[Tweeters] Birds and road salt article
clsouth at u.washington.edu
Wed Jan 16 07:51:57 PST 2013
I've been thinking about this issue of birds being attracted to de-icing salt, but didn't really want to put out a salt lick. Now that I have read this article, I see that I was correct.
I think, instead that I will buy some bird grit, and put that out. That way, I know the birds won't get sodium poisoning. Also, I always have a heated bird bath during the winter, so that water is always readily available.
clsouthwick at q.com
On Tue, 15 Jan 2013, Rob Sandelin wrote:
> Date: Tue, 15 Jan 2013 20:07:35 -0800
> From: Rob Sandelin <nwnature1 at gmail.com>
> To: tweeters at u.washington.edu
> Subject: [Tweeters] Birds and road salt article
> CROSSING PATHS NEWS NOTES, WA Dept. Fish & Wildlife
> Crossing Paths with Wildlife in Washington's Towns and Cities
> January 2013
> Can we de-ice our roads without hurting wildlife (ESPECIALLY BIRDS)?
> When Washington winter conditions include ice on our roads, driveways and sidewalks, de-icer applications become a
> safety necessity. But can we have safe human travel corridors without hurting wildlife attracted to salt and grit?
> Wildlife biologists say the answer is "maybe" and it depends on what's used where.
> De-icers used by federal, state and local government road crews, as well as by private citizens at home and work, are
> mostly one of three types: 1) salt based (usually sodium chloride or common table salt, but also magnesium chloride,
> potassium chloride, and calcium chloride), 2) acetate based, or 3) sand.
> Salt based de-icer has been used for over a century in North America and remains the most commonly used type because
> it is relatively inexpensive, available, and effective.
> Large mammals, such as moose, elk, deer, bighorn sheep and mountain goats, are attracted to road salt, which sometimes
> becomes a factor in motor vehicle collisions with these big animals.
> Perhaps less familiar to most is the attraction to salt by some birds.
> "It's all about the salt for winter finches," said Washington Department of Fish and Wildlife (WDFW) biologist Chris
> "Winter" or Cardueline finches, of the Fringillidae family, including siskins, crossbills, grosbeaks, finches,
> goldfinches and redpolls, are seed-eaters that move south in winter when seed is scarce in their more northern
> breeding areas. They are known to love salt, with research showing they prefer sodium over other minerals, regardless
> of size. Salt is used by birds not only to fill a need associated with a vegetarian diet, but also as grit to aid in
> the grinding of food in their crops.
> But research shows that birds ingesting relatively small numbers of road salt granules or small quantities of sodium
> chloride solutions, are at risk of sodium poisoning.
> Normally the salt glands of birds excrete sodium and chloride to maintain proper chemical balance. But those glands
> can be compromised by lack of access to fresh, open water or exposure to certain pesticides or oil, and birds die of
> salt "poisoning" or toxicosis.
> Cold weather that freezes areas of freshwater may force birds to use more saline waters that remain open because of
> the high salt content, including melted snow on roadways. Using salt water to dilute salt ingestion only makes the
> problem worse.
> If birds aren't killed by the road salt itself, they are killed when motor vehicles collide with them on those roads.
> In fact, some research indicates salt ingestion increases the vulnerability of birds to vehicle collisions by causing
> impairment - they are too weak or slow to avoid moving vehicles.
> In one Canadian location - Mount Revelstoke Park -- road mortality of siskins and other winter finches has been seen
> frequently enough over the last 25 years for the birds to be called "grille birds" by the locals, in reference to
> their propensity to be collected by the front end of moving vehicles.
> WDFW biologist Ella Rowan, who monitors WDFW's Wildlife Health hotline, says a call or two every year comes in about
> whole flocks of dead birds in a road, usually winter finches and perhaps where they were ingesting salt-based de-icer.
> So what about the other de-icer types?
> Acetate-based de-icers include Calcium Magnesium Acetate (CMA), Potassium Acetate, and Sodium Acetate. Research
> indicates CMA and potassium acetate do not attract animals and are harmless to them if ingested. Sodium acetate,
> however, may attract animals and contribute to roadkills.
> Sand, of course, is natural, usually composed of crushed aggregate or pure river sand. It has been used to increase
> road or foot traffic traction at least as long as salt, but it obviously doesn't have the actual "de-icing" effect of
> salt. Sand has no negative impact on wildlife, but in the amounts needed to keep roadways safe, it is more expensive.
> Washington Department of Transportation (WDOT) wildlife biologist Kelly McAllister says applying affordable de-icers
> on our state's roads is vital to the safety of winter travelers and we need to look for solutions that don't
> compromise safety. Acetate-based de-icers are very expensive - usually in the range of four to five times as expensive
> as salt-based - they aren't as effective, and they have high oxygen demand when they run off into road-adjacent
> waterways, he says.
> "Providing salt sources for wildlife away from roads is something that is being tried," McAllister said. "I think
> making open water more available to birds that are ingesting salt, to reduce the effects of toxicosis, is another part
> of the solution, but it's obviously difficult to do on a large scale during freezing weather. We're open to ideas and
> citizen help."
> WDFW biologists like Anderson and Rowan recommend that wildlife enthusiasts start at home. Use sand or acetate-based
> de-icers on sidewalks and driveways, or if you must use salt, use it very sparingly and keep it stored out of reach of
> wildlife. Maintain open water for birds during the winter, either by replenishing water at least daily or by using a
> safe bird bath heater element; keep bird baths clean to avoid spreading disease. Provide grit (sand or crushed egg
> shells) in a feeder to reduce the need for birds to go to roadsides.
> And, as always, help birds stay healthy in general by maintaining year-round, sustainable habitat for wildlife in
> your own backyard. If you like watching winter birds close-up by providing supplemental feed, please keep feeders
> clean and use clean, dry feed only to avoid spreading disease.
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