Monday, June 8, 2015

Avian Delights of Early Summer‏

Baltimore oriole
Along with the warming temperatures, the greening of the landscape, and the blooming wildflowers, the songs and colors of birds are one of the intense delights of the spring and summer.  As I write this on June 7, some birds have raised one brood already (bluebirds, mourning doves, tree swallows, robins, meadowlarks) whereas others are in the process of rearing young (Baltimore and orchard orioles) or still sitting on eggs (catbirds) or still making nests (willow flycatchers). 

Tree swallows nest in many of our 25 nest boxes (a male is shown here on top of one) and are constantly flying around our yard and ponds.  The back of the male alternates between appearing bright blue or green depending on the angle of the light since this is a structural color without any pigment involved.  They are dominant over bluebirds competing for the same boxes but the bluebirds manage by producing more broods and starting earlier.

Orchard oriole on red hot pokers
We have Baltimore and orchard orioles nesting in the same large maple tree in our front yard.  It is interesting that they seem not to squabble over territory, perhaps because their preferred habitats and diet are only partially overlapping.
The orchard oriole is unusual in that it is specialized for collection of flower nectar including the piercing of the base of larger flowers or those with long corolla tubes.  This photo shows a male orchard oriole perched on the flower stems of red hot pokers from which it has been drinking nectar.  

A most unusual and the largest of the woodwarblers is the yellow breasted chat.  It is found primarily in early successional habitats and thus must move frequently to find new nesting sites.  The seven acre field where this and another chat were singing was clearcut three years ago and is now filled with shrubs.  This is a poster bird for the advantage of making clearcuts in some but by no means all forest habitat.  Maximizing biodiversity requires a maximum heterogeneity in habitats, a fact that all land managers need to recognize.    

Grasshopper sparrow
The grasshopper sparrow is a bird that requires open grassland breeding habitat, and is thus often found in cattle pastures.  Before the advent of humans, one wonders how many short grass prairies would have been available to them.

The pileated woodpecker would have fared well in the unbroken forests that covered much of the eastern US before the advent of humans.  This male returns regularly to a rotting stump in our front yard to chop away in its hunt for wood grubs.

Canada Geese
One bird I do not encourage to linger around our ponds is the Canadian goose.  This adult with young goslings in tow is a cute picture, but bad ecology.  These geese should be breeding far to the north but individuals that were originally wing clipped and allowed to breed far south of their normal range have become established as transplants.  They foul the shores of their new homes in yards and golf courses and can be aggressive in defense of their young.    

Solitary sandpiper
Two wetland species that I am very happy to see in our yard are the spotted and solitary sandpipers.  It is interesting to see spotted sandpipers with their breeding plumage with a spotted breast.  This is one breeding season transformation that does not make much sense since the male and female are identical and the transition does not seem to affect their visibility to predators.  They breed locally along river banks.  In contrast solitary sandpipers pass through our yard every year on their way to breeding grounds in Canada.  

Spotted sandpiper
I highly recommend leaving your bedroom windows open at night so that you can hear the early morning chorus of the birds that will thrill your heart.  Learn the common songs and follow the movements and breeding of your favorites.  This time of year is one of the highlights for those who enjoy birds and each of us only has a limited number of such opportunities, so do not let them slip by without enjoying them to the max.

Bill Dunson 
Galax, VA and Englewood, FL 

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