I can't help with the species list at Hounslow, but I can with Hobbledown, based on a recent visit. In regards to some animals, I am not sure on the exact species, but will try to be as accurate as possible.
They have:
2 Reindeer (currently off-show)
Two groups of African Pygmy Goats (Last years juveniles in walkthrough)
Two groups of Sheep, mixture of breeds, around 10 or so in total
1 Asian Small Clawed Otter - Female
1 Coati - Female
2 Raccoon Dogs - Sexes unknown
8 Meerkats - Not sure on sexes
2 Zebu
2 Ponies (In quarantine as not long arrived)
6 Lemurs Ring-Tailed , all male, 3 from Chessington, 3 from Bristol.
5 Patagonian Mara and 6 Bennetts Wallaby in a walkthrough, sexes unknown
3 Anglo-Nubian Goats
2 Pigs, species unknown, sexes unknown
4 or 5 Guinea Pigs
A walkthrough of Large Rabbits, species and amount unknown
Reptile House, which houses Corn Snake, Blue Tongue Skink, Tree Frogs and other reptiles, not sure on all species though, but around 8/9 vivarium's containing reptiles and inverts, one had a spider in, but no idea what it was.
A group of Rhea, think was 4 in there
Pair of Capybara
Another off-show group of Lemurs, awaiting move to Hounslow.
2 Bactrian Camels, who share their exhibit with Nilgai (Think there was 3 in there)
Pair of Peafowl (male and female) in Wallaby Walkthrough
2 Golden Pheasant and 5 Lorikeets in a walkthrough
2 Amazon Parrots
Group of 7/8 Alpaca, 5 White, 2 Brown, 1 Black (Black is male called Rufus) 2/3 whites moving to Hounslow.
Prairie Dogs & Muntjac are listed at the Zoo, but not sure whereabouts there are, and didn't see them.
Impressive Birds Of Prey section, called the Raptor Centre, which has a Bateleur Eagle, Harris Hawk, Burrowing Owl (Leucistic one as well), Gyrfalcon, Laggar Falcon, Lanner Falcon, Barn Owl, African Fish Eagle, and a Buzzard. Think couple more BOP but can't remember, but they do two flying displays twice a day.
Another paddock with miniature donkey x 2, and a paddock with miniature ponies x 4, also another paddock with Shetland ponies.
Tortoise exhibit with 1 Sulcata Tortoise and a couple of smaller ones, possibly Hermann's but not sure.
Couple of new additions to the collection off-show at present, and in quarantine and not been announced by Zoo, so can't say what they are. But they are hoping to build a house for them and give outside access. Possibly muted they could go where the Tortoises are and Tortoises found new area in Zoo, but under their planning rules, they are not allowed to currently build a exhibit house more than 2 metres high, so this has meant they've had to re-think how to put the new additions on display.
All exhibits are fairly large, and Wallaby Walk-through probably the biggest in the UK and the Ring-Tailed Lemur walk-through also very impressive.
Lorikeet walk-through is outdoor.
Camel Paddock has nice big pond in it, and its massive.
All domestics in large areas.
Otter exhibit is huge for one otter, and is really impressive and similar to CWP one, but probably larger and bigger pond.
Coati doesn't go outdoors much as she is old, but exhibit is nice size.
Raccoon Dogs exhibit also decent size.
Sheep and Goat walk-through is enjoyable and goats are very playful!
Meerkat exhibit is standard, not the biggest, not the smallest, but bigger than most, and lots of enrichment for them in there as well, with see-saws, ramps, hideouts, caves and lots of cool things, was very impressed.
Only exhibit I would say was small, was the Capybara, but they originally only went there to be held for Hounslow, but are now staying. They have a small wallow and a Paddling Pool type things for water, but they are planning to create new exhibit for them, with a pond.
The Zoo itself is actually away from the play areas. As you walk in, to your right is the gift shop and cafe and around that area is a lot of play area. Then to your left is the Zoo which heads round with walk-throughs. Just past the Lemurs is another massive play area, and there's an option to turn around and leads to a path out the back of the Lorikeet walk-through which leads to massive paddocks which is where the Wallaby Walk-Through starts, before going to to Camels, Alpaca, Ponies, Horses, Donkeys, Nilgai etc. On the right on one section is the BOP display centre, and a small area, which was opened by Steve Backshall and on the left is the Raptor Centre.
Adults can book experiences, and the experience which lasts for 3 hours, pretty much covers all the animals in the zoo, so there isn't really a need to stay when it ends.
Definitely possible to do the Zoo route which doesn't go close to the play areas and all the play areas bar one small one opposite the Raptor Centre, are away from the animals.
I would say it is worth a visit if you get a chance to go, as its a nice collection, in decent exhibits and I think many on here would approve.
I was able to visit as an adult on my own doing an experience, so my advice would be contacting them if you want to go, explain you just want to see the zoo, it wasn't a problem for me, so I don't think it would be a problem, especially if you book the experience.
The place is very themed on a story book (never heard of it though) and it is designed for kids and is advertised as a children's zoo, but it was an enjoyable visit for me.
I can't provide any details on Hounslow, as have never been, but hope the above is helpful for you. Not sure I can provide anything else, as think I covered it all.
