Cross Timbers Wildlife News
Bullbats and other Goatsuckers
Jim Dillard, Wildlife Biologist, Texas Parks & Wildlife Department, Mineral Wells
I can remember as a kid having endless fun chunking small rocks high into the air late in the evenings at bullbats. At least that’s what grandma called them, and as far as I was concerned, grandma pretty well knew everything. They sorta looked like big bats and only came out around sundown. They’d fly high over the treetops in our neighborhood just at sundown catching flying insects and sometimes dive at my small rocks just in case they might be supper. I never did hit one nor did one ever swallow one of the rocks. Even today, when I hear the nasal peent sound of a bullbat flying high overhead, it brings back those memories and I can’t help but look up. Since my rock chunking days are past, bullbats are in no danger.
I’ve learned since they certainly are not bats but go by that moniker for their crepuscular (late evening and early morning) feeding habits, erratic flight and size. They belong to a group of birds called goatsuckers or also known as nightjars for their nighttime singing. The name “goat-suckers” goes way back to ancient times when these birds were thought to suck the udders of goats. In Latin, the family name for this group of birds is Caprimulgidae which means “sucker-of-goats.” People probably saw them flying low around their goats chasing flies and insects and thought they were responsible if any of them didn’t produce milk.
There are several species of goatsuckers found in Texas and three call the Cross Timbers home for at least part of the year. The common nighthawk (Chordeiles minor) (a.k.a bullbat) is our most common summer resident species. After spending the winter in South America, they return to Texas each year to nest and raise their young. Nests are built on bare ground or rooftops of buildings where they lay two eggs that hatch in 19 days. Nestlings must reach inside their parent’s large mouth to reach regurgitated insects. They fly at three weeks of age.
Common nighthawks feed on insects which they catch in erratic flight with their wide gaping mouth. Stiff bristles located at the corner of their mouth also help them catch and hold their prey. They feed primarily at dawn and dusk but it’s not uncommon to see them at night feeding on insects drawn to bright lights in urban areas. There’s probably not a WalMart parking lot in Texas where you can’t see common nighthawks around sundown “hawking” their prey. During the day they roost on the ground, tree limbs or fence posts. On many occasions I’ve seen one sitting silently snoozing on the top of a fence post or bare tree limb during the heat of the day, blending in perfectly with their surroundings with their mottled black-gray-white feather pattern.
Their aerial courtship display is a real delight to see and hear. Males will rise high in the air and then dive toward the ground, pulling up just at the last instant. Air rushing over their primary wing feathers causes them to vibrate, creating a loud hollow booming sound. A lady up in Denton County called me the other day complaining that there was some kind of bird dive-bombing her kids and making loud booming sounds and wondered if she should be concerned for their safety. I started to suggest chunking rocks at them but had second thoughts.
Another common goatsucker species found here in the Cross Timbers and western parts of the state is the poorwill (Phalaenoptilus nuttalli). They’re unique in the bird world for their ability to hibernate for long periods of time, but most migrate to warmer areas to the south for the winter. They’re smaller than the common nighthawk and flutter about at night on short flights to catch insects. They’ll also catch beetles and other insects on the ground. I’ve seen them often while conducting deer spotlight surveys at night when their bright red-reflecting eyes catch the light. On more than one occasion, I’ve had to stop for a second look to make sure I wasn’t seeing a deer’s eye. Usually, when that red eye begins to fly off I know it’s p-r-o-b-a-b-l-y not a deer. They prefer open hillsides, canyons and deserts. Eggs are laid on open ground or a flat rock. Disturb a poorwill on its nest and it will open its mouth wide and hiss at you like a snake. Their distinctive poor-Will, poor-Will call is beautiful to hear on a cool summer night and if you’re up close, you can hear more clearly poor-Will-low, poor-Will-low.
The Chuck-Will’s-Widow (Caprimulgus carolinensis) with its distinctive chuck-Will’s wi-DOW call leaves nothing to the imagination about how it got its four-syllable common name. Males are quite proud of it as they repeat their moon music over and over and over and over, to the point that if you’re camped nearby, you will become less and less enchanted with it as the night wears on. The warmer the night the more they call. They’re the largest member of this family of birds at about a foot long and nest on the ground in woodlands and on cedar hills of central and east Texas. Two eggs are laid on leaf-covered ground and hatch in about 20 days. The female incubates the eggs and feeds the young and may move them if her nest is disturbed. Males have little to do with raising the young which takes around 17 days. Chuck’s mouth is over two inches wide when open and is surrounded by stiff bristles which help funnel in food items including large insects and rarely small birds. They winter in Central and South America and the West Indies.
Cousin whip-poor-will (Caprimulgus vociferus) is more commonly found in east Texas and is not as likely to be heard out our way. The pauraque (Nyctidromus albicollis) is a goatsucker species found in the lower Rio Grande Valley and deep south Texas and the lesser nighthawk (Chordeilies acutipennis) inhabits the desert scrub, arroyos and arid grasslands of west Texas.
Call them bullbats, goat-suckers, nightjars, whip-poor-will pea pickers or whatever you want but they WILL serenade you if you’re out and about on a warm Cross Timbers summer night. Until next time - I’ll see you down the road and God Bless America!