ADVANCED

1. ADVANCED LEC 05 University of Rio Grande Donald P. Althoff, Ph.D. ORNITHOLOGY Anatomy & Physiology Part II Reference Chapters 1 & 6

2. _________ Temperature of Birds • Birds and mammals regulate their body temperatures “just” below temperatures that destroy body proteins. Curved line represents the ________________________ BIRDS

3. Higher Body Temperatures • In frigid Arctic regions and hottest deserts, most birds have 40oC internal body temp. Most birds ________(~104-110oF) • High body temp enhances intrinsic reflexes processing powers—enable active-fast moving capabilities. • Higher temps—higher rate of physiological processes ex. transmission speed _____________ increase 1.8 times with every 10oC increase in temp ex. speed and strength of ______________________________triples with 10oC increase intemp

4. Respiratory SystemsNOTABLE CHARACTERISTICS • Lungs small and compact (compared to mammals) • Lungs are spongy structures “molded” along the ribs. • Dense tissues of avian lungs weigh as much as lungs of mammals of equal body weight but only occupy about have the volume • Healthy lungs are ___________ in color • Healthy lungs are _______________ • AVIAN LUNGS are unique in that air flows in only _____________ (vs. in and out for other vertebrates Gary Ritcheson EKU

5. Respiratory System…con’t • Most birds inhale air through nostrils / _______at the base of the bill • For __________, a flap—or __________—covers and protects the nostrils from water while diving. • For ________________, the operculum is present to keep pollen out. • Nasal chamber “folds” –________– (see Fig. 6-3 Gill) that increase the surface area for air to flow over: a) _______the air b) _______the air

6. trachea Gill Fig 6-2 ↑

7. Ventral view Doral view Interclavicle air sac cervical sac diverticulum of the interclavicular sac to the sternum, coracoid, clavicle, and humerus mesobranchi mesobranchi anterior thoracic air sac recurrent bronchi posterior thoracic air sac opening of mesobranchi into the air sacs abdomenal air sac dorsobronchi cervical sac parabronchi Diagram of the lungs and air sacs of the bird. Ventral view on left, dorsal view on the right. Inspiration part of system shown in “black”; expiration part of system shown in “stipple” pattern. Source: Pettengill (1985) Fig. 22, page 74.

8. Internal structure of bird lung • Interconnecting Bronchial Tubules— tertiary bronchi (parabronchi) secondary bronchi primary bronchi connections to air sac Gill Fig 6-4a

9. Closer look—lung tissue • Tertiary bronchi (i.e., parabronchi) and fine air capillaries constitute most of lung tissue-- About _____of these tertiary bronchi Gill Fig 6-4b

10. Cycle 1 ____-directionalmovement of a single Inhaled volume of air—shown in white 1 inspiration _______________respiratory cycles (inspiration, expiration, inspiration and expiration) are required to move the gas through its complete path. 2 expiration Cycle 2 3 inspiration 4 expiration Gill Fig 6-5

11. Cycle 1 UNI-directional …con’t This “design” ____________contact of fresh air with respiratory surfaces of the lungs. And…most importantly allows a bird to replace nearly _________ in its lungs with each breath This “design” makes for a ________________ of gas exchange than do mammals Cycle 2 Gill Fig 6-5

12. Respiratory System…AIR SACS • Although inconspicuous, the air-sac system is integral part of the avian respiratory system. • Number of air sacs varies from 6 in weavers, to 7 in loons and turkeys, to at least 12 in shorebirds and storks. Most birds _______. • The paired cervical sacs located in the neck are perhaps the most visible: they inflate as large red sacs on the necks of displaying frigatebirdand strutting sage grouse

13. Respiratory System…AIR SACS…con’t • ____________(only 1-2 cell layers thick) • Extend throughout body cavity AND into wing and leg bones • Connect directly to primary and secondary bronchi • Help continuous unidirectional flow of air through lungs…facilitating ____transport • Help remove potentially lethal _________ generated during flight • Air pressure from the single interclavicular sacs is essential for _________ production (more about that when vocalizations are covered).

14. Respiratory System…con’t • During flight: expansion and contractions of the ________ complement the movements of the sternum… this helps pump air through the respiratory system. • High speed video of common starlings shows: furcula bends ________ during wings’ downstroke and then ___________ on upstroke….the expansion is almost ______more than in resting width…and does so with each wing beat! • Rate of breathing varies by species—including by size of bird & by activity. Resting 2-g hummingbird -143 bpm; resting 10-kg turkey breathe – 7 bpm. Increase rate by ___________________!

15. Digestive SystemsNOTABLE CHARACTERISTICS • _____________ • Bill and mouth primary function is _____________ (vs. some “mastication”) • Bill/mouth for some capable of cracking and shucking seeds or tearing prey into bite-size pieces • Crop—for some—is temp food storage • __________: size and degree of presence varies by species…and that is associated largely with diet. A substitute for teeth. • GI-tract size and structure can vary seasonally • Have ______taste buds and _______saliva • _________ digestion begins in the ________________

16. Digestive SystemsNOTABLE CHARACTERISTICS… ____________ • Very muscular structure • Lined with lubricating __________glands • For large prey swallowed whole, it _________greatly (think pelicans!) • In pigeons, it produces what is know as “_________” for young • In pigeons and other species, it can be ________for display and sound resonance • The “crop” is a __________of the esophagus

17. Don’t forget the Hoatzin… modified CROP allows “ruminant-like” digestion Digestive System MAIN TRACT AUXILLARY • Liver • Pancreas • Oral cavity • Pharynx • Esophagus • Crop (*) • Proventriculus • Gizzard • Small intestine • Large intestine • Cecum • Cloaca

18. Earthworm small intestine anus mouth pharynx esophagus GIZZARD CROP

19. esophagus crop proventriculus liver gizzard duodenum small intestine pancreas large intestine cecum cloaca vent Pettingill Fig 34

20. esophagus crop proventriculus pylorus small crop gizzard Small Gizzard Large and muscular Fig. 17-22 p460, PJH

22. Hoatzin • Opisthocomus comes from the Greek meaning "wearing long hair behind" • Nicknames include: reptile-bird (because of their crocodilian odor & harsh monotonous call) flying cow (because of it's clumsiness in the air and unusual diet) • Has a diet of leaves…which means it has to have a way to breakdown cellulose  “______________” stomach

23. Hoatzin (Opisthocomushoazin)

24. Hoatzin…con’t • Skeleton modified to accommodate large crop – fermentation vat housing bacteria that help it breakdown cellulose to obtain “the good stuff” (proteins/sugars) in the plant material (not unlike what ungulates do) • ______bird species that has the “foregut fermentation” approach to handling plant material containing cellulose • Rests on a sternal callous while lengthy digestion takes place. The callosity is an elliptical, horny patch of skin lying over the rear tip of the sternum • Feeds chicks ________________mush of leaves

25. Digestive System –con’t • Length of bird’s intestinal tract averages 8.3 times its body length. In the common swift, it is only 3x. For the common ostrich it is 20x. A) diet—fruit, meat, and insects: __________ B) diet—seeds, plants, & fish: _________ • Near end of digestive tract: small side sacs called _____ (________is singular). Attach to large intestine. A) aid digestion—especially fibrous plant foods B) produces antibodies C) aid absorption of H2O D) aid in metabolism of uric acid into amino acids

26. Digestive System –con’t • Overall, digestive system extracts nutrients and energy with high efficiency a) fruits and berries “pass through” in ______ b) other foods (non-fibrous) < _______ • Like mammals, some nutrients absorbed by active transport. Most birds absorb glucose (i.e., simple sugars) and amino acids by active transport. Other nutrients passively with other fluids. “______________” requires little energy…and concentration dependent. • Toxins in fruits and seeds also may be absorbed indiscriminately

27. Digestive System –con’t • Parrots eat seeds and bitter green fruits—many full of toxins that are distasteful and lethal to other animals • Some parrots eat dirt…long thought to simply provide grit for the gizzard. ____________ in ‘dirt’ has minerals that are _______to toxins. Kaopectate, which consists partly of clay, soothes human upset stomachs in this way. - charged sites of clay minerals “bonds” to + charged toxin molecules • Some variable stomach designs among seed-eaters. Notably the phainopela—in the gizzard, the exocarps from mistletoe berries “off” to the side, then pass in “packet” until excreted (see next slide)

28. phainopelpa Black-sided flowerpecker Violaeous euphonia Primitive flowerpecker Gill Fig 6-21

29. Digestive System –assimilation efficiencies • Raptors: 66-88% energy of ingested meat and fish • Herbivores: 60-70% energy in young plants • Herbivores: 30-40% energy in mature foliage • Spruce grouse: 30% in spruce leaves…a very hard-to- digest foliage • Fruits provide “predigested” nutrients in the form of free amino acids (vs. proteins) and in the form of simple sugars (vs. complex carbs). Such easily digest and absorption allow the 20 minutes or less pass through time

30. Digestive System –Fruits & Fruit-eating birds • ______________________________ favored by cedar waxwings. Because of “abundant” glucose and fast passage through the GI tract, lots of glucose is in the semi-digested fruit pulp just before evacuation. Cedar waxwings may be unique in that they absorb this “extra” glucose via active transport in its rectum. --also, this “junkfood” diet preference requires protein-rich cottonwood catkins to supplement their diet • _______________________________ favored by North American thrushes

31. Digestive System –Sucrose…no Sucrose • Many passerines ______________________—a complex sugar because they lack sucrose, the enzyme facilitating breakdown of sucrose to glucose and fructose. Ingestion of high concentrations by such species can cause sickness and diarrhea—resulting in ____________…thus they avoid it. Ex. Common starling • In contrast, hummingbirds feed on sucrose-rich nectar. They assimilate ________of the energy in nectar. Do this rapidly by means of unusually high densities of sites that actively bind sugar and transport it across cell membranes.

32. Changes in Starling GI tract • Response to___________ availability of certain food types • Higher plant content in diet (need more time to digest to extract nutrients) results in longer intestinal tract (~ _____increase in length) • Besides anatomical changes, digestive enzyme composition changes, too, to different food types they consume: a) simple sugars in fruit vs. b) fat and protein in animal-based food

33. Starling (Sternus vulgaris) Plant material in diet length of intestine Fig. 17-23 p461, PJH

34. Feeding & Digestion • Many specializations—especially with respect to beak & tongue designs • Beak designs include: insect catchers insect net fruit plucker generalized bill flesh tearer dip net fish grasper fish spear mud sifter water strainer seed cracker pine seed extractor

35. Fig. 17-19 p457, PJH • For _______species, ability to raise the tip of the bill without opening the mouth provides opportunity to exploit food sources in the sand (some shorebirds) and/or soil (woodcock) • Woodcock shown here has beak that is 3+ inches long—probes for earthworms American woodcock

36. Woodpecker—probing tongue Mammal-version Anteater---probing tongue with different origin for tongue attachment (on sternum) but same result Fig. 17-20 p458, PJH

37. food-straining (NORTHERN SHOVELER DUCK) fish-eater (sooty shearwater) Fringed, tubular nectar feeder fruit-eater (Diard’s trogon) (bananaquit) general feeder (robin) probing-spearing (woodpecker)

38. NECTAR FEEDERS magnificent hummingbird green violet-ear hummingbird • Note the _____of the bill • Note the __________of the bill fiery-throated hummingbird volcano hummingbird

39. Circulatory SystemNOTABLE CHARACTERISTICS • Proportionately large • 4-chambered—left and right separation • Overall design: similar to mammals (i.e., humans)

40. Circulatory System Pulmonary circulation • Most efficient design of all among vertebrates (along with mammals) Systemic circulation

41. Circulatory System…output • Heart, liver, kidneys and intestines: 8-10% • Brain and eyes: 3-4% • During flight or swimming, cardiac output allocations to flight and leg muscles, respectively, _________ dramatically • Also: _________empty more completely than do those of mammals on each contraction. More ___________ in ventricles than comparable size mammals

42. Pettingill Fig 35

43. Urogential SystemNOTABLE CHARACTERISTICS • Because of “exit” anatomy, the urinary system and the reproductive system considered together—hence the “urogenital” designation • “Exit” point is the _______ a) meeting point for urinary system, digestive system, and reproductive system b) Latin for “sewer” c) same in reptiles, amphibians • _______functional ovary

44. MALE FEMALE adrenal gland ovary testis kidney oviduct vas defrens ureter large intestine cloaca vent Pettingill Fig 36

45. Excretory System • Excretion of water and _______________ takes place in the kidneys and the intestines—and in some species by the action of salt-secreting glands. • Relative to most mammal kidneys, bird kidneys are relatively flat • Different from both mammals and reptiles: A) Urine produced by kidneys mixes with fecal components in the _____________ B) Also, at this point in lower intestine H20 can be resorbed…as needed

46. Excretory System…con’t • Key physiological adaptation: promotion of water economy is the excretion of nitrogenous wastes in the form of __________ • Uric acid are the white crystals that give bird droppings their unusual color. • Nitrogenous waste a result of body structures that produces nitrogenous products that become toxic if allowed to accumulate. For mammals, they handle this by producing urea in aqueous solution that requires large quantities of water. Uric acid can be excreted as a __________________ in which each molecule of uric acid can contain _______as much nitrogen as a molecule of urea

47. Excretory System… Uric Acid…con’t • This process of excretion results in huge efficiencies with respect to ____________: A) 0.5 to 1.0 ml of water to excrete 370 ml of nitrogen as uric acid vs. B) 20 ml of water to excrete same amount of nitrogen as urea • Concentrations of uric acid in the ______—just before defecation—can be as much as _______the acid level in the blood stream! In the mammal world, even the best at this—kangaroo rats—have concentrated urea in urine to “only” 20-30 times.

48. Excretory System… Hummingbirds • Too much ______“problem” • Result of ______composition—lots of water • Anna’s hummingbird documented to, on a daily basis, consume up to _____its body mass in nectar • The rate of water moving through and excreted is among highest known to freshwater amphibians • Kidneys are not different from other birds, just these species have highest rates of evaporative water among birds AND some of the water is keep in the digestive tract and therefore does not pass through the kidneys

49. Excretory System… Salt and Oceanic Birds • Loops of Henle in avian kidney (i.e., nephrons) are short compared to mammals. This poses challenge to birds that drink saltwater. • Saltwater is about 3% salt. Body fluids are about 1% • This high concentration increases need to excrete electrolytes. This salt excretion is aided by presence of ______________ (Gill Fig. 6-27, pg 178). A) just above eyes B) rapid unloading bloodsystem system C) special “infoldings” of cellular lining of the nares. Linings contain secretory tubules… that get salt from ________________ of the _________________ D) tubules connect to central canal and drip out