I think birdsplosion (and many other splosions) refer to the size of the nests, while catsplosion refers to the fact that stopping cats from breeding can be difficult. Having 40 chicks running around will make things a little confusing and keeps dwarfs busy for quite a while trying to catch and cage them. Now try it with (unmodded) cave crocs, who average in nest size 50+.
You can get a nasty birdsplosion if you just lock the doors to the bird-pasture to get chicks, and forget to unlock them until after there are loads of chicks, for example. Yea, the main problem will probably be how long it takes to get all those chicks under control (preferably in cages), and when they grow up, they'll take quite a bit of slaughtering/tanning too. Just realised that I haven't checked yet whether egg-layers' offspring will be auto-assigned to their mother's pasture, the way it works with other animals now?
Cave crocs, yum (value multiplier x4!)
Catch a female and tame it, you get nice big stacks of eggs, for nice big stacks of valuable roasts. Catch a male as well (this can be left hostile and just pitted somewhere, so ones from goblin sieges are ok as well), and you have a crocodile farm, for value multiplier x4 leather and bone goods, and of course food and soap.
edit: bah, it seems that according to the wiki, cave crocs (or saltwater ones) don't actually give leather, just scales (or nothing, with saltwater crocs) :/ Now there's a spot for modding, since of course real-life crocodile leather farms do exist. Then again, one could just buy the caravans empty with all those cave crocodile bone crafts, but I'd much prefer to have my dwarves uniformly outfitted in cave crocodile leather clothing. Gives more flavor to the fort.