As the researchers expected, the lesser scaups housed in groups grew longer penises than those housed in pairs. The results were published Wednesday in the journal The Auk. Blue whales are the largest creature to ever roam the earth, and they certainly have the phallus to match. Blue whale penises range between eight and ten feet, with a foot-long diameter. Each of its testes along can weigh up to 150 pounds and can ejaculate gallons of sperm in a single go. Study plan for waterfowl injury assessment: Determining PCB concentrations in Hudson river resident waterfowl" (PDF). New York State Department of Environmental Conservation. US Department of Commerce. December 2008. p.3. Archived (PDF) from the original on 2022-10-09 . Retrieved 2 July 2019.

Birds have them, bees have them, even regular old fleas have them, but in the animal kingdom, no penis is exactly like the next. Across vastly different species and ecosystems, unique environmental pressures have allowed creatures of many species to evolve an array of shapes and sizes—from the electric blue penis of the leopard slug to the blue whale’s ten-foot phallus.

There's not a binary that is categorically one thing or the other when it comes to genitalia,” says Willingham. The females are kept in a single large indoor pen and the drakes can him them - is that adding fuel to the hormonal fire!

Children will adore this hilarious rhyming story by the much-loved author, Kaye Umansky, one of the funniest children's writers around. Willingham explains that this violent process has caused bedbugs to evolve “something very vagina-like where they tend to get stabbed.” This special less-armored area of their abdomen might minimize harm as the male injects his sperm into the female’s circulatory system. Gender-Bending GenitalsLivezey, Bradley C. (October 1986). "A phylogenetic analysis of recent Anseriform genera using morphological characters" (PDF). The Auk. 103 (4): 737–754. doi: 10.1093/auk/103.4.737. Archived (PDF) from the original on 2022-10-09. Livingston, A. D. (1998-01-01). Guide to Edible Plants and Animals. Wordsworth Editions, Limited. ISBN 9781853263774. Thorkelson, Berit (2005). You Know You're in Minnesota When...: 101 Quintessential Places, People, Events, Customs, Lingo, and Eats of the North Star State. (1st ed.). Guilford, Connecticut: Insiders' Guide. p. 18. ISBN 978-0-7627-3895-3. Apple – OS X Yosemite – Apps". Archived from the original on September 26, 2014 . Retrieved September 30, 2014.

Sometimes, penises pose logistical challenges. That is certainly the case for the leopard slug, which is so well-endowed that it has to go to extreme measures to reproduce. SS: I didn’t know that drakes’ phalluses fell off at the end of mating season and then regrew the following season in proportion to the pressure they felt from other drakes. Like many organisms with intriguing phalluses, flatworms that engage in penis fights are hermaphrodites—just one example that showcases how a sex binary system fails to account for the range, fluidity and diversity of many organisms. Some species of flatworm engage in this duel to see who can inseminate the other. Christidis, Les; Boles, Walter E., eds. (2008). Systematics and Taxonomy of Australian Birds. Collingwood, VIC: Csiro Publishing. ISBN 978-0-643-06511-6.

Madsen, Cort S.; McHugh, Kevin P.; de Kloet, Siwo R. (July 1988). "A partial classification of waterfowl (Anatidae) based on single-copy DNA" (PDF). The Auk. 105 (3): 452–459. doi: 10.1093/auk/105.3.452. Archived (PDF) from the original on 2022-10-09. You just need to go look that one up,” says Willingham. You can see a video of the slugs in action here.