Hippo infant mortality

Hippo infant mortality
10-08-2012

I came across some old articles about hippo babies dying in zoos in Australia, and it got me thinking about hippo babies in zoos around the world.

What's the success rate like? Do baby hippos die frequently in zoos? What methods do zoos employ to improve hippo infant mortality?

11-08-2012

They appear to have very high mortality among newborns in Zoos wordwide. If you look at the European Hippo studbook(sorry no link) it lists many breeding pairs with 50% mortality or more of their calves. Reasons aren't usually given, but one is that some of them drown I think, as the older zoo pools are not designed for tiny babies to get out of easily. but there must be many other reasons too.

11-08-2012

Thanks! 50% seems really high. Have we made no advances over the last hundred years in improving their mortality rate?

11-08-2012

I wonder how does this 50% compare to in the wild?

13-08-2012

Don't quote me on exactly the 50% figure but some pairs have given birth to 10 or more calves- some even higher numbers, of which a high proportion d.n.s.

13-08-2012

The mortality in european zoos is still high, but I think maybe the zoos are not so unhappy about it, considering how problematic it is to find a decent place for any offspring.

Here is the studbook for 2009:
http://www.zoo-ostrava.cz/soubory_texty/250_3.pdf

In 2009, there were 11 births in Europe, but only 4 were alive as of 31.12.2009

13-08-2012

Jana,
I know a fair no. of zoos that actually enable females to calve and have their calves grow up, yet then - as being difficult to place - either neuter or (humanely) euthanize calves.

However, this cannot explain the high post partum infant mortality.

Seems a very interesting notion what actually is available from status data in the wild. I am personally not aware of any (in-depth) research on infant mortality in the wild.

This makes answering a query on whether a 50% mortality in captivity in hippo infants is higher than average to wild hippo births / survivability.

K.B.

13-08-2012

It might also be the individual animal's behaviours. The recent baby hippo that died at Werribee (which I presume you were refering to) was killed by a female (the mother) who is notorious for killing her own as well as other hippo's young.

13-08-2012

Yeah, I came across this story from a year ago: Werribee zoo's hippo baby loss - Local News - News - Wyndham Leader

So I was just wondering if that is normal for other zoos or not. It sounds as though it is.

How do other large mammals' survival rates compare in zoos? Say, elephants and rhinos, for example.

13-08-2012

I think there are three main causes of death;

Attacked/killed by mother/adult.
Accidentally crushed by mother/adults.
Drowning due to pool design.

No doubt there are others too.

I think for a heavy bodied animal like a Hippo, the confines/design of zoo enclosures is likely to produce these sort of hazards for newborns.

Possibly the reason mothers kill newborns is, as with elephants, the lack of herd structure or maternal experience in zoo situations- where normally only a pair or so are kept. But some successful parents still have a number of d.n.s calves interspaced between their successfully reared ones too.

13-08-2012

Is this a good way for zoos to look at this 'problem'?
Hippo numbers are dropping to a dangerous level in the wild, and a time will come when they are in the same state as rhino and elephants in the wild, so a there would have been a lost generation of breeded animals that either didn't survive or where killed because of lack of good housing or new homes.

13-08-2012

from "Horns, Tusks and Flippers: the Evolution of Hooved Mammals", Donald R. Prothero and Robert M. Schoch (2003):

"Although the cow is fiercely protective, and can attack any predator (she can even kill a lion, or bite a crocodile in half), calves are very vulnerable to lions, leopards, hyaenas and crocodiles. Only half survive the first year, 15% are lost in the second year, and 4% each year thereafter until they reach maturity at about 7-9 years of age.

Although hippos have a high infant mortality rate, their populations are actually expanding."


I don't know what studies these figures are from, or how many studies there were, or the sample sizes. Also most calf mortality in the wild is presumably/possibly the result of predation which isn't a factor in captivity.

14-08-2012

Yes, the causes of mortality for wild Hippos as listed are mostly predator-related.

From memory and without referring to S/B. data, most losses of calves in Zoos happen in the first 24 hours.

The famous breeding pair 'Henry' and 'Belinda' at Whipsnade Zoo in the 1950/80's era produced well over a dozen calves during their lifetimes and Henry had a few more with one of his daughters- yet over half of them d.n.s.

Interestingly Whipsnade do still breed Hippos(but on a less regular basis than previously) and I think most births there in recent years have been successful- as with the current calf and the previous one.

15-08-2012

Can the baby hippo not be separated from its mother during the first 24 hours then?

15-08-2012

I doubt it! The mother would probably panic-attack or become enraged, and create even more danger of the baby being crushed etc. I think its one of those species that in captivity is prone to a variety of hazards during the initial period after birth. Also, because Common Hippos are't that easy to place in Zoos, no particular effort is made to ensure every calf that is born, survives. They look great as cute babies, but then later what happens to them if they can't find homes for them?