A Few Winter Field Scavengers

     I was driving along Route 23 through the Twin Valleys of eastern Lancaster County, Pennsylvania, on a cold, windy day, when I noticed several turkey vultures and many American crows in a harvested corn field planted to winter rye to enrich the soil and keep it from eroding.  I pulled into a farmer's lane to get off the highway to view those birds.  And as soon as I did I noticed a great cloud of ring-billed gulls lift off that same field, but farther back.  The gulls swirled over several large, adjoining fields several times then dropped to a field like a blizzard, making that part of the big, open habitat appear white.  The vultures, crows and gulls are adaptable, scavenging birds that are successful in fields and landfills.
     The vultures and crows were in that field because someone spread manure on it that, apparently, had dead chickens in it.  The blades of the spreader that chop up the manure and fling into the fields also did that to the dead chickens.  The vultures and crows saw those chicken parts, including wings, and dropped to the field to eat the meat on them.
     The turkey vultures dominated those chicken remains, but the crows attacked the vultures with feet and beaks.  Those attacks didn't hurt the vultures, but some of them yielded to the crows.  But other vultures fought back in seeming anger, and won.
     While the vultures and crows interacted with each other over food, the ring-bills did not associate with the vultures or crows.  They stayed to themselves, feeding on whatever invertebrates, seeds and grains they could find.
     However, the gulls were restless, taking off into the air in a great, tight ball of themselves.  I looked in the sky for a bald eagle, because those eagles also scavenge dead animals and may have been in the vicinity, frightening the gulls into flight.  I didn't see an eagle, but I did spot a peregrine falcon chasing and diving on a lone gull.  Both birds went over a hill, the falcon right behind the gull, and out of sight.  I never did see them again to know the outcome of that chase.  I presumed the gulls were in a close gathering in the air to protect themselves from the peregrine.  All the gulls moved on after that scare, and many of the vultures and crows left the area as well.
     A couple of handsome red-tailed hawks stayed on the field where they, too, were scavenging chicken meat.  They apparently didn't fear the falcon and I saw the red-tails after many of the other birds left the area.
     Interestingly, several black vultures soared over those same fields, but did not land on them.  I read that black vultures are not interested in small bits of meat, though turkey vultures are.  Therefore, the black vultures sailed on across the sky to look for carrion elsewhere.  Sometimes,it doesn't pay to be particular. 
     Those fields were interesting with wintering, scavenging turkey vultures, American crows, ring-billed gulls and red-tailed hawks that all take advantage of some of our practices, in this case, throwing dead chickens in fields with manure.  It's the plants and animals that have adapted to what we people do that will survive into the future.