1. (formerly Cuculiformes)
Growth & development
Opisthocomiformes
(formerly Cuculiformes)
1 species
Hoatzin

3. Hoatzins are unusual in feeding mostly on leaves
Hoatzins are unusual in feeding mostly on leaves. Their crop is exceptionally large and both grinds the food and starts bacterial decomposition. Some regard the Hoatzin as the only ruminant bird. The bacterial fermentation is a rather odorous process and locally the birds are known as “stinking turkeys”.

4. Crocodillians & the ontogenetic spectrum
Precocial to altricial continium
(Nidifugous to nidicolus)

5. Precocial (10% of species)
Shorebirds, ducks, chickens
Self-feeding
Able to regulate Tb
Independent
The ancestral condition
Hatchling reptiles are precocial as are birds of the more primative bird orders including the ratites. Hence precocial hatchlings is reqarded as the ancestral condition.

6. Altricial (78% of species)
Embryonic, eyes closed, naked
Total dependence, derived condition

7. Video clip from Life of Birds of altricial pelican hatching.

8. Commit this table to memory

9. Drawing and photos of domestic chick embryos
Drawing and photos of domestic chick embryos. Altricials young appear to hatch earlier in the developmental sequence than precocial chicks and thus are more embryonic.
(top fig)
(bottom fig)

10. Gill’s classification of ontogenetic type
Species 10 12 78
Gill presents this simplified figure of developmental (ontogenetic) types. The original classification derived by Margret Nice was more complicated and somewhat arbitrary. Note that 78% of bird species produce altricial hatchlings.

11. Megapodes (mound builders) & Black-headed Duck Total independence
Superprecocial
Megapodes (mound builders) & Black-headed Duck
Total independence

12. Superprecocial Malleefowl
A just hatched Malleefowl chick. Chicks many never see their parents, can fly within a day and are totally independent. Hatchling Black-headed Ducks, which you may recall are obligate brood parasites, are also totally independent of the adults.
Malleefowl

13. Ducks, shorebirds, quail, grouse, murrelets
Precocial
Ducks, shorebirds, quail, grouse, murrelets

14. Precocial
% of
Species 10 12 78
Europeans use the terms nidifugous (=nest fleeing) and nidicolous (=nest loving) rather than altricial and precocial.
Leave nest immediately (nidifugous), find own food (although parents “show” food in some species), thermoregulate, albeit imperfectly in some

15. A precocial duckling.

16. Precocial
Rock Sandpiper Ruddy Turnstone

17. Precocial
Day-old Bobwhite Quail Blue Grouse chick

18. Loons, cranes, rails & grebes
Subprecocial
Loons, cranes, rails & grebes

19. Subprecocial % of Species 10 12 78
Leave nest immediately (nidifigous) and follow parents, are fed directly by parents

21. http://images. google. com/imgres. imgurl=http://www. birdsasart

22. Clapper Rail

23. Blue Crane

24.
Sandhill Crane

25. Gulls, terns, auks, petrels & penguins
Semiprecocial
Gulls, terns, auks, petrels & penguins

26. Semiprecocial % of Species 10 12 78
Able to walk but stay in nest (nidicolous), regulate Tb, fed by parents

27. Semiprecocial
Gull chicks

28. Semiprecocial
Wilson’s Storm Petrel

29. Emperor Penguin, semiprecocial.

30. SA 1 Herons & hawks SA 2 Owls
Semialtricial
SA 1 Herons & hawks
SA 2 Owls

31. Semialtricial % of Species 10 12 78
Gill says semialtricial young are able to walk, but he is incorrect.
Unable to walk*, stay in nest (nidicolous), fed by parents, brooded at first

32. Semialtricial 1 (eyes open)
Least Bittern

33. Semialtricial 2 (eyes closed)
Snowy Owl

34. Songbirds, pigeons, parrots & woodpeckers
Altricial
Songbirds, pigeons, parrots & woodpeckers

35. Embryonic, totally dependent on parents
Altricial
% of
Species 10 12 78
Embryonic, totally dependent on parents

36. Altricial
Swift

37. One-hour old Gouldian Chick

38. Gouldian chicks

39. All gut, no brain
The digestive system of altricial young is well-developed. Altricial chikcs are masters at converting food into tissue. They grow much faster than precocial chicks.

40. Welty 3rd

41. Diet-ontogentic link Altricials eat foods that require skill to obtain
Precocials feed on small inverts and seeds

42. Next section examines the items from the arrow on down in this table.

43. Brown Creeper Least Tern Ruddy Duck Malleefowl Kiwi
This slide illustrates the relation between the tissue maturity of hatchlings, as represented by % water. The proportion of nwater in hatchlings is the same as that in the egg. The more mature a hatchling is developmentally (altricial on top, precocial on bottom) the lower the water content and the higher the energy and yolk content of the egg. Takes more energy to build a more advanced chick.

44. This figure illustrates the sigmoidal pattern of growth exhibited by most birds. There is an inverse relation between adult body mass and growth rate. Small passerines attain adult size in days, it takes the wandering albatross 303 days.

45. Semiprecocial
Growth curves for three species that are roughly the same size. The altricial starling grows the fastest, the semiprecocial tern is a bit slower, and the precocial quail is a lot slower. There is a tradeoff between alrticial vs precocial modes of development. Figure it out. The variables include growth rate, energy allocated to the egg, and predation risk.

46. The Manx Shearwater is semiprecocial the other species are altricial
The Manx Shearwater is semiprecocial the other species are altricial. Nestling mass may equal adult mass (starling), exceed adult mass (shearwater & swift), or undershoot adult mass (woodpigeon). In procellarids (shearwater) the excess mass is fat. Adults abandon the young before development is complete and they use their fat stores to survive and finish development.

47. Same relation as previous figure
Same relation as previous figure. The relative mass of altricial nestlings at fledging (nest leaving) is related to diet, as illustrated in the next figure.

48. Species which capture insects on the wing produce chicks that exceed adult mass. Those that feed on the ground produce smaller chicks. Food hard to get = fat stores, food easy to get = no fat stores.

49. Altricials
The time it takes altricial nestlings to grow from 10% to 90% of adult mass (asymptote). Each dot or circle is the mean for a different species. Dots denote passerines, circles Falconiformes. This log-log plot produces a linear relation between growth rate and adult mass. An arithmetic plot yields a positive exponential.

50. Temperature regulation
Newly hatched chicks very widely in their ability to regulate their body temperature (Tb). A few, such as the Sea ducks, are able to maintain an adult Tb while swimming in water that is near freezing within a few hours of hatching. Most precocial and semiprecocial chicks regulate their Tb imperfectly and need parental brooding for a week or so after hatching.

51. *
These data are typical of early assessments of hatchling thermoregulatory ability. The Domestic Pigeon is altricial, the rest are precocial or semiprecocial. Notice that the ducks maintain their Tb very well whereas the pigeon’s Tb falls over 15 degrees in 20 min. Even the precocial Willow Ptarmigan shows a substantial 8 degree drop. * * *
Semiprecocial

52. Thermoregulatory Index
The % of adult Tb-Ta gradient maintained following 30-min exposure to 20ºC
Studies that have examined the ontogeny of thermoregulatory ability have often exposed chicks and adults to a low temp (often 20 C) for 30 min and expressed the chick’s ability as above.

53. Thermoregulatory Index
Body temp Gradient
Start End Tb-Ta
Adult 40ºC 40ºC 20ºC
Chick 40ºC 22ºC 2ºC
Chick’s 2ºC gradient is 10% of the adult’s gradient

54. Note that although the altricial starling is initially much poor at regulating its Tb it grows rapidly and soon overtakes the precocial quail.

55. House Martin House Sparrow
Circles = house martin, dots = house sparrow. These two passerine species exhibit the usual sigmoidal pattern in development of thermoregulatory ability with the House Martin maturing more rapidly than the sparrow.
House Sparrow

56. Growth & development Ontogenetic types Diet-ontogenetic link
Growth rate patterns
Tissue maturity of chicks
Egg contents