Well, I was a little sick and then forgot about the topic. Sorry.
If you want to program something in ZT, like change of prey, you (most of the time) will look at the .uca file. It's a file you can open with noteblock. (Just open noteblock and drag the file onto it.) Then you change the things you want and save.
You must reach the uca file by using winrar. Winrar is a free program you can download. Drag the .ztd file onto it and it will open the .ztd file in winrar. Then you can reach the .uca file.
Apparently for setting prey animals, this one is of the leopard;
;Man
cPrey = 9503
;giant_panda
cPrey = 5001
;chimpanzee
cPrey = 5003
;plains_zebra
cPrey = 5004
;thomsons_gazelle
cPrey = 5005
;gray_wolf
cPrey = 5015
;olive_baboon
cPrey = 5019
;mandrill
cPrey = 5020
;mountain_gorilla
cPrey = 5021
;red_kangaroo
cPrey = 5023
;common_wildebeest
cPrey = 5025
;ibex
cPrey = 5027
;okapi
cPrey = 5028
;moose
cPrey = 5029
;gemsbok
cPrey = 5031
;american_bighorn
cPrey = 5032
;giraffe
cPrey = 5033
;dromedary_camel
cPrey = 5034
;markhor
cPrey = 5036
;greater_flamingo
cPrey = 5037
;ostrich
cPrey = 5038
;emperor_pengiun
cPrey = 5039
;california_sea_lion
cPrey = 5040
;giant_anteater
cPrey = 5042
;african_warthog
cPrey = 5043
;Blackbuck
cPrey = 5076
;Bongo
cPrey = 5077
;Sable antelope
cPrey = 5079
//Reserved for new prey animals
;Prey animal 0
cPrey = 5300
;Prey animal 1
cPrey = 5301
;Prey animal 2
cPrey = 5302
;Prey animal 3
cPrey = 5303
;Prey animal 4
cPrey = 5304
;Prey animal 5
cPrey = 5305
;Prey animal 6
cPrey = 5306
;Prey animal 7
cPrey = 5307
;Prey animal 8
cPrey = 5308
;Prey animal 9
cPrey = 5309
;Prey animal 10
cPrey = 5310
;Prey animal 11
cPrey = 5311
;Prey animal 12
cPrey = 5312
;Prey animal 13
cPrey = 5313
;Prey animal 14
cPrey = 5314
;Prey animal 15
cPrey = 5315
;Prey animal 16
cPrey = 5316
;Prey animal 17
cPrey = 5317
;Prey animal 18
cPrey = 5318
;Prey animal 19
cPrey = 5319
;Prey animal 20
cPrey = 5320
;Prey animal 21
cPrey = 5321
;Prey animal 22
cPrey = 5322
;Prey animal 23
cPrey = 5323
;Prey animal 24
cPrey = 5324
You would have to add cPrey = number of the animal.. You would have to research the numbers of the original ZT animals. With new animals (made by players), you need their uca number.