Friday, December 21, 2007

Common Feeder Birds: Blue Jay

Photo by John Howard

Thief! Thief! Thief!" the Blue Jay(Cyanocitta cristata) would call from the wild cherry tree in our backyard, complaining of other birds snacking on what he thought was his personal stash. The Blue Jay was one of my favorite birds when I was a kid. It was blue, my favorite color, and it had personality. It would show up at the feeder and challenge other birds to just try and take some of its food. It was top dog and would let all the other birds know it.

It's scientific name of Cyanocitta cristata means "crested blue chattering bird". This description is very appropriate since the Blue Jay is a very noisy bird and can imitate almost anything. I have heard them imitate car alarms, hawks, bells, cats, squeaky gates and growls. Being a member of the crow family, they are also very smart birds. There is one account in an article by R.W. Loftin where a Blue Jay imitated a hawk to make a grackle drop its food. The jay swooped down and grabbed the food before the poor grackle knew what had happened. Another intelligent behavior is "anting". Blue Jays will grasp ants by the head or thorax, then wipe the ants' abdomens on their feathers. The ants produce a chemical called formic acid as a defense. This formic acid acts as an insecticide and helps get rid of mites, fungi and insects that can damage the birds feathers.

Mark Twain even had an affection for Blue Jays. He wrote about them in "Jim Baker's Bluejay Yarn" a story about a blue jay who tried to fill a hole with acorns, and the "hole" ended up being a house.

They love to eat peanuts from a feeder and acorns. They will cache or store acorns in soft ground and cover them with leaves. They don't recover all of them, so they help grow many new oak trees.

You've got to love a bird with such brilliant blue feathers, a color that is not often found in nature. But a fascinating fact is the feathers aren't really blue. There is no blue pigment in the feathers. They are actually a gray-brown. What????

Yep, it's true. There are two ways feathers can produce colors. One way is called pigment color and the other is structural color. Pigment color comes from chemicals that are found in the feather. Pigment color will produce the same color no matter what angle the feather is viewed. There are a few different chemicals that produce pigment colors in feathers. Melanin produces black, gray and brown color. Carotenoids, which we discussed in earlier posts on cardinals and house finches, produce colors of yellow, orange and red and comes from the plant materials that the birds eat. There is also porphyrins which create green feathers in turacos, a family of African birds, and produce reds and browns in owls, and a few other birds. (As a side note, these porphyrins can make saw-whet owl feathers glow pink under a black light. You can learn more about that here.) Lastly, there are psittacin pigments that are found only in parrots and the birds manufacture in their bodies. Nuff said!

Structural colors, or schemochromes, are a little more complicated. In a jay's feathers, there is melanin, that produces a brownish-gray color. Over that is a layer of keratin that contain tiny air cavities that are almost microscopic. Keratin is the fibrous protein that forms hair, nails and feathers. These air cavities found in the feathers scatter the light in such a way as to produce the blue color. The feathers appear blue for the same reason an oil slick appears blue. The blue in oil slicks and feathers results from differences in the distances traveled by light waves that are reflected off of each other. Richard Prum of Yale University did studies on this and called the process constructive interference. If you want to learn more, go here. Fascinating, but trying to completely understand it made my head hurt :) Another side note, the green in feathers are produced when yellow pigment is present along with the air cavities that cause the blue color. Yellow plus blue equals green! Below is a photo of a Blue Jay feather from Terry Lynch's website. Note the main pigment color is brown.

Blue Jays are fascinating birds at so many levels. Take some time to appreciate this bird next time you see it !

Sunday, December 16, 2007

Let it snow, let it graupel, let it stellar dendrite!

December 16th and Indianapolis has been wrapped with a fresh blanket of snow. Southeastway Park is gorgeous with trees branches dusted in white powder. Sledders are out in droves and memories of childhood have come streaming back.

I LOVE snow. Not to drive in it, but I love to look at it and play in it. Being a very active child, my parents encouraged me to be outside as much as possible to keep their sanity. Since we had two blizzards during my childhood, one in January, 1977 and one in January, 1978 , snow became a big part of my outdoor winter fun. We had an awesome sledding hill out behind the house. My place was very popular whenever it snowed and I will have to admit I took full advantage of my power and status in the neighborhood. If you didn't play nice, you had to leave the winter wonderland and miss out on the sled racing and ramp jumping festivities. I was a benevolent host and most kids were welcomed to my yard, except for mean old Conan, the bully, who pushed me down face first in the snow.

The old sledding hill. No, not really, but as a kid I THOUGHT it was that big!

I loved making snowmen, snow forts and enjoyed a good snowball fight. My older cousins had snowmobiles and when we visited my grandparents' farm, they would hitch an inner tube to the snowmobile with a long cord. They raced at top speeds across the fields with the inner tube and occupants bouncing all over the place. Talk about a thrill!

At the time, I only thought of snow as great fun. I had never heard of graupel, a type of snow, or knew anything about stellar dendrites and sectored plates. But as a naturalist, I now realize how complex and delicate each snow crystal can be. Wilson "Snowflake" Bentley (1865-1931) was the first person to photograph snowflakes or snow crystals at the young age of nineteen. His mother had given him a microscope for his fifteenth birthday and he was fascinated with snow. He would look at the crystals under the microscope and try to draw them, but they would melt. He then convinced his parents that he needed a camera, an expensive luxury in that day and age. Over his lifetime, Bentley published sixty articles on snow, dew, frost and raindrops. In 1931, Snow Crystals, a book with 2,435 illustrations was published. He died that same year from pneumonia.

Wilson A Bentley in 1925

Here are a few of the wonderful photos Bentley and others have perfected. Stunning, these give one a new appreciation for the white stuff. A link to the Bentley Snow Crystal Collection by the Buffalo Museum of Science can be found here. Another fascinating website on snow crystals is .
Bentley Photos

Sectored Plate

Stellar Dendrite

Triangular Crystal

Get outside, enjoy that snow and, if you can, take a kid with you. They will love it and just maybe you will, too! I know I sure did (and still do)!


Friday, December 14, 2007

Common Feeder Birds: Northern Cardinal

Male cardinal- photo by John Howard

If you are wanting to learn scientific names, the Northern Cardinal has an easy one to remember: Cardinalis cardinalis. It's name refers to the Catholic church official with robes of the same vivid, scarlet color. It is the male of the species that sports this gorgeous red plumage with a black mask. The cardinal is a large finch approximately 8-9 inches in length and 45 grams in weight, or about eight quarters. Its distinct crest can be raised and lowered in communication.

The brilliant color comes, once again, from carotenoid pigments, chemicals producing a red or orange color, found in plant material that the cardinal ingests. Recent studies have found that brighter males have a higher reproductive success and territories with greater vegetation density. The male is responsible for most of the feeding and will bring the female food. The female will sing from the nest and it is believed this may give the male information about when to bring food to the nest. The nestlings are fed a diet of mostly insects, then given more seed and fruit as they get older.

The female has a more drab brownish-gray color with reddish wings and tail. This is so she is better camouflaged. Both sexes have a massive orange bill used for cracking seeds ( and fingers of bird banders! Ouch!). The young cardinals will look similar to the female, but they will have a dark gray bill instead of the orange of the adult.

Female cardinal-photo by John Howard

Young cardinal with gray bill

I had always wondered why a bird would want to be so brightly colored, that it would be a disadvantage to the cardinal because it could be more easily spotted by predators. But a light came on when a gentleman told me how his son could not see cardinals because he was color-blind. The cardinal, when sitting in a shrub, just disappears and his son cannot spot it at all. It then occurred to me that most mammals are also color-blind, so those predators would not be able to see the cardinal, either. They would still have to be wary around predators such as Cooper's Hawks, though.

Males are very territorial and will fight with other male birds that stray into their territory. I knew of one bird that would fight a mirror on a truck at the plant nursery where I used to work. Everyday this bird would viciously strike at his reflection in the mirror until he was completely exhausted. He must have been thinking, "Wow, this guy is tough!"

An interesting fact is that the cardinal is the most popular state bird. It is the choice for seven states: Illinois, Indiana, Kentucky, North Carolina, Ohio, Virginia and West Virginia.

Many of us take the cardinal for granted. But in areas out west, the cardinal is less common. In California, the cardinal is listed as a species of special concern. This bird may eventually disappear from California due to habitat loss. Its habitat choice contains many small trees and shrubs including hedgerows, forest edge, grasslands with shrubs and plantings around buildings.

At feeders, cardinals love black-oil sunflower seed. They also like fruit trees in the winter, like hawthorn and crab-apple.

Monday, December 10, 2007

Common Feeder Birds: House Finch

I remember seeing my first House Finch. It was the early 1980's and one showed up at our feeder in Lebanon, Ohio, near Cincinnati. My Mom commented on the strange red "sparrow" at the feeder. At that time, the House Finch was a uncommon sight in southeast Ohio and, according to range maps, had not even spread to Indiana, yet. Little did I know that there would be many, many more to come in the following years.
House Finch male-photo by John Howard

The House Finch, Carpodacus mexicanus, has an interesting story. They were native to the Western United States in the 1940's and were trapped and sold by dealers in Los Angeles, California to bird stores in the East under names like "Hollywood Finches", "Red-headed Linnets" an other names to get around the ban on sales of migratory birds. According to an article by J. J. Elliot and R. S. Arbib in the Auk, 1953, the birds that were sold numbered in the thousands. The National Audubon Society got involved to put a halt to this illegal traffic and it is believed someone decided to release some of these finches around Long Island, New York. This is where the first male was observed in April, 1941 near Jones Beach, Long Island. Soon reports and numbers grew. In May, 1943 the first nest with 4 young was discovered in a tree nursery in Babylon, Long Island. In the winter of 1948-49 a heavy snow knocked the original flock back, but by 1949, the flock in Babylon had grown to 70 individuals and 3 other colonies in the nearby areas of Hewlett, Westbury and Lawrence were observed. The following distribution map shows how the individuals have spread over the years. By the late 1970's-early 1980's, the house finch numbers in the east had greatly increased and by the 1990's had almost reached the original population in the west. Nowadays, the house finch is estimated, according to Cornell Birds of North America Online, to have a population between 267 million to over 1 billion for the continental U.S. and Canada!

Maps showing the distribution of the House Finch through time.

Despite its origin, the House Finch is a handsome bird. The males color can range from yellow to orange to red, with the darker red males being in demand with the females. Supposedly, the more brilliant the red, the better the male is at obtaining good food, rich in carotenoids, a chemical found in many plants that have red and orange color. The females will want to choose a male that can provide ample food for her and the brood. The female is white and brown streaked, so she is better camouflaged when sitting on the nest.

House finch female

Look for this native Californian at your feeders. They enjoy nyjer seed (thistle) as well as black-oil sunflower and will also take suet.

Tuesday, December 4, 2007

Common Feeder Birds: American Goldfinch

Summer male American Goldfinch

Wild canaries! That was what my family called them when I was a kid. I later learned their more widely used name of American Goldfinch, Carduelis tristis. This beautiful little bird with the color of sunshine is always a welcome sight.

Winter female American Goldfinch

These bird are sexually dimorphic which means the males and females are different colors. In the spring/summer, the male is a vivid yellow with black cap, black wings and tail. The female is a more dull yellow-brown with olive brown wings. In the fall, the males lose their bright yellow hue and look almost the same as the female, except for their yellow shoulder patch. The females also go through this molt in the fall, but it just results in a duller look. Goldfinch are one of the only carduelis finches to go through a molt in both the spring and the fall. In the spring molt, American Goldfinches only molt their body feathers while in the fall molt they lose body feathers as well as tail and wing feathers. Both male and female have orange bills in the spring/summer and a duller dark bill in the winter.

American Goldfinch winter male, photo by John Howard

Shoulder patch in winter male

American Goldfinch are closely tied to their food source. They are granivorous or eat mostly seeds. Even when they feed their young, goldfinch rely mostly on a seed diet. The Brown-headed Cowbird, which parasitize many birds nests by leaving its young to outcompete the smaller birds, does not survive in an American Goldfinch nest. The cowbird likes a diet rich in insects, which it does not get from the mother goldfinch. Most cowbird babies have retarded growth and die before they can leave the nest. Also, the males brillliant yellow hue is due to the food they ingest. Carotenoid pigments that produce yellow and orange colors in many composites or flowers in the sunflower family which is a favorite food of American Goldfinch. The frequently feed on Prairie Dock, Compass Plant, Rosinweed, and sunflowers. I used to work at a native plant nursery and we would have to put netting over these plants to keep the goldfinches from destroying the seed crops. They could wipe out a whole row of plants in no time. Besides the composites, American Goldfinch also use thistle as a food source and to line their carefully woven nests.

Nesting behavior is another unique characteristic of the American Goldfinch. This is one of the few birds that nest very late in the season. American Goldfinch wait until late June to early July to nest with some of the last eggs being laid in mid-August! Some researchers believe this is timed to coincide with the abundance of food for the nestlings, since so many seed bearing plants are available then. Others believe it is for the thistle down for the lining of the nest. Since they nest so late in the season, they usually only have one brood, usually between 4-6 young.

Many of our winter visitors may be from farther north. The American Goldfinch from the north will migrate south to find food. Most Canadian populations will end up in the United States. At feeders, they enjoy black-oil sunflower seed and nyjer seed(thistle). I have seen as many as 14 American Goldfinch on one of our small thistle feeders at one time.