. S. ENGLAND AND W. F. LAUDENSLAYER, JR.

Toxostoma bendirei

SPANISI{: C~litll~coclreSorlorer~sc, C~ritlncocltrPiqriicc~rto Ri~a+: Thrasher !< .,, Mrrquiwr rLv Ikrriliri* i

endire's Thrasher was the last thrasher described for mainland North America. BMajor Charles E. Bendire collected the first specimen in 1872 near Camp Lowell, now downtown Tucson, Arizona. Although Bendire recognized this as a new species (he Lad heard its song and found its nest), Robert Ridgway when presented with this first specimen did not. He believed it to be a female Curve-billed Thrasher (Toxostoma curvirostre), and Elliott Coues was not sure (Coues 1873).Thus, beginning with the first specimen, our under~tanddir;~of tGs species has been clouded by confusion with similar species, by its miptojwanderings, by its rathe; secretive behavior, and by the meager number of observers that work in its desert hakitats. Much of our limited knowledge about this species is derived from anecdoial information on nesting, distribution, and food habits collected in the late 1800s and early 1900s. Bendire's Thrashers forage primarily on the ground, probing ihe soil for rhe insects and occasionally plucking insects and fruit Birds of from vegetation. They generally inhabit sparse desert habitats in thk America southwestern United States t Life Histories for and northwestern Mexico, the 21st Century although within this range their distribution is spotty

and, in some areas, sdl Breeding and year-round range of Bendire's poorly understood. ~hlikeother southwestern Thrasher. In winter, northern breeders retreat ~oxos~ornathrashers, they leave the northern south and overlap with residents. Boundaries portion of their breeding range in winter, a season shown here are substantiated by specimens and when wanderers sometimes appear at repeated observations. unexpected locatioxw. 2 BENDIRE'S THRASHER

DISTINGUISHING CHARACTERISTICS decurved; bill of immature birds may be as short and straight as Bendire's. Bill color usually black Medium-sizcd songbird; smallcr than other inadult and immature Curve-billedThrashers but sympatric, congeneric ~hrashcrs.Total length of some individuals may be pale towards base maIcsU.2-24.7cm,fcmalc.r;~.7-24.7cm(Ridgway (Kaufman and Bowers 1990) and light yellow 1907);massabout 60g. Scparablc frornothcr North gap of i1i1rnalu1.c~may he conf~iscdwill1 piilc~ American passcrincs c~~ptthrashcrs by coni- horn color ill hi1st8oI' bill in Ikwclirc-'s'l'h~.,~sli(~r. Al binations of the follo\ving characters: niudium all ages, jionyc~l'inglc (wlicrc Llic LIPPCI.and size; wings rclativcly short and rounded; 10 lower bc'ik meet) is rounded in Ucnclilds and primaries; tarsi scutellatc on antcrior surface; bill acutely angled in Curve-billed (Phillipset al. 1964). acuniinale, upper mandiblenot hooked over lower Spots on breast of adults roughly circulal; may be mandible, and culmen weakly decurved distally; triangular in center of lower breast; less distinct colorationon crown, back, wings, and tail relatively from background color than inBendire's Thrasher; unifornl (LC., lacks distinct spotting, streaking, and generally more distinct in T.c, clwvirostrethan barring, and lvingbars, though feather edges may in T.c. pnlnzeri, and generally do not coalesce to be lighter in fresh feathering); external nares not form streaks. Juvenile Curve-billed have distinct, covcrcd by fca thers; and tail as long or longer than triangular marks on breast. Iris generally yellow body. in Bendire's but some individuals orange-yellow; Dislinguisliablc from most potentially sym- Curve-billed generally orange in adult T. c. patric thrashcrs by combinations of the following curvirostre but more yellow in T. c. palrrreri and can characters (see also Appendix 1):dorsal coloration be yellow in immatures. relatively uniformdarkdrab toolive-brown; white markinis on tail feathers limited to corners of outer rectrices (may be absent in worn plumage); DISTRIBUTION distinct white wingbarsand wing patcheslacking; iris yellow to orange-yellow; short, thin, upward- THE AMERICAS pointing, triangular spots on breast arranged in Breeding range. Figure 1. Details of distribution distinct streaks on upper breast, less distinct on poorly understood and documented. Surveys of lower breast, and may extend faintly onto sides breeding birds in New Mexico (Darling 1970) and (all streaks and spots may be absent in worn California (England and Laudenslayer 1989a) plumage); and bill relatively short, not con- greatly expanded known distribution in both spicuously decurved, upper mandible dark gray states, but surveys not available for other areas. and slightly decurved distally, and lower mandible Distribution patchy within breeding range. nearly straight and pale towards base. Apparently suitable breeding habitat has a Most similar to Sage Thrasher (Oreoscoptes discontinuous distribution; many apparently rrtontanus), Gray Thrasher (T,cilzeriuriz), and Curve- suitable sites are not occupied. billed Thrasher especially in worn and faded Isolated observations of birds during the feathering during the late spring and summer breeding season, unsupported by photographs or prior to molt in the fall (Garrett and Dunn 1984, specimens and evidence of breeding, warrant Kaufman 1990, Kaufman and Bowers 1990). Sage skepticism because of similarity with Curve-billed Thrasher is smaller and has a shorter, straighter and Sage thrashers, and by observations away bill. Bill and eye color, and tail markings similar to from breeding areas during pre- and postbreeding Bendire's Thrasher. Sage Thrasher has heavy movements; e.g., Godfrey (1986) reports sight streaking on breast (sometimes extending to sides records from Saskatchewan and Manitoba in mid- and abdomen) and white wingbars which may and late May, and on 21 Jun an immature female not be prbminent evenin freshly moltedfeatl~erin~. was collected in fir-pine forest on Mt. Charleston, Both characters fade considerably by late spring, Clark Co., NV (Austin and Bradley 1965). but in all seasons show more contrast than Sparse or sporadic occurence north of primary a Bendire's Thrasher. brccding range, suggcstcd by sight records but Bold, nearly black, teardrop-shaped_spots and unsupportcd by specimens and photographs. streaks on underside of Gray Thrashcr extend Wiittcr range. Withdraws from breeding areas from breast to flanks; contrast apparent even in inMojave and Great Basindeserts, onthe Colorado worn plumage. Flanks and rump tinged with Plateau, and on the Arizona / New Mexico Plateau cinnamon-rufous. (Fig. 1). Reported to s. Sinaloa (Am. Ornithoi. Curve-billed Thrasher larger than Bendire's. Union 1983), implying movement south of the Bill of adult Curve-billed relatively long and breeding range, but may be regular winter visitor A. S. ENGLAND AND W. F. LAUDENSLAYER, JR. 3 only ton. Sinaloa and casual further south (Phillips SYSTEMATICS 1986). Presence in s. Sinaloa apparently based only on record in Bent (1948).Migrant and casual Based on descriptions by van Rossem (1942), three winter visitor (1)in California west of the deserts, subspecies (T. b. berldirei, T,b. cnndidunr, ond T. b. where individual birds have returned to the same rubricntzm) recognized by Miller et al. (1957) and locations for several winters; (2) at isolated Mayr and Greenway (1960),but not recognized by locations in the California Deserts (England and the American Ornithologists' Union (1957) or Laudenslayer 1989a); and (3) along the lower Phillips (1986). Subspecies distinguished by'van Colorado River (Rosenberg et al. 1991). Hypo- Rossem (1942) solely on coloration. T.b. candidurn thetical in Texas (Arnold 1984). (central w. Sonora) paler, more ashy brown Status in Baja California unresolved. Reported dorsally, and much whiter ventrally than T. b. by Wilbur (1987) as uncommon transient and beizdirei (sw. United States ton. ~onora),with pale winter visitor in Baja California with observations grayish buff flanks and under tail coverts. T.b. south to La Paz. Disputed by Everett (1988) who kbricotum (interior central ands. Sonora) generally states the species is unrecorded inBaja California. darker and redder, with more prominent spotting Likely a migrant and casual winter visitor in Baja than T.b. bendirei. Phillips (1962,1986) states that California as in Alta California west of the deserts apparent differences between subspecies are due (England and Laudenslayer 1989a). Specimens to season, wear, and fading. Most northern and needed to clarify distribution and status relative western birds withdraw from the breeding range to Gray Thrasher, a resident in Baja California. in mid-Aug, just before molting. Most museum specimens with fresh plumages are from wintering OUTSIDE THE AMERICAS grounds in Sonora and Sinaloa, and most northern Not reported. specimens are heavily worn, paler, and with a less cinnamon hue. Phillips (1962) concludes that HISTORICAL CHANGES IN DISTRIBUTION geographic color variation in the species has not Difficult to distinguishchanges from inadequate been proven. knowledge about distribution. New locations Considered a member of the Curve-billed discovered during breeding surveys in New Thrasher complex by Hubbard (1973) along with Mexico (Darling 1970) and California (England Curve-billed Thrasher, Ocellated Thrasher (T. and Laudenslayer 1989a) likely due to better ocellatum), and Gray Thrasher. Hubbard (1973) coverage. Breeding first confirmed in Sulphur proposes isolation in rehgia (pockets of warmer Springs Valley, Cochise Co., AZ in 1985 (Stejskal climate) during Illinoian and Wisconsin Glacial and Witzeman 1985) and in San Luis Valley, CO, periods as mode of differentiation among species. in 1984 (Andrews and Righter 1992). Failure to Gray Thrasher, isolated in the Californian find it previously at these locations may be due to refugium, suggested as the most recent split from range expansion, sporadic breeding, or lack of Bendire's Thrasher, isolated in the Sonoran prior coverage. refugium. Also considered closely related by Engels (1940) and classified a superspecies by the FOSSIL HISTORY American Ornithologists' Union (1983). Reported from Pleistocene asphalt deposits at McKittrick in s. San Joaquin Valley, CA (Miller 1937).LeConte'sThrasher (T. 1ecoiztei)nowresident . MIGRATION in the s. San Joaquin Valley (Laudenslayer et al. , 1992) where l end ire's is-unrecorded. Closest confirmed breeding location to McKittrick NATURE OF MIGRATION IN THE SPECIES approximately 120 kmeast at western fringeof the Post-breeding, most individuals apparently Mojave Desert in Kelso Valley, e. Kern Co., CA depart the northern half of the breeding range (McCaskie 1987, England and Laudenslayer (Fig. 1). Some withdraw from s. Arizona, where 1989a). I-loward and Miller (1933) recorded thc species is less abundant in winter thy1 during 'l'oxoslo~r~cisp. Irom Shcllcr Caw, NM, which may Llic brccding scnson (Monson and Phillips 1981). Migrants presumably move southinto theyearlong be this species. / .' range in Sonora and n. Sinaloa, but the few recoveries of banded birds are all within a short distance of initial banding locations. May extend range further south into Sinaloa during the winter (Am. Ornithol. Union 1983), but movements and -- 4 BENDIRE'S THRASHER

winter distribution in Mexico poorly known HABITAT (Phillips 1986). During migration, some birds Figure 2, P--.r~m---__N____ wander to unexpected locations (e.g., coastal breeding BREEDING RANGE records in California including overwintering habitat of Desert habitats fromsealevel asnear Guaymas, individuals; England and Laudenslayer 1989a). Thrasher Sonora (Belding 1883)to approximately 1,800m as in southern near Escalante, UT (Woodbury 1939), and Lee TIMING AND ROUTES OF MIGRATION Arizona (Cochise Flat, Inyo Co., CA (England and Laudenslayer On theMojave Desert, CA, fall migrationbegins Co.); Prosopis, 1989a). Throughout range, breeders favor immediately after the end of breeding (see Fig. 4). Acacia, and Larrea relatively open grassland, shrubland, or woodland Most birds depart breeding areas by late Jul to are common with scattered shrubs or trees (Fig. 2). Not found early Aug with nearly all gone by late Aug; a few vegetation. Photo within dense vegetationsuch as riparianwoodland may depart earlier. In coastal California, fall by Dale and Marian or desert wash, but may use fringes. Floristic migrants first appear mid-Jul, with movements Zimmerman. composition of habitat varies with elevation and continuing until Oct or early Nov. Spring- migration latitude. At higher elevations and latitudes, begins in Feb, whenbirds aipear in the s. colorado occupies sagebrush (Artemisia sp.) with scattered Desert; continues from mid-Mar through May junipers Uurziperus sp.). At lower elevations in when birds return to breeding areas in the Mojave desert grassland and shrubland, large individuals Desert (England and Laudenslayer 1989a).Timing of one or more of the following spinescent shrubs similar in Arizona, withearliest migrants returning or cacti are almost always present: cholla (Opuntia to Tucsbn area from late Jan to early Feb and to n. sp.),Joshua tree (Yucca Drevifolia),Spanish bayonet Arizona in Mar (Brown 1901, Phillips et al. 1964). (Y. baccata), Mojave yucca (Y. sclzidigera), paloverde Most birds leaven. Arizona by the end of Aug and (Cercidiur~zsy.), mesquite (Prosopis sp.), catclaw " s. Arizona in Sep (Phillips et al. 1964). (Acacin sp.), desert-thorn (Lyciuiii sp.), or agave *, (Agave sp.; Fig. 2). Ins. New Mexico and s. Arizona, MIGRATORY BEHAVIOR the bird breeds in degraded desert-grassland and No information. desert scrub supporting various xerophytic microphyllous shrubs (but little grass); it tends to CONTROL AND PHYSIOLOGY OF MIGRATION avoid the cholla cactus stands that it favors farther 'No information. . north (e.g., near Albuquerque, NM), perhaps because the chollas are often occupied by the 7A. S. ENGLAND AND W. F. LAUDENSLAYER, JR. 5

Curve-billed Thrasher (D. Zimmerman pers. NUTRITION AND ENERGETICS comm.). No information. Information on habitat is nearly all from the United States (e.g., Gilman 1915~1,Grinnell and METABOLISM AND TEMPERATURE REGULAT1,ON Miller 1944, Bent 1948, Phillips et al. 1964, Ambrose No information. 1963, Darling 1970, Szaro and Jakle 1985, England and Laudenslayer 198910, Andrews and Righter DRINKING, PELLET-CASTING, AND DEFECATION 1992); virtually nothing reported from Mexico. No information. Where structure mimics natural habitat, this species is sometimes able to use vegetation around FOOD SELECTION AND STORAGE human habitation and agriculture (Gilman 1915~1, No information. Phillips et al. 1964, Rosenberg et al. 1991); breeds in a number of areas around agriculture where SOUNDS Curve-billed Thrasher is absent. VOCALIZATIONS SPRING AND FALL MIGRATION Development. No information. Little known about habitats used in migration; Vocal array. SONGS. Song complex and probably similar to those used for breeding and continuous (not broken into discrete segments or wintering. abruptly changing character);composed of a highly variable series of elements usually repeated 24 WINTER RANGE times before a transition to the next repeated Structure and floristics of habitat similar to that element (seeFig.3). Described asasweet or melodic used during the breeding season, but little warble (e.g., Phillips et al. 1964) that generally information reported. lacks sharp chips, whistles, and trills. Composition of songs varies greatly, both within and among individuals; no analysis of geographic variation. FOOD HABITS Rates of singing not measured, but songs frequently > losduration, withmany songs giveninsequence. FEEDING Periods of almost constant singing followed by Main foods taken. Insects and other arthropods; long intervals of silence are typical. Many elements also seeds and berries. within each sqng can be heard at > 100 m while Food capture and consumption. Forages others are uttered much more softly. No reports of primarily on the ground (Engels 1940, Ambrose mimicry as in some Mimids. No information on 1963)but will also gleanvegetation for insects and which sex sings. pluck fruit (Ambrose 1963). Uses bill to peck and CALLS.TWO types of calls (Gilman1909, Ambrose probe, and to hammer into the ground (Engels 1963). Most common (but seldom heard) is a chup 1940). Also digs with bill, but digging not as or chek, similar to call of the NorthernMockingbird powerful or efficient as, and used less frequently (Mimus polyglottos) but not as harsh or loud, more than, other thrashers (Ambrose 1963). Does not prolonged and slightly trilled, and repeated 2 or 3 scratch with feet (Engels 1940, Ambrose 1963). times in rapid succession, e.g., chirp-chip-chirp. Based onlife history of prey items found in stomach Second call a quiet whistled qiiee rising in pitch contents, Ambrose (1963) quantified the method ' toward the end. When disturbed from the nest, used to capture prey with the bill: surface glean or ' responds with call described as tirup, tirup, tirup probe 40.8%, digging 22.1%, scratching 18.9%, by Brown (1901). and rock-flipping 18.2%. t OTHER VOCALIZATIONS DIET No information. Mrrjor food iteirrslqrrn~rtilntiveaii~~lysis. a. Anecdotal reports of birds observed foraging or PHENOLOGY carrying prey to the nest indic?te a diet dominated In central Arizona near Phoenix (Gilman 1909) by grasshoppers, beetles, cal?erpillars, and other and in s. Arizona near Tucson (Ambrose 1963), larvae and pupae; seeds and fruit taken less often singing begins early Jan. Song given on 3 Jan, "a (Woodbury 1939, Engels 1940, Bent 1948). In the low warbling song with a decided sparrow 'burr' only quantitative study using stomach contents, to it," not readily recognized as belonging to * Ambrose (1963) found the diet dominated by ants, Bendire's Thrasher. Frequency of singing and termites, and lepidoptera larvae (Appendix 2). loudness increases and 'burr' quality decreases as ,.., . - , - ,- 6 BENDIRE'S THRASHER

Figure 3. Continuous song of Bendire's Thrasher recorded near Hermosillo, Sonora, Mexico; each segment is part of the sequential progression of one song (Hardy et al. 1987,3rd song). Courtesy of the Borror Laboratory of Bioacoustics, Ohio State University. kHz 8

6 ---

4 4hrlI 2 4

0.0 Seconds 0.5 1.O 1.5

breeding season approached (Gilman 1909). Fliglzt. Smooth and easy, similar to that of Continued singing until late Jun at both locations, NorthernMockingbird (Gilman 1909, Engels 1940). and occasionally until the last of Sep near Phoenix, Flight is usual method of locomotionwhenmoving but frequency of singing declines rapidly after any distance (Engels 1940). Regularly observed breeding and may be seldom heard in areas where flying between trees at heights of 7.6 to 15.2m (25- extremely vocalseveral weeksearlier (Visher 1910, 50 ft) above the ground. May fly 275 m (300 yd) to Ambrose 1963). bring food to the nest (Engels 1940). Daily pattern of vocalizing. No information. Places of vocalizing. Song delivered from high SELF-MAINTENANCE perch such as a Joshua tree, juniper, large shrub, Preening, head-scratching, stretching, bathing, fence post, or the roof of a house (Gilman 1909, anting, etc. No information. ASE and WFL). Near Tucson, AZ, singing perches Sleeping, roosting, sunbathing. No information. significantly higher than those used by Curve- Daily time budget. Diurnal. billed Thrasher (Ambrose 1963). May also sing fromlower, more obscure perches (Kaufman 1990). AGONISTIC BEHAVIOR Repertoire and deliv&j of songs. No infor- Physical interactions. No information. mation. Communicative interactions. No information. Social context and presumed functions of vocalizations. song used by males to SPACING defend breeding territory and to attract mates, but No information. no information found to confirm either of these functions or which sex sings. No information on SEXUAL BEHAVIOR function of calls. Matingsystem. Apparently monogamous, but no information in the primary literature. NONVOCAL SOUNDS Pair bond. No information. No information. Extra-pair copulations. No information.

SOCIAL AND INTERSPECIFIC BEHAVIOR BEHAVIOR Degree of sociality. Inconspicuous except when singing. Generally observed in pairs or, immea- LOCOMOTION iately after breeding, in small family groups. One Walking, hopping, climbing, etc. Birds foraging questionable observation of immatures in foraging on the ground hold tail low, move in and out of flocks of 40-50 individuals, moving upslope after bushes varying speed from run to slow walk, breeding (Scott 1888);such behavior neverreported sometimes fly up into a low bush then directly since, despite far more observers in range. .back to the ground; may jump into air as if Play. No information. flycatching (~n@ls1940). Often cock tail over Nonpredatory interpecific interactions. level of back when running (Phillips et al. 1964). Immatures in post-breeding flock observed by (Scott 1888) predominately Bendire's Thrashers A. S. ENGLAND AND W. F. LAUDENSLAYER, JR. 7

but also a few Curve-billed and Crissal Thrashers (T,dorsale). Gila Woodpecker (Melnnerpes uropyginlis) seen attacking a Bendire's Thrasher, but thrasher escaped and pummelled the woodpecker (Gilman 1915b). A pair preparing to start a second brood were driven from a new nest site by Western Kingbirds (Tyrnnnus verticnlis) and returned to the nest used to successfully raise the first brood (Gilman 1915a). Predation. No information.

BREEDING

PHENOLOGY Pair fomntion. In Arizona, birds return to breeding grounds in early Feb, gather in small flocks of unmated individuals (Brown 1901). No other information onwhere or how pair formation occurs. Nest building. No data, but must begin shortly after returning from wintering grounds because nests witheggs found early Mar in Arizona (Brown 1901), end of Mar in California (Fig. 4; England and Laudenslayer 1989a).Earliest date for eggs in Arizona 24 Feb (Brown 1901). exotic vegetation around dwellings and agri- First broodperseason.Difficult to discerndates Breeding n Young cultural fields (Gilman 1915a).Nests occasionally for first brood based on descriptive nature of - Egg in mistletoe (Plzorndendron)on catclaw or juniper. publisheddataand propensity for Migration Unusual locations include under the cave onbeam brood. Based on dates of nests with eggs, first tb4&.9 in a carport (North American Nest Record Card brood initiated late Mar through Apr in California Program), sharing a common wall with a Verdin and Laudenslayer1989a). In s. Figure 4. , (Ar~ripnr~rspnviceps)nest (Gilman 1909), and in a

first initiated as as late Febl ~nnua~cycle of deserted flicker nest (hole in tree; Gilman 1915b). nesting firstweek of Mar but generally breeding and Average height of 39 nests measured by Gilman early Apr (Brown 1901). migration of (1909) 5 ft (1.5 m) (range 3-10 in). The 50 nests Second brood per season. In s. Arizona, reported on by Drown (1901) were typically 2.5- "preparations for a second brood are well under Thrasher in 5.0 ft (.7-1.5 m) high (range 6 in-20 ft). way" by mid-Apr (Brown 1901) and birds known southern to nest for a second time on 20 May (Scott 1888). California, NEST Sole California record of second clutch found last Timing of molt is ~~~~~~~~i~~,N~ information. week of Jun (England and Laudenslayer 1989a). insufficiently Structrire and compositio~tmatter. Open, Third per One record of a bird ' known to be generally bowl-shaped nest similar in general incubating a third brood 0n25Ju1after 'illustrated here; design to that of other thrashers, but usually finer, fledging the first brood on about 1 May and the see text for smaller, and more compact. Outside layer can be second on 6 Jul (Gilman 1915). b details.Thick conspicuous or nearly lacking (Brown 1901, lines show peak Ambrose 1963);composed of sticks which may or NEST SITE activity, thin may not be predominantly thorny (Johnson et al. Selection. No information. lines off peak. 1948, Ambrose 1963). Inner layer a welbformed, Site characteristics. Typically placed inshrubs, symmetrical cup lined with a variety of soft cacti, or trees; no reports of Qests on the ground.' materials (e.g., green or dried grass, horse or cow Common supporting pla~tsinclude cholla, hair, rootlets, feathers, fur, wool, and cotton; mesquite, juniper, and Joshuatree and other species Gilman 1909, Pierce 1921, Johnson et al. 1948). of yucca; fewer reports of nests in catclaw, palo Dimensions. Based on 17 nests, external layer verde, hackberry (Celtis sp.), willow (Snlix sp.), up to 12 in (30.7 cm) in diameter and 3-9 in (7.7-23 saltbush (Atriplex sp), and desert-thorn (Brown cm) deep; internal cup 2.25-3.50 in (5.7-8.9 cm) in 1901, Gilman 1909, Ligon 1961, North American diameter and 1.5-3.5 in (3.8-8.9 cm) deep (Brown Nest Record Card Program). Will also use some 1901). 8 BENDIRE'S THRASHER

Microcliiizate. No information. FLEDGLING STAGE Mainteizance or t'euse of nests, alternate nests. Departure from the nest. Leave nest approx- Bird attempting 3 broods in a single season used imately 12 d after hatching (North American Nest the same nest for the first 2 then moved a few feet Record Card Program). away in thesame tree for the third attempt (Gilman Growth. No information. 19154. No other information. Associntioii withparerits orotlieryouiig. Adults NoiiOw~viiiigiicsts. No infor~~i~itio~i. and im~mlurcsfound in f,imily [locks during Jul inn. Arizona (Wood bury 1939).ins. Arizona, full- EGGS grown young, still in Juvenal plumage, seen Shape. Subelliptical to short subelliptical. regularly on their own with no adults nearby (K. Size. Length: 26.90 mm (24.44-28.94) x breadth Kaufman pers, comm.). 19.24 mm (17.64-20.10; Western Foundation of Ability togetaround, feed, nnd care forself. No Vertebrate Zoology). information. Color. White or very pale blue green, or gray; speckled or blotched with pale purple, buff, red, IMMATURE STAGE and gray (Bent 1948). Little known (See Demography and Popula- Surface texture. Smooth and glossy. tions: dispersal from breeding site or colony). Egg layiig. No information.

INCUBATION DEMOGRAPHY AND POPULATIONS No information. MEASURES OF BREEDING ACTIVITY HATCHING Age at first breeding; intervals betweeit No information on behavior of adults during breeding. No information. hatching. Clutch. Based on inspection of about 500 nests (Brown 1901), 3 is a normal set,4 is not uncon~mon; YOUNG BIRDS only 2 nests with 5 eggs. Conditioiz at lzatclzing. Altricial (naked, eyes Annual aizd lifetime reproductive success. No closed) and nidicolous (remain in nest; ASE). information. Growth and developinent. No information. Nuiizber of bi'oods no~nln~~!jrcnrcdpcr season. Cnirses of death. Two observations of nestling Two broods per scason documentcd in Arizona mortality docuinented the day following strong (Brown 1901) and California (England and windstorms (North American Ncst Record Card Laudenslayer 1989a); suggcstcd in New Mexico Program). by late nesting datc (Ligon 1961). One rcport of three broods in a single season (Gilman 1915a). PARENTAL CARE Raising two broods per season called regular by Brooding. NO information. Brown (1901) and usual by Reed (1904), but Fecding. Nestlings fed by both adults (Jollt~son population statistics not reported. et al. 1948; North American Nest Record Card Proportioiz of total fearales that rear broods. Program, 3 records). No information. Nest sanitation. No information. Parental cam~iizgofyoung.Notknown to occur. LIVE SPAN AND SURVIVORSHIP Few data.U. S. Fishand WildlifeServicereports COOPERATIVE BREEDING 25 recoveries (16 individuals) from 226 banded Not known to occur. birds; one bird banded as an adult was recaptured I and released 4yr and 2mo later (Klimkiewiczet al. BROOD PARASITISM 1983). One published record of a nest near R& Rock, 4 AZ, with 3 Bendire's Thrasher eggs and one egg MORTALITY AND DISEASE from a Brown-headed Cowbird (Molotlirus ofer; No information. Friedman 1934). No reports of cow%'ird eggs or chicks on 38 nest record cards (North American RANGE Nest Record Card Program). Natal plzilopatry. No information. Fidelity to breeding site andwitzterhoim.?range. U.S. Fish and Wildlife Service band recovery data reviewed. All recoveries were from s. Arizona where the bird is resident; all birds had been ND AND W. F. LAUDENSLAYER, JR. 9

banded as adults. Twenty-four of 25 recoveries were within the same 10-min block where originally banded; the other recovery was in an adjacent 10-min block. Seven of 18 birds banded between Sep and Feb were recovered Mar-Aug, the other 11 Sep-Feb. Two of 7birds banded Mar- Aug were recovered during the same period, the other 5 Sep-Feb. These recoveries suggest considerable yearlong site fidelity at this location in Arizona. On 2 separate occasions, birds wintering in coastal California returned to the same location for 4 yr; consecutive years at one location, 3 of 4 yr at the other (England and Laudenslayer 1989a). Dispersalfvom breeding site or colony. In the northern part of the breeding range, dispersal can begin immediately after breeding. Two records demonstrate upslope movements into cooler areas, but this type of movement is not widely reported: (I)in Arizona, post-breeding movements upslope into thickets of low oaks (Quercus sp.) and junipers (Scott 1888),and (2) an immature female inlateJun at approximately 2,500 m in fir-pine forest, Charleston Mountains, NV; this bird may have moved upslope from nearby deserthabitat (Austin and Bradley 1965). Home range. No information.

POPULATION STATUS Estimates or counts of density. Infrequently and competition with Curve-billed Thrasher for a recorded on Breeding Bird Survey (BBS) counts Figure 5. (Fig. 5).In 1977,33 birds detected on 11 BBS routes depleted food supply were contributing to a decline Relative out of 1,832. Mean numbers detected per route in Bendire's populations. abundance of the (1965-1979): Arizona 0.7(26 routes); California 0.1 Bendire's (179 routcs); Colorado 0.0 (23 routes); Nevada 0.1 Thrasher in the (18 routes); New Mexico 1.1 (29 routes); Utah 0.0 CONSERVATION AND MANAGEMENT United States (13 routes). Highest counts were from the Sonoran and southern Desert and New Mexico (Robbins et al. 1986). EFFECTS OF HUMAN ACTIVITY Canada, 1985- Emlen (1974) reported density as 0.2 birds140 ha Understanding based on anecdotal reports; no 1991, based on in desert and 0.0 birds140 ha in urban Tucson. quantitative information available. Populations data from the Trends. No significant trend detected in BBS may persist in rural areas with scattered dwellings Breeding Bird data (1965-1979) from western states (Arizona, near native vegetation (Gilman 1909 and 1915a, Survey. Numbers California, Colorado, Nevada, New Mexico, and Rea 1983) and in agricultural areas with fields ' shown are the Utah), but birds detected on i34 routes (Robbins bordered by mesquite and other shrubs (Ambrose average number et al. 1986). In New Mexico, thought to be 1963), but no information available on whether of individual expanding range, possibly owing to grazing and populations decline, increase, or remain stable. birds seen or 1 Phillips et al. (1964) suggest the species is favored the increase of scattered junipers (Darling 1970). heard per route Populationsmay have declined in partsofArizona by clearing and agricultural activities and is per year. Map by 1940 to 1960 (Ambrose 1963). probably much commoner in Arizona :ow than Jeff Price. originally, while Ambrose (1963) states the species POPULATION REGULATI2N has declined due to habitat destruction. For New Sympatricwith Curve-billed Thrasher through- Mexico, Darling (1970) suggests that the range of out much of range (Gilman 1909, Engels 1940, Bendire's Thrasher has expanded because Ambrose 1963, Tomoff 1974). Engels (1940) overgrazing has greatly expanded the area with concluded that the means of ecological segregation scattered junipers. Remsen (1978) states that between these species could not be determined. potential threats to populations in California Ambrose (1963)suggested thathabitat destruction include harvesting of Joshua trees and other yuccas, - -- . - .." .- ,,,. 10 BENDIRE'S THRASHER

overgrazing, and off-road vehicle activity. Populations have been eliminated by dense Table 1. Measurements of the Bendire's Thrasher based on urbanization around Tucson (Emlen 1974) and by museum skins (Ridgway 1907). Measurements in millimeters. large scale agriculture along tlie Gila River (Rea 1983). MALE(it = 10) FEMALE(11 = 8)

MANAGEMENT Classified as a "Species of Special Concern" by Bill length' 24.3 21.5-25.5 23.4 21.5-25.5 California Department of Fish and Game (Reinsen Wing length 105.7 103.0-107.5 103.2 97.5-108.5 1978),and protected from take. No information on Tail length 111.4 108.0-115.0 107.8 101.5-115.5 other management actions taken in California or Tarsal length 33.8 33.0-34.5 33.2 31.5-34.5 elsewhere. Middle toe length 23.2 22.0-24.0 22.7 21.5-22.7

' Exposed culmen. APPEARANCE

MOLTS AND PLUMAGES with an olive-brown, raw sienna tint that increases Hatclzlings. No description on extent, devel- in intensity towards the sides and bend of the opment, or coloration of down in nestlings. wing; this trait is highly variable. Pale olive-brown Juvenal plumage. No information on develop- streaking can extend from upper breast to upper ment of Juvenal plumage. Juvenal plumagesimilar belly but is variable in extent. Streaks composed of to Definitive Basic plumage except that rump, short, thin, upward-pointing, triangular spots. secondaries and tertials, greater wing coverts, and tail feathers (except central pair) generally fringed BARE PARTS with cinnamon-rufous to raw sienna coloration Bill and gape. Upper mandible dark neutral and underparts narrowly streaked with drab gray, lower mandible dark neutral gray distally, (colors interpreted from Ridgway (1907) and Bent pale horn color towards base. Lining of mouth (1948) after examining specimens at California yellow (Engels 1940). Academy of Sciences). Iris. Iris generally yellow, but some individuals PrebasicI molt (involvingonly contour plumage tending to orangis11 yellow (Rea 1983). and wing coverts) occurs in late summer to early Legs and feet. Tarsi and toes medium to dark fall depending on date of fledging. neutral gray. Basic I plumage. Basic I plumage indistin- guisl~ablefrom DefinitiveBasicplumage (potential to distinguish by retention of worn Juvenal wing MEASUREMENTS and tail feathersmay bepossible, but not reported; Bent 1948). Definitive Prebasic molt occurs from Only Ridgway (1907) reportslinearmeasurements late Jul through Aug on tlie breeding grounds based on sample sizes greater than five (Table 1); prior to migration (Gilman 1909, Bent 1948).Sexes no information available that includes standard alike. No information on schedule or order of deviation or standard error. Mass of yearlong molting of remiges and rectrices. residents in Arizona: 62.2f 5.06 g, 11 = 23 (Dunning Defitzitivc Basic plumage. Dorsum nearly 1984). uniform medium drab to olive-brown from base of bill to rump; tertials and wing coverts also mediym drab to olive-brown but fringes INTERNAL ANATOMY sometimes paler. Tail medium to dark olive-brown; Engels (1940)provides detailed information on shafts of rectrices rufous-cinnamon or raw sienna the internal skeletal and muscular anatomy of, at base, gradually changing to dark olive-brown Bendire's Tl~raslierand five other species of near tip. Inner vane of 2 (sometimes 3) lateral Tr~sostoiirnthrashers found in the Unitcd States, rcctriccs tipped with grayish whit& Rcmigcs and relates diffcrenccs in morphology to slightly darker olive-brown tkan rest of wing and differences in feeding habits and locomotion. Data dorsum. Chin an unmarked light gray with a on bill niorpliology and head musculature are slight tint of olive-brown. Ear coverts finely consistent with field observations that species with stgeaked light gray and olive-brown; may appear straight bills acquire food primarily by pecking, uniform except very close up. Very slight hint of poking, or hammering with the bill and not by malar stripe in some individuals; likely not visible digging. Tendency of frontal region to overgrow except in hand. Breast and belly pale whitish gray base of bill at the nasofrontal hinge is greater in Bendire's Thrasl~erthan in the other species of Andrews, R, and R. Righter. 1992. Colorado birds: a Toxostoitin studied, but also strong in Brown reference to their distribution and habitat. Denver Thrasher (T.r~rfirni). Tendency not found in Mus. Nat. Hist., Denver, CO. Toxosto~irnwith dec~~rvedbills, and believed not Arnold, K. A. (Ed.). 1984. Checklist of the birds of Texas. 2nd ed. Texas Ornithol. Soc., Austin. needed to absorb direct transmission of force Austin, G. T. and W. G. Bradley. 1965. Bird records against the base of the bill at the nasofrontal hinge. from so~~thernNevada. Condor 67: 445-446. Extent of overgrowth of frontal region correlated Belding, L.. 1883. List of birds found at Guaymas, with pecking behavior in woodpeckers and Sonora, in December 1882, and April 1883. Proc. correlation may be true for Toxostoii~nthrashers US. Natl. Mus. 6: 343-344. (Engels 1940). Muscle bundles extending from the Bent, A. C. 1948. Life histories of North American pterygoid to the base of the skull are present in all nuthatches, wrens, thrashers, and their allies. Bull. mimids and aid digging. Bendire's Thrasher and U.S. Natl. Mus. No. 195. other straight-billed species lack several traits Brown, H. 1901. Bendire's Thrasher. Auk 18: 225-231. found in curve-billed Toxostomn: (1) increased mass Coues,E. 1873. Some United States birds, new to science, and other things ornithological. Am. Nat. 7: 321- of several flexor muscles used to move the head, 331. (2) reduction the adductor muscle which of opens Darling, J. L. 1970. New breeding records of Toxostoinn the lower mandible, and (3) fusion of the thoracic cnrvirostrr and T, bendirei in New Mexico. Condor vertebrae. These characters provide strength and 72: 366-367. rigidity when digging to the upper jaw of curve- Dunning, J. B., Jr. 1984. Body weights of 686 species of billed species such as California Thrasher (T. North American birds. West. Bird Banding Assoc. redivivirm). Monogr. No. 1. Lengthof the wing skeletonis lessin proportion Emlen, J. T. 1974. An urban bird community in Tucson, to body size in Toxostonin than in the Northern Arizona: derivation, structure, regulation. Condor Mockingbird. Among the Toxostomn, wing 76: 184-197. Engels, W. L. 1940. Structural adaptations in thrashers proportions of Bendire's Thrasher are the most (Mimidae: Genus Toxostoitm) with comments on similar to the Northern Mockingbird and consistent interspecific relationships. Univ. Calif. Pub. Zool. with observation that flight is used for locomotion 42: 341-400. more frequently than by LeConte's, Crissal, or England, A. S. and W. F. Laudenslayer, Jr. 1989a. California thrashers. Distribution and seasonal movements of Bendire's Thrasher in California. West. Birds 20: 97-123. England, A. S. and W. F. Laudenslayer, Jr. 1989b. ACKNOWLEDGMENTS Review of the status of Bendire's Thrasher in California. Calif. Dept. Fish Game, Wildl. Mgmt. Div. Admin. Rep. No. 89-3. Leopoldo A. Moreno-Matiella translated the Everett, W. T. 1988. Book review: Birds of Baja relevant sections of Phillips (1962). The staff of the California. West. Birds 19: 83-85. Department of Ornithology and Mammalogy at Friedmann, H. 1934. Further additions to the list of the California Academy of Sciences allowed access birds victimized by the cowbird. Wilson Bull. 46: to study skins in the collection. Danny Bystrak at 25-36. the US. Fish and Wildlife Service, Office of Garrett, K. L. and J. L. Dunn. 1984.The identification of Migratory Bird Management, provided bird Curve-billed, Bendire's and Gray Thrashers. banding records. Kenn Kaufman reviewed the Western Tanager 51: 1-3. ' Gilman, M. F. 1909. Among the thrashers in Arizona. entire manuscript and made helpful suggestions. ' Condor 11: 49-54. Cover photo by Dale and Marion Zimmerman. Gilman,M. F. 1915a.Aforty acrebirdcensusatSacaton, Arizona. Condor 17: 86-90. Giln~an,M. F. 1915b. Woodpeckers of the Arizona REFERENCES lowlands. Condor 17: 151-163. Codfrey, W. E. 1986. Birds of Canada. Rev. ed. Natl. Mus. Can., Ottawa, ON. Ambrose, J. E., Jr. 1963. The breeding ecology of @ Toxostortro clrrvirostre and T. berrdrrei in the vicinity Grinnell, J. and A. H. Miller. 1944. The distribution of of Tucson, Arizona. M.S$ thesis, Univ. Ariz., the birds of California. Pac. Coast Avifauna No. 27. Tucson. Hardy, J. W., J. C. Barlow, and B. B. Coffey, Jr. 1987. American Ornithologists' Union. 1957. Check-list of Voices of all the mockingbirds, thrashers and their North Americanbirds. 5thed. Am. Ornithol. Union, allies: Family Mimidae. ARA Records,Gainesville, Washington, D.C. FL. American ~rnithologists'Union. 1983. Check-list of Howard, H. and A, H. Miller. 1933. Bird remains from North American birds. 6th ed. Am. Ornithol. Union, cave deposits in New Mexico. Condor 35: 15-18. Washington, D.C. Hubbard, J. P. 1973. Avian evolution in thearidlands of North America. Living Bird 12: 155-196. 12 BENDIRE'S THRASHER

Johnson, D. H., M. D. Bryant, and A. H. Miller. 1948. Pierce, W. M. 1921. The Bendire Thrasher nesting in Vertebrate animals of the Providence Mountains California. Condor 23: 34. area of California. Univ. Calif. Publ. Zool. 48: 221- Rea, A. M. 1983. Once a river. Univ. Ariz. Press, Tucson. 376. Reed, C. A. 1904. North American birds' eggs. Kaufman, K. 1990. A field guide to advanced birding: Doubleday, Page and Co., New York. birding challenges and how to approach them. Remsen, J. V., Jr. 1978. Bird species of special concern Houghton Mifflin Co., Boston, MA. in California. Calif. Dept. Fish Game, Wildl., Mgmt. Kaufman, K. and R. Bowers. 1990. The practiced eye: Branch Admin. Rep. No 78-1. Curve-billedThrasherand Bendire'sThrasher. Am. Ridgway, R. 1907. The birds of North and Middle Birds 44: 359-362. America: a descriptive catalogue of the higher Klimkiewicz, M. K., R. B. Clapp, and A. G. Futcher. groups, genera, species, and subspecies of birds 1983. Longevity records of North American birds: known to occur in North America, Part IV. US. Remizidae through Parulinae. J. Field Ornithol. 54: Natl. Mus. Bull. No. 50. 287-294. Robbins, C. S., D. Bystrak, and 0.H. Geissler. 1986. The Laudenslayer, W. F., Jr., A. S. England, S. Fitton, and L. Breeding Bird Survey: Its first fifteen years, 1965- Saslaw. 1992.The Toxostonla thrashersof California: 1979. U.S.Fish Wildl. Service Resour. Publ. 157. Species at risk? Trans. West. Sec. Wildl. Soc. 28: 22- Rosenberg, K. V., R. D. Ohmart, W. C. Hunter, and B. 29. W. Anderson. 1991. Birds of the lower Colorado Ligon, J. S. 1961. New Mexico birds and where to find River Valley. Univ. Ariz. Press, Tucson. ' them. Univ. New Mexico Press, Albuquerque. Scott, W. E. D. 1888. On the avi-fauna of Pinal County, Mayr, E. and J. C. Greenway, Jr. (Eds.). 1960. Check-list with remarks on some birds of Pima and Gila of birds of the world, Vol. 9. Mus. Comp. Zool. Counties, Arizona. Auk 5: 159-168. Cambridge, MA. Stejskal, D. and J. Witzeman. 1985. The spring season: McCaskie, G. 1987.Thenestingseason: SouthernPacific Southwest region. Am. Birds 39: 333-336. Coast region. Am. Birds 41: 1486-1489. Szaro, R. C. and M. D. Jakle. 1985. Avianuse of a desert Miller, A. H. 1937. Biotic associations and life-zones in riparian island and its adjacent scrub habitat. relation to the Pleistocene birds of California. Condor 87: 511-519. Condor 39: 248-252, Tomoff, C. S. 1974. Avian species diversity in desert Miller, A. H., H. Friedmann, L. Griscom, and R. T. scrub. Ecology 55: 396403. Moore. 1957. Distributional check-list of the birds van Rossem, A. J. 1942. Notes on some Mexican and of Mexico, Part 11. Pac. Coast Avifauna No. 33. Californian birds, with descriptions of six Monson, G. and A. R. Phillips. 1981. Annotated checklist undescribed races. Trans. San Diego Soc. Nat. Hist. of the birds of Arizona. Univ. Ariz. Press, Tucson, 9: 377-384. AZ. Visher, S. S. 1910. Notes on the birds of Pima County, Phillips, A. R. 1962. Notas sistematicas sobre aves Arizona. Auk 27: 279-288. Mexicanas, 11. An. Inst. Biol. Univ. Mex. 33: 331- Wilbur, S. R. 1987. Birds of Baja California. Univ. 372. California Press, Berkeley. Phillips, A. R. 1986. The known birds of North and Woodbury, A. M. 1939. Bird records from Utah and Middle America, Part I. Allan R. Phillips, Denver, Arizona. Condor 41: 157-163. CO. Phillips, A. R., J. Marshall, and G. Monson. 1964. The birds of Arizona. Univ. Ariz. Press, Tucson. I A. S. ENGLAND AND W. F. LAUDENSLAYER, JR. 13

ABOUT THE AUTHORS A. Sidney England and William F. Laudenslayer, Jr., worked together on the wildlife staff at the Desert Plan Program for the Bureau of Land Management in the 1970s. They were responsible for identifying bird species of concern on Public Lands in the deserts of southern California. While working on this assignment, they first became interested in the biology of Bendire's Thrasher and have been investigating this species in their spare time ever since.

A. Sidney England is currently a doctoral candidate in Ecology at the University of California, Davis. He has B.S. and M. A. degrees in biology from the University of California, Riverside. His dissertation research is concerned with the roles of resource levels, habitat structure, and plant floristics in the organization of avian communities in California chaparral. In addition, he is conducting a long-term study of Swainson's Hawks and is chair of the Swainson's HawkTechnical Advisory Committee in California. Address: Department of Wildlife and Fisheries Biology, University of California, Davis, CA 95616.

William F. Laudenslayer, Jr., is a Research Wildlife Biologist with the U.S.D.A Forest Service Pacificsouthwest Experiment Station. He received an A.B. in biology from EasternBaptist College, St. Davids, Pennsylvania, an MS. in biological sciences from Northern Arizona University, Flagstaff, and a Ph.D. in zoology at Arizona State University. His current research interests include the relationships between snags and cavity nesting birds, rates of snag recruitment and loss, responses of vertebrates to forest disturbance regimes, and characteristics of pre-European forests in California. Address: Forest Sciences Laboratory, 2081 E. Sierra Avenue, Fresno, CA 93710. 4ppendix 1 . Comparison of field identification characters betweenBendirelsThrasher and other similar thrashers from the southwesternUnited States and Baja California.

3ye color (iris) Yellow, occasionally orange-yellow Orange, more yellowish in imrnatures and Golden-yellow similar in T. c. palmeri I

3ill color d,Upper mandible dark gray, lower Nearly black, rarely pale towards base; Similar Siar pale towards base but difficult to see immature may show yellow gape Shorter, straighter 3ill shape Relatively short, not conspicuously 1 ADULT:relatively long and decurved; Intermediate between decunred; ventral edge of lower IMMATURE:may be as short and straight Bendire's and Curve- mandible nearly straight as Bendire's Thrasher billed thrashers

3reast markings Short, thin, upward-pointing, ADULT:roughly circular, may be triangular Bold, nearly black, Heavy streaking triangular spots arranged in distinct in center of breast, less distinct from back- teardrop-shaped spots sometimes extending streaks on upper breast, may be absent ground than in Bendire's Thrasher and less and streaks; extend to to sides and abdomen; in worn plumage; lessdistinct on lower distinct in T. c. palmeri; generally do not flanks; contrast apparent contrast fades in worn breast, may extend faintly onto sides coalesce into streaks. Imm: can have even in worn plumage plumage distinct triangular spots on breast -- Ning markings Lacks distinct white wing bars and Similar Similar. White wingbars, may wing patches not be prominent even in fresh feathering, fades in worn plumage rail markings White markings limited to comers Similar, but less pronounced in T. c. palmeri Similar Similar of outer rectrices, may be absent in wornplumage I Dorsal coloratio Uniform dark drab to olive-brown Grayer Darker, browner; flanks Grayer and rump tinged with I cinnamon-rufous Distinctly larger with longer tail Similar Slightly smaller Smallest Toxostoma I .. . - . - Appendix 2. Composition and size of arthropods, seeds, and fruits in stomachs of Bendire's Thrasher taken in the foothills of the Tucson Mountains and other locations in southeastern Arizona (Ambrose 1963). '

ARTHROPODS SIZERANGE (mm)

ARACHNIDA-Salticidae

ORTHOPTERA-Acrididae

NEIJROPTERA-Myrmeleonidae

LEPIDOPTERA Phalaenidae larvae unidentified larvae unidentified pupae

COLEOPTERA Carabidae larvae Tenebrionidae Tenebrionidae Tenebrio Cerambycidae Curculionidae Dasy tidae unidentified

HYMENOPTERA Formicidae Andrenidae Halictidae

;AMPLE SIZE

~EDSAND F~urrs Cnrt~egieagigan fen Gramineae Condnlia lycioides Sorghttn~sp.

'Column totaled to 99.2% (for arthropods) in original publication. 16 BENDIRE'S THRASHER

EXECUTIVE DIRECTOR The Birds of North America Frank B. Gill The Birds of North America series provides comprehensive, MANAGING EDITOR authoritative summaries of current knowledge of the breeding bird Alan Poole species of North America. Each of these accounts includes a major bibliography of references as well as unpublished information. Their ASSOCIATE EDITORS purpose is to enable informed conservation management of our Robert Chandler native birds and to define directions for future research. Accounts Sandra Gaunt are published separately toinsure timely availability of their contents. Kenn Kaufman Lloyd Kiff The Birds of North America accounts (ISSN 1061-5466) are published Peter Stettenheim bimonthly by The American Ornithologists' Union and The Academy Christopher Thompson of Natural Sciences, Benjamin Franklin Parkway, Philadelphia, PA PRODUCTION AND GRAPHICS 19103-1195. Copyright O 1993 by The American Ornithologists' Christine Bush Union and The Academy of Natural Sciences of Philadelphia. Printed Keith Russell by Smith-Edwards-Dunlap Company, Philadelphia, PA. All rights reserved. MANAGING BOARD Kemp Battle The Birds of North America is supported by charitable and Peter Cannell governmental organizations including: The Office of Migratory Bird Erica Dunn Management (USFWS), National Fish and Wildlife Foundation, The Samuel Gubins McLean Contributionship, The Geraldine R. Dodge Foundation, The Marion Jenkinson Keith Thomson Richardson Foundation, and the American Birding Association. Glen Woolfenden Benefactors of this program include Wallace C. Dayton and Joseph Minturn Wright I11 and Helen Taylor. PUBLICATIONS ADVISORY COMMITTEE SUBSCRIPTIONS Kemp Battle To subscribe or request more information write: Susan Drennan The Birds of North America Kermit Hummel c/o The Academy of Natural Sciences, Subscriber Services Henry Reath P.O. BOX687, Hoirnes, PA 19043 Nancy Steele , , Or Caii toll-free, 1-80C-345-8112 (FAX: 215-586-3232) Dennis Waters IX/ " I I I' * ; h ,

I (<> '\ , +(, J Sr'~ , I ,". :' 5 ,: "I' ,' 1,'it' ... d. I i,' 5 " i ". , A L. I I,. I

4 RECOMMENDED CITATION England, A. S. and W. F. Laudenslayer, Jr. 1993. Bendire's Thrasher (Toxostorrin hciidirci). 111 'l'ho Ilirds of North Alncrica, No. 71 (A. I'oolc and T;. Gill, Bds.). I'hiladclpiiia: Thc Aciitlcmy of Nilltlriil Sci1w-c-s;Washington, 11.C.:'l'hc Amcrican Ornithologists' Union.

I '4