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Crossing Paths is a twice-yearly newsletter for Washingtonresidents enrolled in the Backyard Wildlife Sanctuary Program.Westside: 16018 Mill Creek Blvd., Mill Creek, WA 98012 / 425-775-1311Eastside: N. 8702 Division St., Spokane, WA 99218 / 509-456-4082

www.wa.gov/wdfw

Crossing Paths NewsletterWriter/Editor: Madonna LuersContributing Wildlife Biologists: Russell Link,Patricia Thompson (Seattle-Mill Creek),Howard Ferguson (Spokane), Michelle Tirhi(Tacoma). Printing and Graphics: WDFWPrint Shop and the Washington StatePrinter Graphics Office.

Feral cats are NOT wildlifein need of support

Fall 2003

Wildlife viewingtourism workshopkicks off planning

WITH WILDLIFE IN WASHINGTON TOWNS AND CITIES

(Continued on page 4)

by Dr. Jeff Koenings, WDFW Director

(Continued on page 4)

Thanks to Backyard Wildlife Sanctuarymanager and state Senator Ken Jacobsenof Seattle, who sponsored Senate Bill5011 with the help of Senators ShirleyWinsley of Fircrest and Jeanne Kohl-Welles of Seattle, Washington conductedits first wildlife tourism workshop thisSeptember.

About 150 people, including state andlocal government leaders, gathered inOlympia to explore ways to expandwildlife viewing tourism in Washington’srural communities.

We at the Washington Department ofFish and Wildlife (WDFW) co-hosted theworkshop with the Department ofCommunity, Trade and EconomicDevelopment (CTED) to start developinga statewide strategic plan, as requested bylegislators, for boosting wildlife viewingtourism to provide sustainable economicdevelopment in rural areas and maintainthe state’s diverse wildlife resources.

As I’ve relayed to you before, about2.5 million wildlife viewers spent nearly$1 billion in 2001 in Washington state on

Wild birds and free-ranging cats arenot a good mix.

As a Backyard Wildlife Sanctuarymanager, you most likely keep your catconfined and talk to cat-owning neighborsabout doing the same.

But what about homeless cats?“Feral” cats, which are usually strays

that are untamed or wild, are estimated torange from 60 to 100 million throughoutthe United States. They are NOT wildlife.Feral cats are non-native predators thatcan, and have, seriously damaged wildbird and other wildlife populations.

While domestic cats aresolitary animals, colonies offeral cats often formaround food sources likebird feeding stations,garbage dumps, orplaces where peopledeliberately leave food forthem. In fact, many colonies of feral catsare supported by well-meaning butmisinformed advocates of what’s becomeknown as “TNR” management: Trap,Neuter, Release.

This wrong solution to a tragic problemworks this way: Feral cats are trapped and

taken to a clinic or veterinarian fordisease testing. Those that are seriously illor test positive for contagious diseases areusually euthanized, otherwise they aresimply spayed or neutered. Then the feralcats are released back to where they weretrapped and where they are supplied withfood and water daily.

The theory behind TNR programs,which are funded by both private andpublic entities across the country, iseventual reduction of feral cat colonies.

But sadly, such claims arenot substantiated.

Cat colonies often serveas dumping grounds forother unwanted cats. The

food provided usually attractsmore cats. Contrary to TNR

proponent beliefs, colony cats doNOT keep other cats from joining

the colony. As time goes on, somecolony cats become too wary to becaught, so rarely are all spayed orneutered. With females capable ofproducing up to three litters of four to sixkittens each every year, it doesn’t takelong to grow a feral cat colony.

Well-fed cats, either feral or domestic,become “super-predators” of birds andother wildlife. The need to eat and theinstinct to hunt can and do functionseparately. Any cat owner can attest tothis fact with stories of “gift birds” laid attheir feet by feline companions.

There is extensive documentation thatfree-roaming cats are prolific and efficientpredators, even if, and especially when,they are regularly fed. Almost one-fifth ofall injured wildlife brought toWashington’s wildlife rehabilitatorsacross the state was harmed by cats.

Some TNR advocates believe that feralcat colonies are “wildlife” themselves.

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Living with Washington's Wildlife: Great Blue Heron

(Continued on page 6)

The great blue heron (Ardea herodias)is a large (four-foot-tall), grayish-bluewading bird with a long bill, neck, andlegs. In flight, the great blue heron can berecognized by its long neck folded backon the shoulders, its long trailing legs, andits slow, deep wing beats. Adults can berecognized by the presence of a blackplume. Males and females are identical inappearance.

Great blue herons are found year-roundthroughout Washington. They are at homein both salt and fresh water and are seenon lakes, ponds, rivers, marshes,mudflats, irrigation ditches, and in farmfields and meadows.

Food and Feeding Habits• Herons feed on a variety of prey,

including fish, frogs, young birds andbird eggs, snakes, and insects, as wellas mice, moles, gophers, and othersmall mammals.

• They are “stand-and-wait” predatorsthat remain motionless for longperiods of time, waiting for prey toventure within striking range of theirlong, stabbing bills.

• Herons feed during the day and atnight in lighted areas, generallywithin three miles of their nestingcolony. They tend to be solitaryfeeders, but where the food supply isabundant, many can be found feedingtogether.

• Where water freezes, heronpopulations concentrate along majoropen-water rivers where food isavailable, or they hunt rodentson land.

Nest Sites and Nests• Great blue herons nest in colonies,

also called “rookeries,” which maycontain a few or hundreds of nests.

• Rookeries are usually in isolatedspots away from disturbanceand near suitable feeding areas,although some are in large publicparks and greenbelts.

• Herons nest in deciduous orevergreen trees and snags, usuallynear the top of the tallest ones onvertical branches, often on islands orin trees with water around the base,

presumably to reduce the risk ofpredation by mammals.

• Where trees are absent, nests may belocated on large shrubs, cliffs, andartificial structures.

• Nests are 25 to 40 inches in diameterand 12 inches or more thick,constructed from branches and twigs.

• Rookeries may be used for decades;however, herons will relocate theircolonies in response to increasedpredation on eggs and young,declines in food availability, humandisturbance, and when nest trees fall.

Reproduction• Adult herons can arrive on the nests

as early as February. Nest buildingand repair usually begins in March.

• Three to five pale, greenish-blue eggsare incubated for 25 to 29 days byboth sexes.

• Young birds first fly at around 60days of age and leave the nest at 65 to90 days, at which time they aresimilar in size to adults.

• Great blue herons have one brood peryear, although they may re-nest iftheir first clutch fails.

Mortality and Longevity• Adult great blue herons don’t have

many predators. Bobcats and coyotesoccasionally kill adults feeding atground level.

• Mortality of the young is high: crows,ravens, gulls, eagles, and raccoonsprey upon both the eggs and young.Heavy rains and cold weather athatching also take a toll.

• Six to eight years of age is the normallife span.

Great blue herons are great birds forthe beginning birder to observe, partlybecause of their size. In urban areas,herons have acclimated to people so youcan get a close view of their huntingbehavior. A pair of binoculars or aspotting scope will allow forexceptionally close views of their blackplumes and yellow eyes.

The nesting behavior of great blueherons is not often witnessed because,with some urban exceptions, they nest incolonies in fairly isolated areas. Nestingherons should be left alone, and arearegulations and closures to protectcolonies should be followed. Severalstudies have shown that humandisturbance during the breeding seasoncan cause adult herons to abandon theentire colony.

Great blue herons often congregate atmudflats and eelgrass beds during lowtides from June to December, where theyfeed on small fish. Here you may have theopportunity to view many herons at once.

Tracks: Great blue heron tracks areeasily found in the mud or sand in afeeding site. Their six-inch-long tracksshow four toes and the webbing may ormay not appear, depending on thehardness of the surface.

Droppings and pellets: Great blueheron droppings are semi-liquid and

(Editor’s note: If you’ve got a pondin your Backyard Wildlife Sanctuary,or simply live near a body of water,chances are you’re occasionallyvisited by a great blue heron.Depending on your outlook, heronvisits can be a joy or a frustration.We’ll take a look at this bird in anexcerpt from the “Living WithWashington’s Wildlife” series beingcompiled by WDFW’s Seattle-areaurban wildlife biologist Russell Link.This series of factsheets should beavailable soon at WDFW regionaloffices and on the website, and will bepart of a new book, “Living WithWildlife in the Pacific Northwest”due out next year.)

3

Like those fall leaf colors?Plant deciduous trees now!

Migration isn't just for birdsFall is a favorite season for many bird-watchers

because so many different species migrate through ouryards at this time of year.

But some mammals like bats and whales, butterflies like monarchs and admirals, andeven dragonflies migrate in the fall, too.

Dragonflies? Yes, a small number of dragonfly species move in substantial numbersnow. Dragonfly watching is becoming more popular thanks to more field guides on themarket to help you tell them apart.

One species to look for in Washington is the Common Green Darner (Anaxjunius).

It’s one of the biggest dragonflies, at about three inches in body length with awingspan over four inches. Its thorax is green, abdomen blue to purplish gray, and itsclear wings have pale yellowish areas towards the tips that turn amber as it ages.

Green darners are usually found near ponds or slow streams where they feed onmidges, mosquitoes, and other flying insects. They seldom perch. In late summer andearly fall you might see pairs of them flying in tandem over open water. Many of themmigrate south out of Washington in October.

On Geese and friends . . .When you see geese flying in a “V”

formation, you might be interested inknowing what facts scientists havediscovered about why they fly that way,and the truths they reflect in ourrelationships.

Fact: As each bird flaps its wings, itcreates uplift for the bird immediatelyfollowing. By flying in a “V” formation,the whole flock adds at least 91 percentgreater flying range than if each bird flewon its own.

Truth: People who share a commondirection and sense of communication getwhere they are going quicker and easierbecause they are traveling on the trust ofone another.

Fact: Whenever a goose falls out offormation, it suddenly feels the drag andresistance of trying to go it alone andquickly gets back into formation to takeadvantage of the lifting power of the birdimmediately in front of it.

Truth: There is strength and powerand safety in numbers when traveling inthe same direction with those with whomwe have a common goal.

Fact: When the lead goose gets tired, itrotates back in to wing and another gooseflies point.

Truth: It pays to take turns doing hardjobs.

Fact: The geese honk from behind toencourage those up front to keep up theirspeed.

Truth: We all need to be rememberedwith active support and praise.

Fact: When a goose gets sick or iswounded and falls out, two geese fall outof formation and follow it down to helpand protect it. They stay with it until thecrisis resolves, and then they launch outon their own or with another formation tocatch up with their group.

Truth: We must stand by each other intime of need.

Birches turn nicely yellow in the falland in addition to seeds, they provide lotsof insects for kinglets, sapsuckers,warblers and chickadees, plus leaves formourning cloak and swallowtail butterflylarvae. Keep both these natives wet and infull sun:

• Water birch (Betula occidentalis),hardy clump-grower

• Paper birch (Betula papyrifera),taller, multi-stemmed tree

Oaks often provide warm oranges andbrowns and of course their acorns areconsumed by a wide variety of birds andmammals. If you’ve got the space andpatience for growth, try:

• Oregon white oak (Quercusgarryana), our only native

• California black oak (Quercuskelloggii)

For gorgeous golden color, there’snothing like Quaking aspen (Populustremuloides). Its catkins are eaten bygrouse, pheasants, and siskins, winterbuds by orioles and purple finches,leaves, twigs and wood by everythingfrom deer to rabbits. Aspen’s naturallythicket-forming habit makes it mostsuitable for larger landscapes.

Check out your local tree nursery’sselection of many other deciduous treesand get planting before freeze-up.

What’s not to like aboutall the beautiful shades ofred, orange, and yellowof fall leaves?

If you want more ofthose autumncolors in youryard next fall,plant deciduoustrees now.

Fall is thebest time to plantmost trees and shrubs, since the relocationis easier on dormant root systems that willthen get a jump start on growth nextspring.

There are many colorful species nativeto Washington that are also excellent forwildlife.

Maples come to mind for many fall redleaf fans. We recommend three nativesthat benefit seed-eating grosbeaks,woodpeckers, nuthatches, finches, quail,and grouse, wood-eating deer, mountainbeaver and beaver, and nectar-eating bees:

• Vine maple (Acer circinatum),shade-tolerant understory shrub orsmall tree

• Douglas maple (Acer glabrum var.douglassii), more drought-tolerantsmall tree

• Big-leaf maple (Acer macrophyllum),large fast-growing tree suitable forlarge landscapes

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various goods and services, according toa recently released federal survey. Thesurvey placed Washington seventhnationally in total wildlife viewingspending, just behind states such asCalifornia, Florida and New York.

Wildlife viewers open theirpocketbooks and let their discretionaryincome flow on restaurant meals andmotel rooms, gasoline and galoshes, boatsand binoculars, rain gear and rafts—youname it. And you know it, because asBackyard Wildlife Sanctuary managersyou spend on landscaping plants, nestboxes, bird feeders, and feed throughoutthe year to view wildlife on your ownproperty.

There’s no question in my mind thatour rural communities stand to gain evenmore in the years ahead from wildlifeviewing-related tourism.

Consider that in 1969 there was onlyone major wildlife viewing festival inWashington state. Today there are at leasta dozen festivals, nine of which have beenlaunched since 1990 in communities asdiverse as Othello and Ocean Shores,Marblemount and Walla Walla.

Our Watchable Wildlife programcoordinators Mike O’Malley and ChuckGibilisco are working with George Sharpand Joan Stilz from CTED and NinaCarter from Audubon Washington as partof the planning team for development ofthe statewide strategic plan. A draft of theplan is expected to be presented at a state-sponsored Tourism Forum in Seattle inNovember.

I invite you, as active wildlife viewers,to comment on the draft plan, which willbe available at the forum and posted onour website (www.wa.gov/wdfw).

Some groups have even fought for (andso far lost) accommodations for feral catson wildlife refuges and other publiclands.

In addition to their threats to wildlife,feral cat colonies pose human healthrisks. Even TNR-managed colonies canspread disease such as ringworm,toxoplasmosis, cat scratch fever, andrabies, since every cat is not capturedregularly for health care. Feeding stationsattract raccoons and skunks, the two mostcommon wildlife carriers of rabies, alongwith the cats, which are the mostcommonly reported rabid domesticanimal.

Free-roaming cats of any kind are theirown worst enemy, too. They usually haveshort, miserable lives, due to collisionswith motor vehicles, attacks by otherdomestic and wild animals, accidentalpoisoning or trapping, and parasites anddiseases.

The Humane Society of the UnitedStates reports that the expected life spanof an indoor cat is at least triple that ofcats that spend their lives outdoors.

TNR management of feral cats isclearly not in the best interests of anyone,and it often overwhelms the ability ofwell-meaning people who genuinely wantto help animals. It also undermines effortsof responsible pet owners who keep theircats indoors.

The National Association of StatePublic Health Veterinarians, AmericanAssociation of Wildlife Veterinarians,American Bird Conservancy, AmericanOrnithologists’ Union, and CooperOrnithological Society oppose TNRpractices. In addition, the HumaneSociety of the United States, People forthe Ethical Treatment of Animals, and

American Society for the Prevention ofCruelty to Animals have expressedconcerns about this practice.

So what should be done to protectwildlife and treat all animals humanely?

First and foremost, spay or neuter yourown cats and help promote community-wide spay/neuter information campaignsand low or no-cost spay/neuter clinics.The fewer kittens produced and possiblyabandoned, the smaller feral cat colonieswill be.

Second, keep your cat indoors. Spreadthe word to other cat owners that indoorcats live longer lives and avoid harassingwildlife. Unspayed or non-neutered catskept indoors also won’t add to the feralcat population explosion.

Help inform and educate others thatpracticing TNR is not the solution forferal cat management. Initiate or supportlocal ordinances that prohibit catabandonment and feral cat feeding.Humanely trap and remove feral cats,especially in public areas that providehabitat for wildlife, and take them to ananimal shelter for possible adoption orhumane euthanasia.

For more information contact theAmerican Bird Conservancy’s “CatsIndoors! The Campaign for Safer Birdsand Cats” at 1834 Jefferson Place, NW,Washington, DC 20036(www.abcbirds.org).

Wildlife ViewingTourism Workshop(continued from page 1)

Feral cats (continued from page 1)

Go to the front of the yard!Backyard Wildlife Sanctuary manager Joyce Meyer of King County was ahead of us

when we encouraged in the last edition of this newsletter (Spring 2003) the use of frontyards for wildlife sanctuaries.

“I had 2000 square feet of front lawn removed last year and had LivingearthLandscapes of Redmond re-do my front with a walking path, some native plants, andmostly animal and bird-loving plants,” she wrote. “My existing rhodies were either left orincorporated. I just love the new area and I like to say that the deer trim, water andfertilize my yard now.”

Joyce also reported having a long-tailed weasel, barred owl, and even a bobcat in heryard! We say “go to the front of the yard” with those kinds of results!

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The Great Washington State Birding Trail

The very rare bat colony in an old logcabin north of Spokane that is featured onWDFW’s website “Bat Cam” (http://www.wa.gov/wdfw/wildwatch/batcam/index.html) continues to be monitored byEastern Washington University graduatestudents, this year with the help of radiotelemetry equipment.

The Townsend’s big-eared bat,Corynorhinus townsendii, is a candidatefor state listing as a threatened orendangered species and is considered oneof the rarest mammals in the northwest.They have low populations and lowannual natality rates, probably becausethey have very specific hibernacularequirements involving caves, mines, andbuildings and are very sensitive to humandisturbance. Of the twelve maternityroosts known in Washington, only two arein the eastern part of the state, both inman-made structures.

Like last year, the first 40 or so of thesemigratory bats arrived back at the cabin inearly April. Also like last year, batpresence at the roost was sporadicthroughout the rest of April, May, andJune.

But their overall presence and numberswere consistently lower than last year.

Only five bats were observed in late May,and with the exception of one day when22 bats were present, after mid June therewere only two or four bats.

Researchers began to wonder if thebats had abandoned this roost. In an effortto locate where the bats were roosting,three lactating bats were captured on July2 and radio telemetry transmitters wereplaced on two of them.

The radioed bats were tracked to twodifferent locations, both within threemiles of the original location. One roostwas located in the attic of an abandonedlog cabin similar to the original roost (butpainted a gaudy red) where 175 bats werepresent. The other was located, along withabout 45 bats, in the crawl space of abuilding at a very active youth summercamp.† Both colonies had young.

On July 11 both radioed bats were attheir respective new locations and theoriginal cabin roost (featured on BatCam)had 30 bats. On July 13, one radioed batwas at the “red” cabin and the other wasfound in the original cabin along with 140bats.

By August the original cabin washosting up to 300 bats, including young ofthe year. By early September the bats

Rare bats saga continues with radio telemetry

The first map of the Great Washington Birding Trail, the Cascade Loop, rolled offthe presses last fall. The full-color, foldout map features original artwork of birds anddescriptions of 68 sites from Edmonds to the Skagit, up to the Canadian border, acrossthe mountains to Lake Chelan and back through Leavenworth. The first of six plannedroutes, the Cascades Loop features 225 of Washington’s 365 bird species.

Birding Trail maps are actually driving trips with stops at special places where birdsare most likely to be seen. Each stop describes the habitat, what birds are there in whatseason, where to look, and how to get from a main road to the location.

With 71 million people in America describing themselvesas interested in bird watching, Birding Trails in other stateshave become big business. The Trails and their birdsattract visitors to primarily rural locations, whichspurs economic development and gives localresidents increased incentive to safeguard thenatural areas around their communitiesand region.

The Coulee Corridor route is under development,and following that, a loop around the OlympicPeninsula is planned. You can order over thephone by calling 1-866-WA-BIRDS (1-866-922-4737)or you can†order the map at http://wa.audubon.org/new/audubon/default.cfm?pageID=136

were beginning to disperse, with around150 left. At the same time, the newlydiscovered red roost had around 25 bats.

This movement between roosts is still amystery so research will continue nextyear when the bats hopefully return again.

Winter birdsurveys

discontinuedTen years of the Washington

Department of Fish and Wildlife(WDFW) winter backyard birdsurveys have come to an end. Dueto budget cuts, the survey will notbe continued. WDFW surveycoordinator Patricia Thompsonthanks all Backyard WildlifeSanctuary managers for theirparticipation in this effort to learnmore about Washington’s winteringbird populations. A wrap-up reportwill be sent out to all participantslater this year or as soon as possible.

6

Great Blue Herons (continued from page 2)

mostly white. The ground beneath nestscan become coated with droppings.Undigested material is coughed up as 2 to3 inches pellets, containing signs of fish,rodents, and other prey.

Calls: The normal call of a great blueheron is a deep, hoarse “fraaaahnk” or“braak”. In aggressive situations or whenfrightened, the call is a short, harsh “frankfrank frank taaaaaw”. Herons call inflight and on the ground, during the dayand at night.

An adult arriving at the rookery usuallygives a dull, guttural cry. The young cancry loudly and constantly when hungryand about to be fed.

Tips for Attracting HeronsA pond full of small fish makes a

wonderful heron feeder. Keep the pondstocked with cheap feeder goldfish, givethe heron a place to stalk them, and enjoythe show. To give fish a place to hide, oneor two areas can be kept as hunting spotsfor herons and the other areas can beheavily planted to block access into thepond and provide cover for the fish.

To help preserve heron habitat:• Preserve shoreline trees and any tall

groups of trees by the water.• Protect eelgrass beds, which are great

habitat for herring — a major foodsource.

• Protect wetlands.• Keep pets, especially dogs, under

control and away from great blueherons and rookeries.

• While boating or visiting the beach,give herons and heron rookeriesplenty of space.

• Minimize development near heronrookeries.

Preventing ConflictsMany people are willing to lose some

inexpensive feeder fish to great blueherons in exchange for the opportunitysee one of these magnificent birds.However, some homeowners haveexpensive fish in their pond or havebonded to the ones they placed there andwatched grow. Others object to the messherons sometimes leave behind.

Predation can occur at any time of theyear, although the problem is greatest inspring and early summer, when the birdsfeed their young. Each day, an adult heronneeds about 13 ounces of food, which isequivalent to three six-inch koi or 10 two-

inch goldfish. Herons take twice thisamount when feeding their young.

Herons usually visit ponds wheneverything is quiet, usually early in themorning or in the evening. Once they’vefound an easy source of food, such ascolorful fish in a shallow pond, they willreturn on several consecutive days untilmost of the fish have been taken.

There are several ways of reducingheron attacks on your pond fish. All aremost successful when in place before thebirds discover the easy food source.

(Keep in mind that all heron species,nests, and eggs are protected year-roundfrom persecution, hunting, andharassment under federal and state law. Afederal permit may be obtained from theU.S. Fish and Wildlife Service to uselethal means to control herons whenextreme damage is occurring on privateproperty. Such a permit is only grantedafter all other non-lethal control

These barriers need to be checked dailyfor maintenance and entangled birds.Brightly colored top nets are more visibleto birds and reduce entanglementproblems.

Create a perimeter barrier: Heronswill not normally land directly in thepond, as they will scare the fish. Instead,they land nearby and slowly walk towardthe water. Install two strands of electrifiedwire, eight and 18 inches off the ground,and back from the water’s edge to preventthe heron from leaning over the barrier tocatch the fish. (Strong fishing line may betried at first, but herons are likely to gounder or over it.)

The wires can be hooked up to a switchfor discretionary use; when you want towork near the wires, turn the system off.Be sure to keep the wires away fromshoreline plants that can short the powerout.

For safety, tie a sign, cloth, or othermaterial on the wire for visibility.

Alternatively, or in addition to aperimeter fence, secure a two-foot widestrip of chicken wire flat around the insideof the pond edge and just under the waterin areas where a heron is entering thewater. (Cut the wire as needed to matchthe curvature of the pond.) Herons willhave difficulty reaching over the wire,and will tend to not stand on it because ofits instability. To camouflage and extendthe life of the wire, paint it with dark-colored automobile undercoat paint orother rustproof paint.

Provide hiding places for fish: Plantmat-forming aquatic plants, such as waterlilies, for protection during the growingseason. For year-round protection,construct hiding places on the bottom ofthe pond using cinder blocks, ceramicdrain tile, wire baskets, or upside-downplastic crates held in place with heavyrocks. Deepen areas of the pond to at leastthree feet — too deep for the heron toreach.

Preventative pond and plantingdesign: When designing a pond it ispossible to make life difficult for herons.Dense growths of tall marginal plants orshrubs around the pond will limit theiraccess to the water. Ensuring the pondside is steep and the water is eight to 12inches below the edge of the pond will

(Continued on page 7)

techniques have proven to beunsuccessful.)

Create an overhead barrier:Suspend a taut net (with a mesh size ofthree inches or less) above the pondsurface. Make sure the net is at least twofeet above the pond and cannot fall intothe pond when a heron lands on the netand tries to spear the fish through it.While this may not be the best lookingsolution, it is by far the most effectivedeterrent for most herons.

Exclude herons from large ponds bysuspending parallel strands of steel wire(28-gauge) or monofilament line (50-pound test) over the pond. Wire ormonofilament lines should be spaced nomore than 12 inches apart. Wire or linebarriers should be installed at least twofeet above an area needing protection.Prevent herons from entering under thebarrier by installing a two-foot high wirefence or a perimeter barrier as describedbelow.

7

Habitat fragmentation may help spread WNV

also help because the heron will not beable to reach the fish.

Scare tactics: Although law protectsthese birds, you may harass them withoutobtaining a permit as long as the birds arenot nesting or touched by a person or an“agent” of a person (e.g., a trained dog).There are a number of commercialdevices available that work in different

Great Blue Herons (continued from page 6)

ways. Some work on a “tripwire” basis,producing a loud noise and, in somecases, a visual deterrent which scares theheron away. The “Scarecrow“” detects thepresence of the heron using infrareddetection, and scares it away by sprayinga high-pressure jet of water. Theeffectiveness of scare devices is oftenshort term as birds may quickly becomeaccustomed to them.

(Excerpted from an article by Laura Spinney)

Researchers have found that themosquitoes that transmit West Nile Virus(WNV) to birds are quite particular aboutthe species they feed on. One of theirfavorites, the brown-headed cowbird,happens to be increasing in numbers andpushing westwards through the US as aresult of the fragmentation of its habitatby humans, showing how we might bedriving new epidemics towards ourselves.

The primary hosts of WNV are birds.Mosquitoes that normally feed only onbirds maintain a cycle of infection withinthem, and the virus only breaks out of thatcycle to infect other species when “bridgevectors” - mosquitoes that bite bothhumans and birds - come into contactwith an infected bird.

For that reason, the degree of contactbetween bird and mosquito – or horse andmosquito in the case of another, far morevicious neurological disease calledEastern Equine Encephalomyelitis (EEE)- is thought to be a major factordetermining whether the virus crosses thespecies barrier. When contact is high, thevirus amplifies itself more quickly andthere is a higher chance that the bridgevector will come into contact with it.

To investigate how the degree ofcontact affects viral levels, and hence therisk of infection for humans, ThomasUnnasch of the University of Alabama atBirmingham and colleagues analyzed thestomach contents of bird-bitingmosquitoes in three states: New Jersey,New York and Tennessee. They used areverse transcriptase-polymerase chainreaction to detect the presence of WNV,and another sensitive assay to determinethe species of origin of the mosquitoes’blood meals.

At all the testsites, they foundthat of the 24 birdspecies themosquitoes fed on,three accounted formore than 50percent of theblood they had

ingested. Of these, the most notable wasthe brown-headed cowbird.

Similarly, in Alabama’s TuskageeNational Forest, which saw an epidemicof EEE in 2001, the first year of the study,the mosquitoes favored two species: theAmerican robin and the brown-headedcowbird, with the cowbird accounting formore than 40 percent of their blood meals.

The American crow seemed not to beto the mosquitoes’ liking at any of thesites, although American crows areregarded as “sentinels” for the arrival ofWNV because they are highly susceptibleto it and die off quickly once infected.

In both the EEE and WNV studies, theresearchers were surprised to find that thebirds the mosquitoes preferred to bitewere not endemic to the swamps theythemselves inhabited. The birds’ usualhabitats were grasslands or higher altitudeecosystems.

According to Unnasch, that suggeststhe mosquitoes’ habitat could be largerthan was previously thought, and theymight forage outside swamp areas beforereturning to them to digest their meals andlay their eggs. At the same time, forestclearance could be enabling grassland-dwelling cowbirds to stray closer tomosquito-ridden areas. “What we areseeing is a consistent pattern of these

arboviral vectors targeting just a very fewspecies,” he says.

His team also found that in July andAugust a higher proportion of themosquitoes’ blood meals came from hostsother than birds. Before that July drop-off, however, birds were their maintargets.

Unnasch thinks that the mosquitoesmight be zeroing in on fledglings ofcertain species. He suggests that youngbirds are a dead-end population. Becausethey are virally naive, they die quicklyand provide no reservoir for transmissionto other birds or humans.

However, fledglings abound early inthe season and transmission generallypeaks in late summer, he says, so moreresearch is needed to explain the delayed,late summer peak.

“This to me is really interestingbecause of the increases we have seen inbrown-headed cowbirds with thefragmentation of the landscape,” saidSharon Collinge of the Department ofEnvironmental, Population andOrganismic Biology and theEnvironmental Studies Program at theUniversity of Colorado, Boulder.“They’ve moved westwards and they tendto forage more around forest edges.”

Plastic herons: Artificial plasticherons are very popular. Their success isbased on the principle that herons areterritorial and will not feed close toanother heron. Unfortunately, this is notcompletely effective at any time,especially in late winter and early springwhen the herons are searching for a mate.In this case, it may actually attract heronsto your pond.

8

Tell Your Friends:

Washington Departmentof Fish and WildlifeBackyard Wildlife Sanctuary Program

Westside: 16018 Mill Creek Blvd.,Mill Creek, Wa. 98012 / 425-775-1311

Eastside: N. 8702 Division St.,Spokane, Wa. 99218 / 509-456-4082

Personalized PlatesHelp Wildlife

The Washington Department of Fish andWildlife will provide equal opportunities to allpotential and existing employees without regardto race, creed, color, sex, sexual orientation,religion, age, marital status, national origin,disability, or Vietnam Era Veteran’s status.

The department receives Federal Aid for fishand wildlife restoration.

The department is subject to Title VI of theCivil Rights Act of 1964 and Section 504 of theRehabilitation Act of 1973, which prohibitsdiscrimination on the basis of race, color,national origin or handicap. If you believe youhave been discriminated against in anydepartment program, activity, or facility, or if youwant further information about Title VI or Section504, write to: Office of Equal Opportunity, U.S.Department of Interior, Washington, D.C. 20240,or Washington Department of Fish and Wildlife,600 Capitol Way N, Olympia WA 98501-1091.

The Backyard Wildlife Sanctuary program, along with other non-game functions ofthe Washington Department of Fish and Wildlife (WDFW), is funded by the sale ofWashington state personalized motor vehicle license plates. These distinctive plates— in your choice of unclaimed word(s) up to seven letters — cost an extra $46 forthe first year and an extra $30 for each subsequent year.You can pick up an application form at any statelicensing or WDFW office, or by contacting theDepartment of Licensing at P.O. Box 9042, Olympia,WA 98507, 360-902-3770 (telephone menu option #5).

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OLYMPIA WAPERMIT #26

600 Capitol Way N • Olympia WA • 98501-1091

Electronic delivery availableA few Backyard Wildlife Sanctuary managers are getting this newsletter via e-mailnotification of its posting on WDFW’s website, rather than a printed copy in the mail.If you want electronic delivery of future editions, send your complete name andcurrent delivery address, along with your e-mail address, to newsletter editorMadonna Luers at luersmel@dfw.wa.gov.

Personalized Plates Help Wildlife

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