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Lucy’s Warblers

Lucy's Warbler by Jeremy Hayes

Lucy’s Warbler by Jeremy Hayes

Just four inches long and very active, Lucy’s Warblers have been known in the past as Mesquite Warblers due to their close ties to these trees. Being one of the two cavity-nesting warblers we have in United States, they choose old woodpecker holes as well as peeling bark crevices as their nesting sites. Lucy’s Warblers are in population decline and listed as a Species of Conservation Concern by Arizona Game and Fish – primarily due to the loss of available nesting sites which occurs most commonly in dense mesquite bosque along major waterways. Even in an urban environment, Lucy’s Warblers seek out mesquite trees, which leads us to our three major projects with these birds.

To learn more about this little warbler click here:

Nestboxes and Lucy’s Warblers

Unlike many other species that are limited by lack of available nesting sites which have been helped by the creation of appropriate nestboxes, for a long time no one knew exactly what type of nestbox Lucy’s Warblers would prefer – so much so that even literature says that they do not use nestboxes. Over the last few years Tucson Audubon has received reports of Lucy’s Warblers nesting in small decorative boxes and gourds as well as various other small cavities. Knowing that there’s an opportunity to make a big conservation effort and to increase the state of scientific knowledge on this species, we’ve undertaken a project to better understand Lucy’s Warbler nesting and to develop nestboxes that they’ll readily use. Our study efforts aim to determine the nesting preferences of Lucy’s Warblers with the ultimate goal of increasing Lucy’s Warbler populations by creating functional habitat especially via viable nestboxes in Tucson’s urban areas.

Nestbox Preference Experiment

Experimental Nestbox Set Up on 7B Ranch Trail by Jennie MacFarland

After studying their natural nests one thing stood out the most: the apparent preference of two points of exit in the natural nests located in peeling bark of mature mesquite trees. Thus we created 8 different designs of nestboxes to suit Lucy’s Warblers and placed them in the three experimental locations are:

  1. 7B Ranch on the San Pedro River
  2. Along the Santa Cruz River in Tubac
  3. Tanque Verde Wash in Tucson

Each box was installed in the same conditions with order varied randomly to know that Lucy’s are going for a specific design box and not its placement on the tree. We ended up with 12 nestboxes at each point.  With the help of numerous volunteers and staff who built, installed and monitored these boxes, we have collected a lot of valuable data.

In 2018, a total of 62% of the experimental sites had a Lucy’s Warbler nest (37/60). With each field site having 20 locations, we had 14 nests in the Tanque Verde Wash, 16 on the 7B Ranch Trail, and 7 on the Anza Trail. In addition to the experimental locations, we’ve had over 800 participants from the public install boxes in their own yards, creating a community of citizen scientists. We estimate that over 200 Lucy’s Warbler young have fledged from our boxes in 2018 alone. A whopping 75% of the used experimental boxes were either a small or a large triangle. A clear winner, the triangle box is a success.

Lucy’s Warbler feeding nestlings in Triangle Nestbox. Photo by Paula Redinger

In 2019, we had 76 Lucy’s Warbler nests across our 60 experimental points. This year has been the most successful so far. Six of our enclosed design boxes got used by Bewick’s Wrens but no other species used the triangle design besides Lucy’s Warblers, which further solidifies how specific our boxes are to their needs.

Our most successful site was 7B Ranch Trail in Mammoth. At the 20 points there were a whopping 47 nesting attempts in our boxes! We were able to document re-use of nests as well as Lucy’s Warblers simultaneously nesting just inches away from each other. Lucy’s Warblers are not communal nesters so this finding is quite unusual. In scientific literature their breeding territories are described as 98 feet in good closed-canopy habitat. This further supports our theory that these birds are a cavity-limited species and given plenty of food that the bosque provides to sustain multiple families, they will utilize suitable nestboxes in close proximity. The preference for triangle design nestboxes persists in the data we’ve gathered so far. In 2018, the most used design was a triangle box (small and large) at a combined 74% of all nests being in a triangle box. In 2019, the most used design was once again the triangle with 78%, and in 2020 triangle designs also had a majority 78% which further strengthens our data.

Results graph showing nests per type of nestbox. 2018-2020

So what’s next? We are continuing our project to gather more data and eventually publish our findings to contribute to the scientific knowledge about this species. We are planning on expanding our project to more locations in southeast Arizona and beyond, turning stands of young mesquites into suitable nesting habitats with the help of nestboxes. We live in the center of the Lucy’s breeding range, so there is no better place to study their nesting behavior. We want to see a Lucy’s Warbler nestbox in every eligible yard.

How can you help?

  • Click here for Lucy's Warbler nestbox plan

    Click here for Lucy’s Warbler nestbox plan

    Purchase a Lucy’s Warbler nestbox at our Nature Shop or construct your own using this plan. Fact sheet and mounting directions can be found here.

  • Please register your nestbox to help us learn more about this secretive species:
  • Please consider showing your support of the Lucy’s Warbler Nestbox Project by donating your skill, materials or funds for construction of more nestboxes.

If you are already involved in this project in any way, thank you! You make it possible to have a community science effort that yields significant scientific results.

For more information contact Olya Phillips:

Nesting Height Experiment

Height Experiment Results 2020

Height Experiment Results 2020

After identifying the preferred nestbox type, Tucson Audubon has set out to identify if Lucy’s Warblers have a nesting height preference. In 2019 we created an additional 60 points with 5 boxes each installed at 1, 3, 5, 7, and 9 feet off the ground. After 1 year of observations the results show an apparent preference for boxes installed higher off the ground. In 2020 we expanded the height categories to 12 and 15 feet to see if 9 feet is indeed the preference or if they will go for highest available box. We found that they indeed go for the highest available. What does this mean for the nestbox in your home? Install it at 5-10 feet off the ground. Make sure to have foliage around the box as they love the security.


Lucy’s Warbler Study Sponsors:

A special thank you to the organizations and individual donors who make our projects possible!

By purchasing this license plate for your vehicle, portion of the proceeds go to fund on-the-ground conservation projects in Arizona.


Foraging Study 

Lucy’s Warbler by Joan Gellatly

Tucson Audubon has set out to study how Lucy’s Warblers use native and non-native types of mesquites as a food source. This is part of our larger effort to determine what Lucy’s Warblers need to successfully nest in urban Tucson which includes our nestbox experiment. We would love your help in watching Lucy’s Warblers forage for insects in locations where both types are present. Tucson Audubon has found a few such locations but you may know of one as well. It only takes a few minutes and we have lots of great information for you including how to tell native mesquites from non-native mesquites. We need your help with this urban conservation!

Do you know of a place that should be added to our map of locations that have both native and non-native mesquites? This could be in your own neighborhood! Fill out our survey here:


Tucson Audubon Society
300 E University Blvd. #120 Tucson, AZ 85705

Mason Center
3835 W Hardy Rd.
Tucson, AZ 85742

Paton Center for Hummingbirds
477 Pennsylvania Ave.
Patagonia, AZ 85624
520 415-6447


Tucson Audubon Society
300 E University Blvd. #120
Tucson, AZ 85705

Mason Center
3835 W Hardy Rd.
Tucson, AZ 85742

Paton Center for Hummingbirds
477 Pennsylvania Ave.
Patagonia, AZ 85624
520 415-6447


Tucson Audubon Society
300 E University Blvd. #120
Tucson, AZ 85705

Mason Center
3835 W Hardy Rd.
Tucson, AZ 85742

Paton Center for Hummingbirds
477 Pennsylvania Ave.
Patagonia, AZ 85624
520 415-6447

Michael T. Bogan (he/him)

Michael is an Assistant Professor of Aquatic biology at the University of Arizona. Originally from California, he earned his PhD at Oregon State University, where his research focused on stream ecosystems of the Madrean Sky Islands and Sonoran Desert. He is well-known for his work on Santa Cruz River Heritage Project, and his beautiful photos of dragonflies. His research topics include Arid Lands, Conservation Biology, Invasive Species and Population and Community Ecology.

Michael serves as the faculty advisor for the UA chapter of the Society for the Advancement of Chicanos Hispanics and Native Americans in Science, a national Diversity in STEM organization. Michael is a partner on our Santa Cruz River Heritage Project work and has contributed to the Vermilion Flycatcher in the past year.

Michael has a hard time choosing a single favorite bird, but says that Curve-billed Thrashers are pretty hard to beat. “I could watch them goofing around through the leaf litter and be entertained for days!”


Alberto Búrquez

I currently work at the Instituto de Ecología, Department of Ecology of Biodiversity, Universidad Nacional Autónoma de México (UNAM). I got my bachelor and master’s degree at UNAM, and my PhD at the University of Cambridge, UK. I do research in Ecology, Evolutionary Biology and Ethnoecology. Drylands ecology and societal use of resources in water-limited systems have been an ever-present passion through my life. It might be because I am a Sonoran Desert born person. However, my personal theory is that once someone experiences the desert landscapes they are smitten for life. I am passionate about bird and honorary bird species like bats and hawkmoths, particularly in their mutualist interactions with plants. My current projects include: 1) Columnar cacti: ecology, evolution, societal services. 2) Effects of extreme events on vegetation, 3) Species Distribution and Biogeography, 4) Indigenous lands and ecosystem processes, and 5) drought and freezing resistance in plants at the edges of distribution.


Jeanne Calhoun

Fascinated by wilderness and everything wild since growing up backpacking with her family in the Sierras, Jeanne pursued a diverse environmental career over the past 30+ years.  With a Bachelor’s in Biology (Carleton College) and a Master’s in Geology (Oregon State University), she pursued multiple aspects of environmental protection, with the last 23 years focused on ecological conservation in Arizona, working for The Nature Conservancy, US Fish & Wildlife Service, and the US National Park Service.  During her ten years at TNC, Jeanne was responsible for on-the-ground conservation in four ecoregions in Arizona, management of TNC’s preserve system, land management and restoration, government relations, and water policy.

Jeanne spent seven years with the USFWS where she oversaw threatened and endangered species issues in southern Arizona. She enjoyed the challenges of dealing with controversial issues such as the international border, proposed mining projects, energy infrastructure, wilderness management and climate change.

Most recently, she worked for Grand Canyon National Park as Chief of the Science and Resource Management Division, where she oversaw all science research as well as natural and cultural resource management activities in the park.  During her years at the Grand Canyon, Jeanne initiated the first Paleontological Resources Inventory for the park, led a Climate Change Analysis for the park’s watershed, reinitiated the effort to designate 94% of the park as Wilderness, and led publication of the Natural and Cultural Resource Condition Assessment for the park.

Recently retired, Jeanne has a passion for water sports, hiking and exploring Arizona’s spectacular landscapes, and is learning how to play the saxophone.


Colleen Cacy

Colleen is a partner with the firm Gadarian and Cacy, PLLC, a Tucson law firm specializing in professional Tax Strategy, Estate Planning and Asset Protection law.

  • J.D. from the University of Kansas School of Law (1986)
  • President of the Board of the Southern Arizona Estate Planning Council
  • Elected member, American College of Trust and Estate Council
  • Memberships: Executive Committee of the Probate and Trust Section of the State Bar, the State Bar of Arizona, the Probate and Trust and Tax Sections of the State Bar, the American Bar Association, and the Pima County Bar Association.
  • Past President of the Board of ZUZI Dance Company


Richard Carlson

Richard started birding as a child in Minnesota 70 years ago. After a brief interlude at Harvard, where he majored in caving, mountain climbing, winter mountaineering and economics, he began birding again in Washington DC with the Maryland Ornithological Society. He was one of Chan Robbin’s volunteers in establishing the first Breeding Bird Surveys. Bribed by the Nixon administration to leave town with a fellowship to Stanford, he moved West in 1969. He worked at Stanford Research Institute, where he co-authored “Solar Energy in America’s Future” and led field trips for the Santa Clara Valley Audubon Society. He became President of the San Francisco Bay Bird Observatory and expanded his birding to Latin America. He has birded throughout the Neotropics and in Africa, Australia, Antarctica, India, China and Europe. He hopes to ultimately see at least half the birds of the world. He and his wife Pat now migrate between homes in Tucson and Lake Tahoe depending on where the birds are.


Tricia Gerrodette

Tricia never wound up with a career but instead had a variety of jobs and life experiences. She's been a bookkeeper, a typist, a proofreader and then a test analyst for a defense contracting company. She was a tour guide for trips into Mexico's Copper Canyon for Elderhostel (now Road Scholar). The trips focused on Mexican and railroad history as well as the history and culture of the Rarámuri (Tarahumara) natives.

Secretary of the board for Tucson Audubon, member of the board for Friends of the San Pedro River, president of the now-defunct Huachuca Audubon Society, treasurer for Sky Island Unitarian Universalist Church, Water Sentinel with Sierra Club Water Sentinels, Steering Committee for Sustainable Water Workgroup.

When Huachuca Audubon Society disbanded in May 2016, Cochise County became part of the "assigned" territory for Tucson Audubon Society. That was a huge amount of land, although not too many people, to absorb. I was invited to be on the Tucson Audubon board to help with that effort, and to help protect the San Pedro River. That work still continues! Photo by Mark Levy.

Kathy Jacobs

Kathy Jacobs is a professor of Environmental Science at the University of Arizona and Director of the Center for Climate Adaptation Science and Solutions (CCASS). CCASS is a component of the Arizona Institutes for Resilience, and builds capacity to accelerate adaptation and on-the-ground solutions to climate issues.  She is currently a member of a team that is building the Indigenous Resilience Center at the UA.  From 2010 – 2013, Jacobs worked in the Office of Science and Technology Policy in the White House. She was director of the Third National Climate Assessment, and the lead advisor on water science, policy, and adaptation. From 2006-2009 Jacobs was Executive Director of th

e Arizona Water Institute, a consortium of Arizona’s three universities focused on water sustainability. She worked 23 years for the Arizona

Department of Water Resources, including 15 as the director of the Tucson Active Management Area.  She was engaged in multiple aspects of implementing Arizona’s Groundwater Management Act, including development of water conservation programs and the Assured Water Supply Rules.  Jacobs has served on nine National Academy panels; she earned her M.L.A. in environmental planning from Berkeley.


Elisabeth (Lissie) Jaquette

Elisabeth (Lissie) Jaquette had been an occasional birder prior to moving to Arizona in 2018. Since connecting with Tucson Audubon, she has become increasingly passionate about birding, and is excited to give back by serving on the board. Lissie first became involved with Tucson Audubon by participating in the Habitat at Home program, then by joining as a member, and more recently by volunteering with the Southeast Arizona Birding Festival, the Birdathon, and several bird surveys.

Lissie’s education includes a BA from Swarthmore College and an MA from Columbia University. Since 2017 she has served as Executive Director for the American Literary Translators Association, a non-profit membership organization.

When Lissie is not birding, she enjoys hiking and trail running in the Sonoran Desert, and translating literature from Arabic to English (her latest book was a finalist for the 2020 National Book Awards). She lives in Tucson with her 1-year-old son, Cassin (named for the kingbird); dog, Cooper (named for the hawk); and husband, Dan (sadly not named for any birds).


Riana Johnson

Riana Johnson is a skilled researcher with experience in quantitative, qualitative, and data visualization within the energy efficiency and utility industry. She brings creativity along with strong data analysis skills to her work. She uses her background in fine art and econometrics to deftly craft data visualizations and tell data-driven stories. Riana is a new birder and loves living in Tucson where the Vermillion Flycatchers are plenty. She recently started a chapter of the Feminist Bird Club in Tucson where she can mix her passion for activism, art, and birds. Riana has degrees in Political Science and Studio Art from New York University and a Masters of Public Policy from the University of Arizona.


Linda McNulty

Linda McNultyLinda’s education includes a Bachelor of Science in Nursing from the University of Rochester, and a Juris Doctorate from the University of Arizona, where she graduated Summa cum Laude and was elected to the Order of the Coif. A recently retired partner at the law firm of Lewis and Roca, LLP, Linda was a member of the firm’s Real Estate and Finance practice group. Her law practice focused primarily on commercial real estate, business and natural resources law. Linda has served a number of board roles, including: President of the Tucson chapter of Commercial Real Estate Women (CREW) and member to the board of directors of the Pima County Sports and Tourism Authority, the Arizona Center for Law in the Public Interest, and the Wilderness Land Trust. Early in her career, Linda worked for the Arizona Department of Water Resources and she’s maintained a connection to water policy issues in Arizona. Linda has been a member of Tucson Audubon Society since 1976 and lives with her husband Michael in Tucson.


R. Cynthia Pruett

Cynthia-Pruitt-with-raffle-tickets-by-Kendall-KroesenFor a long period I was what you might call a "lapsed birder". I started birding in college with a boyfriend who became my husband and we traveled all over the United States while he was in the service; leading to a pretty comprehensive bird list. Then suddenly, other life activity got in the way and for about 25 years birding was shelved. In the late 80's I was introduced to an avid woman birder at an environmental conference and the passion came back. My work career involved many executive jobs, some of them key environmental positions, which only reinforced my understanding of the need to protect important habitat around the world. It's (the birding) led to many trips to many countries, a joy of seeing both new and revisited birds and of course, to becoming active in Audubon chapters, both here and in Virginia.


Cynthia M. VerDuin, CPA

Cynthia began birding when she was 10 by participating with her girl scout troop create a bird-watching badge. In the 90’s she began birding with family, friends and with bird walks in various Ohio regions. Since 2010, she has enjoyed Tucson Audubon bird walks and short trips. Beginning in 2016, she has participated in the Birding Festival, serving as a volunteer in 2017-2019 and at Meet your Birds events. She served on the Gala and Finance committees in 2016-2017, and joined the board in 2018. She now serves as Treasurer and Search Committee co-chair.

Cynthia founded her accounting firm in 2007, focusing on not-for-profits, small companies and individuals, providing accounting, tax planning and reporting services, calling upon her Kent State University (BA degree in accounting with honors) and her experience at one of the “Big Eight” accounting firms (Arthur Andersen). Cynthia is also a Physical Therapist and commercial hot air balloon pilot, and enjoys hiking, birding, biking and swimming.