think youíre hot. Try living in a space no bigger
than, well, a beehive with 20,000 of your closest
friends. Or, wearing a down coat as summer temperatures
start to cook.
have their strategies for cooling down as the mercury
rises. So do animals.
a really hot day, youíll see crows and other birds
holding their mouths open. They are practicing what
scientists call gular fluttering ó panting.
they donít have sweat glands, the best way for them to
achieve evaporative cooling is to pant like a dog,"
notes John Marzluff, a professor of wildlife sciences at
the University of Washington.
nature photographer Gerrit Vyn also notes birds flatten
their feathers in the heat, to reduce their insulating
capacity ó the opposite of fluffing up in the cold.
have multiple strategies to beat the heat.
bumblebees, flight is the ticket. The convective cooling
of their self-made breeze helps them cope.
honeybees, cooped up by the thousands in their hive,
have to take multiple steps to survive ó and protect
next yearís brood, maturing in cells deep in the hive.
starters, like people, theyíll head outside. As much
as a third to half the residents of the hive will
evacuate on a hot day, diminishing the heat all their
bodies are generating.
that isnít enough, they will practice what Tom Seeley,
professor of biology in the department of Neurobiology
and Behavior at Cornell University, calls "social
ventilation." The bees will stand at the entrance
to the hive, line up, and beat their wings in synchrony
to generate air velocities of more than 6 feet per
second. "Itís quite a breeze, you can put your
hand in front of a hive and actually feel a draft,"
on really hot days where all that does is pull in more
hot air, itís time to turn to the specialized skill of
the water-collection bees. Elders in the hive, they are
the only ones trusted with this crucial task.
how do they know when itís time to head out to get
water to cool down the hive? Seeley and his team
reported in their paper published in The Journal of
Experimental Biology in March, they take their cue from
other bees begging them for water. All it takes is an
antenna tap and tongue touch from a begging bee, and
they are out of the hive, on their lifesaving mission.
their proboscis, they will lap and suck up water, which
they store in their honey sac, taking only about 60
seconds to tank up. Each bee can carry only about 50
micrograms of water in a flight ó 80 percent of her
own body weight, and doubling the size of her abdomen
ó yet only about a quarter of one drop of water. A
water-collecting bee will make flight after flight after
flight for the good of the hive.
spreader bees back at the hive offload their water,
sucking it into their own bodies, then painting it with
their tongue in a thin film over the brood cells, where
it evaporates, cooling the hive. When the begging stops,
the collector bees finally rest.
help bees out on a hot day, Tim Lawrence, director of
Washington State University Extension for Island County,
recommends providing water with a drip from a hose, or
even in a dish ó as long as there is something
floating in it, so bees wonít drown.Lawrence said he
has been fascinated with bees since he cut down a bee
swarm on a tree branch in third grade, took it to his
mother and told her he wanted to become a beekeeper.
"Everything they do is incredible."