The Blue Grosbeak: Does it disappear in the sky or the water? You decide.
For the meanings of bird parts which you do not understand in this Hub, please see my bird glossary.
If what you want is not in there, please let me know so that I can add it in the glossary.
Their family tree:
Let me start by telling you that they are in the ‘Family Emberizidae’. This is ‘Subfamily Cardinalinae’, ‘Cardinals, Grosbeaks and Allies’.
There are 39 species in this family, chiefly in tropical America. Only ten of those species appear to be in North America. The birds in this family basically have bright colors and conical bills which they use to crush seeds. Instead of migrating, some of these birds stay all year and are very territorial but not all of them. There are some which go to the tropics as soon as the season for breeding is over.
The only ones in this group which I will be describing are the grosbeaks. They are the Black-headed Grosbeak, the Rose-breasted Grosbeak, the Yellow Grosbeak and the Blue Grosbeak. The one talked about in this Hub is the Blue Grosbeak. (The other two: the Pine Grosbeak and the Evening Grosbeak are with the finch family.)
Blue GrosbeakClick thumbnail to view full-size
When you see the Blue Grosbeak what you see is a beautiful blue bird which has a bill that is silvery colored. On its blue wings are wingbars with a chestnut tinge. Since it lives in shrubby habitats across the southern United States, it is a bird which is very different.
Both sexes are distinguished by their large, deep bill and double wing bars. These features, as well as the grosbeak’s relatively larger size, distinguish this species from the Indigo and Lazuli Buntings.
The length of both the male and the female grosbeak averages at about 5.9 to 6.75 in. long, or (15 to 17.15 cm). When flying, they have a wingspan of about 11 in. (28 cm). They weigh from between 0.9 to 1.1 oz. (26 to 31 g).
The male looks like a beautiful deep blue bird with two chestnut wingbars and bill which is a dark silver and tough. In weak light it may look black. When breeding, it has alternate plumage: It is blue all over with brown wingbars. When nonbreeding, it is in basic plumage: The body is blue and the edges of the feathers are brownish.
The female :
The female is mostly brown, with buff, rusty to black - wingbars.
In the first year there is the female which resembles the adult female because it is brown w/rusty wingbars and has less blue on the upperparts.
In the same year there is the male which goes through its first summer of life. At this time its plumage is between the adult female and the adult male, and it has uncertain measures of blue mixed with brown.
When the second winter arrives the juvenile male earns its adult feathers.
Which blue do you think it is?
Most of the work on building the nest is done by the female of the family, but the male occasionally chips in and helps too. The nest is small and compact and it has a cup shape to it. The materials which it is made from are bark strips, twigs, cotton, rags, rootlets, newspaper, snakeskin, dead leaves other materials and even string cellophane. They are all woven together.
It also has an inner cup which is approximately 2” – 3” from the inside of one edge to the inside of the other edge. This is where the eggs are laid. Measuring from the top to the bottom at the center of the cup comes to about 2” in depth. The inner cup is usually lined by using materials such as hair, fine grasses and rootlets.
Cowbirds are always laying their own eggs in grosbeak’s nests. This causes the grosbeaks to be massively parasitized by them.
Nest Placement -
You will basically see a Blue Grosbeak construct their nest low in a shrub or small tree, or perhaps something like a briar, a tangle of a vine or some other vegetation. They generally do this close to roads or other uncluttered areas.
Blue Grosbeak at tube feeder
It eats mostly insects – grasshoppers & crickets in general - but they will also eat snails, spiders, grains, seeds and wild fruits. The Blue Grosbeak forages on the ground and in shrubs and trees.
They also have a decent share of grains in their diets and this consists of seeds from bristlegrass, panicgrass, oats, corn, wheat, alfalfa and rice. They obtain food from foliage by hovering and gleaning it. They also hunt for insects by sitting on a perch and flying out when they see one which is of their liking.
When the eggs are in the nest they are a pale blue and unmarked. After they are laid, they are kept warm for a period of 12 – 13 days and the birds come out in a helpless state. Once the eggs have hatched, the nestlings go through another period of nesting for about 9 – 10 days. The adults may choose to lay eggs once or twice during the breeding season.
The eggs are 0.6"-0.7" wide by 0.7"-0.9" long of a group of about 3-5 eggs in a lay.These are then incubated for 12-13 days. The number of times that they lay their eggs is 1-2 times. After the young are born, their nesting period is only 9-10 days.
When that time comes they have to be fed by the adults for a bit because you will see cute little birds which are helpless, with brownish grey down and closed eyes. The adult removes the head, legs and wings of an insect previous to their feeding of the young.
Blue Grosbeak singing
There is not much to their song other than it sounds blurry and it is rough-sounding. It has an assortment of rattling warbles and various interchanging tones which may be repeated often. It is made of short phrases which rise and fall. The sound of the song may suggest to several listeners different birds in the area of a Purple Finch, a House Finch or an Orchard Oriole. The only difference being that the grosbeaks song is slower and more guttural.
The call is simply a pink sound or a chink sound.
The first ones to arrive during the breeding season are the males who come before the females appear. The males create feeding flocks. Every pair of adults that will be raising young has an area of 2 – 20 acres which it defends while they are building their nest and incubating. Once this time is over they allow the area to become smaller after the fledglings have hatched. Since they are more than likely monogamous then it is possible that each couple will raise two broods while the adults work as one in one breeding period. Before the adults - and the young - fly somewhere for the winter, they gather in congregations to feed in grain and rice fields plus grasslands.
The habitat and the range of the Blue Grosbeak:
The Blue Grosbeak is a migratory bird, with nesting grounds across most of the southern half of the United States and much of northern Mexico. Central America as far south as Panama and in very small numbers to northern South America. There has even been a record in eastern Ecuador in South America.
This bird breeds in tangled vine and shrub habitats across North America – as far north as New Jersey in the east, central California in the west and North Dakota in the central United States. Within these states it may breed in old fields, a row of hedges, trails of power-lines, forest edges or the edges of streams, for starters. More are deserts, mesquite savannas, southern pine forests and saltcedar forests.
Their requirements about their habitats consist of a small amount of tree species, low shrub thickness and limited canopy coverage. When they find a place for their nest, it is usually about 1 – 3 m (3.3 - 9.8 ft.) above ground. Often at the edge of an open area.
The Blue Grosbeak starts breeding from the west coast starting with California and heading east to Idaho, North Dakota, Illinois, even New Jersey and then southward almost in every bit of the United States. From the US it goes into northern Mexico. Mexico is divided by the Tropic of Cancer which divides the country into two zones, tropic and temperate. Land north of the dividing line has the cooler temperatures during the winter months.
During these months the birds migrate with most stopping at Central America - which is a sort of ‘bridge’ between North and South America – while small amounts of the birds continue going to South America. There are even records of some which have been in Ecuador.
Conservation facts and interesting facts:
In the capsule on Nesting was mentioned a fact about the Brown-headed Cowbird laying eggs in the grosbeaks nest. This has not affected the grosbeaks population.
Even though they are not common, Blue Grosbeaks spread wall-to-wall across the southern part of the United States. Between the years of 1966 – 2010 their total population became larger by approximately 1% per year. This was reported by the North American Breeding Bird Survey. Due to an evaluation made by Partners in Flight, their breeding population is internationally at 24 million. This leaves 74% breeding in the United States, and 57% for the part of the year they spend in Mexico.
Grosbeaks seem to always live in low densities. Looking back to ecologists who lived in the nineteenth century there were reports from back then which stated this fact. Back at that time and leading into the twentieth century, the breeding area broadened. Perhaps it was due to forest cutting.
The fully grown longleaf pine forests in Florida plus combined loblolly-shortleaf pine forests from eastern Texas have these birds living at immense densities (an average of 80 breeding males within each square mile). Since their wintering grounds are out of state, we have no known results of agriculture and any forest cutting.
Within their breeding zone, they can profit from a few present movements of human modernizations of land but not others. They do well in land which has been used for farming or gardening but is deserted.
Interesting facts –
Other names: Guiraca bleue (French); Piquirgrueso azul, Ruiz azul grande (Spanish)
- The Blue Grosbeak formerly was placed in its own genus, Guiraca. Similarities with buntings in genetics, behavior, molts, and plumages led to its inclusion in the bunting genus Passerina. Genetic evidence indicates that the Lazuli Bunting is its closest relative.
- In the southern part of its breeding range, the Blue Grosbeak commonly raises two broods per year.
- It uses snakeskin as nesting material, which is thought to thwart predators.
- The Blue Grosbeak was first described in 1758 by Linnaeus, Swedish botanist, physician and zoologist.
© 2014 The Examiner-1