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4. Initiating Reproduction: Photoperiod. Gonads enlarge when artificial day > 10 hrs. Initiating Reproduction: Air Temperature. Cold snap early in breeding season delays nesting. Egg laid when temp -30 o F. Sperm production reduced at lower temperatures.
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Initiating Reproduction: Photoperiod • Gonads enlarge when artificial day > 10 hrs
Initiating Reproduction: Air Temperature • Cold snap early in breeding • season delays nesting • Egg laid when • temp -30o F • Sperm production reduced at lower temperatures
Initiating Reproduction: Rainfall • Nesting occurs 10-14 days after heavy spring rain • Heavy rains in July often initiate second nesting
Initiating Reproduction: Food • Nesting initiated any time of year. Corresponds to Cone Irruption
Control of Testes Development: Hypothalamus, Pituitary Gland Fig. 4-31 in Podulka et al. 2004
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. 4-31 in Podulka et al. 2004
Stimulation of Testes Development • Follicle-Stimulating Hormone Stimulate Testes / Sperm Development • Luteinizing Hormone Stimulates Testosterone Production
http://www.wtamu.edu/~rmatlack/pigeon_dissection/male_reproductive.jpghttp://www.wtamu.edu/~rmatlack/pigeon_dissection/male_reproductive.jpg
Bird Sperm Fig. 4-108 in Podulka et al. 2004
Detecting Male Reproductive Condition: Cloacal Protuberance (Passerines) Fig. 4-109 in Podulka et al. 2004
Male Reproductive Anatomy Deferent Duct (Vas Deferens) Seminal Vesicle Papilla
Cloacal Phallus = “Penis” (Waterfowl, Ratites, Red-Billed Buffalo Weaver) Ostrich Goose Lake Duck
Cloacal Phallus = “Penis” (Waterfowl, Ratites) Fig. 14-12 in Gill et al. 2007
Bird “Penis”: Relationship to Mammalian Penis 9 Fig. 4-71 in Podulka et al. 2004
Cloacal Phallus = “Penis” (Red-Billed Buffalo Weaver) Prolonged Rubbing (10-20 Minutes) Stimulates Female (Enhanced Sperm Transfer?)
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. 4-31 in Podulka et al. 2004
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
Female Reproductive Anatomy Ovary Oviduct Cloaca Fig. 4-111 in Podulka et al. 2004
Ovum (Gamete) Maturation (Oogenesis) (Meiosis Partially Completed at Birth)
Follicles (Immature Eggs) in Ovary http://www.soupsong.com/ova.jpg
Follicle Maturation and Ovulation • Infundibulum Raises Up, Swallows Egg Fig. 4-111 in Podulka et al. 2004
Copulation 5 3 (Cloacal Kiss, Insemination)
Copulation: Acrobatics (Swift) (Flamingo) Aerial Copulation Head in the Water
Copulation: Endurance 500 Copulations per Clutch 25 Minute Continuous Copulation (Goshawk) (Aquatic Warbler)
Copulation (Papillae Contact Openings of Oviduct)
“The Long and Winding Road” Oviduct Opening to Infundibulum (Top Speed: < 30 Minutes)
Sperm Production Rooster: 7-8 Billion Sperm / Ejaculation
Fertilization: Sperm-Storage Tubules Fig. 14-13 in Gill 2007 Fig. 14-17 in Gill 2007
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
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 Frequent Copulations Large Testes High Quantity Mate Guarding Long Sperm
Fertilization: Sperm Competition Strategies Dunnock • Male Pecks at Female Cloaca until Competitors Sperm Ejected Fig. 14-10 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 Fig. 12-21 in Gill 2007
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
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