Elephants Elephants - Wildpro - Twycross Zoo

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Musth period and duration
Eight males (three African, five Asian) have been through some kind of musth
(one has not had a full musth and another is irregular). The African males had
their first musth from between 18 and 22. The Asians appear to start earlier,
with ages seven, 11 and early teens stated for those whose history is known.
Duration lasts from one month to 3-4 months. In most animals, the intensity of
the musth comes and goes.
Access to females by bulls
All mounted females with the exception of one (who has since deceased). Of the
8 bulls that have mated females 6 have produced offspring. All collections
reported daily access to females with exceptions being due to staffing levels,
bull in musth and weather conditions.
Mating observations
Males; Musth - Of the bulls over 8 years old, only one has not mounted
females though he has had access (Fed collection - he has since deceased).
Males; Mating - Of the Africans, only the adults that have been in musth have
mated (the others are all aged 8-11), of the Asians, only the elephant that has
not mounted has not mated. Of the eight animals that have mated, six have
sired offspring. The two that have mated, but not sired, are both only eight
and nine. Summary – only one bull that is in musth has not mated (since
deceased). There appears to be a big age difference between Asian and African
as to when males come in to musth and will mate successfully with females –
need a much larger sample size to investigate fully.
Females; cycling – 34 out of 64 females are cycling regularly (one has uterine
polyps and another has tumours on her vaginal wall that prevent her from
conceiving). For Asians, the youngest is four and the eldest is 48, for Africans
the youngest is eight and the eldest is 34. The top end of this range is due to
these being the eldest elephants in the respective population.
Of the non-cycling females, one is acyclic, six are probably too young, three
have reproductive disorders (ovarian cysts x 2 and the other had mucus build
up in the uterine horn – disappeared now), two were cycling and appear to
have stopped (possibly something to do with having two adult bulls on site)
and for the remaining 13 the reason is unknown.
Age for first observable oestrus (N = 12) ranges from four to 34 but mainly
between eight and 14 in Asians and 12, 13, and 14 for Africans.
Females; pregnancies – African – 14 pregnancies in 11 females, 100% survival
of offspring, two still pregnant at time of writing. Two females have been
pregnant more than once.
Asian – 25 pregnancies in 14 animals (of 33), three currently pregnant, 17
produced live calves (68%), four stillborns. Ten females have given birth to
live calves, two have given birth to stillborns as a result of their only
pregnancy and two females are pregnant for the first time. Six females have
given birth to one live calf, two have had two calves, one has had three and
one has had four and is currently pregnant with her fifth calf.