To report technical problems,
e-mail webmaster@lslbo.org

Archived Postings

May 20, 2007 – May 27, 2007

It always amazes me how quickly the spring passes. We are so busy in our day to day activities that it seems like only last week that the morning temperatures were below zero and the lake was still covered with ice. Suddenly June is nearly here, we are wearing shorts, the vibrant green leaves are out, and the boreal forest is bustling with activity. When did all this happen? It makes you think about how short of a summer season we have here and how many ways there are to enjoy the outdoors and everything it has to offer. For us, it’s enjoying the diversity of songbirds that are now in the area. We have observed most of the migrant species that we expect to see during a normal spring migration at the LSLBO. Migration is still occurring as young males and females and some of the late migrant species are now arriving. These new arrivals will add nicely to an already good spring in terms of banding. As we enter the last week of May, the LSLBO has banded over 800 birds representing 44 different species. We have not seen any crazy hectic days with the nets dripping with birds, it has been a nice and steady banding season. So far white-throated sparrows, Lincoln’s sparrows, ovenbirds, and black-capped chickadees have all broken previous LSLBO spring banding records. Swainson’s thrushes are currently moving through the area in large numbers and are making a solid run for a record breaking spring. With two weeks left in the spring migration monitoring period, there are still a lot of birds to band, a few new species expected to show up, and hopefully a few surprises in the nets. Yellow-bellied flycatchers are one of those species still expected to arrive at the LSLBO. Unfortunately their arrival throws a wrench into the cog of the otherwise smoothly running banding machine. Yellow-bellied flycatchers are members of the genus Empidonax, a group of birds in the flycatcher family that are practically identical in plumage and pose a challenge for most birders. The two other Empidonax flycatchers that have already arrived in area are the alder flycatchers and least flycatchers. Despite the similarities in appearance, the alder and least flycatchers have enough morphological differences that make distinguishing those two species apart during banding quite easy. Alders are overall bigger than the least flycatchers, and by bigger we mean the wing cord averages eight millimeters longer and they weigh about three grams more; that is a huge difference in the songbird world. Another morphological difference is the presence of an emarginated sixth primary on the least flycatchers (this is one identification feature you can’t see through binoculars, trust me). The arrival of yellow-bellied flycatchers opens a new set of challenges because their measurements overlap those of both the alder and least flycatchers. The emargination of the sixth primary is “variable”, which means it’s not a definitive identification mark because it might only sometimes be visible. No matter how many feather measuring tricks we have up our sleeves, the most reliable way to distinguish our three Empidonax flycatchers apart is by their songs, each one is unique. Actually, the alder flycatcher is a favorite among bird enthusiasts because their song can be paraphrased as saying “free beer”. Unfortunately, birds tend not to sing when being banded and we are forced to pull out the various measuring instruments and scratch our heads for a little while. Hopefully, after enough measuring, the banders have enough information to be confident of which of the three Empidonax is about to be fitted with a band.

2010