giraffa cameleopardalis) have a shorter lifespan in zoos than when protected in the wild [17], an effect seemingly linked to poor nutritional status and low energy intake, suggesting inadequacies in zoo diets [17].…”