[bsg] Grasshopper Sparrow, drought and grass.

  • From: Terry Davis <terkchip@xxxxxxxxx>
  • To: "LABIRD-L@xxxxxxxxxxxxxxxx" <LABIRD-L@xxxxxxxxxxxxxxxx>, "bsg@xxxxxxxxxxxxx" <bsg@xxxxxxxxxxxxx>
  • Date: Sun, 17 May 2015 18:17:57 -0500

Hi all, I just threw this together real quick. Comments appreciated....

It sure seems that Grasshopper Sparrow reports have been falling way off
in the past few years, especially this spring season and last. This past
winter failed to produce a single bird- at least for my efforts. Last I
checked (correct me if I'm missing records/ reports), there hasn't been a
single report this spring season of migrants or possible breeders- as of
yet- and the season is nearly over. We used to think that the first
migrants and breeders arrived later in May but that old notion had been
somewhat thrown to the side over the past ten or so years, when birds
showed up singing here in n-w La by around the 3rd week or slightly later
in April. However, numbers still seemed to increase later in May during
most of those years as well.

If one looks back, it seems the most frequent and notable sightings were
either during years of drought or years when drought, at the very least,
closely preceded the period when higher numbers were found. During years
before and after drought, the preferred grass types, especially those in
breeding areas, grow notably sparser than in other years. Clumping type
grasses will clump either way, but aside from the Hill Farm in Homer (not
familiar with grass situ there except somewhat in winter), many previously
established breeding locations have been located within agricultural and
pasture areas along the Red River valley, where native clumping-type
grasses have become quite rare to absent. In years of drought, however,
even many of the non-native and non-clumping grasses take on more of a
clumping or patchy form- and are therefore more/less usable by the birds.
The birds prefer this grass form, so that they can run like mice between
the clumps without having to fly. Any birder familiar with breeding
Grasshopper Sparrow will tell you that the only birds that somewhat
frequently visible are singing males. One has to work hard and do loads of
walking for any others. One might use the food availability argument but
again, the birds are more often seen in years when the supply should be
lower, rather than burgeoning- such as years when there's lots of seeds,
insects and lush bushy grass, yet hardly a Grasshopper Sparrow in sight.
Then again, many insects are known to respond to drought with rapid
increases in number, which also leaves that path full of potholes. My
personal opinion is that the answer lies within the density and patchiness
of grass. I had been searching for some years before finding the first
breeders that had been found in several decades in Wardview in northern
Bossier Parish, quite a few years ago- when suddenly, after many, many
strike-outs, there they were......

I've only looked for them on a few occasions thus far this spring but have
struck out every time. John Dillon mentioned that he hasn't been able to
search of them much at Hill Farm, either. However, Charlie Lyon has checked
for them on quite a few occasions recently at several of the known breeding
locations during his big year quest and has reported no success thus far. I
think it's more likely that we are not missing the birds....They're just
simply not there.

Good birding,

Terry Davis

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