World of Birds

A look into the flight style of the Turkey Vulture.

Hawaii is home to many endemic birds, including the I'iwi. In this episode you will learn a bit about this little honeycreeper and the threats it is facing.

Ever wonder how birds survive winter or other rough times where food may be hard to find, here is a look into one of the behaviors birds use to survive these time periods.

With how difficult it can be to find food in the winter, many species choose to migrate south, but what about the insect eating birds we see during the winter months like Brown Creepers and Kinglets?

A look into one of the ways Ruffed Grouse deal with winter conditions.

A look into the details of a bird's facial anatomy, their eye rings.

A bird's anatomy can be highly variable, from the broadest being body shape, color, bill, wings and feet. Down in more minute features that can often get overlooked. 

When drawing, we are always told the eye is the most important feature that you want to stand out. But how often do you notice the intricate feathers or bare skin that are around that eye. What color they are, do they form a shape or particular pattern?

Bare skin surrounding a bird's eye is called an orbital ring. This can be of various thickness, from a thin ring like the killdeer to excessive like a white-eye, a group of birds named after this large orbital ring they have.

If a bird has a particular colored feathers around their eye, it is often referred to as an eye ring, generally, a different color than the rest of the face or head. This difference can be subtle or bold, broken or complete.

The bare skin or feathers can be of various thickness, each variety of this part of a bird's anatomy can help add to its overall appearance.

Birds such as killdeer can have a red orbital ring around their eyes, or a stunning blue like on a Double-crested cormorant. They can even change as a bird ages, if you look closely at a fledgling tufted titmouse, you may notice that the flesh around their eye is actually a bright yellow, which will fade eventually to a pale gray that we are more often familiar with this common backyard bird. Orbital rings are believed to help indicate to other birds that they are sexually mature and healthy.

Other birds, feathers may make up this eye ring. From there, this group of feathers may have different colors as it encircles the eye. If all these feathers are the same color, they are referred to as a complete eye ring, if it is broken up with a different color, it's an incomplete or broken eye ring. One form of a broken eye ring is called an eye arc, generally seen as a partial eye ring directly above and directly below the eye. This characteristic can be seen in species such as the Northern Parula. 

How bold or subtle an eye ring can also vary, a good comparison is the very subtle eye ring on the Orange-crowned Warbler and the bold white eye ring of the Connecticut Warbler.

It's interesting to note that the appearance of an eye ring can also be affected by other parts of a bird's facial anatomy such as eye lines, lores, and eyebrow/ supercilium.

A look into how what a bird eats can affect it color, with a spotlight on the Cedar Waxwing

If you see a flock of Cedar Waxwings, you may notice that some have yellow tipped tails while others may be orange. That color change is a direct result of something relatively new being included in their diet.

When a waxwing’s tail feathers grow in, they are typically a bright yellow, but when the tail is growing in and they eat berries from the honeysuckle plant, an introduced invasive plant that produces a high yield of dark red berries, their tail feathers will grow in at varying levels of orange. This is because these berries contain high concentrations of carotenoid pigments and when ingested, get deposited in their feathers. Carotenoids are one of the four different pigments that make up a feathers color, creating shades of yellow, orange and red. This pigment cannot be created though, it must be ingested, generally getting this pigment from the fruit, berries, and seeds they eat.

These berries become ripe around the same time that Cedar Waxwings are nesting, because of this the young end up being fed a high percentage of these berries, resulting in most of the young growing in orange-tipped tails. Though, later in the season when they molt again but don’t have access to the berries of the honeysuckle, their new tails feathers grow back in with the typical bright yellow tips. So, when you see a Cedar Waxwing with an orange or red tail, it is most likely an individual that hatched that year.

Another backyard bird that this change can be seen in is the Northern Cardinal. Their color is even impacted by the same plant as the Cedar Waxwing. Males who feed on a large percentage of the honeysuckle berries grow in feathers that are a much more vibrant red than ones that have a more varied diet.

Unfortunately, the berries from the honeysuckle plant are not as nutritious, so while male cardinals that eat them can be a more vivid red and may appear as a better mate from a female's perspective, studies have shown that these same males typically weight less and are probably not as healthy as males who have not included as many of the berries in their diet and are not as vividly colored.

Another backyard bird's whos color can be affected by what's included in their diet is the House Finch, the males can have varying shades of red depending on the percentage of berries they eat.

An additional drastic example of diet affecting a bird's color can be seen in flamingos. These birds' diet consists of krill, brine shrimp and other invertebrates, who in turn, feed on algae high in carotenoids. As the carotenoids in algae goes up the food chain, the concentration of this pigment increases, resulting in the pink you see in the brine shrimp and krill, and in the bright pink you see in the plumage of flamingos. In captivity, where flamingos may not naturally have access to this pigment, their feathers would be gray or a very pale pink. To recreate this coloration, zoos feed their flamingos a special diet containing synthetic canthaxanthin to achieve this pink color.

A look into the life of the Evening Grosbeak, a large boreal finch that is a welcome guest at any bird feeder.

A look into one of the ways birds express color.

A quick look into the world of Hummingbirds.

A quick episode about an unique woodpecker adaptation.

A quick look into what makes bird eggs so unique and what shapes their appearance.

A look into some of the ways birds change in appearance as they age, from fledgling to an adult.

A look into how biologist classify what a species is in the bird world.

All about the bird family Parulidae, also called new world warblers or wood warblers.

A little episode about the Steller's Sea eagles biology and life history.

A look into some of the strategies birds use to survive winter conditions.

A look into some of the amazing adaptations that Owls have.

This episode goes over the bird family Charadriidae, which contains plovers, dotterels and lapwings. There are a total of 68 species in this family in 10 genera.

Bird songs Copyright Macaulay Library

This episode features the hoary redpoll, a small round finch species that lives high up in the arctic tundra.


Bird songs Copyright Macaulay Library