Aids and the bubonic plague are examples of a
countermigration stream
migration stream
pandemic
parish

AIDs and the bubonic plague are examples of a pandemic.

The word pandemic  is from the Greek word pandemos which means pertaining to all people.  The word "pan" means all and the word "demos" means people.

A Pandemic is said to be a disease outbreak of global proportions.  It usually caused by  the emergence of a new or novel virus among humans. It is easily transmissible  and causes serious illness.

The bubonic plague, called the black death was the worst pandemic in history killing 75 million people.

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.