Money has a surprisingly short lifespan.

 

Money has a surprisingly short lifespan.

Sure, the cash in your pocket right now has gone through several pairs of hands but it’s actually not that old!

Depending on its denomination and the transaction, a bill’s lifespan is surprisingly short, with most of it not even reaching its teens.

The US Federal Reserve estimates it thusly: with the $1 bill lasting only 6.6 years, the $5 bill 4.7 years, $10 5.3 years, $20 7.8 years, $50 12.2 years, and the $100 estimated to last 22.9 years.

The relationships between group size, survival, and longevity vary greatly among social species. Depending on demographic and ecological circumstances, there are both positive and negative effects of group size variation on individual survival and longevity. For socially foraging species in particular there may be an optimal group size that predicts maximum individual survival that is directly related to the potential for information transfer, social coordination, and costs of conspecific interference. Our aim was to investigate this central aspect of evolutionary ecology by focusing on a socially foraging bat, Molossus molossus. This species optimizes foraging success by eavesdropping on the echolocation calls of group members to locate ephemeral food patches. We expected to find the highest survival and longest lifespans in small groups as a consequence of a trade-off between benefits of information transfer on ephemeral resources and costs of conspecific interference