Reproduction
Howler Monkeys: Louder Calls Trade-Off For Smaller Balls, Researchers Say [VIDEO]
Howler monkeys are fairly small animals, but can roar as powerfully as tigers. This ability comes at a evolutionary trade-off, though: howler monkeys with louder calls often have smaller reproductive organs, a recent study revealed.
Latest Research Articles
Butterfly Evolution: Why Only Some Males Are Able To Attract Females
Falling In Love Increases Reproductive Success in Birds, Researchers Say
Human and Male Seahorse Pregnancies are Surprisingly Similar
Male Orangutans Attract More Females by Having Padded Cheeks
'Virgins Births': First Case Discovered in Vertebrates
Mysterious Evolution of Shark Penis: Blame Sonic the Hedgehog?!
Fearful Frogs Build Secret Sex Chambers to Get in the Mood
Baboons Don't Think Big Butts Are Sexy
Scientists Discover Vampire Squid's Unique Reproductive Strategy
BPA Exposure Disrupts Turtle Reproduction
Invasive Species Use "Kissing Landmarks" to Find Love
Mares Love Deep-Voiced Whinnys