The Ruby Throated Hummingbird has a resting heart rate of 250 beats per minute. When it is threatened or chased, it's heart rate can reach 1200 beats per minute. Predict its lifespan and justify your explanation.

Answer 1

There are many animal species that seem to have an average life span of about 1 billion heartbeats. Birds and humans included.

See
http://www.beholders.org/mind/scienceandfacts/124-1billionheartbeats.html

for more about that.

Hummingbirds don't spend a lot of time resting. I'd expect an average heart rate of 500 b.p.m. At that rate, one billion beats would take 4 years.

That happens to be the observed average life of that bird species. Some have lived 12 years.