a regulator for automatically regulating temperature
Once settled, they lower their body temperature, just as we lower the
thermostat in our houses to save energy a night.
unit of heat raising 1 gram of water by 1 degree centigrade
The higher the fat content the better, since
calories – the units of energy in food – are concentrated in fats.
a hidden storage space
After most of the other birds have flown south to warmer climates, chickadees return to their
collect or look around for, as food
As the days shorten, the temperature drops, and since chickadees
forage only during daylight hours, they have the least amount of time to eat during the season when they need the most fuel.
a supply of something available for future use
They also seek out wintering insects between the cracks in the tree bark and feast at bird feeders
stocked with fatty treats like sunflower seeds, peanut butter, or mealworms.
reduction of the transmission of sound, heat, or electricity
Feathers are the perfect
insulation, trapping air between them and acting as a barrier between the cold outdoor weather and the birds’ bodies.
a small amount of solid food; a mouthful
They stash away bugs, seeds, or fat from dead animals, tucking these
morsels into crevices in tree bark.
dash violently or with great speed or impetuosity
Chickadees living near Fairbanks, in interior Alaska, experience -30° to -40°F on a regular basis, with temperatures sometimes
plunging to -60°F or colder.
gathered together or made less diffuse
The higher the fat content the better, since calories – the units of energy in food – are
concentrated in fats.
extremely and sharply
Although fragile in many ways, the tiny chickadee shows how tough it really is by surviving the
bitterly cold winters of northern North America.
But even such energy efficiency by itself is not enough to survive the
frigid winter days.
crowd or pack to capacity
As darkness falls, they
cram themselves into little hollows in the trees.
hold back or set aside, especially for future use
By lowering their body temperature, or “thermostat”, by nearly 20°F, their fat
reserves last longer, enabling them to withstand the cold until it’s light enough to forage again.
subnormal body temperature
For humans, becoming hypothermic (having lower body temperature) like this would be deadly, but chickadees use
hypothermia to their advantage.
rise in temperature
Then, when this blood returns to the main part of the body, it is
warmed up again as it passes the warm blood entering the legs.
a light growth that makes up the covering of a bird's body
Like all birds, chickadees have
feathers, so in a sense, they wear little down parkas all the time.
keep or lay aside for future use
Since they don’t have a way to
store food to eat later, they must eat enough each day to survive the long, 18-hour night.
a substance that can be consumed to produce energy
In the same way that we must burn more
fuel in the winter to keep our houses war, chickadees also need more
fuel to stay warm.
a ceremonial dinner party for many people
They also seek out wintering insects between the cracks in the tree bark and
feast at bird feeders stocked with fatty treats like sunflower seeds, peanut butter, or mealworms.
continue in existence after
But even such energy efficiency by itself is not enough to
survive the frigid winter days.