Dying without wings
Natalie CooperTrinity College Dublin
@nhcooper123
Kevin Healy @healyke
…in this world nothing can be
said to be certain, except
death and taxes…
Benjamin Franklin@benfranklin
There is great variation in the
lifespans of living things…
How can we explain this variation?
log(Lifespan) = log(a) +blog(Body
mass)
log
(L
ifesp
an
)
log(Body mass)
log(a)b
log
(L
ifesp
an
)
log(Body mass)
log
(L
ifesp
an
)
log(Body mass)
log
(L
ifesp
an
)
log(Body mass)
log
(L
ifesp
an
)
log(Body mass)
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?
log
(L
ifesp
an
)
log(Body mass)
log
(L
ifesp
an
)
log(Body mass)
Foraging environment?
We tested our predictions on 779 mammals and 546 birds
(N = 1325)
log
(L
ifesp
an
)
log(Body mass)
log
(L
ifesp
an
)
log(Body mass)
Activity period?
Foraging Environment?
Crepuscular species have the shortest
lifespans
Foraging Environment?
Activity period?
Burrowing?
Arboreal, semi-arboreal and
fossorial species have the longest
lifespans
When you’re activeWhere you’re active
Are bats really exceptional?
log
(L
ifesp
an
)
log(Body mass)
log
(L
ifesp
an
)
log(Body mass)
Be active at day or nightForage in safety
Be bigFly
Live in a burrow