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Male Reproductive Condition (Breeding Season). http://www.wtamu.edu/~rmatlack/pigeon_dissection/male_reproductive.jpg. Control of Testes Development: Hypothalamus, Pituitary Gland. Fig. 4-31 in Podulka et al. 2004. Control of Testes Development: Hypothalamus, Pituitary Gland.
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Male Reproductive Condition (Breeding Season) http://www.wtamu.edu/~rmatlack/pigeon_dissection/male_reproductive.jpg
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
Bird Sperm Fig. 4-108 in Podulka et al. 2004
Sperm Production Rooster: 7-8 Billion Sperm / Ejaculation
Male Reproductive Anatomy Deferent Duct (Vas Deferens) Seminal Vesicle Papilla
Copulation (Papillae Contact Openings of Oviduct)
“The Long and Winding Road” Oviduct Opening to Infundibulum (Top Speed: < 30 Minutes)
Avian Breeding Systems I) MONOGAMY (One Male PAIRS with One Female during a Given Breeding Season) Greater than 90% All Birds are Normally Monogamous
“Mr. Mom”: Northern Mockingbird Female: Builds New Nest Male: Takes Charge of Fledglings
“Mr. Mom”: Australian Malleefowl • Male Build Nest (4 Tons) of Sand, Dirt, Decaying • Vegetation • Male Opens Nest with Each Female Visit • Female Lays Egg, Leaves • Male Regulates Temperature by Adjusting “Compost Heap”
Avian Monogamy: Why? Hypothesis: Males Increase Nest Productivity
Avian Monogamy: Why? Test of Hypothesis: Males Increase Nest Productivity Snow Bunting Fig. 6-37 in Podulka et al. 2003
Avian Monogamy – Length of Pair Bond Song Sparrow – 1 (2-3) Breeding Seasons Dusky Grouse – Copulation Only Ruby-Throated Hummingbird (A Few Days) Royal Albatross (15 Years)
Avian Monogamy – Extended Monogamy Potential Benefits • Secure Better Territory • Start Nesting Earlier • More Effective Cooperation in Breeding • activities Royal Albatross Sandhill Crane * Emperor Penguin Gulls Mute Swan
Avian Monogamy – Extended Monogamy Experienced Couples (vs. New Couples) Black-Legged Kittiwake • Breed Earlier • Lay More Eggs • Raise More Young
EXTRA-PAIR COPULATION (Outside the Pair Bond) Pair-Bond Only 14% of Socially Monogamous Bird Species Studied to Date are Genetically Monogamous (Gill 2007)
EXTRA-PAIR COPULATION (Outside the Pair Bond) On average, more than 11% of Offspring are Sired by Males Other than Social Father (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? (Increased Offspring Quality) • Blue Tits Engage in Extra-Pair Copulations with • Distant, Genetically Different Males. • These Offspring (Heterozygotes) more likely to survive winter than • offspring of Social Mate
Fertilization: Sperm-Storage Tubules EXTRA-PAIR COPULATION(Outside the Pair Bond) Fig. 14-13 in Gill 2007 Fig. 14-17 in Gill 2007
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
AVIAN BREEDING SYSTEMS: POLYGYNY 1) Resource Defense Polygyny
AVIAN BREEDING SYSTEMS: II) POLYGYNY 1) Resource Defense Polygyny MALE • Win - Win FEMALE • Disadvantage: Less Parental Aid • Advantage: Best Territories, More • Nest Productivity than in Subpar • Territories
AVIAN BREEDING SYSTEMS: POLYGYNY 2) Female-Defense Polygyny • Male Fights for Control of Clusters of • Nesting Females • Male Dominance Hierarchy Develops • Top Male Involved in 90-100% of Copulations Montezuma Oropendula
AVIAN BREEDING SYSTEMS: POLYGYNY 3) Lek Polygyny • Males Defend Territories in Lek that • does NOT contain Resources or • Colonies of Females • Evolutionary Basis Unclear • Perhaps Evolves where Resources, • Females not Clumped
AVIAN BREEDING SYSTEMS: III) POLYANDRY • Females Defend Territories • Males select Females with Best Territories • Males Incubate Eggs, Raise Young, etc.
AVIAN BREEDING SYSTEMS: III) POLYANDRY Wilson’s Phalarope • Female Directly Defends Male until Male • Accepts Clutch • Female Produces a Second Clutch, then • Attempt to Defend Another Male to • Incubate Eggs, Raise Young • Evolutionary Basis Difficult to Explain
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