Pileated woodpeckers are the largest living woodpeckers in North America. They use their powerful beaks to carve large rectangular holes in trees while searching for their favorite food, carpenter ants. Other species like wood ducks, pine martens, swifts and even bats use the holes for nesting and shelter. Photo by Elena Calderone '21
Depictions of lively chickadees and brightly-colored cardinals on holiday cards and decorations can often coax a smile out of even the most cranky recipients and observers.
“There’s a reason for that,” said Dan Cristol, Chancellor Professor of Biology at William & Mary.
Cristol, an avid ornithologist, cited a 2021 study from King’s College London which indicated that seeing or hearing birds was the dominant factor in mood-lifting nature encounters, and that the cheering effects of bird observations can last as long as six hours after the experience, even among those suffering from depression.
Northern mockingbirds are expert mimickers. Males add to their song as they age, and may learn up to 200 sounds throughout their lives. (Photo by Elena Calderone ’21)
“So, it’s notable that Christmas cards and other greetings have birds on them as symbols of home, happiness and celebration,” said Cristol.
Birds benefit humans in numerous ways, but they’re in trouble. Avian populations in the United States and Canada have declined by almost 3 billion individuals over the past 50 years. That’s a population decline of more than 25% in less than an average human lifetime.
Habitat loss, window strikes and environmental contaminants are a few of the top reasons for declining bird populations, but faculty and students at W&M are determined to address these challenges. A key factor in this ongoing endeavor is W&M’s personal approach to education, which provides undergraduates with an unusual opportunity to participate in applied research in numerous fields, including bird conservation.
“Some students apply to W&M specifically because they want to do undergraduate bird research with faculty,” said Cristol, “And a lot of graduate students also choose W&M because they want to study birds.”
W&M has an extensive history of studying and aiding birds.
Cristol’s predecessor, Mitchell Byrd, began inspiring students with his ornithology class in 1956, guiding hundreds of students in bird conservation research. Byrd was instrumental in the regional recovery of both the bald eagle and peregrine falcon and also worked tirelessly to conserve other species. Byrd went on to found the Center for Conservation Biology with former student Bryan Watts, who now serves as its director.
The osprey is a large hawk that lives near water and dives to catch fish, using barbed pads on the soles of its feet to grip its slippery prey. The osprey was viewed as a success story when the species rebounded following the ban of DDT. Recent CCB surveys show populations declining sharply again in the Chesapeake Bay, this time likely due to human overfishing of menhaden. (Photo by Elena Calderone ’21)
“He really built a national reputation for William & Mary in bird work that continues today,” said Watts, director of the CCB, in a 2008 article.
Cristol concurs.
“And his name is Byrd, after all,” said Cristol.
Founded in 1992, the CCB is a powerhouse of ground-breaking bird conservation research, carrying out 30 to 40 major studies per year and providing valuable information daily to the conservation community.
“The CCB works with birds of conservation concern throughout the Western Hemisphere,” said Watts. “We have done projects from the high Arctic to Argentina. We have decades long commitments to about 100 species and work with other species as the need arises.”
Projects are selected to fill in gaps in existing information and increase public awareness. CCB’s website provides a wealth of information about its essential conservation work.
“One of the driving themes to our work is that we believe that how a society treats wildlife is a reflection of its moral/ethical compass,” siad Watts. “Through research and education we can change how people think about and care for wildlife. This is an important part of growing as a responsible society.”
Both undergraduate and graduate students study birds at the CCB, and there are also plenty of opportunities on the W&M campus.
The eastern screech-owl is a small owl named for its high-pitched, trilling call. These owls can be either gray or reddish in color and will readily use nest boxes for rearing young. (Photo by Elena Calderone ’21)
Cristol has mentored students in applied research since 1996. Recent projects include the effects of deer overpopulation on the avian community and the positive and negative impacts of golf courses in relation to birds. As is the norm at W&M, those papers, which have undergraduate first authors, are in the process of being submitted to scientific journals for publication. Information gleaned from the research can be utilized to determine effective conservation measures.
Cristol’s own work, including current and former students, takes place at superfund sites, the government’s highest-priority toxic waste sites around the country. At those sites, Cristol determines local birds’ levels of exposure to legacy pollutants, such as dioxin or mercury, and calculates the extent of contaminant-related population declines. He also helps to develop optimal restoration strategies.
Cristol’s research has so far resulted in two large settlements with chemical companies to fund bird-related research and education and to create new habitat to aid in replacing birdlife lost through contaminated sites.
“Globally, billions of birds die each year from collisions with human-made structures,” said Swaddle. “Window collisions account for most of this problem.”
To combat this challenge, students in Swaddle’s lab focus on technology.
“Our group has designed and tested several technologies that reduce collisions,” said Swaddle. “We use fundamental knowledge about how birds sense their world to make structures such as windows and communication towers more evident to them. This helps to promote bird conservation while also allowing for economic development for people.”
Green herons have been observed constructing lures from items like feathers, twigs and insects, then using them as tools to attract fish. Populations of this bird declined by about 51% between 1966 and 2019, mostly due to habitat loss and draining or development of wetlands. As Leu’s 2023 study indicates, constructing living shorelines to protect coasts can provide valuable habitat for these birds. (Photo by Elena Calderone ’21)
Matthias Leu, associate professor of biology, is a conservation biologist whose work includes bird studies with students. For example, a 2023 study focused on whether wading birds prefer natural fringe salt marshes to human-engineered living shorelines, an effective means of shoreline stabilization that uses native vegetation, often in combination with low sills, to protect shorelines from erosion due to severe weather and rising sea levels.
Leu’s research indicates that wading birds use living shorelines for habitat at least as much as they use natural fringe salt marshes. Thus, living shorelines hold promise for bird conservation by way of providing valuable habitat that isn’t available with harder methods of shoreline stabilization like bulkheads and riprap.
For students who aren’t yet sure if they want to do bird-related research, Cristol’s ornithology class provides an introduction to the field. Lecture information includes everything from the physics of flight to why owls ears’ are asymmetrical, while labs consist mostly of outside trips to identify and observe birds in their natural habitat.
The Bird Club of W&M also encourages students to experience the cheering benefits of birds. W&M students are invited to attend popular Friday afternoon bird walks, and binoculars are provided. All levels of bird-watchers are welcome, from first-timers to experts.
“Friday afternoon!” said Cristol. “At other schools, people might be doing something different to get ready for the weekend. Here, they go birdwatching, which is fantastic!”
What can the general public do to help birds?
One of the biggest challenges birds face is loss of habitat, so creating habitat with an emphasis on native plants is a powerful move that gives birds food to eat, water for drinking and bathing and locations to shelter and nest. Native plants host native bugs, which are the best food for native birds. Even small yards make a difference, and that difference is amplified when neighbors join the effort, creating larger patches of uninterrupted habitat.
Homeowners can also add decals, dangling cords and other treatments to windows to decrease the likelihood of window collisions.
Additionally, light pollution interferes with bird navigation and migration, so installing shielded light fixtures and turning off outdoor lights or using motion sensors are more bird-friendly options.
Catios are another thing to consider. Domestic cats kill a whopping 2.4 billion birds each year. Catios are the next best thing to roaming free, allowing cats to breathe fresh air and experience the outdoors without killing birds or being exposed to outside dangers.
Community science is an effective way to participate in bird conservation.
The eastern bluebird can spot an insect on the ground from 60 feet away. Populations of this brightly-colored insectivorous bird were low in the early 20th century due to competition for nesting sites. A key factor in its recovery was the installation of human-made nest boxes to provide places for them to raise their young. (Photo by Elena Calderone ’21)
Also called citizen science, these projects allow non-scientists to participate in conservation research by providing valuable data.
The CCB monitors Osprey Watch and the Nightjar Survey Network. The website provides guidance for newcomers to osprey observation, while the Nightjar Survey Network is best for more experienced birders who can identify species by their calls.
“Small steps can make a huge difference, especially when people work together,” said Cristol. “Researchers here at W&M and around the world are determined that birds will brighten human lives for generations. The efforts of the general public can play a huge role. Maybe this year, when people send that holiday card adorned with cheerful birds, they can also head out into the yard to plant a native shrub and spread a little cheer for the birds as well.”
Like all swallows,barn swallows are acrobatic fliers and catch insects in mid-air. These birds historically nested in caves, but now build their nests in man-made structures. (Photo by Elena Calderone ’21)Baltimore orioles eat fruit, nectar and insects. They often visit oriole feeders to feast on halved oranges, nectar and jelly, but native fruit-producing plants provide the best nutrition for these birds and will keep them coming back for more. Orioles also migrate at night, so they have a high risk of building collisions. Taking steps to decrease light pollution can help to decrease those fatalities. (Photo by Elena Calderone ’21)Barred owls eat small mammals, amphibians, reptiles, and sometimes fish and crayfish. They’re sometimes active during the day, allowing bird watchers to see them in action. (Photo by Elena Calderone ’21)Brown creepers hunt for insects on large, old trees. These birds work their way up from the bottom of the tree trunk to within a few feet of the top, devouring insects as they go. Due to their specialized form, Brown Creepers have difficulty going back down the tree, so when they get to the top of one tree, they fly to the bottom of another one and start the process all over again. This species frequently collides with windows, so adding treatments like decals and hanging cords can help to decrease those fatalities. (Photo by Nick Newberry ’17)Cedar waxwings eat fruits like cedar, dogwood, serviceberry, juniper and winterberry. They have a complex courtship dance that includes the male and female hopping back and forth, sometimes touching beaks. The male then passes a small gift, such as a berry or flower petal, to the female. (Photo by Elena Calderone ’21)Carolina chickadees weigh less than half an ounce. These feisty little birds construct nests made of moss, and are one of the earliest nesters among songbirds. Recent studies show that chickadees have a complex language that uses syntax, something that scientists once thought was unique to humans. Installing nesting boxes in your yard can help chickadees and other cavity-nesting birds. This nestling is being carefully handled by students in Dan Cristol’s lab to dispel the myth that parents will reject their babies if they’re handled by humans. (Photo by Dan Cristol)Chipping sparrows are often seen in parks and backyard bird feeders. According to the American Bird Conservancy, they usually build nests in shrubs and small trees but have been known to nest in more unusual areas such as a strand of drying chili peppers, a hanging basket filled with moss and an old fashioned mower in a tool shed. (Photo by Elena Calderone ’21)The common yellowthroat is a small, insectivorous bird that forages near the ground for prey like insects and spiders. Populations of this bird declined 26% between 1966 and 2019, mostly due to habitat loss and degradation. Protecting wetlands and planting native plants will provide habitat for this species. (Photo by Elena Calderone ’21)Downy woodpeckers are frequent visitors to backyard feeders. They tend to eat insects that larger woodpeckers can’t reach, including those found on smaller branches and twigs. Downy woodpeckers supplement their insectivorous diet with seeds and sometimes even drink from hummingbird feeders. (Photo by Elena Calderone ’21)The gray catbird is named for its cat-like call. Like its close relative, the Northern Mockingbird, this species mimics the sounds of other species and incorporates them into a song that can last as long as 10 minutes. (Photo by Elena Calderone ’21)The hermit thrush is sometimes called the American nightingale and is notorious for its beautiful song. These birds sometimes shake bits of grass with their feet to stir up insects, a behavior known as “foot quivering.” Hermit thrushes are frequent victims of window collisions, so window treatments such as decals and hanging cords can decrease these fatalities. (Photo by Elena Calderone ’21)Indigo buntings migrate at night, using stars to navigate. Light pollution can interfere with nighttime migration, so these birds have a high risk of colliding with tall buildings. Taking steps to decrease light pollution is likely to have a positive effect on this bird’s future. (Photo by Elena Calderone ’21)The northern parula is a small warbler that weighs in at 0.2 – 0.4 oz. It nests in tree mosses, such as Spanish moss and old man’s beard. These birds eat mostly spiders, caterpillars and other insects and sometimes snack on berries and nectar. Creation of habitat with native plants can entice them to your yard by providing food and shelter. (Photo by Elena Calderone ’21)Bald eagles have a spectacular courtship display in which the pair joins talons high in the sky and spiral toward the ground together. In the twentieth century, populations declined sharply due to DDT, poisoning and trapping. The recovery of this species is considered a testament to the effectiveness of the Endangered Species Act. (Photo by Elena Calderone ’21)
Red-headed woodpeckers catch insects in mid-air and also eat acorns, fruit and beech nuts. They cache extra food in trees, covering it with wood or bark. This species declined 54% between 1966 and 2019, largely due to loss of habitat. Leaving dead tree snags in your yard when possible and planting nut-producing trees can help woodpeckers and other birds. (Photo by Elena Calderone ’21)The ruby-crowned kinglet is a tiny, but energetic little bird that weighs 0.2-0.3 oz. Females lay as many as 12 eggs in a single nest. According to All About Birds, each egg weighs about a fiftieth of an ounce, but an entire clutch can weigh as much as the female herself. (Photo by Elena Calderone ’21)The snowy owl can eat more than 1600 lemmings per year. These daytime hunters prefer open areas, and the whitest birds are always males. Populations of this species declined by 64% from 1976-2016, and it is on the watch list for wildlife officials. (Photo by Elena Calderone ’21)
Thewhite-breasted nuthatch’s name comes from its behavior of securing nuts and large seeds in tree bark fissures and then hammering at the nut to “hatch” seed from the inside. They often cache seeds in tree bark, and supplement their diet with insects. (Photo by Elena Calderone ’21)The white-throated sparrow is a wintertime visitor to Virginia. These birds have a high-pitched, whistling song and are frequent visitors at backyard bird feeders. Although White-throated sparrows are still abundant, populations in the U.S. declined by 69% between 1966 and 2019. According to the American Bird Conservancy, this species is No. 1 most frequent victim of window collisions. Adding treatments like decals and hanging cords to windows can decrease these fatalities. (Photo by Elena Calderone ’21)Wood ducks live mostly in wooded swamps and nest in holes in trees or nest boxes. After hatching, nestlings jump from the nest, from heights as high as 50 feet, then follow their mother to water. These ducks eat seeds, nuts, fruit and insects and can fly up to 30 mph. (Photo by Elena Calderone ’21)
Yellow warblers are insectivorous birds that weigh in at 0.3-0.4 oz. They’re so tiny that they’re sometimes caught in the webs of large spiders. Because they migrate at night, they have a high risk of colliding with buildings. Decreasing light pollution can lower that risk. (Photo by Elena Calderone ’21)The yellow-bellied sapsucker doesn’t actually suck sap. It drills shallow horizontal rows of holes around the trunks of trees and harvests them for sap and insects stuck in the sticky substance. Hummingbirds sometimes use these sapwells for a quick snack, too. (Photo by Elena Calderone ’21)
