Just a few thoughts following up on the Colobus walkthrough. Despite being to London Zoo a number of times I've never been inside the Snowdon so I can't say with any authority about space, however...
* ZSL won't mix any species that is particularly rare or delicate (Goliath heron, shoebill, Congo peafowl) or that will possibly be harassed or killed (doves).
* I can't see it being big enough for bongo or pygmy hippo. Mix would be fine however.
* Red river hogs, like all pigs, make an absolute mess of exhibits. I would think it was unlikely that ZSL would try and house them together, but it might work. The mix would be fine, as above.
* Duiker would work, but would you see a small solitary antelope in the bottom of the aviary?
* Grey parrots - I would love to see a zoo do a big flock and mix with primates. Think it would be very impressive. Interaction with other species should work well.
* Other primates would work, but it would need to be a guenon as mangabeys and baboons are too aggressive for a walk-through.
* As mentioned colobus do spend alot of time lying about. They are a bit like lemurs needing to sun themselves in order to get going. I suspect this is due to their vegetarian diets.
It will be interesting to see which way they go and what works.
Goliath herons can be put in mixed aviaries (eg Dierenrijk in the Netherlands have done this).
Congo peafowl can also go in mixed aviaries (they currently live with green woodhoopoe at the zoo).
Shoebills were just a suggestion; it's a species I definitely think could come to the zoo at some point.
I agree about the bongo and pygmy hippos; definitely not enough room as of right now.
If I'm honest, red river hogs would be their best bet for hoofed mammals from Central Africa. Duikers already live with the okapi so there's no need to get more, plus colobus are more or less exclusively arboreal.
There is a path round the bottom of the aviary that has been closed for a while now, it allows you to see the bottom dwellers up close. I reckon they'll open that back up when this new exhibit opens.
Again, what guenon species though? There really aren't many in captivity atm, maybe De Brazza's or L'Hoest's could work, or potentially owl-faced.
I agree about the baboons and mangabeys, way too aggressive.
In regards to birds, doves do do well in a mixed aviary but maybe not with colobus around (though in my experience colobus aren't really aggressive to birds).
The birds I suggested have mostly been proven to work well together in a mixed walkthrough aviary setting (hornbills, turacos, crakes, doves, starlings); these are the species most often found in aviaries like the Snowdon around the zoo.
Currently, my suggestions for the new exhibit would include:
- Colobus
- De Brazza's monkeys
- Red river hogs
- Yellow-backed duikers
- Goliath herons
- Emerald starlings
- Great blue turacos
- White-crested hornbills
- Tambourine doves
- Black crakes
- African pygmy geese
- African grey parrots
I'm not saying that these would all work together etc, but I think a mixed exhibit with these would be cool.