Monday, June 19, 2006

More on what I saw at the zoo

Wa-hey: we have images! Here are some of the long-promised Marwell Zoo pictures I wanted to post a while back (go here). Essentially this is an assortment of some of the neatest, most exciting animals you can ever expect to see in captivity.

We start with the fossa Cryptoprocta ferox. Marwell currently has one male (the animal pictured here) and one female, and they've successfully bred them. Fossas are bizarre, looking like a mixture of cat, dog, mongoose and civet. Though classified conventionally as viverrids they are actually part of an endemic Magadascan clade located at the base of Herpestidae. They can shin up vertical poles and can also climb down, head first and with their ankles rotated somewhat. More on them another time, maybe when Mary* shows up and starts telling me about her latest adventures with lemurs. We got images of the male scent-marking a tree stump: see photo below.

* Mary Blanchard, Liverpool-based primatologist working on lemurs.

Above, the back end of an Okapi Okapia johnstoni. Marwell has lots of them, and has had breeding success. Famously discovered by Harry Johnston and named by P. L. Sclater in 1901 (Johnston thought he was tracking down reports of a new forest-dwelling equid), Okapia is a short-necked forest-dwelling giraffid, though how typical it is in the grand scheme of giraffid diversity and evolution has proved controversial. Males have short curved ossicones (so this animal is a female) that they fight with, and Marwell had (until recently) a really old gnarly male with (relatively) huge lumpy ossicones. If I remember correctly he was - at 30-something years old - the oldest okapi in captivity, and thus probably the oldest okapi in the world. They're supposed to be silent, but juveniles make coughs, bleats and other noises. Lots more could be said, they're fascinating.

Also above we have a male Greater rhea Rhea americana (also called Common rhea). Nice photo. Note the lone capybara in the background. Dave and I had a discussion today about flightlessness in ratites: a single evolution of flightlessness at the base of the clade, or multiple separate origins of it within the group? Well, that's the big question isn't it. No time to discuss it now, another time. Interesting thing about Rhea: contrary to what you might think, they apparently don't like open grassland habitat, and in the wild chose open woodland environments. Males court multiple females, get them to lay their eggs in a single nest, and then take over incubation and post-hatching duties. This form of behaviour is sort of similar to the creching present in ostriches, and the parental behaviour of male cassowaries, emus and kiwis.

Here's the male fossa scent-marking (with his anal glands). Bet you've never seen that photographed before.

Gemsbok Oryx gazella, also called Beisa oryx or African oryx. That last name is particularly stupid given that all extant oryxes are African (or Afro-Arabian if you want to be more precise). As is the case in other hippotragine antelopes, males and females look alike. All oryx are dry-adapted (as is their closest extant relative, the Addax [which they also have at Marwell]), and fantastic tales are told of their physiology. Nice pigmentation they have. This is the closest I've ever got to one.

Collared peccaries Tayassu tajacu. They have loads. Until recently there was just a single wire fence seperating the peccaries from the public, and I always thought this was a bit dangerous in view of the immense teeth these animals have. They've now installed a separate barrier fence that keeps people further back from the animals. I'd like to think this is because one of the peccaries chewed someone's arm off, but sadly I lack confirmation of this fine theory. Peccaries are omnivores, though they mostly eat vegetation (predominantly roots, fruits and tubers), and the suid-like rhinarial disk they have is obviously great for rooting in soil. They have particularly short tails (with only seven caudal vertebrae or less), hind feet strongly modified for cursoriality (some of them even lack digit II), and vertically implanted canines where the lower canine fits into a special pocket on the side of the muzzle. A similar feature is seen in hippos, so some workers think that peccaries and hippos are each other's closest relatives (which, if correct, would mean either that peccaries are whippomorphs, or that Whippomorpha is not monophyletic*). Then there's the fact that peccaries haven't always been restricted to the Americas and previously occurred in Africa.

* If you're wondering what the hell I'm talking about you'll have to wait for a future post, sorry.

There are three extant peccary species (with the third being Catagonus wagneri, a taxon only discovered in living state in 1974 - go here for more). However, Mark van Roosmalen has reportedly discovered a fourth species recently. The type specimen was eaten however. For more on this go here.

And that's that. Spent all day dealing with British dinosaurs, but you don't want to hear about that.


Anonymous Anonymous said...

"The type specimen was eaten however."

Could you expand on that?

Doug M.

5:20 AM  
Blogger Carel Brest van Kempen said...

I'm interested to learn more about rhea habitat. I've never seen the birds in the wild, but the ones I've worked with in zoos, when startled, would often run headlong into a tree trunk that they'd shared their paddock with for ten years. I always assumed that behavior must have evolved in a region where trees wee scarce. Maybe our rheas were just particularly stupid.

9:46 AM  
Anonymous Anonymous said...

About rhea habitat it is true that you usually see the Greater Rhea in scrub/Woodland habitat(Chaco, Cerrado and Campo). However the only active nest I've ever found interestingly enough was on top of a small knoll in open grassland, though there was woodland within sight, so perhaps the male wants a good view when incubating.
The Lesser Rhea prefers more open habitat. The northern montane form I've never come across except in open, completely treeless puna while the southern subspecies occurs in grassland or scrub steppe.
As a matter of fact ratites are not not nearly as much birds of open habitat as is often claimed. All cassowaries are of course strictly forest birds and so are the kiwis (though the extinct eastern kiwi may have preferred more open habitat). The emu is often found in bush (e. g. mallee) or woodland. It avoids both desert and dense forest.
The ostrich does live in desert, but its preferred habitat seems to be savanna or open bush. I've actually found it breeding in quite dense bush and even mopane woodland, though it does seem to shun Brachystegia woodland.

That the male takes care of the eggs and young (simultaneous polygyny combined with serial polyandry) is probably primitive within the paleognathae (including the tinamoes), though it has been modified a bit for the kiwis and ostriches. Houde (1988) suggested that it also applied to the extinct lithornithids based on the large amount of eggshells associated with individual nests.

8:43 PM  
Blogger The Ridger, FCD said...

Cool photos! Thanks for sharing!

12:37 AM  
Anonymous Anonymous said...

Horses and ponies run into trees and other solid objects when scared enough. It occurs frequently during thunderstorms...

1:05 AM  
Blogger Matt Mullenix said...

So peccaries are closer to hippos than pigs? I had heard they wern't "true pigs," whatever that means....(it's been said of me, too).

Is this a convergence deal? If so, a mightly good one---they sure look like little piggies.

1:07 PM  
Anonymous Anonymous said...

The peccary-hippo connection is out. Instead, hippos are anthracotheres (almost wrote "anthracosaurs"... ouch...). Ref: some paper by a couple of Frenchmen in early 2005.

11:35 AM  
Blogger Darren Naish said...

For the record, note that I wasn't outing myself as a supporter of the proposed hippo-peccary affinity in the post: I was merely noting that 'some workers' favour this view. It's Martin Pickford in particular who's supported this (see Pickford 1983). I don't know if he still supports it, but no one else seems to: the proposed synapomorphies are either more likely to be plesiomorphies (J. van der Made, pers. comm.) or aren't convincing in view of the fact that basal hippos lack characters that unite suids and peccaries (Boisserie 2005).

The Frenchman that David is referring to is presumably Jean-Renaud Boisserie. In his 2005 paper he supported the old and popular idea that hippos descend from anthracotheriids. Indeed most workers - morphologists and molecular biologists - seem ok with the idea that hippos actually aren't in the same clade as pigs and peccaries (Suiformes), but instead form Whippomorpha with whales.

At the moment it does seem after all that pigs and peccaries are close kin and that they form a clade (Suoidea). As Susan Herring wrote in 1972, this probably means that Romer was about right in stating that 'the peccaries are an offshoot of the primitive pigs'. There's a lot more that I'd like to say about pigs and peccaries, but I can't do it now.

Refs - -

Boisserie, J.-R. 2005. The phylogeny and taxonomy of Hippopotamidae (Mammalia: Artiodactyla): a review based on morphology and cladistic analysis. Zoological Journal of the Linnean Society 143, 1-26.

Pickford, M. 1983. On the origins of Hippopotamidae together with descriptions of two species, a new genus and a new subfamily from the Miocene of Kenya. Geobios 16, 193-217.

11:58 PM  
Blogger Darren Naish said...

I made a mistake: the detailed, similar snout anatomy present in both suids and peccaries is more likely shared, not convergent. Me silly. I'm now going to change the blog post accordingly (thanks for bringing attention to this).

Incidentally, the proper name for peccaries might not be Tayassuidae, but Dicotylidae. The latter was named by Gray in 1868 but, last I read, the author for Tayassuidae hadn't been discovered. More on this in a future post devoted to peccaries.

8:02 PM  
Blogger Unknown said...

is this the 'marwell' zoo just outside Soton? I now repent never visiting it. I'm still prisoner of the old misconceptions about zoo as being awful places where animals are held in cages...

12:04 PM  
Blogger Darren Naish said...

I'm posting the following comment on behalf of my colleague David Hone ( Thanks for the comment Dave! He says....

If I've not said so already can't remember) congratulations on completing the PhD. Just browsing you blogspot and noted your Marwell post. Out of interest, the old male Okapi at Marwell was named Kibali. I used to work with him at London zoo. He was 26 when I was first there, back in 1994, and was already the oldest known in captivity (though the
then record was 28 I believe). I last saw him in 2002, and so he was at least 33 and probably 34.

I assume the poor old guy has passed on by now, but at least he shattered the Okapi longevity record. Incidentally, he was one of the best mannered animals I have ever worked with, which brings me to collared peccary.

These buggers are evil and i was always concerned about the fence at Marwell. Various locals in Peru assured me that these things will happily kill (and then eat) humans if they are in a large enough pack. Certainly this is true of the chaco in Argentina. Working with them in a zoo and a park in Peru, I can assure you they are ill tempered and attack anything without provocation if they possibly perceive it as a threat (anything bigger than themselves, which is most things) with teeth and hooves. Even at their size they are quite capable of taking off fingers or breaking
arms (or so I'm told).

Well, enough ramblings,



9:26 AM  

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