Absence of evidence for a hibernation "trigger" in blood dialyzate of Richardson's ground squirrel.

In order to examine evidence for a blood-borne “trigger” for mammalian hibernation, serum dialyzate from hibernating Richardson's ground squirrels (Spermophilus richardsonii) was injected into summer-active ground squirrels of the same species. Four independent trials involving 52 animals were performed. In all trials, no effect of the dialyzate was seen on nest building, weight gain or loss, or on occurrence of hibernation.