Foam Lake Birding No. 155

FOAM LAKE BIRDING

No. 155

                        The first signs of autumn are here.  The Golden Rod in our yard is blooming which has always reminded me that a new school year was about to begin.   Some grain fields are starting to turn and some of our summer birds, like the Yellow Warbler and Purple Martin, have already started heading south.  Finally, as I was writing this article, a Swainson's Thrush landed on the railing in our garden.  These thrushes nest in the boreal Forest and are found here only in the fall and spring during their migration. 

            However, summer is still officially here and so discussion about another summer bird is in order. 

            In the last article I mentioned that the nests of many small song birds were parasitized by the Brown Headed Cowbird, Canada's only completely parasitic bird.  In the southern US there are two more cowbirds along the Mexican border.  As a point of interest, Eurasia has the Cuckoo (the bird of the cuckoo clock).  We do have some other birds that are occasionally parasitic but, unlike the cowbirds, they do build their own nests and rear their own young. 

            Since the arrival of Europeans to the Americas the Brown Headed Cowbird has "morphed" from a unique and interesting bird to a bit of a pest.  Historically, the cowbird has had a symbiotic relationship with the vast roving herds of bison (buffalo) and antelope.  As the herds roamed about the continent the cowbirds moved with them making traditional nesting and rearing of young impossible.  As a result they became parasitic (lay their eggs in other birds' nests).  Whenever bison were present in a certain area in the spring the cowbirds would parasitize the nests in that particular area and then move on with the herd.  Next spring the herds would be in a different area and the nests in that area would be parasitized and so on.  This constant roaming minimized the harm caused by parasitism.  Since the disappearance of the bison the cowbirds have switched their attention to cattle which do not roam.  Since the cowbirds no longer roam they parasitize the same areas year after year causing considerable problems especially for species at risk.  The cowbird's egg (she lays only one) hatches out earlier than those of the host bird usually resulting in the cowbird being the only chick hatched.  It is not uncommon to see two 'tiny" Chipping Sparrows feeding a very much larger dark grey juvenile cowbird.  To reduce parasitism authorities have had to occasionally exterminate cowbirds in order to restore the reproductive capabilities of threatened species.  However, one recent turn of events has led to some unintended control of cowbird parasitism.  Many farmers have gotten out of the cattle business leaving large tracts of land without suitable habitat (no cattle) for the cowbirds with the resultant reduction of parasitism. 

            The sparrow sized Brown Headed Cowbird is quite easy to identify.  The males are pure black with a distinctive brown head; the females are an even dark brown.  To see cow birds, especially males, one has to drive out into the country and find a herd of grazing cattle.  The cowbirds are almost sure to be there.  In spring, the females can often be seen in town clambering in the shrubs and bushes looking for nests in which to lay their eggs, often being harassed by potential host birds. 

            Both of this week's photos were taken last year several miles east of Foam Lake near some pasturing bulls.  One picture shows two male cowbirds; the other shows a female cowbird and a Clay Coloured Sparrow.  I am not sure how well the distinctive features will show up in a black and white photo but a bird book will help.

Foam Lake Birding No. 154

FOAM LAKE BIRDING

No. 154

            After the deluge of several weeks ago (two inches in thirty minutes) we lost our Yellow Warbler family that I mentioned in my last article.  Whether the weather or a predator was responsible is impossible to tell but the young are gone and the nest is abandoned. 

            Another pleasant little bird that is commonly found in urban yards is the Chipping Sparrow.  Like the Yellow Warbler it seems to like being in the presence of man and often nests near buildings.  It especially likes building its nest in foundation plantings of cedar and juniper.  We have had them nesting in our yard in the past but not this year.  

            Like Yellow Warblers Chipping Sparrows are often parasitized by the Brown Headed Cowbird.  Yellow Warblers will usually abandon the nest or build a new one over top of the old one (cowbird's egg and all) thus eliminating the problem of feeding a young cowbird.  On the other hand the Chipping Sparrow will hatch and rear the young cowbird.  It is not unusual to see two "pint" sized chippers feeding a young cowbird twice their size.  As youngsters on the farm my brothers and I would go around from nest to nest and throw out the cowbird's eggs if there were any.  I hope the Yellow Warblers and Chipping Sparrows appreciated the effort. 

            In the summer time the Chipping Sparrow is very easy to identify.  It is a small brown bird with plain grey undersides and face, rusty red cap and a thin black line through the eye.  Like all sparrows males and females are the same.  There is no other bird like it except during spring migration when it can be confused with the American Tree Sparrow and the Swamp Sparrow that are on their way north.  The Swamp Sparrow is a darker bird that is quite secretive staying close to the ground under shrubbery; the American Tree Sparrow is paler with a distinctive black spot in the middle of its breast.  Both of these latter two birds prefer rural to urban settings and are seldom seen in town.  Probably the easiest way to identify the "Chipper" is by its song.  The Chipper's song is a long rattle (two seconds or so) in one pitch.  The only other bird that has a very similar song is the Dark Eyed Junco but the two birds are entirely different in appearance so misidentification is not a problem.  The Chipper also makes a distinct "chip" sound when calling or disturbed: hence its name.  Chippers are often seen on lawns stirring up insects to feed their young. 

            In the south western USA there are two other similar sparrows, the Rufous-Crowned and Rufous-Winged Sparrows.  With the exception of the American Tree Sparrow, four of the five species can be present in the same areas in the winter time.  It makes for some interesting birding.  For some fun check out the five birds in a good bird book for the similarities and differences, 

            This week's photos were taken in our back yard in the spring a few years ago.  One photo clearly shows the colour patterns especially the black eye line; the other is just a good profile.  The apple blossoms add appeal. 

Foam Lake Birding No. 153

FOAM LAKE BIRDING

No. 153

            It has been a while since the last article but various family events have kept me busy elsewhere.  Now, it is back to local birds. 

            With the plentiful moisture this spring and subsequent heat the vegetation is very lush providing birds with ideal habitat to raise their young.  At present we have House Sparrows, House wrens, Purple Martins, Robins and Yellow Warblers nesting in our yard with Brown Thrashers, Brewers Blackbirds, Chipping Sparrows, Grackles and Mourning Doves just a "stone's throw" away.  Some species, such as Robins, House Sparrows and Flickers, have fledglings already. 

            A pair of flickers and their four youngsters have been in our yard for a number of days now.  With the recent hot weather they have spent a lot of time at our bird bath drinking and bathing.  It was fun watching the young ones copying their parents' behavior.  It reminded me of little children hesitatingly entering a swimming pool for the first time.   After the bird bath they flew to the ground looking for their favourite food, ants.  What a nice way to get rid of troublesome pests.  As I mentioned in a previous article, "I do like Flickers". 

            This week I am featuring a bird, the Yellow Warbler, that I had covered before in Article No. 89.  As I had mentioned in that article the Yellow Warbler is the only warbler that can be commonly found in urban yards.  We have had their nests in our yard in the past and we have one again this year.  This year's nest is very close to our house only about a foot away from our dining room window.  Whenever we sit down for meals we can and do watch the parents busily feeding the young. It certainly provides us with quite a bit of entertainment. 

            Because of its vibrant yellow colour and cheerful song the Yellow Warbler has always been my summertime "happy bird" as it were.  Even in inclement weather its presence raises one's spirits.  So it is with this week's picture of a male drying himself off after one of our recent intermittent rain showers.