Dying without
wings
Natalie Cooper
Trinity College Dublin
@nhcooper1
Kevin
Healy
@healyke
…in this world
nothing can be
said to be
certain,
except death
Benjamin
and taxes…
Franklin
@benfrankl
There is great
variation in
the lifespans
of living
things…
How can we
explain this
variation?
Body Mass…
log(Lifespan) =
log(a)
+blog(Body mass)
log
(Lifespan)
b
log(a)
log(Body
log(Body
log
(Lifespan)
log(Body
log
(Lifespan)
log(Body
log
(Lifespan)
log(Body
log
(Lifespan)
Why do some
species live
longer than
expected given
their body
size?
A quick side
step into life
history
theory…
Why do species
have different
life history
strategies?
Variations in
extrinsic
mortality…
Species with
adaptations that
reduce extrinsic
mortality should have
longer lifespans than
expected given their
body mass
How can
species
reduce their
extrinsic
mortality?
Flight?
log(Body
log
(Lifespan)
log(Body
log
(Lifespan)
Activity
period?
Foraging
environment?
Burrowing?
Burrowing?
We tested our
predictions
on 779
mammals and
546 birds (N
= 1325)
Body Mass…
log(Body
log
(Lifespan)
log(Body
log
(Lifespan)
Activity
period?
Foraging
Environment?
Crepuscular
species have the
shortest
lifespans
Activity
period?
Foraging
Environment?
Burrowing?
Arboreal, semiarboreal and
fossorial species
have the longest
When you’re
active
Where you’re
active
Are bats
really
exceptional?
log(Body
log
(Lifespan)
log(Body
log
(Lifespan)
Be big
Fly
Be active at
day
or
night
Forage in
safety
Live in a
burrow