'Rain' of dead birds on central NJ lawns explained; Federal culling program killed up to 5,000 Associated Press, January 27, 2009 Study May Give Hope That Ivory-billed Woodpeckers Still Around Science Daily (Jan. 19, 2009) A new study conducted by University of Georgia researchers reveals that the ivory-billed woodpecker could have persisted if as few as five mated pairs survived the extensive habitat loss during the early 1900 s.
Lecture 3 Avian Adaptations Chapters 4-6 (Feathers will be covered in lab)
Why are birds birds?
Common Loon
Wandering Albatross
Great Blue Heron
Northern Goshawk
Blackburnian Warbler
MN Volunteer 2006
Birds are Adapted for: 1. Weight reduction while retaining skeletal strength 2. Power 3. Balance Flying Machines!
Weight Reduction 1. light skeleton relative to body weight Pneumatic (hollow) bones Reinforced with internal struts
Weight Reduction 2. truss-like structure - pectoral girdle - a tripod of bones (scapula, coracoid, and furcula)
Pectoral Girdle Keel Note: Responsible for terms in red
Weight Reduction 4. Reduction and fusion of finger and wrist bones - Most wrist bones fused into carpometacarpus, only 2 free bones - Fingers reduced/fused to 3 (metacarpus) - digits 1+2 are fused (pollux) supports the alula Figure 2-9
Wing and Alula
Weight Reduction 5. reduction of tail to a pygostyle
Weight Reduction 6. flattening of sternum - sternal keel for flight muscle attachment Keel
7. Feathers Weight Reduction 8. no teeth gizzard 9. no urinary bladder nor urethra 10.one ovary and one oviduct - active for a very short period (e.g., in Starling 1400 x normal during breeding season) 11.reduced skull size - one/sixth that of equivalent rat
Birds are Adapted for: 1. Weight reduction while retaining skeletal strength 2. Power 3. Balance
Power Adaptations 1. high body temperature - highest among the vertebrates - 42 C (107 F) in sparrows, 43.5 (110 F) in thrushes (dogs 38.3 [101F], humans 37 [98.6F]) 2. fast digestion - e.g., fruit passes through Cedar Waxwing in 16 min
Drunk birds give airport trouble Clayton News Daily, Jonesboro, GA, 7/2006 There were these little birds that kept flying around and acting crazy. They were flying all over the entrance road and disturbing people as they drove into the airport, says Ken Martin, the environmental compliance manager at Hartsfield-Jackson Atlanta International Airport.
Power Adaptations 3. flight muscles - 2/5 of body weight in strong fliers 4. large 4-chambered heart (40% larger than mammals of similar size) 5. blood - high sugar concentration; twice that in mammals 6. high blood pressure, 120 mm systolic in man, but 135 in pigeon, 162 mm in duck, and 180 mm in chicken
Power Adaptations 7. lungs and air sacs (many have them occupy hollow interior of bones) - better O 2 utilization, greater cooling capacity 8. lungs of man about 5 % of body volume but in birds 20 % (2 % lungs and 18 % air sacs) 9. Broadened and shortened humerus 10. Broadened ulna 11. High Metabolism
High Metabolism
High Metabolism Flight muscles Adapted for high aerobic respiration Enables sustained flight Aerobic capacity of songbirds (Order Passeriformes) highest among vertebrates
Birds are Adapted for: 1. Weight reduction while retaining skeletal strength 2. Power 3. Balance
Balance Adaptations 1. center of gravity through reduced skull size and bulk just below the wings 2. fusion and elongation of pelvic girdle to support upper weight, but also for walking
Note how far back pelvic girdle is placed
Balance Adaptations 3. liver is on right to match single ovary on left 4. wide separation of legs to aid in egg-laying 5. general streamlining
Skeletal System 1. Function a. Support b. Protection - e.g., of internal organs c. Articulation - e.g., of muscles d. Manufacture of blood corpuscles e. Calcium storage
Skeletal System 2. Modifications a. Pectoral girdle scapula - thin, blade-like, long in strong fliers coracoid - stout bone furcula - 2 clavicles (or wishbone) Sternum (keel)
Skeletal System 2. Modifications b. Pelvic girdle Synsacrum Fusion of vertebrae and pelvic bones long and narrow in walking birds short and wide in flying birds Framework for support of the body by the legs
Pelvic Girdle Note: Responsible for terms in red
Skeletal System 2. Modifications c. Fused bones - especially in the hand and vertebrae Note: Responsible for terms in red
Skeletal System 2. Modifications d. Sclerotic ring
Transverse Section Thru Eye
2. Modifications Skeletal System e. Single condyle - provides greater neck flexibility; some hand functions performed by the bill
Skeletal System 2. Modifications f. Hyoid apparatus -allows great extension of the tongue in hummingbirds and woodpeckers e.g., up to 4x length of bill
Hyoid Apparatus
Hyoid Apparatus
Red-bellied Woodpecker
Skeletal System 2. Modifications g. Vertebrae and ribs Vertebrae vary from 39 to 63 most vertebrae are fused ribs (double articulation) uncinate processes increased support and strength both for flying and diving (e.g., loons the process extends across two adjoining ribs) - bones are "thin, flat"
Skeletal System 2. Modifications h. Legs Femur is short and flat Fibula - very small, splinter bone Tibiotarsus tibia and proximal fused tarsal bones, the drumstick Tarsometatarsus fused tarsals and metatarsals, (sometimes referred to as tarsus )
Leg Modifications Ankle joint is intertarsal (bends forward) Birds walk on their toes
2. Modifications i. Toes Skeletal System Generally 4 toes First is usually directed backward (hallux)
Birds: Flying Machines with adaptations for every lifestyle