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How did the goose cross the road?

Even though geese are accomplished flyers  —  they can soar 1.6 km high and reach speeds of 100 km per hour  —  they still prefer to walk across a road.  Why not fly and avoid danger?

Geese certainly can fly across a road. Explorers report them flying even across Mount Everest. Migrating bar-headed geese routinely over fly the Himalayas. Migrating Canadian geese fly, in fair weather, up to 1.6 kilometers (a mile) high, reaching speeds of 70 to 100 km/hr (45 to 60 mph).

So geese could fly across a road. There are exceptions: they can't fly while molting (mid June to mid July). Also domestic geese have largely lost flying ability. Moreover, people often remove part of their wings (pinioning) to prevent domestic geese from flying away. Consequently, domestic geese only flap their wings furiously and maybe lift off a couple of feet.

So why don't wild geese fly across roads?

Why do geese walk across a road when they can fly, thereby not getting hit by a car? Angelo, Staten Island, New York, USA

Primarily because a goose is a grazing animal and grazers walk as they graze.   Their legs are positioned to their bodies farther forward than either duck or swan legs.  They can, therefore, "walk and graze on dry land," writes biologist Chuck Fergus in Wildnotes of the Pennsylvania Game Commission. 

Walking uses far less energy than flying.  Conserving energy for fleeing danger and long migrations helps the species survive.  Researchers (A.J. Woakes et al) at the Universities of Birmingham and Wales found that the rate of oxygen consumption was significantly higher for flying rather than walking geese.

Geese tend to walk to their feeding site from water.  "Because they are grazers, they will do more walking, but they don’t avoid flying," emails biologist Marion E Larson of the Massachusetts Division of Fisheries and Wildlife.

They fly to migrate thousands of miles.  Also they fly from their nighttime home waters (river, pond or lake) to nearby fields to graze during the day, and then fly back to the lake for the night.  Such forays may take them a few hundred yards or over 20 miles, depending on food availability.  But food drives the flights, not predators.

"Because they're big, strong and aggressive, geese are less subject to predation than most other waterfowl," Fergus says.  Hawks and owls — airborne dangers — are about the only predators immatures need worry about.  Few adults need concern themselves at all.  Furthermore, wild geese are smart and quickly learn where refuge-area boundaries are in regions where humans hunt them.

Geese become accustomed to road traffic.  Intelligent and wary with keen hearing and vision, geese easily avoid traffic.  On land, they feed in groups and at least one goose always scouts for trouble.  Indeed, the grazing flock multiplies a lookout's sharp senses.

So, to answer your question, "Canadian geese prefer to walk or swim.  They do not like to fly," says the New Mexico State University Cooperative Extension.  And they don't need to fly to avoid a mere car.

Further Reading:

Heart rate and the rate of oxygen consumption of flying and walking barnacle geese (Branta leucopsis) and bar-headed geese (Anser indicus) by S. Ward, C. M. Bishop, A. J. Woakes and P. J. Butler, Universities of Birmingham and Wales, July 2002

Canada Goose by Chuck Fergus, Pennsylvania Game Commission Wildlife Notes

How geese squeeze oxygen from thin air, CBS News, July 2009

Canada Geese in Massachusetts, Massachusetts Division of Fisheries and Wildlife

April Holladay lives in Albuquerque, New Mexico. Her column, WonderQuest, appears every second Monday of the month on WonderQuest.com. To read April's past columns, please visit her website. If you have a question for April, visit this information page.

(Answered 11 Jan. 2010)

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Readers' Answers

• The reason geese walk across a road is 'cos it's just too dang far to walk around....
  
  No, seriously, they walk because the energy-expenditure of running to gain take-off speed and flying such a short flight isn't worth it. They fly short distances usually only when compelled to avoid a threat such as an off-leash dog. That said, if the flock 'leader' decides to fly even a short distance, the rest will also, as there's a strong compulsion within flocking animals to remain bunched together as a defensive strategy.  Loblollyboy, Vancouver, Canada
   
• The width of the road is shorter than the takeoff run of this heavy bird, and it takes less energy to walk across than it would to fly.  Also, the takeoff direction usually would not be directly into the wind, increasing the takeoff run.  Shakyace, Tijeras, New Mexico, USA
• Geese need a running start to fly.  It's a little silly to go further away from the road to get a running start just to fly over a road and land on the other side. The old saying says geese are silly but they're not stupid.  Cheryl, Russell, Manitoba, Canada
• Getting airborne takes a lot of energy.  For short distances, it is simply not worth the effort unless they're running away from something.  A goose flying a short distance is like a human sprinting.  You move fast, but tire quickly.  It's easier to maintain flight once airborne.  Flight is energy efficient for longer distances.  Thus, it's easiest to walk a short distance and to fly longer distances. Jay Armada Michigan, USA
• Geese prefer to walk (as opposed to fly) when:
  
  1.  The distance they are traveling is short and within direct visual contact.
  2.  They have a relatively clear line of sight to any possible nearby threats.
  
  Getting off the ground isn't a trivial task, and at certain times of the year when they are heavy, it takes a good bit of distance, too. Heavy geese are unstable flyers until they've built-up airspeed, so they must fly the first 100 yards or so in a straight line with as few obstacles as possible.   Geese are smart about this, so if the trip will be short, and all other factors are essentially equal, they'll save the energy and just walk.  Walking also gives them an opportunity to graze and examine their territory (geese are fiercely territorial). 
  
  Having said this, individual animals clearly have preferences.  Some will refuse to fly unless they must cover a large distance.  Others will take flight seemingly on a whim.  From my own experience, if there are no clear-cut "walk or fly" deciding factors, in the spring males prefer to fly, while females will tend to walk (or run).  If you have a group of geese, then often all it will take is for a single goose to decide to fly, and all will take to the air. 
  
  Terrain also is factor.  Geese going down a clear hill will almost always fly if the situation permits.  Conversely, geese will almost always walk up small hills.
  
  The bottom line is "geese are smart".  They will do whatever makes the best sense to their internal programming.   Roark, Danbury, Texas, USA