As if someone turned off a switch, October brings an end to the summer ambiance we have enjoyed for the last several months. Days become shorter, nights become cooler, the leaves begin to fall, and many local species begin a long journey south in search of a warmer climate to spend the winter months.
As I wrote about in last month’s column, monarch butterflies are currently making an extraordinary migration to Mexico. Each night, they will stop to roost, with some roosts numbering in the tens of thousands of butterflies. Seeing one of these roosts can be a magical experience.
In addition to the monarchs, raptors are also heading south before the onset of winter. Better known as birds of prey, raptors include species of hawks, falcons, owls, and vultures. The term raptor is derived from the Latin word rapere, which means to seize or take by force. There is no denying that they are well deserving of this name, as they can snatch an un-suspecting critter in a blink of an eye with extreme strength.
Of the local raptors, none are more impressive than a peregrine falcon. Built for speed, a peregrine can reach speeds of 200 mph as it drops from the sky in what is known as a stoop. Feeding primarily on medium-sized birds such as pigeons, gulls and ducks, a peregrine will stoop on its prey and catch it in one of two ways. For smaller quarry, the peregrine will merely grab it with its sharp talons and fly off to a safe location to feed. For a larger prey, the peregrine will smack it from the sky with its large feet with such force that it will stun or even kill the prey instantly. Once on the ground, they can break a still alive victim’s neck using their notched beak as if it were a can opener.
The population of peregrine falcons crashed during the mid 1900s and were listed as an endangered species due to the use of DDT. Used to control mosquitoes, DDT initially entered the environment low on the food chain. As contaminated organisms were consumed, the chemical was passed onto the predator and stored within their fatty tissue (a process known as bioaccumulation). As the toxin moved through the food web, the concentration became greater in top predators (a process known as biomagnification). Thanks to the banning of the chemical DDT, not only have we have seen a resurgence of this majestic bird to a status of no longer being listed as endangered, it is once again common to spot ospreys and eagles on the North fork.
Two other falcon species, the American kestrel and the merlin are also quite common during this fall migration. The kestrel is the smallest falcon of North America with a wingspan of up to twenty-four inches. Because of its small size, the kestrel feeds on much smaller prey than the peregrine. Insects such as grasshoppers, dragonflies and beetles make up a majority of its diet with the occasional small bird or rodent also being consumed. The slightly larger merlin feeds primarily on small, flocking songbirds. Their feeding techniques are different from that of a peregrine. Instead of stooping on their prey from above, they use quick wing beats to chase down their prey and snatch it from midair.
Another raptor commonly cruising salt marshes and farm fields this time of year is the northern harrier, which is also known as a marsh hawk. With a wingspan of four feet, they are much larger than the previously mentioned birds. Their feeding method is also quite different and can be useful when trying to ID this bird while in the field. With only a couple of wing beats, they are capable of soaring great distances while only a few feet above the ground. Unlike most hawks, harriers rely heavily on their hearing rather than vision to find food. In fact, their heads are more “owl-like” than a typical hawk, allowing the slightest sounds to be funneled directly to their ears. Flying close to the ground, they listen for mice or voles rustling in the marsh grasses. When a favorable sound is heard, they drop from the air to pounce on potential prey.
Additional raptors such as red-tailed hawks, coopers hawks, sharp-shinned hawks, gyrfalcons, osprey and even bald eagles can be seen flying through the North Fork this time of year. The rate at which they pass through the region is amazing and can make the odds at spotting them very high. My favorite places to watch for them are wide open areas such as salt marshes and farm fields. With the abundance of food in these locations, it is only a matter of time before one flies by looking for a meal. Cool, breezy days are the best times to be on the lookout, as the cold temps will increase their drive to feed and the breeze will let them to cover greater distances with little energy expenditure.
Over the last few days I have been spotting more raptors on a daily basis than I have all summer. As temps drop, this frequency will only continue to increase. So grab your binoculars, head to the nearest open field and spot some of the North Fork’s birds of prey.