Characteristics of Birds Reference Chapters 1-2 ADVANCED LEC 02 ORNITHOLOGY University of Rio Grande Donald P. Althoff, Ph.D.

Characteristics of Birds Result in… Efficient mode of _________________ Further ______________ (i.e., higher levels of process some sensory input) Promote _____________ Increased ______________ efficiency Improved senses of _______ and ________

Accomplished by being able to…. __________ ________________ under adverse conditions Graham Owen Gallery FLIGHT

Flight: KEY STRUCTURES ________ Feathers Feathers ___________ ….and some _____________

Perfection of ENDOTHERMY Allows activity under _______ environmental conditions Specialization of __________ anatomy (i.e., wings & feet have enabled efficient use of this bigger activity window)

Birds arose from _________ STOCK Similarities to reptiles include…. ____ occipital condyle (mammals have 2) Lower mandible articulates with movable _________ bone (mammal’s lower mandible hinged directly to skull—at least for many species) Ears have _______ bone

Single “ear bone” (common to birds, amphibians, reptiles, and

Key MORPHOLOGICAL trends towards… Overall, a ______ skeletal structure --transformed wrist and shoulder --”some” hollow bones (as noted) --evolution of the bastard wing—or ______, which prevent _________ at low speeds Muscular design that provided a __________ that could produce the main components of flight: _____________

Gill Fig. 5.5 (p121): The slot created by the extended alula keeps the airflow close to the wing during takeoff and landing. A) Steep angle of attack w/o ALULA B) Steep angle of attack with ALULA

alula

Key characteristics….that were improvements over reptilian stock… Feathers Wings Lightness _____________________ _______________–must make “quick” adjustments in focus because one is often moving faster _______________ _________________________

Feathers _____________ air-resistance Control heat loss (hot conditions) /retention (cool conditions (i.e., ______________) ____________________ Wings—conquer air space * read Gill p40: what is difference between _________ theory vs. _________ theory for development of forelimbs into wings?

Lightness Feathers: “the” __________ materials for their size and weight known ! ! ! No _________ nor _____________ No ________ ( ….forget about the egg tooth! ) _______________________ bones

Lightness…con’t Radical _________ of intestines __________ of urinary bladder ________(sacs) in bones, body cavity, and elsewhere

Centralization & Balance All locomotor muscles toward body’s _____________…wings controlled by _________ strings Gizzard (in lieu of teeth) and other abdominal organs in _______________

Visual Acuity ______ eyes _______ field of vision Remarkable ________ determination Brain with enlarged ______ and __________ centers

Respiratory System ____________ of fresh air over lung surfaces Lungs _________________with each breath (unlike mammals) ________…ensuring lots of incoming O 2 and outgoing CO 2 No diaphragm—meaning less weight, too

Rapid Circulation & O 2 Carrying Capacity Increased heart rate Blood stream O 2 carrying capacity greatly increased red corpuscles (____________) are _________________ (unlike mammals)- -more ___________ blood per cubic millimeter

Limited Body Fluids & Excess Weight With rapid exchange of air via respiratory system, ____________ needed for cooling Highly sensitive diet with _________________ & ____________________ substances...except for the hoatzin, there are no true ruminating birds. Few species are consistent “grazers” (i.e, year-round)

Feathers…again _________ to birds—no other vertebrates have structure similar to a feather Different _____ of feathers for _______________

Feathers: Functions…again…plus… Efficient flight Thermoregulation _______________ _____________ (some species) ____________/mating displays and attraction

Feathers con’t Feathers are “_______” __________ growths of skin Develop from ___________ (like mammal hair) _____________ coloration vs. _____________ coloration From Pettingill 1985 Fig. 20

Feathers con’t Feathered areas: ________ Unfeathered areas: ________ Counts: __ types __ tracts Number: ____ hummingbird ______ tundra swan

Other Coverings _______ on bill _______ on feet (reptile-like) _______ on toes ALL of these have ______ in skin (aka integument)

Reproduction ____________…link to reptiles _________________ care… advanced over reptiles High potential for ___________ a) _______ clutches b) _______ clutches c) ___________ capabilities