Bio 123: PP19 Material Flashcards
What is the class that birds fall under?
The Aves
Avian Diversity
-11,000 species
- worldwide distribution
-one of the most beloved groups of vertebrate animals
- Very diverse in form and function, but they have underlying uniformities
- First birds appeared during the Jurassic age
What is a common characteristic that all birds share?
They all have feathers
Earliest evolution of Birds
Birds evolved from the transitional species called Archaeopteryx. This species had both reptilian and bird characteristics.
What were some characteristics of the Archaeopteryx?
-Toothed beak
- Wing claw
- Airfoil wing with contour feathers
- Long tail with many vertebrae
What is the science of birds?
Ornithology
When did bones first appear?
With boney fish
What is the breakdown of bird anatomy?
They have a body spindle-shape with 4 divisions; the head, neck, trunk, and tail
Forelimbs of birds
They are modified as wings
Characteristic of flying birds
They have a fully ossified skeleton with air cavities. These cavities allow the birds to be less dense which is important for birds that are capable of flying.
Mouth of birds
They do not have teeth, they only have a beak
Brain of birds
They have a large cerebellum with advanced optic lobes. This is important because it gives the birds balance and stability
Heart of birds
They have a four chambered heart and it is fully divided between the left and right sides. Birds are the first animals on the planet to have a true 4 chamber heart.
Respiration of birds
Birds have two cycles of respiration with air constantly moving over its lungs
Thermoregulation of birds
Birds are endothermic
Waste of birds
They do not have a bladder, they have uric acid main waste which is combination of its poop and liquid waste.
Type of fertilization of birds
They have internal fertilization and are oviparous
Baby bird characterisitcs
Are either precocial or altricial
Most diverse order of bird
The Passeriformes (known as the song birds) are the most diverse order of birds. Which includes 6,500 species. These birds have a syrinx which allows them to use their vocals to create songs.
Septum
Separates Deoxygenated blood and oxygenated blood
Endothermic
Mammals and birds maintain a constant internal temperature.
Altricial
Young that are helpless at birth and completely rely on parental care for survivorship.
Precocial
Young that are ready to withstand their environment as soon as they are born.
Syrinx
Is a specialized characteristics for the production of song.
What are the two hypotheses for the origin of flight?
-From the Trees Down Hypotheses
-From the Ground up Hypotheses
Explain from the Trees Down Hypotheses
Ancestors of birds were arboreal and their feather allowed them to glide/jump from tree to tree and over time these short glides became longer until they were able to fully fly over longer distances.
Explain from the Ground Up Hypotheses
Birds lived and ran on the ground and their feathers allowed them to have short spurts of galloping and moments of airlifting off the ground. Over time, as speed increased and birds had better developed feathers, birds were able to use their speed to take off and begin to fly.
Arboreal
Living in trees
What are some adaptations for Powered Flight?
-Having wings and feathers for lift and propulsion
-Wing length and taper wings reduce drag
-Birds must overcome drag and gravity to be able to fly
-Reduction in mass; shown through having no urinary bladder, only have one ovary, and having small gonads
-Having powered muscles
-Having large hearts
-Two cycles of respiration (complex lungs)
-Having big brains
-Having a stiff/fused vertebral column
-Having pneumatized bones
Taper wings
Wings that are angled and slighted bended down at the tip. Best way to overcome drag and gravity.
Drag
Is friction that is created as you move through the air.
What are the skeletal adaptations for flight?
Having pneumatized bones and a keeled sternum
Pneumatized bones
Bones that have air pockets throughout
Keeled sternum
allows for additional surface area for flight muscles to grow
What is the tradeoff for having pneumatized bones?
Because the bones are birds are filled with air pockets, birds can easily break their bones
Contour Feathers
They are flight feathers and are asymmetrical
Aftershaft
Some feathers have aftershafts which attach at the base of contour feathers. Aftershaft feathers are used for insulation
Filoplumes
Have a tactile/sensory functions and are found near the face.
Down Feathers
Are used for insulation and for waterproofing the body of the bird.
Avian Respiration
Birds have a 4 chambered heart and they are endothermic animals.
-They have air sacs in their lungs that allows birds to have 2 cycles of inhalation and exhalation to move oxygen throughout their system.
- Birds have constant flow of air through their lungs, which is highly efficient for their active lifestyle.
Explain the double respiration cycle of birds
Cycle 1: During inspiration, air is moved towards the posterior air sac and then the air flows OVER the lungs.
Cycle 2: Air moved from over the lungs and towards the anterior air sacs is then going through expiration. As this is happening, air is also filling the posterior air sacs (cycle 1).
Why do birds have double respiration cycles?
It is to double the oxygen efficiency in their body since they have very high metabolic rates.
What is the bird species we need to know for the exam?
Passeriformes
Passeriformes
Have a specialized structure for the complex creation of sound known as the syrinx.
Vision of birds
They have excellent vision, some species have huge eyes relative to their body size (hawks, owls, eagles)
Why do birds need acute, sharp vision?
Having good eye sight is essential for safe flight.
Hearing of birds
They have hearing similar to humans even though birds have small ‘ears’. They have a modification in their ear bones to allow for this hearing to occur.
Hearing of Owls
Owls have specialized hearing that allows them to locate prey in the dark. They are also able to locate prey in horizontal and vertical planes.
Cognition development of birds
Birds are known to be really smart and have advances in the development of their cerebral cortex. Some birds are believed to be able to talk and understand human language as well as be able to solve puzzles. Some of these species are the Psittacine and Corvid Birds
Cerebrum
Responsible for conscious thought and actions
Psittacine birds
e.g Parrots
Arctic Terns
The most extreme migration on the planet. Where birds spend the summer in the Artic and then migrate to Antartica.
Migration of birds
-Some species move halfway across the world
- Birds need be able to navigate well and have endurance to be able to migrate
- 40% of birds migrate seasonally (5 billion birds per year)
-Banding studies has shown origins, pathways, and destinations of bird migration.
Navigation
How birds know where to go and why
Migration
Leaving one area and coming back to that same area at some point
Why do birds migrate?
The cold is intolerable to birds since they are endothermic animals. They also migrate to help reduce competition if there go towards an area that has more resources based on seasons.
-Food resources decrease in the winter
-Avoid winter climates and winter storms
-Reduce competition
Navigation Mechanisms of Birds
-They use UV light and Polarized light to help navigate certain landmarks to help them move from point A to point B
- They use the sun as a compass
- Odors (when they begin to get close to where they are going, they can detect familiar smells)
- Magnetism (can utilize the earth’s magnetic fields for navigation
-Use the stars as compasses
Philopatry
Love of home
Conservation concerns having to do with Bird Migration
- Landscape changes and human development is in essence leaving birds stranded from location they would previously migrate towards.
-As these stop over areas decrease it is increasing the mortality rates of birds
