Chapter 1 Flashcards
The Diversity of Birds
Characteristics of birds
- vertibrates
- bipedal
- 4 chambered hearts
- unidirectional lungs
- endothermic (102F-109F)
- calcium carbonate eggshells
- syrinx (extensive sound capabilities)
- see some ultraviolet
- can hear above and below our range
Kingdom of birds
Anamalia
Phylum of birds
Chordata
Class of birds
Aves
How many orders?
40 orders
How many genera?
> 2,000 genera
How many families?
247 families
How many species?
> 10,500 species (range 10k-11k)
Estimate of how many individuals?
300 billion individuals
Describe feathers
filamentous, soft, flexible, lightweight
Use of feathers
- flight
- insulation
- repelling water
- camouflage
- attraction of mates
- social communication
Describe beak/bill
Horny sheaths that cover jaws
What is the upper beak on birds called?
Maxilla
What is the lower beak on birds called?
Mandible
What is the horny sheath that is the bill called?
Rhamphotheca
What are the maxilla and mandible reinforced with?
Struts called trabeculae
What is the gizzard?
- hollow organ in digestive tract that helps to digest unchewed food.
- Muscular organ with a hardeded inner surface with ridges or tooth-ike projections to grind up food.
How are birds adapted for flight?
- hollow bones (w/ trabeculae) and light
- fusion of bones in hands (carpometacarpus), legs (tibiotarsus, tarsometatarsus), tail (pygostyle), pelvis, and head
- furcula (fuzed clavicles) acts as a spring to help power flight
- keeled sternum
- uncinate processes on ribs
What is the furcula?
The “wishbone”, the two clavicles fused together
What is the pygostyle?
The last few vertibae fused together to support muscels and tail feathers for flight control and stability
Function of keeled sternum
To support the massive pectoral muscles needed for flight
What are uncinate processes?
Projections from ribs to connect to one another to allow more rigidness that other ribs (ribs cannot compress as much).
Birds do not have muscles past their heel, so how do they perch/ grasp something?
The muscles that cause the feet to grasp are found above the ankle/heel, with tendons that extend to the feet. When the muscles contract, it pulls on the tendons. When a bird pulls legs up, their feet automatically close.
What is the hallux?
The first toe. In most birds, the hallux extends backwards to form an arragement called anisodactyl.
Describe anisodactyl feet.
Three toes facing forward and one (the hallux or first toe) pointing backwards.
What causes variation in birds?
Variation in traits has arisen through the process of adaptation via natural selection.
What is natural selection?
Natural selection refers to the differential survival of individuals with adventageous, heritable traints.
What happened to the galapagos finches from 1976 to 1978?
During a bad drought, the food available for the galapagos finches changed. There were fewer small seeds and more large seeds. This caused bills that were larger to become favored, and therefore more common.
What is adaptive radiation?
A process by which organsisms diversify from an ancestral species into a variety of new forms, particularly when a change in the environment makes new resources abailable or opens new environmental niches.
How are Hawaiin Honeycreepers examples of adaptive radiation?
One origional bird came to Hawaii, and the organisms diversified and created many species of birds whoes bills changed and diversified based on the food source or niche they filled. (ie netar or seeds)
