Temperature strategies of heterotherms

Question 1

Insects
Certain insects (especially larger ones: locusts, moths, butterflies, bumblebees)

Answer 1

raise the
temperature of their thorax when preparing to fly. At other times they act as strict
ectotherms. They need to warm their flight muscles to 40oC before they can provide enough
power for flight. They do this by activating their flight muscles so that they work against
each other, producing heat but little wing movement other than small rapid vibrations. Once
in the air the muscles generate enough heat to maintain flight.

Question 2

How do insects prevent overheating when flying in a warm environment?

Answer 2

By regulating blood flow from thorax to abdomen. At temperatures >40oC the sphinx moth diverts blood
from thorax to abdomen, which is relatively inactive and poorly insulated

Question 3

Honey bee swarms regulate the core temperature of the swarm

Answer 3

by shivering movements and
changes in swarm structure. At low temperatures (e.g. 5oC) the swarm closes ranks to
restrict air flow and retain heat. The temperature of a honey bee hive is maintained at 35oC
which speeds the rate of development of the young. At high ambient, bees fan their wings to
evaporate water to cool the hive.

Question 4

Reptiles: Brooding pythons

Answer 4

A brooding female Indian python coils its body around its eggs and raises its body
temperature by shivering thermogenesis to warm the eggs.