Western and Eastern meadowlarks look very similar and it is difficult to tell them apart, until they sing. Their mating songs are quite different. The Western meadowlark has a melodious song, whereas the song of the Eastern meadowlark sounds more like a whistle. Even though their ranges overlap in the central United States, they do not interbreed and are two different species. How would speciation most likely have occurred in these two species of meadowlarks?

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.  

condensation. good luck!