Island Paradise limits the number of animals a player can have on their island at any given time. The number of animals you may have on an island is not limited by the size of your island, but by a player's level.
To quote Echo from the forums, "We want the game to run well on multiple computer and browser types. If we allowed you to put a ton of animals on your islands, the game would lag to the point of being unplayable (once you hit the perfect number). In time we will allow for more animals as we make optimizations and updates to the game." 
In other words, because of the sheer amount of animation that goes into each individual animal, it is impossible to allow unlimited numbers of animals. Meteor Games' other game, Ranch Town, has animals with far less animation than that of Island Paradise. True, players are able to put as many animals as there is space on their Ranch as they want, but the trade off is animation. In a simple comparison, the cows of Island Paradise "moo" when clicked, change direction, and are capable of moving freely from one part of the island to another independently. The coding that goes into enabling animals to walk, without bumping into each other or other objects requires your computer to do more work, and too many animals overloads your computer's capabilities and causes lag. The cows of Ranch Town stay on the spot, blink, twitch their ears and swish their tails, all in unison. The uniformity and fixity of animals on Ranch town enables the developers to give players "unlimited animals" - until they run out of space on their ranch, that is.
The developers will try to work upon allowing more animals, but it is unknown how long this will take, as the code has to be optimized so that older computers can handle it without problems. It is not so much a matter of Meteor Games needs to buy more servers to handle it as not everyone has super computers that can process the animations required for so many animals.
Not all browsers and not all computers were created equal. Some browsers may handle the code for 98 ostriches better than others, just as some computers will handle 98 ostriches better than others. If you think all browsers and computers are fully capable of handling a hundred or more animals, see Ostrich Island (below).
How many you can haveEdit
The animal limit increases as you level up as can be seen in the chart below. You can also affect the number of animals you can have by purchasing a Barn. You can also increase your animal limit by purchasing a Maximizing Animal Trough, Animal Booster Totem, Island Expansion, Big Beast Booster. Pirate Totem and/or a Barn Skin. Please see each item for the increase to your animal limit.
|Levels||Number of Animals||Level 1 Barn||Level 2 Barn||Level 3 Barn||Level 4 Barn||Level 5 Barn|
|1-4||10||Cannot purchase barn yet||Cannot purchase barn yet||Cannot purchase barn yet||Cannot purchase barn yet||Cannot purchase barn yet|
All pets, such as the Dog, Cat, Panda, Kangaroo, Fox, and Leopard do not count towards the animal limit as they serve no purpose (they all give nothing to harvest). The maximum number of animals a player can have is 32 useful animals, and many not useful animals.
Your Animal Limit increases by 20 for each Island Expansion you purchase. As of March 3, 2011 you could have a maximum of 4 Island Expansions which boosts your overall Animal Limit by 80.
Animal Limit hasn't increased even when I gain a new levelEdit
After gaining a new level that allows you to unlock a new number of animals allowed, you may need to close your game window and reload it for the new limit to come into effect.
If that does not work, you may need to clear the Meteor Games cookies. You can find the instructions for doing so here. After clearing the cache, reload the game.
If none of the two solutions work, you can contact Support to inquire.
Ostrich Island/Lag IsleEdit
The island can be found here. This island is not a real player's island, but one created by the developers to show why there is an animal limit. Caution: The island has 98 ostriches and may cause extreme lag when loaded. It may also crash your Flash, computer, or browser.
If you press Shift-F while Ostrich Island is open, the number of fps (frames per second) can drop significantly below the normal 30-31. The more fps there are, the smoother the game will run.
While it is true that some players can open Ostrich Island and experience no lag whatsoever, it is hardly fair to players who have less capable computers and browsers not to be able to play because they would experience the lag.
What to do with spare animalsEdit
Before the addition of selling from gifts, players would have to place individual animals upon their islands first before they were able to sell them one at a time using the delete tool.
Animals can also now be stored in the Barn, which allows users to cycle through which animals they want to put out.
The animal limit used to be at 18 animals. This was changed on January 12, 2010.