Saturday, June 8, 2013

Recently fledged Common Raven


At the end of March this year I spotted a Common Raven going into a crevice above a rock face of a local cliff area called Castle Rock (as part of it looks sort of like a castle). I started watching this area and observed a pair of Common Ravens spending time around this location. On March 27 I spotted one of the ravens inside the crevice which now had what looked like nesting material in it--the photograph of that is the second pic here.
I continued off and on to check this apparent crevice nest. At the end of May I saw what appeared to be a nestling inside the crevice. I continued birding in the riparian forest across the Arkansas River from this cliff area. When I was about a quarter mile away I heard a lot of raven racket and walked to a spot where I could see the cliff area through my binoculars. I could see a lot of raven action with the parent birds calling loudly so I expected that the nestling may have fledged or they were trying to get it to fledge. I went back to a location directly across the river from the crevice nesting area and saw a fledgling raven close to the bottom with the apparent 2 parent birds closely watching (within a hundred feet at all times) and calling what appeared to be encouragement to the fledgling to hop up the slope to where they were. However the fledgling, which called back in fledgling voice (kind of plaintive in tone) but stayed below the ledge the parents were on as it could not figure out how to hop/fly up to them. As the fledgling was in a dark area I did not get photos of that.

Two days following the fledging I was walking on the trail across the river from the crevice nest. The two raven parents were in trees on this side of the river and they would call occasionally so I thought they were trying to get their fledgling to cross over to this side where the trees provided some shade from the hot sun. As I walked past one tree between the parents they both started loudly calling and circled that tree next to me. I looked over and the fledgling, as shown in these pics, was perched on a low branch only about 35 feet from where I was on the trail. I got these photos of this recently fledged Common Raven and left as the parents were quite agitated.

The last several years I have followed a pair of Common Ravens (likely not this pair) as they have nested and their surviving fledglings (often high mortality from these cliff nests) until they have taken flight far away. I have never been close to a fledgling and the fledgling didn't know what to think of what was making clicking noises at it (from my camera)so it just sat there looking at me. The average clutch size for this species is about 5 according to Birds of North America online though the ones I have followed previously only had 3 that made it to fledging. The last 2 years I have been able to follow them more closely and only 1 fledgling survived in each of those two nestings. I could never see due to the distance if there were more than one nestling in this crevice nest and only saw the one fledgling (though others could have fledged earlier that I was not there to see). ' The next day after I took these photos the flegling was gone from this tree and I was not able to refind it.