Date: 9/30/17 10:40 pm
From: Nagi Aboulenein <nagi.aboulenein...>
Subject: Re: [Tweeters] Red-breasted Sapsucker
Hi Linda - your question about well clustering prompted me to do some modern-style research (aka googling 😊). I came across an article by Laurie Eberhardt at Valparaiso University, that stated that sapsuckers tend to drill their holes one at a time with about 3 days between holes, at about 7 meters high, and within about 1 meter of a branch. They drill the holes in a vertical sequence starting at the bottom of a vertical string, working their way upwards one hole at a time, shifting over to a new vertical sequence at some point. The reason for drilling in that order, as speculated/hypothesized by the author, seems to be that sap dripping from the newest hole then tends to be captured by bark and older holes underneath the current hole, making it easier for the bird to catch it on a later visit.

Given that the holes in the cluster seem to get drilled over quite an extended period (about 1 new hole every 3.1 days), it may take weeks or even months for a full new cluster with a few dozen holes. That would makes it less likely in my mind for it to be related to a reaction of the tree to the drilling of a hole or holes.

But I'm no biologist or sapsucker expert, so take my musings with a big sack of salt 😊.

Good birding.

Nagi Aboulenein

On Sep 30, 2017, 22:02 -0700, Linda Phillips <linda_phillips1252...>, wrote:
> I had a 4 woodpecker day Saturday at Wallace Swamp Creek Park in Kenmore.
> RB-Sapsucker was the one I missed but I’ve seen them occasionally over the past few weeks and there are freshly dug wells on one of their favorite trees.
> I was asked recently why they cluster the wells so densely  on the tree, rather than a random well here and there. I had no answer but an idea came to me that I want to check with my fellow Tweeters to see if anyone can confirm or give a reason against my hypothesis.
> The reason the sapsuckers clusters the wells is because damage to the tree makes it send more sap to that area in an attempt to heal, so a new well near the old one will yields more sap than an isolated one. Similar to when humans have an injury the area is red and swollen because blood rushes to the area.
> What do you think?
> Linda Phillips
> Kenmore
> Sent from Mail for Windows 10

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