by Jeannie Marcure

MacGillivray’s Warbler – Photo Credit: Dan Casey

Now that spring has finally arrived, it’s time to start watching for some of our most colorful and elusive summer residents. Warblers (and colorful birds in general) have long been favorites of mine but until recently my sightings have been rare and mostly limited to the Tally Lake Campground area.

Our home is in Shelter Valley south of Kalispell and when we bought the land 17 years ago, it had been rather rudely logged leaving a dry habitat of Larch and Douglas Fir. There were many stumps and weeds to deal with and at that time, Warblers were the last birds we expected to attract. However, as we cleaned up the stumps and weeds, we were also able to plant a couple of small aspen groves and purchase a small recirculating birdbath. After these two additions we slowly began to see more and more Warblers – mostly migrants for a while, but now we enjoy several species as summer residents. Their regular visits to our water feature have allowed us to photograph and study their behaviors.

Last summer for the first time we had a resident pair of MacGillivray’s Warblers, complete with a very vocal male claiming his territory by way of almost constant song. Seeing these neat little birds almost daily tweaked my curiosity, so I did a little online research and came up with some interesting facts.

MacGillivray’s were first discovered by John Townsend who gave them the scientific name “tolmiei” in honor of his friend William Tolmie, an employee of the Hudson Bay Company. Despite this, however, John James Audubon later named the species MacGillivray’s in honor of Scottish ornithologist William MacGillivray.

The male MacGillivray’s is slightly larger than the Common Yellowthroat and has a dark hood, olive upperparts and unmarked yellow underparts. The prominent white arcs above and below the eye are probably his most identifiable feature. The female is colored similarly, but both the hood and yellow underparts are much paler. She also sports the bold white arcs above and below the eyes. The immature MacGillivray’s is similar to the adult female but is slightly duller and also has a slightly paler throat. The species most similar to the MacGillivray’s is the Mourning Warbler, which lacks the broken eye ring and is found in the eastern US and Canada.

MacGillivray’s Warblers are found in the western US and western Canada and prefer open woodlands such as old logging sites and burned areas. They also like brushy areas in mixed deciduous forests. Arrival on the breeding grounds occurs in late May, and they stay until late August. Most winter in Mexico and Central America.

Feeding primarily on insects, MacGillivray’s spend most of their time on or near the ground. Monogamous pairs build a cup-like nest in a shrub or the lower fork of a tree. The female incubates the three to five lightly spotted eggs for eleven days. After being cared for by both parents, the young fledge in approximately nine days. The short time spent on the breeding ground allows for only one brood per year.

According to the Cornell Lab AllAboutBirds website, even though the species experienced a 35% decline in population between 1966 and 2014, MacGillivray’s Warblers are a species of low concern at this time. It is thought that since this bird has a preference for cleared or regenerated land, it has probably benefitted from logging and other human activities. 

Perhaps the best place in the Flathead to observe a variety of warblers including MacGillivray’s is the Tally Lake Campground. Located approximately 25 miles from Kalispell, this area is a comfortable afternoon drive from almost anywhere in the Flathead. Once there, grab your binoculars and check out the brushy shoreline and the creek edge trail found in the group camping area. If you’d like the opportunity of birding this area with a group, you might consider attending this year’s Wings Across the Big Sky Bird Festival, which will be held in Kalispell on June 8-10. The festival’s brochure says that the planned field trip to the Tally Lake area offers participants the possibility of seeing every warbler species found in N.W. Montana. Whichever you choose, I hope that your summer will be filled many warbler sightings!