horns and antlers more than decoration

Bragging might be rude in the human world, but for a bull moose or a mountain sheep, it's part of the job.

by Claire Eamer

Bragging might be rude in the human world, but for a bull moose or a mountain sheep, it’s part of the job. Moose and sheep – along with animals such as pigs, horses, and camels- are ungulates, four-legged vegetarians that walk on

toes protected by tough hooves. They have some of the biggest weapons in the animal kingdom. And they flaunt them.

Consider the moose, the world’s largest living deer. A really big bull moose – and the Yukon has some big ones – can weigh as much as a polar bear and carry a set of antlers as wide as a king-size bed. Moose grow new antlers every year, starting in late spring. While they grow, they’re covered by soft skin, called velvet, which is full of blood vessels to nourish the antler bone. Early in fall, when the antlers are full-grown, the velvet starts peeling away. It’s the start of the mating season, or rut, and time to show off.

Braggarts in the forest

Yukon government moose biologist Rick Ward says the rut changes moose. “Bulls stop eating and lose considerable body mass. Testosterone levels rise, their necks and other muscle groups swell and bulk up, and the hide on their front quarters becomes thick and tough.”

Bull moose compete for the chance to mate with a cow moose. Sometimes they fight, but fighting is dangerous and uses a lot of energy. That’s where bragging and bullying come in.

The first brag is antler-thrashing. Male moose batter bushes and small trees with their antlers, cleaning off the last scraps of dried velvet and polishing the tines to sharp, white points. The broken bushes are markers that a big, tough bull is in the neighbourhood.

When a bull moose encounters another male, the real show begins. It’s called a dominance display. The bulls approach each other slowly, at an angle so that each can show off his enlarged muscles and swollen neck. With each heavy, dragging step, they tip their antlers from side to side. Often, they make low, rhythmic grunts or pause to thrash nearby trees. There’s plenty of time for a smaller male to decide he doesn’t have a chance and give in.

If the bulls are evenly matched, they fight. They clash antlers violently and push with all their weight and strength, ploughing up the ground with their hooves. The struggle goes on until the loser tries to disengage by turning away. He has to be quick to avoid being gored as he turns.

Avoiding unnecessary fights is worthwhile. Ungulate specialist Valerius Geist says active bulls receive 30 to 50 puncture wounds during the six-week rut.

 

Bullies on the mountain

For their size, mountain sheep are even more heavily armed than moose. A big ram weighs only about as much as a large man, but more than 10 per cent of that weight can be in the massive horns that sprout from its forehead. Yukon mountain sheep belong to the species called thinhorns, but that doesn’t mean their horns are puny. They’re just a bit thinner than those of the bighorn sheep that live farther south.

The horn is a hollow bone core surrounded by a sheath of keratin, a protein similar to the stuff in your fingernails. Sheep horns keep growing from year to year, curving as they get longer. By the time the ram is eight years old, his horns usually curl in a full circle on either side of his head.

The horns are rippled and ridged, with one thick ridge running the length of the outer edge. Geist says when a ram attacks, it rises up on its hind legs and jumps into the attack, flicking its horns forward so it hits with that ridge, with “the combined effect of a sledgehammer and a karate chop.”

Like moose, rams have ways of avoiding fights that they’re unlikely to win. They’ll pose sideways, head high, to look as big as possible, or make the opening moves of an attack to show they’re serious. Sometimes it takes a clash of the horns for one ram to decide the other is too strong to challenge.

“Rams have another behaviour that is quite neat,” says John Loehr, a Finland-based sheep biologist who has done much of his research in the Faro region. “They do something called a ‘low stretch’ where the displaying ram will lower his head and stretch it out as far forward as it goes and cruise past whoever he is trying to impress.” Usually the stretching ram is dominant, and the other ram will give way.

If neither ram concedes, the resulting fight can be bloody. Geist saw two evenly matched rams fight most of a day and into the night. “I heard clashes during the night,” he says. “In the gray light of dawn, two exhausted rams lay on a ledge, still displaying horn to one another.” The rams fought another five hours before one of the combatants finally gave up.

For more information about Yukon moose and sheep, go to the Environment Yukon website, www.env.gov.yk.ca,  or contact the Wildlife Viewing Program at wildlife.viewing@gov.yk.ca or 1-800-661-0408 local 8291 (toll free in the Yukon).

This column is co-ordinated by the Yukon Research Centre with major financial support from Environment Yukon and Yukon College. The articles are archived at www.taiga.net/yourYukon.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Crystal Schick/Yukon News file
Ranj Pillai, minister of economic development, during a press conference on April 1.
Government rejects ATAC mining road proposal north of Keno City

Concerns from the First Nation of Na-Cho Nyäk Dun were cited as the main reason for the decision

asdf
WYATT’S WORLD

Wyatt’s World for Dec. 2, 2020

Whitehorse and Carcross will be among seven northern communities to have unlimited internet options beginning Dec. 1. (Yukon News file)
Unlimited internet for some available Dec. 1

Whitehorse and Carcross will be among seven northern communities to have unlimited… Continue reading

Willow Brewster, a paramedic helping in the COVID-19 drive-thru testing centre, holds a swab used for the COVID-19 test moments before conducting a test with it on Nov. 24. (Crystal Schick/Yukon News)
An inside look at the COVID-19 drive-thru testing centre

As the active COVID-19 case count grew last week, so too did… Continue reading

Fossil finds at Mt. Stephen. (Photo: Sarah Fuller/Parks Canada)
Extreme hiking, time travel and science converge in the Burgess Shale

Climb high in the alpine and trace your family tree back millions of years – to our ocean ancestors

Black Press Media and BraveFace have come together to support children facing life-threatening conditions. Net proceeds from these washable, reusable, three-layer masks go to Make-A-Wish Foundation BC & Yukon.
Put on a BraveFace: Mask fundraiser helps make children’s wishes come true

From Black Press Media + BraveFace – adult, youth and kid masks support Make-A-Wish Foundation

Colin McDowell, the director of land management for the Yukon government, pulls lottery tickets at random during a Whistle Bend property lottery in Whitehorse on Sept. 9, 2019. A large amount of lots are becoming available via lottery in Whistle Bend as the neighbourhood enters phase five of development. (Crystal Schick/Yukon News file)
Lottery for more than 250 new Whistle Bend lots planned for January 2021

Eight commercial lots are being tendered in additional to residential plots

The Government of Yukon Main Administration Building in Whitehorse on Aug. 21. The Canada Border Services Agency announced Nov. 26 that they have laid charges against six people, including one Government of Yukon employee, connected to immigration fraud that involved forged Yukon government documents. (Crystal Schick/Yukon News file)
Charges laid in immigration fraud scheme, warrant out for former Yukon government employee

Permanent residency applications were submitted with fake Yukon government documents

Whitehorse City Hall. (Joel Krahn/Yukon News file)
City hall, briefly

A look at decisions made by Whitehorse city council this week

Karen Wenkebach has been appointed as a judge for the Yukon Supreme Court. (Yukon News file)
New justice appointed

Karen Wenckebach has been appointed as a judge for the Supreme Court… Continue reading

Catherine Constable, the city’s manager of legislative services, speaks at a council and senior management (CASM) meeting about CASM policy in Whitehorse on June 13, 2019. Constable highlighted research showing many municipalities require a lengthy notice period before a delegate can be added to the agenda of a council meeting. Under the current Whitehorse procedures bylaw, residents wanting to register as delegates are asked to do so by 11 a.m. on the Friday ahead of the council meeting. (Crystal Schick/Yukon News file)
Changes continue to be contemplated for procedures bylaw

Registration deadline may be altered for delegates

Cody Pederson of the CA Storm walks around LJ’s Sabres player Clay Plume during the ‘A’ division final of the 2019 Yukon Native Hockey Tournament. The 2021 Yukon Native Hockey Tournament, scheduled for March 25 to 28 in Whitehorse next year, was officially cancelled on Nov. 24 in a press release from organizers. (John Hopkins-Hill/Yukon News file)
2021 Yukon Native Hockey Tournament cancelled

The 2021 Yukon Native Hockey Tournament, scheduled for March 25 to 28… Continue reading

Most Read