Thursday, February 14, 2013

Pirate Bird

In the spring of 2012 I made a trip to Sabine Pass to check on migrants, hoping to catch a nice fallout, when I happened upon a Crested Caracara (Caracara cheriway) on the edges Hwy 87.   A bird of prairies, grasslands, and pastures, it was perched atop the bare branches of a tallow tree. It probably had been touring the highway for easy roadkill and decided to take a break upon this reviled invasive tree. It wasn't a restful break that's for sure, because a mockingbird was mobbing it for all it was worth.   Soon blue jays and grackles joined in on the fray.  It sat there in all its glory, ignoring the mobbers as if they didn't exist.......meaningless confetti. 
It’s also known as Audubon’s Caracara, King of Vultures, Caracara eagle, Common caracara, and King buzzard, and in Mexico it is known as a Mexican eagle or Mexican buzzard. Like the falcons they are related to they possess a "tomial tooth"on the upper mandible providing them with an effective means of dispatching live prey by the severing of its captive’s spinal cord. 

This bird is odd looking to say the least with its chicken-like legs and odd looking head.  I recall someone once saying that it looked as if it had an unruly toupee upon its head. In the book “Birds of America” I found this quote- “Perched upright in the cactus or mesquite, with a strange grandfatherly appearance, or flying slowly with stiff outstretched neck, Audubon’s Caracara strikes the observer with singular grotesqueness.”  Strange looks aside, it is a wily creature and like most other breathing animals on this great blue planet it will do whatever it takes to survive and flourish.

Though it is considered a predator they are opportunistic feeders and scavengers, usually hanging around with the likes of roadside carrion eaters such as black and turkey vultures and it never passes up an opportunity to steal or "pirate" food if the occasion presents itself. They’re  even so bold as to harass bald eagles and osprey (18) on the wing in an attempt to get them to drop prey they possess in their talons. They've also been seen attacking brown pelicans with pouches filled with fish, causing them to disgorge so that they could get it for themselves. The Texas naturalist Roy Bedichek in his book Adventures with a Texas Naturalist said "...he is a porch-climber and a thief, and the name "eagle" is a misnomer." Obtaining prey also comes by other means- They have been seen taking advantage of leftovers "at hen houses, slaughterhouses and garbage dumps." (2)There have been instances noted where they actually watched nesting songbirds as they went about their duties of hunting and feeding their young and then in turn went looking for their nests. Observers actually witnessed them raiding the nests of loggerhead shrikes and mockingbirds, in both instances leaving with a nestling or nestlings in its bill. (1) They have also been observed following tractors that were plowing fields and taking grasshoppers and small mammals that had been killed by the plow. (2) Their legs and claws are adapted for walking and running allowing them to actually chase down evading prey. 

Being opportunists the list of food items is endless which includes carrion, rabbits, other birds (16) (17), young of other birds, skunks, prairie dogs, opossums, mice, rats, squirrels, snakes (15) (19), turtles and their eggs, crabs, lizards, young alligators, frogs, crayfish, fish, insects and their larvae, earthworms, spiders, scorpions.

I canvassed the internet for crested caracara lore and found the following:


~ observed "shredding" cow patties in search of dung beetles (8) 
~ observed pursuing an American kestrel (6)
~ observed "taking" a Rhode Island Red rooster from someones barn. (7)
~ like other raptors they like wildfires- they will either wait at the fires edge keeping an eye out for escapees or they'll wait until the fire burns out and then scrounge for what didn’t escape. (5)
~ a group of four caracaras were observed attacking and killing Franklin gulls (10) and Golden Plovers (11).
~ a cattle rancher reported that caracaras were killing and eating his newborn calves (12).
~an observation in Bent’s Life Histories noted its liking of turtles- “Mr. Grimes sent me a photograph showing the shells of 43 mud turtles and a box tortoise, (and) the head of a large snapping turtle, a small garfish, and the remains of a bass that he picked up in a few minutes around a caracara’s nest that held large young.”  “At a distance of 100 feet I could plainly hear the bird’s mandibles clack against the turtle’s shell, as she held it down with her feet and strained and pulled at what it contained.” (14)  Also turtle eggs- I came across Jamie Felton's photostream on Flickr that contained nice photos of a pair of caracaras consuming eggs that had just been laid by a soft-shelled turtle. (13)

~ Also in Bent’s were details of them hunting in pairs- “One was hidden behind a tussock of grass while the other danced before a young lamb, trying to lead it from the place where its mother was grazing to where its companion was hidden.”  (14)

 ~ someone noticed what appeared to be a growth on the breast of a caracara. Turns out it was just its crop that was distended due to being full after the bird gorged itself.   This has also has been noted in black and turkey vultures (7) and in Harris and Red-tailed hawks. (4)
~ a caracara was observed chasing and harassing a turkey vulture forcing it to regurgitate food it had just eaten. The caracara then landed and ate this....yum. (9)
~ a group of caracaras were observed attacking and pursuing cattle egrets. (3)

An odd, but truly interesting bird to say the least. 

Photo of Crested Caracara with "bulging" crop courtesy of Greg Lavaty
Photo of Crested Caracara pair feeding on coachwhip snake courtesy of Greg Lasley
Photo of Crested Caracara with fish in mouth courtesy of Jamie Felton (photo does not have Creative Commons License)  

References and Suggested Reading:

(10) Caracara killing gulls


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Monday, February 11, 2013

Bird Counting

Ever wonder how to make counting large numbers of birds you see easier?  Check out Bird Counting 101 and Bird Counting 201 courses put out by eBird.

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