Spring Azure

Starting yesterday afternoon we have seen quite a few "little blue" butterflies make their way through our backyard. These butterflies are part of a group called the Spring Azure complex, which is made up of several species that scientists are still trying to tease apart.


These little blue butterflies drink nectar from such plants as butterfly weed, clover, and a variety of asters. Their caterpillar host plant preferences are dogwood, blueberry, and cherry trees.

Splish Splash

Nearly all birds bath frequently in water to keep their feathers in good condition and during the summer, bathing in water also helps the bird to keep cool.

Once in the water, the bird fluffs its feathers to expose the skin, submerges its belly and breast in the water, rolls back and forth by dipping its head into the water and creates a shower by flicking its wings. When finished, the bird shakes off the excess water and then flies off somewhere to dry and preen.

In our backyard it has been especially dry due to lack of rain, so when the bird bath is full of water, there is a line of birds ready for a bath and a drink! Here is a video I made this afternoon of the activity at the bird bath. In it you will see: Brown-headed Nuthatch, Carolina Wrens, Brown Thrashers, Northern Mockingbirds, House Finches, Northern Cardinals, and Chipping Sparrows.




For information about bird baths and to learn about creating a backyard habitat for wildlife see:
http://www.audubon.org/bird/at_home/pdf/GFLchap3.pdf

Nest Update: House Finch

The house finch nestlings have just about outgrown their nest and will most likely fledge tomorrow. Below is a short video of the male feeding the 4 nestlings. The parents feed their young by regurgitation of crop contents. The young are fed mostly plant material: small flower buds and seeds.

First of the Season

Yesterday we saw our first Monarch Butterfly of the season. Monarchs are a butterfly of great interest not only because of their beauty but also because of their migratory behavior.

To learn about the Monarch Migration through a great slide show click here: Monarch Annual Cycle

The monarch in our backyard was newly arrived from Mexico. It was looking for a place to lay its eggs. The only type of plants monarchs can lay their eggs on are Asclepias also known as milkweed. They will lay one egg per leaf and can lay many eggs in one day. A single Female will lay around 700 eggs before she dies. And 700 eggs from just one butterfly means monarchs need a lot of milkweed!


You can find milkweed at your local garden shop, or you can grow them from seed.

To find out more about the Monarch Migration, see Journey North's website. There you can learn more about monarch natural history, see live maps of monarch sightings, and even report your own sightings!
www.learner.org/jnorth/monarch/

Nest Update: Brown-headed Nuthatch

There has been a flurry of activity at the nuthatch nest. It is quite obvious that the eggs have hatched, both parents have been bringing lots of food to the nest.

Brown-headed nuthatches lay 3-7 eggs. The eggs are incubated for 2 weeks. Once hatched, the parents bring the nestlings a variety of small soft-bodied grubs, spiders, and caterpillars.

In this video I made this morning, you will see just what the nuthatches are feeding their young.



Once the nestlings get a little older, the parent will begin feeding them hard bodied insects such as cockroaches; they will also feed them pine seeds (which are a large part of the adult diet). The nestlings will fledge the nest 18 days after hatching and will continue to rely on the parents for food over the next 2–4 weeks. Family groups remain together throughout summer, so we look forward to seeing the nuthatches grow up.

References:

Withgott, J. H., and K. G. Smith. 1998. Brown-headed Nuthatch (Sitta pusilla). In The Birds of North America, No. 349 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Nest Update: House Finch

These are the 10 day old chicks.
They have grown so much, the female no longer sits on the nest: there is no room for her! They will leave the nest and become fledglings at in about 6 days, when they are 16 days old.

And if you think that looks like bird poop on the nest, you would be right. As in most birds, when House Finch nestlings defecate, the feces are contained in a membranous sac. The parents eat the nestlings' fecal sacs for about the first five days. This is because most of the food has not been digested, so it is still nutritious for the parents. But as the nestlings get older they digest more, so most songbird species then stop eating the sacs and carry them away to dispose of them. But House Finch parents do not remove them, and the sacs accumulate around the rim of the nest.

References:

All About Birds

Barn Owls

The Barn Owl (Tyto alba) is one of the most widespread of all owls. Versatility in the use of nest sites and in selection of prey, strong powers of flight, and an ability to use human-modified habitats undoubtedly are significant factors in the large geographic range of this species.

Despite being common in some areas and often nesting close to human habitations, the secretive, nocturnal activity of Barn Owls cause to be them inconspicuous to most people. But, due to modern technology, the hidden lives of these owls can now be viewed without causing any disturbance to them!

The interesting, seldom viewed behaviors of these owls can be viewed through several cameras that have been set up in nesting boxes.

At this site, the pair of owls are in the mating stage and have not yet laid any eggs:
BarnOwls Italy,Texas

At this site, the pair have 7 eggs that are just in the hatching stage; so far two of the seven eggs have hatched. The streaming video has sound so you will hear a lot of crying hatchlings!
BarnOwls Benecia, California

Young owls fledge the nest at 8-10 weeks old, so there is plenty of time to watch these chicks grow!

References:

Marti, C. D., A. F. Poole and L. R. Bevier (2005). Barn Owl (Tyto alba). The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North American Online database.

Brown-headed Nuthatch

Early this spring a pair of Brown-headed Nuthatches excavated a nesting cavity in a Maple snag (dead tree) in our backyard. The female has been sitting on eggs for over a week now. The male diligently brings her food about twice an hour and every few hours she takes a short break from incubating her clutch.

Here is some edited video footage I captured of the male bringing the female food and the last part is the female taking a look outside of their nesting cavity.

April 1st Bird Count

This morning's backyard bird count yielded 19 year round residents, 2 winter residents, and 4 summer residents. We are now seeing more summer residents and less winter residents as they are leaving to go to their summer breeding grounds.

Here is this list. I have indicated if the bird is a year round resident, winter resident, summer resident, or a migrant just passing through. I have also indicated the conservation status of each species.

Eastern Towhee (Pipilo erythrophthalmus)
Year Round Resident, Populations declining throughout range

Brown-headed Cowbird (Molothrus ater)
Year Round Resident, It is a common bird across most of North America, but numbers are declining in most areas

Red-shouldered Hawk (Buteo lineatus)
Year Round Resident, Populations appear stable, but may be declining in some areas

Red-tailed Hawk (Buteo jamaicensis)
Year Round Resident, Increasing across most of range

Northern Mockingbird (Mimus polyglottos)
Year Round Resident, Common and widespread

Northern Cardinal (Cardinalis cardinalis)
Year Round Resident, Population density and range increasing

Tufted Titmouse (Baeolophus bicolor)
Year Round Resident, Populations increasing and expanding range northward

Eastern Phoebe (Sayornis phoebe)
Year Round Resident, Populations stable

Carolina Wren (Thryothorus ludovicianus)
Year Round Resident, Populations stable or increasing

Carolina Chickadee (Poecile carolinensis)
Year Round Resident, Slight, but significant population decreases across range

Brown-headed Nuthatch (Sitta pusilla)
Year Round Resident, Decreasing because of habitat degradation

Brown Thrasher (Toxostoma rufum)
Year Round Resident, Populations declining slowly throughout range

Blue Jay (Cyanocitta cristata)
Year Round Resident, There is a slight but significant decline in Blue Jay numbers across the United States, with most of the decline in the East

House Finch (Cyanocitta cristata)
Year Round Resident, Common and benefiting from human development

American Robin (Turdus migratorius)
Year Round Resident, Populations stable or increasing throughout its range

Great Blue Heron (Ardea herodias)
Year Round Resident, Populations are stable

Mourning Dove (Zenaida macroura)
Year Round Resident, Widespread and abundant

American Crow (Corvus brachyrhynchos)
Year Round Resident, Populations slightly, but significantly increasing

American Goldfinch (Carduelis tristis)
Year Round Resident, Abundant and widespread

White-throated Sparrow (Zonotrichia albicollis)
Winter Resident, Declining over much of breeding range

Yellow-rumped Warbler (Dendroica coronata)
Winter Resident, Populations stable or increasing in most areas

Hooded Warbler (Wilsonia citrina)
Summer (Breeding) Resident, Common and increasing in some areas

Chipping Sparrow (Spizella passerina)
Summer (Breeding) Resident, Populations appear healthy

House Wren (Troglodytes aedon)
Summer (Breeding) Resident, Populations have increased over the long- and short-term across the continent

Yellow-throated Vireo (Vireo flavifrons)
Summer (Breeding) Resident, Has disappeared from some small forest areas, but is increasing slightly rangewide

For more information on point counts, visit the Point Count Database: www.pwrc.usgs.gov/point/

References:

http://www.birds.cornell.edu/AllAboutBirds/BirdGuide

Nest Update: House Finch

This morning two of the finches have hatched. The other two eggs should hatch within the next day.