One of the best ways to start a fight among American ZooChatters is to ask if Los Angeles Zoo is worth it. At the risk of being lambasted, in my opinion no, it is not. I also hate the Los Angeles area in general (and remember it's my home town). Even when I visit California I do whatever I can to avoid the area. Traffic is a nightmare and you might be better off cutting off across the desert (via Palmdale) and crossing the mountains via I-15 and taking that to San Diego Safari Park. If you have time make a detour en route to The Living Desert, which is in my top five zoos (and while not the same as Arizona-Sonora Desert Museum will give you a similar desert zoo if you don't make Arizona).
I have just realised I have seen a good proportion of the fossils and replicas in the La Brea tar pits museum because there was an exhibition at the Natural History Museum in London which focused on the Tar Pits and used many of the exhibits there, so I'm wondering whether it is still worth it to go.
In addition, I can tell after a while researching etc., that Los Angeles is not really my kind of city. Not walkable, not really public transportable, sprawling etc. I guess I might just end up not going instead and then on the LA day go to Living Desert zoo. I just had a look at the species list, and I would probably go if it had nothing but its fox species
For Philly, and DC, I think it depends on what species you want to see. I love Philly, but they don't really have anything that you aren't going to see elsewhere, other than maybe the Guam birds. The Zoo360 is really neat but is completely dependent on the animals having access to use it, wanting to use it, and the weather being okay.
If you go to DC, get there early - grounds open at 8am, buildings at 9am. The zoo is practically empty the first two hours, and the animals are pretty active.
Make sure to get a zoo membership somewhere before you come! A few don't get you discounts elsewhere or only allow members from nearby zip codes (SDZ, DC, WCS come to mind), but if they're in the AZA reciprocity program like most are, you'd get 50% off at other places; free zoos will usually give you a percentage off of food or the gift shop. Philly's membership for one person is $60. Their entry fee is $24 and parking is $16, so going there twice a year with a membership already saves me $20. Since you won't be driving, membership would cost you $34 more than admission, which you'll easily make up for with the money it saves you at other zoos.
That sounds like a really good program! I've checked with my uncle about whether he'll be free the suggested dates but he says he's normally really busy with work that kind of period and can't afford to take even a single day off. So, I guess no Philly in the interest of saving time and money. I guess that means that in the case of trip 1 there isn't much use for the reciprocity programme, but I think it may come in useful in other trips, so thanks for mentioning that, I had no idea it existed!
As for the early opening, I'm always an early riser on zoo days, so I will be outside the gate a good ten minutes before opening time!
While LA is obviously not an amazing zoo, I'd still say it deserves a visit. The species collection is really impressive, with some extreme rarities like Mountain Tapir and Uakari, and while the exhibitry isn't the greatest they're at least making substantial improvements (LAIR and Rainforest of the Americas).
I'd totally agree with this. Living Desert is an underrated gem and definitely worth visiting.
OK well I guess that is settled then. Living Desert it is!
As for LA, well given the trip in question is quite a while away (around a decade actually

) I'm not sure the uakaris and the Mountain tapirs will still be there, but we'll see - maybe they will hold on until then
I'm assuming to referring to Guam Rails and Kingfishers here? They are relatively common in zoos.
@amur leopard If you go to Shedd, make sure to buy your tickets ahead of time and get there as soon as the aquarium opens. Not doing this causes you to wait in a line that is usually at least an hour and a half. On especially busy days this line can get as long as FIVE HOURS!!!!
I will absolutely do that. I might be getting also one of those city pass things which gives me free entry into the Field and Shedd as well as a few other places for like 90 dollars, which is a pretty good deal, and I think they are skip the line tickets too, so that should be good.