To be fair, if you go to visit any zoo thinking before-hand that it'll be perfect, then you will leave the zoo disappointed, because no zoo is perfect. This I completely disagree with. The wonderful plant-life and general "tropical" feel, the numerous steep canyons and even the 1930's-era Reptile house gives San Diego a lot of character. For Mammals I agree it isn't the most unique species-wise (although there are some really nice primates), but for Birds there are some really nice species. But what even is San Diego's comfort zone? Their last two major developments, Elephant Odyssey and Africa Rocks are pretty risky for exhibits with a massive budget; Elephant Odyssey was a $45 million dollar exhibit that's theme was centered around animals that are extinct, while Africa Rocks was a $70 million dollar exhibit that had African Penguins as its drawcard species.