Not all females like macho males

July 30, 2003

BEING a big, macho male doesn't always impress the fairer sex. Contrary to commonly accepted theory, the females of some species are partial to weedier partners.

Animal behaviourists usually expect males to compete with each other for mates, with females preferring the larger, more aggressive or better-endowed winners. But this is not so for certain salmon and quail.

Some male coho salmon, known as jacks, stop growing earlier in their lives and remain smaller than their larger cousins, known as hooknoses, says behavioural ecologist Jason Watters of the University of California, Davis. When the salmon migrate from the Pacific Ocean to inland rivers to spawn, hooknoses dominate jacks and compete aggressively with each other to mate with females. But contrary to what biologists had assumed, the females prefer to mate with jacks if they get the chance. "That shakes up everybody's point of view a little," says evolutionary biologist Steve Shuster of Northern Arizona University in Flagstaff.

Watters tracked the mating experiences of 15 female coho salmon in a Californian coastal stream. The females work harder on their nests and spawn longer with jacks than with hooknoses, Watters told an Animal Behavior Society meeting in Boise, Idaho, last week. The female salmon may prefer jacks because their earlier maturation could be a sign of increased quality and success. Other males have to spend an extra year growing into hooknoses before they can mate.

The females may also prefer to avoid the physical abuse of mating with aggressive males. "Hooknoses were the only ones that chased or bit females," Watters says. "Jacks pull up beside females and wiggle. They don't touch them, they just advertise."

Female Japanese quail have similarly contrary tastes, animal behaviourist Alex Ophir of McMaster University in Ontario, Canada, told the meeting. Male Japanese quail are exceptionally aggressive towards each other, and this abuse often spills over into courtship and mating. To see how the females feel about this, Ophir let female quail watch a fight between two males, and then separated the combatants and placed them on opposite sides of a female's cage to see which one she would gravitate towards. Virgin females tended to prefer the dominant males that had won the fight, but females with a little sexual experience were more likely to choose the loser.

"People just expect the dominant guy to win," says Ophir. "But females learn through personal experience that these males can be hurtful." Shuster thinks the idea that females may not always prefer dominant males will catch on. "Conventional wisdom is that males should always try to be these macho aggressive guys," he says. "But this shows there is also a place for the nicer guys."
Author: Betsy Mason New Scientist issue: 2 AUGUST 2003

UK CONTACT - Claire Bowles, New Scientist Press Office, London:
Tel: 44-0-20-7331-2751 or email

US CONTACT - Michelle Soucy, New Scientist Boston Office:
Tel: 1-617-558-4939 or email


"These articles are posted on this site to give advance access to other authorised media who may wish to quote extracts as part of fair dealing with this copyrighted material. Full attribution is required, and if publishing online a link to is also required. Advance permission is required before any and every reproduction of each article in full - please contact Please note that all material is copyright of Reed Business Information Limited and we reserve the right to take such action as we consider appropriate to protect such copyright."

New Scientist

Related Salmon Articles from Brightsurf:

Alaska's salmon are getting smaller, affecting people and ecosystems
The size of salmon returning to rivers in Alaska has declined dramatically over the past 60 years because they are spending fewer years at sea, scientists report.

Chinook salmon declines related to changes in freshwater conditions
A new University of Alaska-led study provides the first evidence that declines in many of Alaska's chinook salmon populations can be attributed in part to climate-driven changes in their freshwater habitats.

Size matters in the sex life of salmon
For Atlantic salmon, size matters when it comes to love.

What does drought mean for endangered California salmon?
Droughts threatens California's endangered salmon population -- but pools that serve as drought refuges could make the difference between life and death for these vulnerable fish.

Salmon provide nutrients to Alaskan streambanks
Nutrient cycling of stream ecosystems dependent on portion of salmons' lifecycle.

Melting glaciers will challenge some salmon populations and benefit others
A new Simon Fraser University-led study looking at the effects that glacier retreat will have on western North American Pacific salmon predicts that while some salmon populations may struggle, others may benefit.

Bigger doesn't mean better for hatchery-released salmon
A recent study in the Ecological Society of America's journal Ecosphere examines hatchery practices in regards to how Chinook salmon hatcheries in the PNW are affecting wild populations over the past decades.

Salmon get a major athletic boost via a single enzyme
A single enzyme anchored to the walls of salmons' blood vessels helps reduce how hard their hearts have to work during exercise by up to 27%.

Salmon are shrinking and it shows in their genes
Male salmon are maturing earlier and becoming smaller, and it shows in their genes.

Young salmon may leap to 'oust the louse'
A study by Simon Fraser University aquatic ecologists Emma Atkinson and John Reynolds reveals that young salmon may jump out of water to remove sea lice.

Read More: Salmon News and Salmon Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to