[sidetrack]The whole regaining of animal companions is pretty skimpy. IMC I have a HR version that emulates Stephan Brust's example of calling in the Taltos series.
The basics are:
Spend a day calling a creature, you need some 'props' such as food and runes scribed in the ground. These props can help limit what type of animal responds. Once the critter arrives, you need a diplomancy check to convince it to sign up as a companion.
You can also improve your odds of getting the critter you want by researching the proper place in advance, making sure that the desired critter is nearby.
Generally it takes about a week worth of preparation to get exactly what you are looking for.
You can rush the process to call a creature in an hour, but the calling is not limited in any way.... and since the 24 hour version limits to the proper HD... as well as possibly aggravating the critter to be in a less than jovial mood, this can be a dangerous prospect. The critter could very well be much more powerful than you can handle and may want to eat you..forcing a rushed diplomancy check...

You can still only try once per day.
I was working on a set of tables for each terrain type, but my campaign splintered and died before the Druid who lost her Clawfoot got around to looking for a new companion.[/sidetrack]