1. 4

2. Initiating Reproduction: Photoperiod
Gonads enlarge when artificial day > 10 hrs

3. Initiating Reproduction: Air Temperature
Cold snap early in breeding
season delays nesting
Emperor Pengun
Egg laid when
temp -30o F
Sperm production reduced at lower temperatures

4. Initiating Reproduction: Rainfall
Nesting occurs days after heavy spring rain
Heavy rains in July often initiate second nesting

5. Initiating Reproduction: Food
Nesting initiated any time of year. Corresponds to Cone Irruption

6. Male Reproductive Condition

7. Control of Testes Development: Hypothalamus, Pituitary Gland
Fig in Podulka et al. 2004

8. Control of Testes Development: Hypothalamus, Pituitary Gland
Hypothalamus Secretes Gonadotropin-
Releasing Hormone into Anterior
Pituitary (GnRH)
Anterior Pituitary Secretes Follicle-
Stimulating Hormone (FSH)
and Luteinizing Hormone (LH)
into Circulatory System
Fig in Podulka et al. 2004

9. Stimulation of Testes Development
Follicle-Stimulating Hormone Stimulate Testes / Sperm Development
Luteinizing Hormone Stimulates Testosterone Production

10. Wingfield and Hahn (1994).

11. TESTOSTERONE: Negative Feedback

12. http://www. wtamu. edu/~rmatlack/pigeon_dissection/male_reproductive

13. Spermatogenesis

14. Bird Sperm
Fig in Podulka et al. 2004

15. Detecting Male Reproductive Condition:
Cloacal Protuberance (Passerines)
Cloacal Region becomes Swollen during the Reproductive Season
Fig in Podulka et al. 2004

16. Male Reproductive Anatomy
Deferent Duct
(Vas Deferens)
Seminal Vesicle
Papilla

17. Ostrich Goose Lake Duck Cloacal Phallus = “Penis”
(Waterfowl, Ratites, Red-Billed Buffalo Weaver)
Ostrich
Goose
Lake Duck

18. Cloacal Phallus = “Penis”
(Waterfowl, Ratites)
Fig in Gill et al. 2007

19. Relationship to Mammalian Penis
Bird “Penis”:
Relationship to Mammalian Penis 9
Fig in Podulka et al. 2004

20. Cloacal Phallus = “Penis” (Red-Billed Buffalo Weaver)
Prolonged Rubbing (10-20 Minutes) Stimulates Female
(Enhanced Sperm Transfer?)

21. Female: Ovary, Oviduct

22. Control of Ovary Development: Hypothalamus, Pituitary Gland
Hypothalamus Secretes Gonadotropin-
Releasing Hormone into Anterior
Pituitary (GnRH)
Anterior Pituitary Secretes Follicle-
Stimulating Hormone (FSH)
and Luteinizing Hormone (LH)
into Circulatory System
Fig in Podulka et al. 2004

23. Stimulation of Ovary Development
(Usually, Left Ovary Only; Some Raptors: Both)
Follicle-Stimulating Hormone Stimulates Ovary Development and Follicle/Egg Production
Luteinizing Hormone Stimulates Ovulation and Progesterone Production

24. Ovary Oviduct Cloaca Female Reproductive Anatomy
Fig in Podulka et al. 2004

25. Ovum (Gamete) Maturation (Oogenesis)
(Meiosis Partially Completed at Birth)

26. Follicles (Contain Immature Eggs) in Ovary

27. Follicle Maturation and Ovulation
Infundibulum Raises Up, Swallows Egg
Fig in Podulka et al. 2004

28. Copulation 5 3
(“Cloacal Kiss”, Insemination)

29. Copulation: Acrobatics
(Swift)
(Flamingo)
Aerial Copulation
Head in the Water

30. Copulation: Endurance
500 Copulations
per Clutch
25 Minute Continuous
Copulation
(Goshawk)
(Aquatic Warbler)

31. Copulation
(Papillae Contact Openings of Oviduct)

32. Oviduct Opening to Infundibulum
“The Long and Winding Road”
Oviduct Opening to Infundibulum
(Top Speed: < 30 Minutes)

33. Fertilization

34. Sperm Production
Rooster: 7-8 Billion Sperm / Ejaculation

35. Fertilization: Sperm-Storage Tubules
Fig in Gill 2007
Fig in Gill 2007

36. (Frequently, Shared Parental Care)
Avian Breeding Systems
Monogamy
(Frequently, Shared Parental Care)
“Well over 9/10’s of all passerine subfamilies are normally
monogamous. ..Polyandry [multiple mates] is unknown”
David Lack, 1968

37. Pair-Bond EXTRA-PAIR COPULATION (Outside the Pair Bond)
Only 14% of Socially Monogamous Bird Species Studied to Date are
Genetically Monogamous

38. Fertilization: Sperm Competition Strategies
Frequent Copulations
Large Testes
High Quantity
Mate Guarding
Long Sperm

39. Fertilization: Sperm Competition Strategies
Dunnock
Male Pecks at Female Cloaca until Competitors Sperm Ejected
Fig in Gill 2007

40. Frequency of Extra-Pair Bonds (130 Bird Species)
More than 50% of Tree Swallow Nestlings
can be Sired by Extra-Pair Copulations
Fig in Gill 2007

41. EXTRA-PAIR COPULATION:
(Why?)
Females increase fitness by improving quality of offspring
Blue Tits Engage in Extra-Pair Copulations with
Distant, Genetically Different Males.
These Offspring more likely to survive winter than
offspring of Social Mate

42. Resource Defense Polygyny
AVIAN BREEDING SYSTEMS: POLYGYNY
Resource Defense Polygyny

43. AVIAN BREEDING SYSTEMS: POLYGYNY
Female-Defense Polygyny

44. Lek Polygyny AVIAN BREEDING SYSTEMS: POLYGYNY
Defend Display Territory rather than Valuable Resource
Difficult to Explain

45. AVIAN BREEDING SYSTEMS: POLYANDRY
A female courts male until it mates.
Male raises the clutch.
Female moves on to look for another male
with which to breed.

46. AVIAN BREEDING SYSTEMS: POLYANDRY

47. 1 http://www.penguin-quilts.com/IMAGES/MATING.JPG2 3
!House_Sparrows_mating_I_IMG_0066.jpg 4
20blog.JPG 5 6 7 8 9
300x420,0.jpg 10 11

48. 12 http://www.bto.org/nnbw/nesting_birds/images/house_sparrow.jpg13 14 15 16 17 18
%7B2C5DEB F-AFD3-94E59299B98D%7D 19 20 21
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49. 24 http://www.walesbiomass.org/images/2.2.2-Song-Thrush-Eggs.jpg25 26 27 28