Testing values of crested porcupine habitats by experimental food patches.

We established depletable, artificial food patches in three habitats used by Indian crested porcupines (Hystrix indica) in a desert biome, and measured the number of food items remaining (i.e., "giving up density"=GUD) following nightly foraging bouts. Porcupines discriminated between resource types (peanuts vs. garbanzo beans), and exhibited clear habitat preferences in the face of uniform resource availability in time and space. Lowest GUD's (=lowest foraging costs) were in the habitat of densest cover, and during dark (little or no moon) nights. The results indicated a high sensitivity to predation risk. Crested porcupines behaved as expected of optimal foragers, and appear to be excellent subjects for further field experiments using the GUD approach.