Elephants Elephants - Wildpro - Twycross Zoo
Elephants Elephants - Wildpro - Twycross Zoo
Elephants Elephants - Wildpro - Twycross Zoo
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72<br />
Table VI. GESTATION DATA ON ASIAN FEMALES<br />
Asian female<br />
group<br />
Gestation<br />
length<br />
Standard<br />
deviation<br />
Sample<br />
number<br />
Reference<br />
EAZA zoos 671 days 18 days 81 Oerke pers<br />
comm.<br />
EAZA zoos 600-692 26 (Flügger et al<br />
2001)<br />
Asian logging<br />
camps?<br />
<strong>Zoo</strong>s and circuses<br />
mainly Europe<br />
<strong>Zoo</strong>s 610 – 720,<br />
mean 660<br />
598 days (Kurt and<br />
Khyne U Mar<br />
1996)<br />
644 (Kurt and<br />
Khyne U Mar<br />
1996)<br />
32 (Whalley<br />
1994)<br />
Pinnawela 618 15 (Poole et al<br />
1997)<br />
Pinnawela 585-618 (Dastig 2002)<br />
Kurt and Khyne U Mar compared available data from zoo and circus born<br />
elephants to those born in camps in South Asia (Kurt and Khyne U Mar 1996).<br />
It is stated that gestation periods were calculated from last successful mating<br />
to birth, but an allowance should be made for the fact that the data come from<br />
several sources and therefore total accuracy cannot be guaranteed, and some<br />
may have been underestimated. Data in the table above shows that gestation<br />
in zoos tends to be longer in Asian elephants than those in semi-wild states<br />
(Dastig 2002)) such as Pinnawela and logging camps<br />
African cows data (from Oerke) has a mean gestation of 639 days (± 14 days),<br />
with a range of 624-663 days. The average range is taken as 630-660 as most<br />
cows give birth within this range.<br />
Note that is has been known for twins to delivered with a long time between<br />
births (this can be several months) (Hildebrandt et al 2000). For example, at<br />
Port Lympne <strong>Zoo</strong>, one calf had a gestation of 682 days and the other 718 (both<br />
were still born), cited in (Kurt and Khyne U Mar 1996). This may be explained<br />
by looking at the uterus of an elephant (Fig. 9). An elephant’s uterus has two<br />
horns that are widely separate; in the case of twin calves one foetus is in each<br />
horn.<br />
Kurt and Khyne U Mar suggest that there is a correlation with long gestations<br />
and the likelihood of stillbirths. A correlation is also apparent between length<br />
of gestation and infant birth weight; 600 day calves have a mean weight of<br />
60kg, those born after 650 days have a weight of 110 kg and after 680 days of
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