Horned Grebe | Chiristopher Ciccone | Audubon Photography Awards
One only needs to look at the difference between the broad flat bill of the Northern Shoveler, in comparison to the delicate thin beak of the Anna’s Hummingbird, and the sharp hooked snout of the Bald Eagle to see how much variation there is amongst bird bills and beaks. Over millions of years, birds have adapted their anatomy to their unique ecological niche, in part due to the food sources available to them. Sink your beak into this article, where we look at some of the specialized beaks of several local bird species and how that helps them snag their favorite snack.
Thrushes: Berry Specialists
Thrushes, including our local Varied Thrush, Swainson’s Thrush, and American Robin, are all known for their love of berries. Their beaks are relatively short and stout, with a slight curve. This shape allows them to easily grasp and crush berries, extracting the juicy pulp inside. Additionally, these birds often have small, hair-like projections on the tip of their tongues, which help them extract small seeds from the pulp.
American Robin | Sharon Wada
Oystercatchers: Shellfish Connoisseurs
Black Oystercatchers are aptly named for their diet of shellfish, particularly oysters and mussels that are prevalent along our rocky shorelines. Their long, slender, and slightly curved beaks are perfectly adapted for prying open mollusk shells. The tip of their beaks are often slightly flattened and blunt, which helps them exert pressure on the shell without damaging their beaks.
Black Oystercatcher | Peter Monteforte | Audubon Photography Awards
Mergansers and Cormorants: Slippery Snacks
Mergansers and cormorants are skilled at catching and consuming small crustaceans and fish. While they have slightly different beak features, both types of birds dive to catch their prey and are able to grasp wet and slippery aquatic snacks.
Cormorants have long, slender beaks with a sharp hook at the end, ideal for grasping slippery fish. Their beaks are also equipped with backward-facing barbs, which help them hold onto their catch while swimming. Cormorants are expert divers with streamlined bodies and long necks. They can move swiftly in the water using their powerful webbed feet to propel themselves underwater in pursuit of prey.
Mergansers have thin, long and narrow bills with serrated edges, resembling a saw. This unique beak shape is perfect for grasping and holding onto slippery prey. Mergansers’ beak shape, combined with their diving prowess, makes them highly effective hunters in aquatic environments.
Double-crested Cormorant, Red-breasted Merganser, and Pelagic Cormorant | Sharon Wada
Raptors: Talons and Tearing
Raptors like hawks and eagles are formidable hunters, preying on snakes, fish, rodents, birds, and other small mammals. While they use their muscular legs and taloned feet to snag their prey, their beaks are sharp and hooked at the end, ideal for tearing flesh into smaller bite-sized pieces.
Bald Eagle eating a salmon | Sharon Wada
Herons: Precision Spear
Green and Great Blue Herons are known for their long, sharp, spear-like beaks, which they use to great effect in catching fish and frogs, among other small creatures, passing through shallow waters. Herons wade into the water with their long legs, often concealed amongst the reeds and grasses along the shoreline, and patiently wait for the perfect moment to strike their prey. Their precision strike can often result in spearing the fish.
Great Blue Heron spearing a fish | Sharon Wada
Bewick’s Wren: Insectivore Extraordinaire
The Bewick’s Wren possesses a slender, slightly down-curved beak that is perfectly adapted for its diet of spiders and insects. This beak shape allows the wren to probe into crevices and under bark to extract insects, spiders, and other small invertebrates with remarkable precision. The wren’s keen eyesight, coupled with its agile and curious nature, enables it to detect and capture its prey swiftly.
Bewick’s Wren | Sharon Wada
The Role of Beak Anatomy
The diverse shapes and sizes of bird beaks are a result of evolution, with each species’ beak shape reflecting its diet and foraging behavior. Beak anatomy plays a crucial role in determining the efficiency with which birds can consume their food. For example, birds that consume hard seeds often have thick, strong beaks, while birds that feed on nectar have long, slender, and curved beaks for accessing flowers. Just as birds who consume slippery fish often have barbs or serrated edges to help with grasping, and flesh-eating birds have sharp beaks for tearing. By studying and appreciating the intricacies of bird beak anatomy, we can gain a greater understanding of these fascinating creatures and the environments in which they thrive.
Food Chain Concerns, A Ripple Effect
Understanding what birds are consuming is crucial for conservation efforts. In our urban Seattle-area, birds face additional toxins introduced to their food sources, which often have deadly impacts on birds further up the food chain. For example, the use of anticoagulant rodenticides in bait boxes around the city is an effective method to control rodent populations, however, raptors all too often fall victim to secondary poisoning after consuming rodents that have eaten from these bait boxes.
Common household insecticides and herbicides can also be harmful to plant and bug-consuming birds. These pesticides and other pollutants can also wash into our storm water system and flow into lakes, streams, and the Puget Sound. Contaminants pose risks to marine birds which feed on fish and other marine life that have ingested these toxins. You can help keep our local water systems clean by proper handling of chemicals, or avoiding them all together. To learn more, visit the King County Stormwater Runoff page on their website.
Explore other articles in this issue of EarthCare Northwest
Barred Owl Diet: Insights from Pellet Analysis in Seattle
University of Washington student researcher Olivia Cavalluzzi spent her summer analyzing nearly 600 Barred Owl pellets to uncover interesting insights into their diet, behavior, and role within the Seattle-area food chain.
Bird Feeding 101: Suet
Feeding wild birds is one way to attract a variety of species to your balcony, yard, or window. If you are new to feeding birds, seed and nectar feeders are common choices, but suet feeders can be a wonderful alternative or supplement.
The Collision Buffet: How Bird-window Collisions Supplement the Diets of Urban Scavengers
Bird fatalities, while tragic, play an important and unnoticed role in our urban food chain, especially for scavengers like crows, gulls, and rats. Birds Connect Seattle is studying carcass persistence, or how long a dead bird remains before it is carried away by scavengers, as part of the Seattle Bird Collision Monitoring Project.