Date: Wed, 22 Aug 2001 07:33:18 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Robert Ringler Subject: Re: Alder Fly ID MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Matt, Thank you for your detailed description. As you noted these criteria are helpful for identification in the hand but difficult to interpret in the field. I received a private reply for the other Alder Flycatcher reported. It was identified visually in the field using the field marks suggested by Sibley plus personal experience with the species. Personally, I back off from identifying Traill's Flycatchers in the field unless they are vocalizing. Most of the differences noted by Sibley are measurements, not field marks, and he closes his discussion with: "Identify by voice". Both species have a variety of vocalizations and unless you are familiar with all of them even vocal identification can be difficult. In the past the only visual field mark being touted was the presence or lack of a narrow eye-ring. Even this is difficult to see. If anyone else would like to contribute to the discussion please feel free to chip in. It is difficult enough deciding first that the bird you are watching is an Empidonax and not a pewee, and second that it is a Traill's type and not another Empidonax. To take the third step and name the species we could use some other suggestions. Bob Ringler ----- Original Message ----- From: Matt Hafner To: Sent: Tuesday, August 21, 2001 9:23 PM Subject: [MDOSPREY] Alder Fly ID > Bob and others, > > Since I was one of the people to report Alder Flycatchers recently, so I will give some information as to how they were identified. > > While banding, all Alder and Willow Flys are officially submitted as Traill's Flycatcher with the specific identity placed in the remarks column. The majority of these birds show characteristics that lean towards one specie. There is also a wing formula that contains a narrow range of overlap( I think it's in Pyle). > The things we look for are: > > Lores: Alders tend to have paler lores than Willow this time of year. > > Head Feathers: Alders tend to have large dark centers to all the feathers on the top of the head, while on Willow they are small or lacking. > > Wing bars and Tertials: Alders tend to have wingbars and tertials that are more contrasting than Willow. > > Back color: Alders tend to have a more olive back than Willow. > > Since some of these characteristics vary with age, the Adults tend to be more clear cut than the young birds. > I'm am not stating that all Traill's Flycatchers can be separated using these field marks, but they can be helpful. Also, I would not try to use these characteristics in the field as lighting can be very misleading and birds are hardly ever as cooperative in the field as they are in the hand. ;) > > The adult birds that I have banded this year and called Alders had all of the above characteristics pointing toward Alder. Also, the wing formula measured out on the Alder side not near the overlap. For what it's worth (bird calls in the hand aren't always reliable), the first Alder called repeatedly with a "peep"-like note, that I found described by Sibley and Bent and quite unlike the "whit" of a Willow. > > Hope this helps. > > Matt Hafner > Chestertown, MD > > ======================================================================= > To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com > with the following message in line 1: signoff mdosprey > ======================================================================= > ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================