Chong yee ting

6s (3)

Class:Aves

•Homoiotherm

•vertebrates

•There are around 10,000 living species

•Most birds can fly, walk and run, many can swim and dive

•Size of the birds can vary from the tiny flowerpeckers & hummingbirds

•have a keen eyesight and good hearing but sense of taste and smell is poor

(diagram)

•Have feathers covering the body

•legs are covered with dry scales

•hollow bones

•have a beak for feeding

•forelimbs have been modified to become wings

•have lungs for breathing

types of wings:

•elliptical wings•high speed wings•high aspect ratio wings •soaring wings with slots.

Different shapes of wings correspond to beneficial characteristics:

•speed•low energy use

•Hollow bones reduce weight

•Bird’s flight muscles work continuously, pushing the air down to produce lift that balances the weight.

•large birds : have just enough power to fly near the minimum power speed OR flightless

•The actual available power dwindles as the size of the bird increases

Feathers have evolved to serve a variety of functions :

•flight •heat conservation•waterproofing•camouflage• display

three main types •filoplumes (sensory feathers) •contour feathers•down feathers (insulation).

Owls : •velvet-like projections •fly silently

Sand-Grouse: •feathers with highly curled barbs •hold water

Examples:

Feathers for different functions

•Sexual,internal fecundation

•on land

•lay eggs with chalky shells

•Males have two testes and females have one ovary

Male Female

•Pairing:|A sequence of behavioural activities

•Nest building:One of the pair or both birds construct a nest

Examples:

•do not have a diaphram

•push the sternum in and out

•75% of the fresh air into bones and fills them with air.

•25% of the air goes directly

Importance

•for flying need high metabolic rate

•birds evolved from theropod dinosaurs•around 150–200 million years ago

Evidence

•Bird-like respiratory systems in dinosaurs•hollow bones

•birds' beaks have evolved to suit the ecological niche they fill

•diet are varied (e.g fruit,seeds)

•On some birds, the tip of the beak is hard, dead tissue

•On other birds, (e.g ducks) The beak grows throughout the bird's life.

Gannets

Gannets hunt fish by diving from a height into the sea and pursuing their prey underwater.

adaptations which enable them to do this:•they have no external nostrils•they have air sacs in their face and chest under their skin•their eyes are positioned far enough forward on their face

•Chromosome(Z,W)

male:ZZ

female:WZ

•Sex determination

determined at fertilization determined at temperature

•Red blood cells have a nucleus.

1.http://en.wikipedia.org/wiki/Bird

2.http://www.birding.in/ornithology/bird_flight.htm

3. http://www.birding.in/bird_topography.htm

4. http://www.biology-questions-and-answers.com/birds.html

5. http://www.birding.in/birds.htm

6. http://www.thewildclassroom.com/biodiversity/birds.html

7. http://en.wikipedia.org/wiki/File:Bird_Diversity_2011.png

End

Sources