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<br />Area Manager
<br />DRAFT
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<br />(Homoptera: CicadelIidae); dragonflies and damselflies (Odonata); and caterpillars (Lepidoptera
<br />larvae). Non-insect prey included spiders (Araneae), sowbugs (Isopoda), and fragments of plant
<br />material. The flycatcher breeds in dense riparian habitats from sea level in California to just over
<br />7,000 feet in Arizona and southwestern Colorado. Historic egg/nest collections and species'
<br />descriptions throughout its range document the flycatcher's widespread use of willow (Sa/ix sp.)
<br />for nesting (PhilIips 1948, Phillips et aI. 1964, Hubbard 1987, Unitt 1987, T. Huels in litt, 1993,
<br />San Diego Natural History Museum 1995). Currently, flycatchers primarily use Geyer willow,
<br />Goodding willow, boxelder, saltcedar, Russian olive (Elaeagnus angustifolio) and live oak
<br />(Quercus agrifolia) for nesting. Other plant species less commonly used for nesting include:
<br />buttonbush (Cephalanthus sp.), black twinbeny (Lonicera involucrata), cottonwood, white alder
<br />(Alnus rhombifolia), blackbeny (Rubus ursinus), and stinging nettle (Urtica sp.). Based on the
<br />diversity of plant species composition and complexity of habitat structure, four basic habitat
<br />types can be described for the flycatcher: monotypic willow, monotypic exotic, native broadleaf
<br />dominated, and mixed native/exotic (Sogge et aI.1997).
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<br />Throughout its range, the flycatcher arrives on breeding grounds in late April and May (Sogge
<br />and Tibbitts 1992; Sogge et aI. 1993; Sogge and Tibbitts 1994; Muiznieks et ai, 1994; Maynard
<br />1995; Sferra et aI. 1995, 1997). Nesting begins in late May and early June and young fledge
<br />from late June through August (WiIlard 1912; Ligon 1961; Brown 1988a,b; Whitfield 1990;
<br />Sogge and Tibbitts 1992; Sogge et aI. 1993; Muiznieks et al. 1994; Whitfield 1994; Maynard
<br />1995).
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<br />Population Dynamics
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<br />Territories. Sites and Flvcatcher Movement Patterns. Flycatcher territory size likely
<br />fluctuates with population density, habitat quality, and nesting stage. Estimated territory sizes
<br />are 0.59 to 3.21 acres for monogamous males and 2.72 to 5.68 acres for polygynous males at the
<br />Kern River (Whitfield and Enos 1996), 0.15 to 0.49 acres for birds in 1.48 to 2.22 acre patches
<br />on the Colorado River (Sogge I 995c), and 0.49 to \.24 acres in a 3.71 acre patch on the Verde
<br />River (Sogge 1995a).
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<br />Seventy percent of the breeding sites where flycatchers have been found are comprised of five or
<br />fewer territorial birds. The distribution of breeding groups is highly fragmented, with groups
<br />often separated by considerable distances (e.g,. in Arizona, approximately 55 miles straight-line
<br />distance between breeding flycatchers at Roosevelt Lake, Gila County, and the next closest
<br />breeding groups known on either the San Pedro River, Pinal County or Verde River, Yavapai
<br />County). To date, survey results reveal a consistent pattern range-wide; the flycatcher population
<br />is comprised of extremely small, widely-separated breeding groups that frequently include
<br />unmated individuals. Movement data indicate that flycatchers can disperse to areas as much as
<br />200 kilometers away from past recorded locations.
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<br />The site and patch fidelity, dispersal, and movement behavior of adult, nestling, breeding, non-
<br />breeding, and migratory flycatchers are just beginning to be understood (Ken wood and Paxton
<br />2001, Koronkiewicz and Sogge 2001). From 1997-2000,66 to 78 percent oftlycatchers known
<br />to have survived from one breeding season to the next returned to the same breeding site and 22
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