Monday, January 30, 2017

The first spring migrant has returned- right on schedule!

Every year, the first species that is detected returning from parts south of us is the Purple Martin.  They seem to always get reported from somewhere in the last week of January, when we are still in our coldest month.  And this despite relying entirely on flying insects for their food!  

Right on schedule, Martins were reported a few places over the weekend, as close as East Baton Rouge and St. James Parishes.  However, the earliest bird reported this year, spotted sometime last week, was in Oak Grove in the far northeast corner of the state (!).

The fact that the first martins are back, however, does not mean their nesting boxes will be full this week.  There is usually a time lag of several weeks between the first report and the bulk arrival of the species.

Usually the first birds back are males, which is actually a widespread pattern among songbird species.  Males precede females in spring migration, so as to have an edge against rival males of their species in procuring nesting territories.

One of the oddities of our spring migration schedule is that it is likely to be a solid month before any other species arrives back.  The next returnee to be reported is less easy to predict- a Swallow-tailed Kite or Northern Parula perhaps?


Sunday, January 8, 2017

Brazen Cooper's Hawk at Harahan Walmart

Yesterday afternoon I was at the Walmart in Harahan, pulling out of parking space in the crowded lot.  The local flock of panhandling Boat-tailed Grackles took flight in apparent alarm, so  I stopped to scan for a raptor.  Sure enough, an adult Cooper's came bombing through.  However, it was not flying at normal height, but weaving and maneuvering among the cars and shoppers.  It then dove into one of the small ornamental trees near the store front, scattering several House Sparrows from its foliage, and quickly reappeared, heading back along a row of cars.  It flew at eye level ten feet in front of two oblivious shoppers, and swept up to the top of a rather short light pole.  

I pulled up that aisle, trying to get close, when it dove back to near ground level and zipped between two parked cars.  It seemed to be using these to conceal itself as it hunted, but came up empty, and flew across Jefferson Highway to park on a wire in front of the Chisesi Ham warehouse.

I say it was hunting, but I suppose it may have just become frustrated trying to find a parking space.

Cooper's Hawks are one of our most frequently seen urban raptors, but it was not always so.  As recently as the 1990's, urban Coop nests were noteworthy and sightings still pretty infrequent.  Its recent increase in numbers and urban occurrence have been reported in many parts of the country, begging the question what could cause these changes in such widespread areas essentially simultaneously.


Thursday, January 5, 2017

Blue Jays imitating...Cooper's Hawk?!?

Vocal mimicry is well known in the bird world, but prominent in relatively few taxa- most famously parrots and mynas in the realm of pets, and in members of the family Mimidae (most notably Northern Mockingbird) among our native species.

One additional case of local relevance to birders has always been the penchant of Blue Jays for imitating one particular hawk species, the Red-shouldered Hawk.  Jays are quite good at rendering the strident kyah notes made by the hawk, and do so a lot.  Because both species are common in our area, birders hear a lot of both the hawk and its impersonator.   The jays can be very convincing-  usually sounding a little more frail than the real raptor- but I find myself sometimes uncertain of whether I am getting duped.

At any rate, I had never heard a jay imitate another raptor until today.  On my way out to my car in the driveway, I heard an apparent Cooper's Hawk in my live oak.  Coops make a series of short chants, quite different from a Red-shouldered.  The sound appeared to be coming from the exact location in the tree where a Blue Jay was moving about, seemingly unconcerned about any nearby predator.  I became suspicious.  The jay then moved fifteen feet through the crown of the tree, and the Cooper's Hawk call moved with it.

Another identification complication to add to the list!  Bring it.