U.S. Fish & Wildlife Service Southwestern Flycatcher Arizona Ecological Services Field Office

Southwestern Willow Flycatcher Western Riparian Specialist When imagining wondrous arrays of colorful , one usually pictures the tropics. However, southwestern riparian habitats, the lush ribbons of vegetation running along our streams and rivers, contain the highest density and diversity of species outside tropical rain forests.

Sadly, only a fraction of these desert oases remain unchanged in the United States. As this habitat continues to decline, so too do the birds in our southwest skies. One bird in immediate danger is the southwestern willow flycatcher.

This subspecies of the willow flycatcher is an olive-gray bird with a white throat and yellow-gray rump that measures about 5¾ inches in length. It can be distinguished from other subspecies by Southwestern willow flycatcher. /USGS Photograph its song, a sneezy fitza-bew, its call, a repeated “whit,” and by where it lives: In late May and early June the flycatcher populations. Managing for these habitat widely scattered riparian habitats in the nests and lays three to four eggs in one- areas is presenting water and reservoir desert Southwest. day intervals with the young fledging operators with exciting and challenging in early July. There is usually only one opportunities. The flycatcher reminds observers of a brood raised per year, but multiple sentinel constantly at attention, whose clutches are not uncommon. Exotic species of plants, such as salt flitty wing movements resemble salutes cedar (tamarisk) and Russian olive, can and constant tail motions signal a Loss and modification of riparian habitat take advantage of germinating conditions readiness for action. It feeds on and nest parasitism by the brown-headed for much longer than native riparian in lush, multi-layered riparian zones by cowbird are key factors in the decline trees because they flower over much snatching them on the wing or harvesting of flycatcher populations. River and longer periods than do cottonwoods them from dense vegetation. Its mission stream impoundments, ground water or . These plants significantly to control insects in riparian areas is an pumping, and overuse of riparian areas change the environment and the ability of essential function benefiting people as have altered up to 90 percent of the native to live within it. Although well as plant life. flycatcher’s historical habitat. flycatchers can thrive in these habitats, there is concern about other effects these The southwestern willow flycatcher Flood control projects have inadvertently exotic plants exert on the ecosystem. breeds in Arizona, New , and depleted the cottonwood and willow trees southern California, plus portions of the flycatcher uses for nesting. These Livestock grazing can be compatible southern Nevada and Utah, southwest trees—a vital, defining part of riparian with the development of flycatcher Colorado, and possibly western Texas. ecosystems—need periodic flooding to habitat. However, livestock overgrazing It winters in the rain forests of Mexico, reproduce. Flood control efforts have can also impact the riparian habitat of and northern South altered this natural cycle in many areas the flycatcher. These cool and shady America. and also made it possible for non-native stream side habitats are preferred by species to move into stream side habitats. livestock that consume cottonwood and The flycatcher is a late spring breeder willow saplings when grass species are seen and heard in riparian forests by In recent decades, the deposition of not available, depleting the density mid-May. Its nest, a tiny cup about 1¾ sediment along lake shores and reservoir of vegetation. Since salt cedar is inches deep, is made of compact fiber, deltas, together with fluctuating reservoir unpalatable to cattle, struggling willow bark, and grass about three to 15 feet levels, has resulted in dense riparian and cottonwood saplings are eaten above the ground in trees and thickets. vegetation that provides breeding instead, thereby accelerating the change The rim is lined with feathers and the habitat for flycatchers. These scenarios in habitat. inside is lined with a layer of grass and have resulted in some large breeding other plant material. Another threat is the brown-headed cowbird. This bird lays its eggs in the nests of other species. It removes one or more eggs from the nest and replaces them with its own. The eggs of the cowbird hatch sooner, the young grow faster, and are much larger and more demanding than those of the nesting bird. These young cowbirds then crowd out and starve the other hatchlings. Sometimes flycatchers will abandon their nests and start over, often too late in the season. Cowbird parasitism can greatly reduce the nesting success of the southwestern willow flycatcher. Healthy populations of birds can recover from losses due to nest parasitism, but cowbird parasitism on populations whose numbers are already reduced due to habitat loss can be the final straw.

What is being done to bring our flycatchers back? The southwestern Southwestern willow flycatcher in habitat. /USGS Photograph willow flycatcher was listed as ‘endangered’ by the U.S. Fish and Wildlife Service on February 17, 1995. “Studies have shown that predation on For Additional Information California and New Mexico also classify insects by birds actually results in the Field Supervisor the southwestern willow flycatcher as improved health of trees and forests,” Arizona Ecological Services Field Office endangered and Arizona recognizes it said Bill Howe, nongame migratory bird 2321 W. Royal Palm Road as a “species of greatest conservation coordinator for the Fish and Wildlife need.” State and Federal laws, including Suite 103 Service’s Southwest Region. “The Phoenix, AZ 85021 the Migratory Bird Treaty Act and the southwestern willow flycatcher and www.fws.gov/southwest/es/arizona/ Endangered Species Act, prevent “take” other insectivorous birds in riparian of the flycatcher, which is defined as woodlands consume huge numbers of [email protected] Email hunting, trapping, wounding, harassing insects per day, including mass quantities 602/242-0210 or otherwise harming the species. of mosquitoes.” 602/242-2513 Fax

The destruction of tropical rain forests Today, an increasing number of diverse U.S. Fish & Wildlife Service where the flycatcher winters makes conservation partners are working www.fws.gov the conservation of breeding habitats together to reduce the landscape February 2012 in the southwest United States even stressors to our riparian areas to more urgent. Interestingly enough, the improve the abundance of native riparian survival of riparian ecosystems may plants. To save the southwestern willow depend on the flycatcher as well. flycatcher, we must save these beautiful desert riparian ecosystems and the wondrous array of life within them.