Compared with some other states, bird-rich Arizona comes up short when you look at nesting warblers. There are about fifty members of the wood warbler family in North America, and only eleven of these nest in Arizona. Nevertheless, we have some special warblers that are found only in the southwest part of the country. Four of our nesting warblers are not found beyond Arizona and its neighboring states: Grace’s Warbler, Red-faced Warbler, Painted Redstart and Lucy’s Warbler. Each of these are impressive birds deserving their own article, but perhaps the most special one is Lucy’s.
If you are familiar with these four, you know how beautifully colorful the other three are, and may wonder why I would choose Lucy’s, a pitch black-eyed tiny creature that’s gray above and off-white below. Granted, it has rarely-seen rufous color on its crown and rump, but in no way is this comparable to the technicolored Grace’s, Red-faced and Painted. So, what is so appealing about Lucy’s? Well, in the first place it’s her size. At give-or-take four inches, this hummingbird-sized warbler is smaller than all other U.S. warblers. In addition, this is only one of two warblers that nest in cavities, and the only one in the west.
Although she will nest opportunistically in an unoccupied Verdin nest, a Gila Woodpecker-drilled saguaro hole or even in a clay bank crevice, her favorite spot may be a narrow wedge between the bark and the tree of a mesquite. Here’s how Herbert Brandt described one of these nests in his 1951 classic, Arizona and Its Bird Life: “I found myself at one of the daintiest creature homes it’s been my pleasure to visit. Skillfully tucked down in a fold behind thick, rough bark was an artistic, silvery cup which held four wreathed gems of eggs. Within this ancient skin-wrinkle on the mesquite’s brawny arm, snuggled a Lilliputian cradle, the natal home of the smallest of all our many warblers.” Brandt measured this nest at 1.75 inches in diameter and just .75 inch deep. Incredibly, despite this Lilliputian-sized, hard-to-find incubator, much larger Brown-headed Cowbirds are known to parasitize these nests.
Lucy’s Warbler was discovered by Dr. James Cooper, the ‘Gentile Naturalist’, at Fort Mohave, Arizona in January 1861. He dedicated the bird to the “interesting little daughter” of Spencer Baird, curator of the Smithsonian Institution, and it was named after this 13-year old girl, Lucy Hunter Baird. Not a bad choice, after all, since Lucy developed a passion for ornithology, and eventually held a 14-year appointment with the American Ornithologist’s Union.
‘Birds of the World’ (Cornell Laboratory of Ornithology) says “Unlike many cavity nesting species, Lucy’s Warbler will not use nest boxes, and no direct management actions specifically targeting this warbler have been taken.” This text was written in March 2012. On July 6, 2020, Tucson Audubon Society’s Citizen Science Coordinator, Olya Phillips, conducted a Zoom-connected, free-to-the-public one-hour presentation titled. ‘Lucy’s Warbler Nest Box Findings’. This was a fascinating presentation that disclosed Tucson Audubon now has placed more than 3,000 nest boxes specifically designed for Lucy’s Warbler, and that warblers nested in 165 of these this year, raising a potential total of 825 young. You can follow videos of the nest-building and chick-raising efforts of one of these families at http://tucsonaudubon.org/lucycam/ where you can also learn how to buy and install your own nest box. It might be time for Cornell to update their Lucy’s Warbler section.
This article originally appeared in the Saddlebag Notes newspaper, Tucson, Arizona on August 1, 2020