After months of planning, coordination, and a lot of patience, the US Fish and Wildlife Service and the Natural Resources Branch of Fort Hood successfully monitored and filmed a blackcap vireo nest.
On April 7, Sydney Dragon, a Student Conservation Association intern for the USFWS from the Arlington Ecological Services Field Office, came to Fort Hood and set up hunting cameras to watch for the secret birds known as the black-headed vireos. They collected footage for three months, collecting over 90 video clips.
“Using surveillance cameras can be an effective way to monitor secret species,” Dragon said. “There were many incredible moments that were filmed.”
Black-headed vireos were added to the endangered and threatened species list by the US Fish and Wildlife Service in 1987, when only 350 birds were known. A small four-inch bird, the black-crowned vireo is usually heard long before it is seen. The songbird sings distinct, loud songs, which help biologists locate the nests, which are built two or four feet from the ground, usually in thick foliage.
The camera has been set to record for 30 seconds when motion has been detected. Scott Summers, an environmental protection specialist in the Natural Resources Branch of the Public Works Branch, was in charge of checking the camera every few days, replacing the SD cards and seeing if the nest had populated .
“We were surprised to see the Carolina Wren visiting the nest, and we were jumping for joy when we found the footage of the Painted Sparrow visiting the nest with food in its mouth,” Dragon explained. “We got to see the diversity of insects that black-crowned vireo parents brought to the chicks and witnessed the insurmountable care these parents gave to their chicks. “
The unusually rainy spring and summer in central Texas caused some problems. Summers feared that continued rain would reduce the chances of capturing high-quality footage due to lens humidity and decreased bird activity, among other issues.
Summers was careful when approaching the cameras, so as not to disturb the birds’ natural behavior. Their hard work paid off, receiving better images than they ever hoped for.
“The black-crowned vireo family clips at the nest are my favorite,” Dragon said after viewing the footage. “Watching both parents take care of the baby birds together is truly a precious moment.”
Dragon said the parents of the black-crowned vireo share nesting duties, such as incubation, feeding and brooding. Once the nest is built, one egg is laid per day, until the usual clutch of four eggs is in the nest. The eggs are then incubated for 14-19 days. As hatchlings, chicks are naked, blind, and completely dependent on their parents, both of whom feed their young. They open their eyes around the fifth day after birth, have most of their feathers by the 10th day and normally fly to the nest around the 12th day.
Summers said they ended up filming four different nests, but only two provided optimal footage and footage. After seeing the first newborn, Summers said he really hopes he will live to adulthood for several reasons: he doesn’t like to see nests fail after forming an emotional attachment, and he hoped to finalize the footage sooner rather than later, given all the recurring events. rain.
“Unlike hawks, which can defend nests better by being a counter-threat to danger, songbird nests are more sensitive. It’s more difficult to be a songbird,” he explained. “But luckily, songbirds have a better than average chance here at the Great Place.”
Summers said Fort Hood and the military are good stewards of their land, which translates into better habitat and the ability for wild songbirds to thrive. He said that higher quality habitat makes it easier to take sufficient quality images in a short period of time, despite the rains.
One of the greatest threats to the black-crowned vireo population is the brown-headed cowbird, a parasitic bird species that, if left unchecked, is detrimental to vireo nests. Summers said brown-headed cowbirds are considered obligate brood pests because they do not nest and care for their young. Instead, cowherds lay their large eggs in other bird nests. The larger cowbird chicks then prevail over the vireo chicks for food, which has historically reduced the blackcap vireo population.
Summers said that 2013 Fort Hood Garrison Hall of Fame laureate John Cornelius, a biologist who studied birds here in the mid-1980s, found that 90% of nests were parasitized by cowbirds. In 1989, Fort Hood estimated that there were less than 200 male black-crowned vireos at the facility. After partnering with the US Fish and Wildlife Service to save the species, the Fort Hood Natural Resources Branch decided they needed to control the cow population to help recover the black-crowned vireos.
The birds were removed from the endangered species list in 2018 thanks to a resurgence in the population. In 2019, there were approximately 8,000 male black-crowned vireos located at Fort Hood, a steady and steady increase over the past 30 years.
Video footage from the Nest camera can be viewed at https://youtu.be/-lJ8ysG07no or with a commented audio description at https://youtu.be/tnyP6ITbibc.