Ostriches and Gazelles feed next to each other. They both watch for predators and alert each other to danger. Since the visual abilities of the two species are different,
they can each identify threats the other animal would not as readily see.
Parasitism
Competition
Commensalism
Music

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.