THE AVIFAUNA OF APACHE COUNTY, ARIZONA GARY H. ROSENBERG. Museum of Natural Science, Louisiana State University. Baton Rouge, Louisiana 70803 SCOTT B. TERRILL, Departmentof BiologicalSciences, State Universityof New York at Albany, 1400 WashingtonAve., Albany, New York 12222 In general, the distributionand the seasonalstatus of the avifauna of Arizonaare fairly well understood.The Birdsof Arizona (Phillipset al. 1964) encompassesthe entirestate and is fairlycomplete for all seasons.Large sec- tions of the state, however, have received relatively little ornithological coverage. The entire region of Apache County in northeasternArizona is one such area. Even though this area is quite interestingornithologically, before 1976 it receivedlittle coveragerelative to the many popularbirding "hot spots"in other sectionsof the state. It is possibleto assemblea list of those speciesthat breed in Apache County usingPhillips et al. (1964), its revisionby Monson and Phillips(1981), and severaldetailed studies (e.g. Carotherset al. 1973, Franzreb1975). Yet there remain substantialgaps in our knowledgeof migrant, wintering,and some nestingspecies found in Apache County. Since the mid-1970s, primarilyas a resultof the "vagranthunting" boom that swept parts of the West, Apache County has been visitedrepeatedly during all seasons.A significantincrease in knowledge of the statusand distributionof birds in northeasternArizona has resulted. This paper em- phasizesthe diversityand ornithologicaluniqueness of Apache County and summarizes the status of the birds found there. Apache County coversan area of approximately15,000 km2 in the north- eastern corner of Arizona. It extends from the White Mountains in the south to the Utah border in the north. The entire eastern border is shared with New Mexico and the county extendsabout 85 km to its westernborder shared with Navajo County. Much of the area of Apache County is part of the Nava- jo Indian Reservation.The elevationsrange from 1689 m along the Little Colorado River to 3476 m at the summit of Mr. Baldy in the White Moun- tains. The climateis similarto that of the Great Basin Desert:hot and dry in the summer, cold and wet in the winter. The higher mountainousareas within the county are generallysnow-covered from Novemberto April, and sometimeswell into May. HABITATS Vegetationalassociations found in the county are very diverse,ranging from sage-dominatedgrassland in the northernportion up throughpinyon- juniper forests,to spruce-fir-aspenforest at the higher elevations.We have divided the environmentof Apache County into seven arbitrarilydefined categories,mostly on the basisof vegetationalassociation. These categories are labeled accordingto the dominant perennial plant speciesfound in a given associationor for some common feature or features we consider biologicallyappropriate to the discussionof the distributionof birds in this area. Western Birds 17:171-187. 1986 171 AVIFAUNA OF APACHE COUNTY 1. Spruce-Fir-Aspen.This association encompasses most of the area locatedat high elevations in the White and Chuska mountains. The White Mts. reach an elevation of 3476 m at the summitof Mt. Baldy, which is one of only two mountainsin Arizona that rise above timberline. The dominant tree speciesfound here are Englemann Spruce (Piceaenglemanni), White Fir (Abiesconcolor) and QuakingAspen (Populus tremuloides).There are numerousgrassy meadows with streamsbordered primarily by Bebb Willows (Salix bebbiana)and Thinleaf Alders (Alnus tenuifolia).There are many small,and severallarge, lakes within this elevational range. Most high elevation habitatwithin Apache Co.•is restricted to the White Mts., but a smallpatch is found in the ChuskaMts. in the northeastsection of the county.These mountains are poorly known ornithologically,and, becauseof their closeproximity to the RockyMountains in northernNew Mexicoand southernColorado, may resemblethem more closely than other rangesin Arizona. A recent summertrip to the Chuska Mts. revealed several new local recordsincluding a new breedingspecies for Arizona, the Ham- mond'sFlycatcher. No winterdata are yet availablefor this area. 2. PonderosaPine. Thisassociation covers the area in elevationimmediately below the spruce-fir-aspenhabitat. The dominant tree speciesin this habitat is Ponderosa Pine (Pinusponderosa), but Douglas-fir(Pseudotsuga menziesii) stands are quite prevalentin the wetter drainages.Large expansesin both the White Mountainsand the ChuskaMountains are monotypicPonderosa Pine forests.A pine forestlocated in the Carrizo Mountainsin the extreme northeastcorner of Apache County has been visitedonly once or twice, yet the closeproximity of thesemountains to the mountains in southwesternColorado makes them potentiallyvery interesting. 3. Pinyon-Juniper.Below the PonderosaPine belt is the pinyon-juni•)erassocia- tion, which is widespreadthroughout the county. The dominanttree speciesin this habitatare the Pinyon Pine (Pinusedulis), the Utah Juniper (Juniperusosteosperma) and the One-seed Juniper (J. monosperma).This habitat has a relativelylimited breedingavifauna similarto that of other pinyon-juniperforests in Arizona. Even thoughthis habitat probably covers most of the forestedarea in the county,it receives relativelylittle coverage. 4. Riparian Woodland, Riversand Streams.These habitatsare very importantto many nesting,wintering and especiallymigrant bird populationsin Apache County. The countyis arid, with perennialwater restrictedto thoserivers and streamsdraining the White and Chuska mountains. The Little Colorado River is the main northern drainagefor the White Mountainsand, along with its tributaries,accounts for mostof the perennialwater found in the county. Dominantplant speciesare the Narrowleaf Willow (Salix exigua), the Thinleaf Alder (AInus tenuifolia) and the American Dogwood (Comus stolonifera). Narrowleaf Cottonwoods (Populus angustifolia)are alsofound commonlyalong some of the largerstreams. The mosthighly visited locali- ty in Apache County (and probablythe bestknown ornithologically)is a sectionof willow-alder-dogwoodriparian woodland along the Little ColoradoRiver at its con- fluence with the South Fork of the Little Colorado River (hereafter referred to as South Fork). Here the breedinggrounds for severalmore typically"eastern" species, in- cludingVeery and AmericanRedstart, reach their southwesternlimit. This localityis excellentfor migrantsduring the springand fall, and especiallygood for eastern "vagrants."For example, KentuckyWarbler, Worm-eatingWarbler, Yellow-throated Warbler and Swainsoh'sWarbler were all found in the same group of trees within a few-weekperiod in spring1981. Migrantsare, in general,highly concentrated around water and its associatedvegetation throughout the county. 5. Grasslandand RockyCliffs. This broadly defined category includes the vastma- jority of the area in Apache County. Most of the land is heavilyeroded, overgrazed grasslandand is dominatedby the shrubBig Sagebrush(Artemisia tridentata) in the north. This habitatis somewhatdepauperate for birds;however, winterraptor popula- tionscan be quite high. 172 AVIFAUNA OF APACHE COUNTY 6. Lakes,Reservoirs, Sewage Ponds and Marsh.Apache County contains several small lakes and reservoirswhich provide excellentnesting habitat for ducks. Addi- tionally,many species of migratingshorebirds and waterbirdsfrequent these areas. Manylakes, such as Ganado Lake, have restricted hunting on themand can potential- ly supportlarge numbers of winteringducks. Most of the higherelevation lakes, where manyof the nestingspecies of ducksoccur, are frozenover duringmost winters. Lowerelevation lakes are irregularlyopen during the winter.The manysewage ponds throughoutthe countyare particularlygood for migratingshorebirds. The American Avocethas recently nested on severalof thesesewage ponds, providing new breeding localitiesfor Arizona (Witzeman 1982). 7. Oases,Towns and Agricultural Land. Thiscatch-all category refers to mostof the habitats,such as rows of plantedtrees and agriculturalareas, that appear as lush oasesin an extremelyarid landscape.These habitats may be somewhatmarginal for breedingbirds, but their value to migrantsis extremelyhigh. Disturbed,wet, grassy fields in the Springervilleregion serve as the only nestinghabitat in Arizona for Bobolink,Common Snipe and possiblyWilson's Phalarope. These oases range in size from a smallclump of saltcedars (Tamarix) around a sewagepond at Tez Nez Iah to the entire towns of Ganado and Springerville. OCCURRENCE BY HABITAT TYPE The occurrenceof birdsin each habitattype during each seasonwas deter- mined using The Birds of Arizona (Phillipset al. 1964), An Annotated Checklistof the Birds of Arizona (Monson and Phillips 1981), American Birds (includingAudubon Field Notes) and the field notesof many observers (Table 1). Seasonsare defined as follows: winter = December through March, spring = April through early June, summer = mid-June through mid-August,fall = mid-Augustthrough November. Also calculatedare the number of residentsand the number of "pure" transientsfor each habitat during each season(Table 1). Table 1. Bird speciesoccurrence in seven Apache Co. habitattypes. These numbers were calculatedfrom The Birds of Arizona (Phillipset al. 1964) and field notes of many observersincluding the authors.Each numberrepresents the total numberof speciesfound within a particularhabitat during a particularseason. Numbers of per- manent residentsand pure transientswere also calculatedfor each habitattype. The numbersshould not be interpretedas