Sunday, October 25, 2015

Raptors of Shoshone Tecopa and the Amargosa River
      Just about every type of  Vulture,Hawk, Eagle, and Falcon appear in our area at some time .
Here are a few of my favorites.

Northern Harrier (juvenile plumage)
Northern Harriers breed regularly in Shoshone, and Tecopa Marsh. On the first night that I arrived here from Maine  in 2009, I witnessed the “mid-air food toss” at sunset of the male Northern Harrier dropping a fresh prey item in flight to the female who swooped up, grabbed it easily and disappeared back down into the nest area. I have been hooked on Harries ever since. They are present year round in Tecopa Marsh but the birds are not necessarily the same individuals year round.  On Tecopa Marsh, Harriers often easily move Coyotes away from the nest area by landing near the Coyote, allowing it to approach, then moving to an enticing nearby spot, and repeating the process until the Coyote is out of the Harrier territory.  Northern Harrier is a “California Species of Special Concern” due to marsh-like habitat destruction throughout California. 
Adult female Northern Harrier
      In the spring, as early as February, the sky-dance of the male Northern Harrier begins. He can be heard over Shoshone Wetlands or Tecopa Marsh, calling rapidly while making rapid ascents and descents . Usually he is displaying to the female, but I have observed a male sky-dancing another male apparently as a territorial display, laying claim to the prime Harrier habitat, not to mention the female therein. Males are known to have more than one female, sometimes several, correlating to his ability to provide. Reverse sexual dimorphism is very apparent when the pair is seen together. The female looks almost twice as big as the male. 

Their plumages are completely different. Northern Harriers are easy to identify with a little practice, and can be found in marshes from Alaska to Central America.
                   There are 13 Species of Harriers in the world.  Our Northern Harrier is extremely closely related to the Hen Harrier which occupies similar habitat types throughout the Northeastern Hemisphere, from Portugal to Japan.

                                                American Kestrel

At 7.5”-8” this is the 2nd smallest of all the worlds’ 39 Falcon species, all in the genus Falco. Only the Seychelles Kestrel is smaller.American Kestrel has a huge range. It covers most of the Western Hemisphere from Alaska to Tierra del Fuego.. They are beautiful, graceful, and take a variety of prey from grasshoppers, dragonflies, to lizards, and small birds.
                Locally, Kestrels are often seen in  winter hunting from power poles and wires around Shoshone, and a pair is often found around Tecopa Marsh, and or the Amargosa Canyon during breeding. Kestrels will use a nest box of the following dimensions.

                                 Prairie Falcon

             Prairie Falcons are our year round resident falcon. They do breed in this area, I have found their nests more than once. They breed up on high cliffs. Prairie Falcons average only slightly smaller than Peregrine Falcons. Reverse sexual dimorphism is apparent in the size differences between males and females. According to “Falcons of the World” by Tom J. Cade, males weigh as low as 17.5 ounces and at the most 22.5 ounces, females as much as 34.5 ounces.  Imagine a 17.5 ounce male and a 34.5 ounce female! When seen as a pair they seem almost a different species. Prairie Falcons can take a great variety of prey items from large insects and small birds to Chuckwallas Desert Iguanas, Desert Cottontails, Black-tailed Jackrabbits, and any type of rodents.
See the powerful legs of Prairie Falcon

Prairie Falcon putting on the brakes

Peregrine Falcon

Peregrines are occasionally seen in Shoshone and Tecopa in the non-breeding seasons. Over the last few years, a pair has been seen during June, which indicates possible breeding somewhere in this area. The closest known breeding pair is Mt Charleston in nearby Spring Mountains.
        Peregrines, are mainly bird catching machines. They use many different hunting strategies.

 Peregrines the fastest known birds, when diving, called the stoop, from amazing heights at even more amazing speeds! Although average prey sizes are not quite so dramatic, even the 6 foot wing-spanned Great Blue Heron is not safe from a Peregrine. Imagine a 47 inch tall Great Blue Heron a formidable predator, being hit by the talons of a 53 ounce Peregrine Falcon from behind in the neck at 275 miles per hour!

Peregrines reverse sexual dimorphism is exaggerated with males weighing in from 24.5 to 30 ounces and females up to 53 ounces.
 Weight References: Falcons of the World ,by Thomas Cade

Red-tailed Hawk

Red-tailed Hawks are also year round resident species.  Locally they are known to breed on the high walls of the Amargosa Canyon, and occasionally in rare, tall isolated trees or groves of trees. The Amargosa Canyon sometimes has two pairs of Red-tails nesting in the cliff faces. Dark plumage varieties of Red-tails as well as typical “western” plumage forms are found in the Amargosa Canyon. 
Chocolate plumage Red-tailed Hawk

Red-tailed Hawks take a variety of snakes, big lizards, rodents, rabbits, road kill, and road injured animals and birds of any type. Many Red-tailed Hawks are injured or killed in collisions with vehicles.
In 2012 as Staff Naturalist for Shoshone Village, I helped kids at Death Valley Academy in Shoshone, make wildlife videos as a joint project with Partners for Fish and Wildlife. Check this one out” Red-tailed Hawk eating Coot brains, a Death Valley Delicacy” by one of the kids in 10th grade at the time.

Red-shouldered Hawk

   Red-shouldered Hawk
   Juvenile Red-Shouldered Hawks often winter in Shoshone. They do breed locally as close by as Pahrump, NV. 27 miles away. It is not known whether the Red-shouldered hawks that often arrive in Shoshone are dispersing from Pahrump or whether they are from far away. 
This Juvenile Red-shoulderd Hawk has been hanging around the new Shoshone bird pond for a few weeks.

More raptors soon!

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