MTPR

'Field Notes': Bird Watching At The Polson Dump

Apr 24, 2016

Bird watching at the Polson dump is not for the faint of heart. The task requires an unnatural tolerance of gigantic machinery operated by large men wearing overalls and permanent looks of disapproval. But if you're serious about observing gulls, you need to go to where trucks discard trash at the edge of town. Evidently it's much easier for gulls to pick through our leftovers than to catch freshwater shrimp and fish.

We approach the small guard house that leads into the dump. A gruff man waves us in when told that we're here to see the birds. Aware of our role as avian lunatics, we approach the trash-churning bulldozers. It's 10 o'clock mix-up time, the equivalent of a bird buffet.

My guide parks at the edge of the dump. Using the truck as a blind, he sets the spotting scope. Initially, I see only a mess of grey and brown bodies with white bellies, but we explains that these impossibly similar birds hide their differences in their beaks and legs. After a few unsuccessful attempts at identification, I begin to recognize the distinctions. The few herring gulls have peach-colored legs. The common ringbill gull does in fact have a black ring around its bill. The occasional California gull has a distinctive red dot on its beak.

The birds gather together in a feeding flock with the hope of snatching another's meal. Even though the refuse spread is large and seemingly endless, this instinct remains.

Approximately 1,000 California, ringbill and herring gulls make up this flock. When threatened with the arrival of a newcomer.Two ringbills ferociously peck and push at the unwanted herring. In breeding colonies, the characteristically pushy ringbills steal the eggs of the other birds. The less confrontational herrings prefer to eat dead and dying fish, making them the targets of the ringbills' ruthlessness. There is an invisible code, a set of unalterable rules that governs the dump. Violators are swiftly taught a lesson.

We spot a rare mew, a species that usually stays near the coast. The bird is distinguished by it short, solid yellow beak. After barely catching a glimpse of yellow, we watch a bulldozer send the entire colony into flight. The birds dive jaggedly with flapping wings and snapping beaks, vehemently staking their new claims.

The gulls deceptively settle at the edge of the dump after rummaging through the revealed trash. Once faced with near extinction, these all-terrain, all-weather wonders are willing to do whatever it takes to survive. Gull feathers were sent into the millinery trade until a 1916 treaty protected non-game birds. Today, the exploding gull population has been directly linked to the increasing number of landfills, which provide a dependable food source for adults and allow young birds to survive until they develop hunting skills.

According to gull expert and Nobel Laureate, Nikolaas Tinbergen, "A gullery is no city of friends." It's incredible that the horrors of murder, infanticide and thievery are hidden within this odd group of birds that spends a considerable amount time inexplicably staring at their feet.

"Field Notes" is produced by the Montana Natural History Center.

(Broadcast: "Fieldnotes," 01/08/16. Listen on air or online Sundays at 12:55 p.m., Tuesdays at 4:54 p.m., and Fridays at 4:54 p.m., or via podcast.)