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Urban Crow Population on the Rise

Sam Eaton

Many cities across the country are experiencing a new baby boom. But this time it’s not the humans that are multiplying, it’s crows. In Seattle scientists say the recent rise in their numbers may owe much to the crow’s ability to mimic the human lifestyle and thrive in the face of growing sprawl. KUOW’s Sam Eaton followed scientists over the summer as they tracked these intelligent birds through their breeding season. He files this report.

THERE’S OWL DAY, EDIBLE PLANT DAY, AND HUMMINGBIRD DAY. BUT TODAY AT WEST SEATTLE’S “CAMP LONG” NATURE CENTER… IT’S CROW DAY… AND THE AUDITORIUM IS PACKED. I’m just thrilled to have all you folks here that are interested in crows and natural history… (fade under following track) URBAN NATURE ENTHUSIASTS AND THEIR CHILDREN HAVE COME HERE FROM ALL OVER TO LEARN ABOUT THE LATEST SCIENCE ON CROWS… A BIRD THAT’S BEEN SO SUCCESSFUL LIVING AMONG HUMANS THAT THEIR POPULATIONS IN CITIES LIKE SEATTLE HAVE EXPLODED. AFTER A SLIDE SHOW PRESENTATION, THE AUDIENCE DONS BINOCULARS AND SETS OFF FOR THE PARKING LOT WITH UNIVERSITY OF WASHINGTON CROW RESEARCHER JOHN WITHEY AS THEIR GUIDE. There’s one in the grass and it looks like it’s picking at the grass… now it’s moving around… IT’S THE BEGINNING OF MATING SEASON FOR THE CROWS. WE WATCH AS THEY GATHER BITS OF STRAW AND TWIGS FOR THEIR NESTS. NINE-YEAR-OLD KATHLEEN MIKULI (mick-KOOH-lie) IS THRILLED BY THE SIGHTING. There very amazing and it’s interesting how they communicate also. ANOTHER PARTICIPANT, LORRIE FARMER, SAYS SHE’S BEFRIENDED A CROW IN HER BACK YARD AND CAME TO CROW DAY TO LEARN MORE ABOUT THE BIRD’S COMPLEX SOCIAL BEHAVIOR. I think they’re quite intelligent they seem to have a different interaction than most birds with humans, kind of a complex interaction of sorts, and that attracts me to them. BUT AS FUN-NATURED AS CROW DAY SEEMS, BIOLOGIST JOHN WITHEY SAYS CROWS HAVE THE POTENTIAL TO CAUSE SERIOUS PROBLEMS IN URBAN ECOSYSTEMS ALREADY UNDER STRESS. I think the more important implications are you know what does urbanization do to the bird populations. And as much as I like crows, when you have a lot of crows other birds tend to not do so well. THIS POTENTIAL TO WREAK HAVOK ON NATURE ADDS AN ELEMENT OF URGENCY TO WITHEY’S RESEARCH. HE’S TRYING TO FIND OUT WHY CROW POPULATIONS IN CITIES ARE SKYROCKETING EVEN THOUGH THEIR BREEDING RATES HAVE STAYED NEARLY THE SAME. HIS THEORY IS THAT CROWS, LIKE MANY HUMANS, PREFER TO RAISE THEIR YOUNG IN THE QUIET SUBURBS. BUT THE YOUNG CROWS, AGAIN LIKE HUMANS, ARE ATTRACTED TO THE EXCITEMENT OF URBAN CORES, WHERE THEY CAN EASILY FIND MATES AND LIVE OFF DISCARDED HAMBURGERS AND FRENCH FRIES WITHOUT THE THREAT OF PREDATORS. In a way I call it the young urban crow phenomenon, the “yukies.” You know if you just want to hang out with other crows and find easy food, then coming into urban areas is a good way to go. AND AS HUMAN SETTLEMENT IN THE WEST CARVES ITS WAY FURTHUR INTO THE WILDERNESS, REPLACING FORESTS WITH TRASHCANS AND MANICURED LAWNS, WITHEY SAYS WE’RE CREATING THE PERFECT HABITAT FOR CROWS. THAT’S WHY TRACKING THEM ACROSS THE SUBURBAN-URBAN DIVIDE IS SO IMPORTANT. (climbing tree) I'm just going to crawl out on the branch to reach in, (squawking crows) those are the nestlings if you can hear them, they think they're going to get fed... EVERY SUMMER WITHEY DONS A CROW-PROOF HELMUT AND CLIMBS INTO THE CROWNS OF TREES WHERE NESTS ARE CAREFULLY CONCEALED. ON THIS DAY, HE’S FIXING COLOR-CODED LEG BANDS ON A GROUP OF SCRUFFY NESTLINGS, HIDDEN IN A CHERRY TREE ON THE UNIVERSITY OF WASHINGTON CAMPUS. THESE NEW RECRUITS WILL BE ADDED TO HIS ARSENAL OF ABOUT 400 BANDED CROWS, ALLOWING WITHEY TO FOLLOW THEIR MOVEMENTS. AND WHAT HE’S FINDING SO FAR IS THAT CROWS HATCHED IN THE SUBURBS ARE IN FACT HEADING INTO THE CITY. One moved from North of Woodinville into Seattle, so 20 or 30 miles. Another moved from Duvall into Bellevue so that's about 30 miles as well. Both of those seem to be spending time with bigger groups of immature crows so it seems like if they're moving around a lot they're with other similar aged crows just hanging out just looking for good places to find garbage and go into McDonalds. THAT MAY BE THE IDEAL LIFESTYLE FOR CROWS, BUT FOR OTHER BIRDS, LIKE THE SPARROW-SIZED JUNCO, THE INCREASING CROW POPULATION IS YET ANOTHER MARK AGAINST IT. (SFX: walking on gravel path) There's a Junco just flew up from, that's not where the nest is but that might be a re-nest under that tarp even, the nest I know of is just over the other side here. IN A QUIET SUBURBAN NEIGHBORHOOD NORTH OF SEATTLE, U-W FOREST ECOLOGIST JOHN MARZLUFF IS LOOKING INTO THE WIDER PICTURE OF URBANIZATION, WHERE SPECIES LIKE SONGBIRDS TEND TO LOSE OUT IN THE FIGHT FOR HABITAT. So there's the nest, one egg kicked out of the nest down here, so could've been that a predator came in and it ate a couple of the eggs. WHILE CROWS ARE ONLY ONE OF MANY NEST PREDATORS THAT THRIVE IN THE SUBURBS, MARZLUFF SAYS THE CUMULATIVE EFFECT-PAIRED WITH THE RAPID PACE OF HUMAN DEVELOPMENT-IS CAUSING A DRAMATIC SHIFT IN THE COMMUNITY OF BIRDS THAT LIVE HERE. Where we're standing, only about months ago was forest and now it's grass, and for a bird to be able to respond to those kind of changes it has to be able to remember what's happened in an area and adjust rather quickly to n