Winter on the Upper Texas Coast is a good time to see birds of prey. With less foliage on the trees, they stand out more while perched, and with the ground open, their favorite food, rats, are much easier to hunt.
When March rolls around, though, these conspicuous aerial predators become even more visible, as individuals from South Texas and the Tropics pass by, headed for the North to nest. Nature tells them to breed early, so their young can be out hunting when other chicks are leaving the nest.
Today we will look at five such hunters from different branches of the raptor world and examine their hunting and migration. There is great variation of wing shapes, bringing on various foraging styles, and a plethora of vertebrates that fall victim to their skill.
Osprey are by far our largest migratory raptor in the area, as we have very few eagles, and the caracara are nonmigratory. Osprey are quite conspicuous all winter, floating high overhead on crooked wings and sitting atop telephone poles with their piscine prey. They catch the surface-feeding fish with a specialized foot that has a wider grasp than other diurnal predators. They have certainly rebounded from the endangered status following the ecological train wreck caused by DDT.
Peregrine falcon are the fastest carnivore on the planet, diving at speeds exceeding 180 mph. Their tapered wings and slight build allows for such blinding velocity. Reduced leg and talon size requires they kill with their beak, snapping the neck’s occipital condyle of the hapless prey. Worldwide in distribution, our sojourners follow the coastline up from the Tropics, nesting as far north as the High Arctic.
Red-tailed hawk are common residents here in the cool season, but leave the area by the end of March to nest across the inland areas of North America. A large, bulky buteo, red-tails are powerful enough to take down modest mammals like possums and small raccoons with their razor-sharp talons and wicked beak.
As a buteo, red-tails soar on wind and thermals, but have the visual acuity to spots prey items unobtrusively sneaking through high grass and bushes. Plumage is highly variable, from very dark Harlan’s red-tails to light-colored Krider’s. Between these races and genetic anomalies such as melanism, some individuals get birders very excited, only to then realize they are seeing just another Red-tailed Hawk.
Accipiters breathe fear into the hearts of small birds, as there is really no escape. With short, wide wings and a long tail, they can match a songbird move for move through the canopy, killing it with multiple stabs of their long talons. Two species pass through our area in March, the ferocious Cooper’s hawk and the smaller, feisty sharp-shinned hawk. Like most hawks, immatures are brown with ventral streaks, but adults are beautiful with a steel-blue back and reddish barring below.
Northern Harrier seem like the easygoing raptor, floating along over grassland perhaps 10-15 feet above the ground. Suddenly, with a lightning-quick plunge, they drop on the rodent of choice, often the ubiquitous cotton rat. Unusual in hawks, harriers have sexual dimorphism, with gray males and brown females. They are more easily identified by their white rump patch and dihedral wings, held tilted up like turkey vultures. The vast majority of harriers will leave for prairies across the American West, always at their remarkably slow pace.
The absence of these wintering raptors seems to leave a void in the rodentivores (rat eaters), but that’s partially filled with cold-blooded predators coming out of hibernation, such as snakes. If we don’t interfere too much, nature has a way of working out its complexities.