Thursday, April 30, 2015

Holy trees! Sapsucker Damage by Irene Shonle





I love the return of spring… there is so much going on, from the Western Chorus Frog singing in the twilight, to the return of the hummingbirds, to the moose with their newborn calves. Another pleasure is that for a brief time, our woodpecker diversity increases from the usual Downy and Hairy Woodpeckers (with the occasional Northern Flicker thrown in).  I make a point of looking carefully every time I hear the rat-tat-tat of a woodpecker in the spring, because it just might be a Red-naped or Williamson’s Sapsucker.

The beautiful Red-naped Sapsucker


These flashy birds live in the high country, but at least at my house, they never stick around much past May.  (Don’t mind me… just coming through….. ) And I only get the Red-naped – I have yet to see a Williamson’s, although they are reported for Gilpin County (http://coloradocountybirding.org/Checklists.aspx)

Red-naped Sapsuckers, as you might suspect from the name, love to drill  trees for the sap (nutrient-and-sugar-rich phloem).  While aspen and willows are preferred, they will also use other species, although they usually will only attack pines where the bark is not too thick. The holes are ¼’ and are in neat, evenly spaced horizontal or vertical rows.  People often mistakenly blame insects for this damage.
http://pep.wsu.edu/hortsense/images/Large/sapsucker2.jpg
Typical sapsucker holes -- photo by C.R. Foss (http://pep.wsu.edu)
  Sometimes the holes can be enlarged so it looks like some sort of odd board game (see below).
Enlarged Sapsucker holes in a young Ponderosa

Usually the shallow damage is not severe enough to harm the tree, although it's possible.  The most commonly recommended damage control meth­od is to wrap burlap around the affected area to discourage sapsuckers from returning. You could also try hanging bright, shiny objects such as pie tins or shiny streamers on the tree as scare devices. These techniques may or may not be effective, and they may just shift the bird’s attention to another part of the tree or to a nearby tree. If the sapsucker appears to favor a specific tree, it may be best to use it as a sacrifice tree, so the bird leaves other trees alone.

Sapsuckers also create nest cavities in  aspen and Ponderosa snags (or sometimes still alive but partially decaying trees).

Interestingly, many other animals benefit from the work of the sapsuckers, including bats and hummingbirds!  They take advantage of the anticoagulant that sapsuckers have in their saliva that prevents coagulation of the sap, partaking of the free-flowing goodness even hours after the bird has left.

Sapsucker wells may even allow for the return of broad-tailed hummingbirds to the mountains before many flowers are blooming.  This is because the phloem sap is very similar in sugar content to flower nectar.  Sometimes insects will get stuck in the sap, providing a protein boost.

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