Biology Reference
In-Depth Information
insectivores.
Birds that feed primarily on insects.
isotherm.
The “line” visible on a weather map where temperatures average a particular
temperature.
kettle.
A swirling mass of hawks numbering anywhere from several to many thousands.
lacrimal gland.
A tear gland at the base of the nictitating membrane that maximizes lub-
rication during blinking.
lek.
An area where males gather to display and attract mates.
migrational orientation.
Taking a direction and keeping it during a leg of migration.
mimids.
Birds in the mockingbird family, including thrashers and catbirds.
neotropical migrants.
Birds that spend winter in the Caribbean or Central or South
America and breed in temperate North America.
nictitating membrane.
A semitransparent inner eyelid that helps protect bird eyes and
keep them moist.
nocturnal migrants.
Birds that migrate at night.
owl pellets.
Thebones,fur,teeth,andotherindigestiblematterthatanowlregurgitatesin
a dense, compact mass.
perching reflex.
A mechanism whereby the stretched tendons of the lower leg automat-
ically flex the foot around the branch and lock it in place while a bird is perching.
proventriculus.
A glandular chamber of the stomach where powerful acids start dissolv-
ing the food.
rictal bristles.
Specialized feathers found near the beaks of some insect-eating birds that
provide tactile sensitivity and may sometimes help funnel insects into the bird's mouth.
shadowboxing.
A nontechnical term for when a bird fights with its own reflection in a
window or mirror.
socially monogamous.
Birds that defend a territory and raise young as a pair, but may
sometimes mate with other individuals.
specialists.
Bird species that have restricted habitat, nesting, or food needs.
syrinx (also song box).
The structure used by birds to produce sound, located where the
trachea branches into the bronchial tubes. The separate branches and sets of muscles al-
low many species to produce harmony with their own voice.
tubenose.
A name for some ocean birds, such as albatrosses, that have huge glands that
excrete salt at the end of “tubes” on their upper bills.
unihemispheric slow-wave sleep.
A state in which one side of the brain may be asleep
while the other half is awake.
