A bicuspid aortic valve is a congenital heart defect where the aortic valve only has two leaflets instead of the normal three. This abnormal valve can lead to problems later in life, including aortic stenosis, regurgitation, and less commonly, an increased risk of stroke. In this article, we will examine the evidence on whether a bicuspid aortic valve increases stroke risk and the potential mechanisms for how it could contribute to stroke. What is a bicuspid aortic valve? During normal fetal development, the aortic valve forms with three leaflets or cusps. A bicuspid aortic valve only has two leaflets instead…
Author: Peter Knight
The Hermit Thrush is a small North American songbird that belongs to the thrush family. It is a popular backyard bird that can be found across much of the United States and Canada. Hermit Thrushes have distinctive brown backs and reddish tails. Their underbellies are white with dark spots on the breast. These songbirds get their name from their shy, reclusive nature. Hermit Thrushes are elusive birds that prefer dense underbrush and forested areas. While they may visit backyards, Hermit Thrushes are typically wary of humans. When it comes to feeding Hermit Thrushes, it helps to understand their natural diet…
Birds have evolved over millions of years to become incredibly efficient and skilled fliers. Their aerodynamic body shape, powerful flight muscles, and specialized feathers allow birds to take to the skies and soar great distances with minimal effort. But when it comes to mechanical flight efficiency, which bird reigns supreme? Researchers have investigated the flight dynamics and energy expenditure of numerous avian species to determine which birds are the most metabolically efficient in flight. Measuring Flying Efficiency The metabolic efficiency of bird flight is determined by measuring the energy expended per unit time during sustained flight. Researchers may use respirometry…
The California gull (Larus californicus) is a medium-sized gull that breeds primarily in the interior of western North America. It is the state bird of Utah and holds special meaning as a symbol to the people of that region. The California gull has long been associated with Mormon pioneers who settled in Utah in the mid-1800s. During their initial years in the Salt Lake Valley, swarms of crickets destroyed their crops. Miraculously, seagulls appeared and devoured the crickets, saving the crops and allowing the pioneers to survive. This event came to be known as the “Miracle of the Gulls” and…
Barn owls are one of the most widely distributed birds in the world and can be found on every continent except Antarctica. Despite their name, barn owls do not actually require barns or other human-made structures to thrive. However, they will readily nest and roost in old barns, abandoned buildings, and hollow trees if suitable habitat is available. This has led to the common name “barn owl”, though they are not true owls in the strictest sense. Do barn owls nest in barns? Barn owls sometimes nest in barns or other agricultural outbuildings, but they do not depend on these…
The greater scaup is a species of diving duck found across North America. It gets its name from the sound the males make during breeding season. The greater scaup has a very distinct call that helps observers identify it in the field. In this article, we will explore what a greater scaup sounds like, when and why it makes these vocalizations, and how its call differs from other waterfowl species. Description of the Greater Scaup’s Call The most recognizable sound of the male greater scaup is a rhythmic, cat-like “scaup, scaup” vocalization. This distinctive, squeaky call is produced during courtship…
Hummingbirds are well known for their ability to hover in midair as they feed on nectar from flowers. This remarkable feat is made possible by specialized adaptations in their anatomy, including their skeleton. A hummingbird’s skeleton is designed to be extremely lightweight in order to enable flight, while still providing enough strength and structure for the bird’s muscles to power its wings at high frequencies. In this article, we will take a close look at the bones that make up a hummingbird’s skeleton and how they work together to enable these tiny birds to fly like no other. We’ll explore…
Birds flying in flocks manage to stay close together and coordinate their movements without colliding into each other, which is remarkable given the speeds at which they fly. So how exactly do they do it? There are several factors that allow flocking birds to fly safely together. Spacing Between Birds Birds maintain a minimum distance between each other while flying in a flock. Studies have found the spacing ranges from 1 to 5 bird lengths apart on average. This gives them enough buffer room to avoid collisions despite rapid changes in speed or direction. Having space between them is key…
Opening The blue jay is a very recognizable bird with its bright blue plumage, white undersides, and black necklace across its throat. However, there are some other birds that can be mistaken for a blue jay at first glance due to their similar color patterns. Determining the specific species requires a closer look at size, range, behavior, and other identifying characteristics. Birds Commonly Confused with Blue Jays Some birds that often get confused with blue jays include: Steller’s Jay The Steller’s jay looks almost identical to the blue jay with its blue and black feathers. However, the Steller’s jay has…
Bank swallows are small, migratory songbirds that nest in colonies in natural and man-made settings with vertical surfaces. They build nests out of mud in cavities or on vertical surfaces, often on riverbanks, ocean bluffs, and under bridges and highway overpasses. Bank swallows are found throughout North America and are drawn to open areas near water where they can gather mud and insects. When do bank swallows nest? Bank swallows arrive at their breeding grounds between early April and early May. The exact timing depends on the location and weather conditions. They are one of the earlier swallow species to…