4

Initiating Reproduction: Photoperiod

• Gonads enlarge when artificial day > 10 hrs

Initiating Reproduction: Air Temperature

• Sperm production reduced at lower temperatures

• Cold snap early in breeding season delays nesting

• Egg laid when temp -30o F

• Nesting occurs 10-14 days after heavy spring rain

• Heavy rains in July often initiate second nesting

Initiating Reproduction: Rainfall

Initiating Reproduction: Food

• Nesting initiated any time of year. Corresponds to Cone Irruption

Male Reproductive Condition

Fig. 4-31 in Podulka et al. 2004

Control of Testes Development: Hypothalamus, Pituitary Gland

Fig. 4-31 in Podulka et al. 2004

• Hypothalamus Secretes Gonadotropin- Releasing Hormone into Anterior Pituitary (GnRH)

• Anterior Pituitary Secretes Follicle- Stimulating Hormone (FSH) and Luteinizing Hormone (LH) into Circulatory System

Control of Testes Development: Hypothalamus, Pituitary Gland

Stimulation of Testes Development

• Follicle-Stimulating Hormone Stimulate Testes / Sperm Development• Luteinizing Hormone Stimulates Testosterone Production

Wingfield and Hahn (1994).

TESTOSTERONE: Negative Feedback

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

Spermatogenesis

Fig. 4-108 in Podulka et al. 2004

Bird Sperm

Fig. 4-109 in Podulka et al. 2004

Detecting Male Reproductive Condition:Cloacal Protuberance (Passerines)

Deferent Duct(Vas Deferens)

Seminal Vesicle

Papilla

Male Reproductive Anatomy

Ostrich

Lake Duck

Goose

Cloacal Phallus = “Penis”(Waterfowl, Ratites, Red-Billed Buffalo Weaver)

Fig. 14-12 in Gill et al. 2007

Cloacal Phallus = “Penis”(Waterfowl, Ratites)

Fig. 4-71 in Podulka et al. 2004 9

Bird “Penis”: Relationship to Mammalian Penis

Cloacal Phallus = “Penis”(Red-Billed Buffalo Weaver)

Prolonged Rubbing (10-20 Minutes) Stimulates Female(Enhanced Sperm Transfer?)

Female: Ovary, Oviduct

Fig. 4-31 in Podulka et al. 2004

• Hypothalamus Secretes Gonadotropin- Releasing Hormone into Anterior Pituitary (GnRH)

• Anterior Pituitary Secretes Follicle- Stimulating Hormone (FSH) and Luteinizing Hormone (LH) into Circulatory System

Control of Ovary Development: Hypothalamus, Pituitary Gland

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

Fig. 4-111 in Podulka et al. 2004

Female Reproductive Anatomy

Ovary

Oviduct

Cloaca

Ovum (Gamete) Maturation(Oogenesis)

(Meiosis Partially Completed at Birth)

http://www.soupsong.com/ova.jpg

Follicles (Contain Immature Eggs) in Ovary

Fig. 4-111 in Podulka et al. 2004

Follicle Maturation and Ovulation

• Infundibulum Raises Up, Swallows Egg

5

3

Copulation

(“Cloacal Kiss”, Insemination)

Head in the Water

(Flamingo)Aerial Copulation

(Swift)

Copulation: Acrobatics

Copulation: Endurance

500 Copulations per Clutch

(Goshawk) (Aquatic Warbler)

25 Minute Continuous Copulation

Copulation

(Papillae Contact Openings of Oviduct)

“The Long and Winding Road”

Oviduct Opening to Infundibulum

(Top Speed: < 30 Minutes)

Fertilization

Sperm Production

Rooster: 7-8 Billion Sperm / Ejaculation

Fertilization: Sperm-Storage Tubules

Fig. 14-13 in Gill 2007 Fig. 14-17 in Gill 2007

Monogamy(Frequently, Shared Parental Care)

Avian Breeding Systems

“Well over 9/10’s of all passerine subfamilies are normally monogamous. ..Polyandry [multiple mates] is unknown”

David Lack, 1968

EXTRA-PAIR COPULATION(Outside the Pair Bond)

Pair-Bond

Only 14% of Socially Monogamous Bird Species Studied to Date are Genetically Monogamous

Fertilization: Sperm Competition Strategies

Large Testes

Long Sperm High Quantity

Frequent Copulations

Mate Guarding

Fertilization: Sperm Competition Strategies

Fig. 14-10 in Gill 2007

Dunnock

• Male Pecks at Female Cloaca until Competitors Sperm Ejected

Fig. 12-21 in Gill 2007

Frequency of Extra-Pair Bonds (130 Bird Species)

More than 50% of Tree Swallow Nestlings can be Sired by Extra-Pair Copulations

EXTRA-PAIR COPULATION:(Why?)

• Blue Tits Engage in Extra-Pair Copulations with Distant, Genetically Different Males.

• These Offspring more likely to survive winter than offspring of Social Mate

AVIAN BREEDING SYSTEMS: POLYGYNY

Resource Defense Polygyny

AVIAN BREEDING SYSTEMS: POLYGYNY

Female-Defense Polygyny

AVIAN BREEDING SYSTEMS: POLYGYNY

Lek Polygyny

AVIAN BREEDING SYSTEMS: POLYANDRY

AVIAN BREEDING SYSTEMS: POLYANDRY

1 http://www.penguin-quilts.com/IMAGES/MATING.JPG

2 http://scienceblogs.com/retrospectacle/mating%20close.JPG

3 http://upload.wikimedia.org/wikipedia/commons/archive/1/11/ 20071013152142!House_Sparrows_mating_I_IMG_0066.jpg

4 http://www.jennifermarohasy.com/blog/archives/Cassowaries%20Mating% 20blog.JPG

5 http://farm1.static.flickr.com/179/430750607_364fcc6c09.jpg

6 http://people.eku.edu/ritchisong/gullsmating.jpg

7 http://www.hiltonpond.org/images/CloacalProtuberance02.jpg

8 http://ocw.tufts.edu/data/5/215794/12007_medium.jpg

9 http://www.theage.com.au/ffximage/2008/03/29/majviagra_narrowweb__ 300x420,0.jpg

10 http://www.backyardbirdcam.com/gallery/sparrow-house-f-lg2.jpg

11 http://www.nps.gov/archive/whsa/bird%20list/house%20sparrow.jpg

12 http://www.bto.org/nnbw/nesting_birds/images/house_sparrow.jpg

13 http://aishah776.files.wordpress.com/2007/06/dscn1144.jpg

14 http://www.parismina.com/images/turtle2.jpg

15 http://www.naturealmanac.com/archive/wild_turkey/pics/turkey-nest.jpg

16 http://www.kabri.net/tikey%20baby.JPG

17 http://www.cookiemadness.net/egg%20whites.jpg

18 http://pro.corbis.com/images/42-16420777.jpg?size=572&uid= %7B2C5DEB80-2648-428F-AFD3-94E59299B98D%7D

19 http://feredayisland.co.nz/Pictures/beat_egg_yolk.jpg

20 http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/19510.jpg

21 http://www.nicholsoncartoons.com.au/cartoons/new/2002-20-23%20Bali%20 Indonesia%20Bashir%20gets%20bile%20drip%20520.JPG

22 http://www.ucmp.berkeley.edu/glossary/gloss3/phycobilins.gif

23 http://www.cabinetmagazine.org/issues/20/assets/images/Cyanea.jpg

24 http://www.walesbiomass.org/images/2.2.2-Song-Thrush-Eggs.jpg

25 http://www.isledegrande.com/gi-ncnature/redwingedblackbirdeggs-9.jpg

26 http://www.scienceclarified.com/images/uesc_04_img0177.jpg

27 http://www.audubon.org/bird/puffin/virtual/pics/tern_w_two_chicks.jpg

28 http://www.londons-swifts.org.uk/GC_Swifts_mating%20(5).jpg