WESTEt BIRDS Volume 29, Number 2, 1998 BIRDS OF THE MAD RIVER RANGER DISTRICT, SIX RIVERS NATIONAL FOREST, CALIFORNIA JOHN E. HUNTER, USDA Forest Service, Six Rivers National Forest, 1330 BayshoreWay, Eureka,California 95501 GJON C. HAZARD, Department of Wildlife, HumboldtState University,Arcata, California 95521 The Mad River RangerDistrict (MRRD) of the Six RiversNational Forest (SRNF)is locatedin northwesternCalifornia (Figure 1). We compileddata on the statusand distribution of the birdsof thisarea for threeprimary reasons. First,except for collectingtrips to SouthFork Mountain and nearby areas in the 1930s (Grinnelland Miller 1944), thisarea hasbeen littlestudied (Harris 1996). Whilethe MRRD wasincluded by Harris(1991, 1996), we soughtto providemore detailed information for a uniquearea. Second, we hopedto provideresource managers and otherswith localstatus and distribution data. Much of our data has been gleanedfrom obscuresources not generally accessibleto mostworkers. While more detailed distribution and life history dataare neededfor mostspecies, this report can serve as a startingpoint for furthermanagement considerations and research.Third, while the MRRD containsseveral noteworthy birding areas in Humboldt(e.g., Mount Lassic and BlakeMountain) and Trinity(e.g., RuthLake, HettenshawValley, and Ant Point)counties, the isolationof thisarea relativeto populationcenters hasresulted in relativelylittle recreational birdwatching to date.We hopethis report will stimulateothers to explorethe MRRD and other portionsof interior northwestern California. STUDY AREA We includedall areaswithin the administrativeboundaries of the MRRD, includingprivate inholdings. The 113,000-ha MRRD liesprimarily within southwesternTrinity County, with someportions extending into southeast- ern HumboldtCounty (Figure 1). The climateand vegetationof the MRRD exhibit characteristics of both the humid coastal belt and the more arid interior of northwesternCalifornia. Miller (1951) noted that the moisture Western Birds 29:65-82, 1998 65 BIRDS OF THE MAD RIVER RANGER DISTRICT, CALIFORNIA 0, 10 20I Kilometers • ChromeRidge BlakeMountain '•,• ,• ,• ,• N Mountain Pine Horse Ridge Valley MendocinoCounty Figure I. Locationof the Mad River Ranger Districtin relationto the Six Rivers National Forest in northwestern California. gradientnear the Humboldt-Trinitycounty line hasplayed an importantrole in the distributionof the birdsof this region. The avifaunaof the MRRD reflects the transitional nature of this area from the conifer-dominated Klamath Mountains to the oak (Quercus spp.), brush, and grassland- dominated habitats of interior central California. Physiographically,the MRRD generallyfalls in the High and Inner North CoastRanges Districts of Hickman (1993), while the remainder of the SRNF lies to the north in the Klamath Ranges. 66 BIRDS OF THE MAD RIVER RANGER DISTRICT, CALIFORNIA Exceptfor fiat areasin valleys,the topographyis moderateto steep. Elevationsrange from 440 m alongthe lowerNorth Fork Eel Riverto 1850 m at Horse Ridge.Regionally important waterways originating within the MRRD are the Mad, the NorthFork Eel, andthe Van Duzenrivers (Figure 1). The entireeastern boundary of the MRRD is formedby the extensiveridge knownas South Fork Mountain. The climateof the MRRD is characterizedby hot, dry summersand cold, wet winters. The summer dry seasonis not moderatedby coastalfog, and summershowers are infrequentand short. Averageannual precipitation varies from about 125 cmat the lowerelevations to 200 cm at the higherelevations. Moderate to heavysnow can fall above 600 m elevation,and sometimespersists into Juneabove 1200 m. About 60% of the MRRD is coveredwith Douglas-fir(?seudotsuga rnenziesii)forests in manysuccessional stages resulting from naturaldistur- bancesand intensivetimber harvest(USDA 1995a). Other coniferspecies such as pines (Pinus spp.) and White Fir (Abies concolor) also may be presentin the overstow.The midstorymay be dominatedby conifersor hardwoodsincluding Tanoak (Lithocarpusdensiflora), Pacific Madrone (Arbutusrnenziesii), or CaliforniaBlack Oak (Q. kellogii). True firs (Abies spp.) cover about 12% of the MRRD; White Fir (A. concolor) becomes prevalentabove 1500 m, and somestands of Red Fir (A. rnagnifica)occur at the highestelevations. About 23% of the coniferforests can be character- izedas late mature and old growth with dominant conifers >53 cm diameter at breastheight. Oregon White Oak (Q. garryana)and California Black Oak woodlandsand annualgrasslands occupy about 17 and 6% of the MRRD, respectively. About 5% of the MRRD consistsof miscellaneouscover types. Near MountLassic, stands of open-canopyJeffrey Pine (P. jeffreyi) woodlands are found. Most riparian habitatsconsist of narrow bandsalong perennial streamsand rivers that are dominatedby Red Alder (Alnus rubra). The banksof the upperMad Riversupport remnant stands of BlackCottonwood (?opulus trichocarpa) and willow (Salix spp.) habitats. Other riparian speciesof the MRRD includethe BigleafMaple (Acer rnacrophyllurn)and OregonAsh (Fraxinuslatifolia). Chaparralhabitats consist of mixturesof ceanothus(Ceanothus spp.), manzanita(Arctostaphylos spp.), mountain mahogany(Cercocarpus spp.), Brewer'sOak (Q. g. breweri),and other brushspecies, and are most conspicuousin the southernportion of the MRRD. Chamise(Adenostorna fasciculaturn) is knownonly from a single locationnear the confluenceof Hoaglinand Salt creeks. Ruth Lake (445 ha whenfull) was formed by a dam on the Mad Riverin 1962 and providesthe only open-water habitat. Ruth Lake is steep-sidedand has very little emergentvegetation. Exposed mudflats appear at the southend of the lake as waterlevels recede in the late summerand fall. Fieldsand pasturesoccur in a few locationssuch as HettenshawValley. Commercial buildings, human dwellings,and outbuildingsare foundprimarily near the communityof Mad Riveralong the lowerVan DuzenRiver and the communityof Ruthalong the upper Mad River.Hunter et al. (1997) and USDA (1995a, 1995b) provided more detailed information on the MRRD. 67 BIRDS OF THE MAD RIVER RANGER DISTRICT, CALIFORNIA METHODS Much of our data resultedfrom our personalfieldwork in the MRRD and information solicited from other observers. We also consulted the SRNF bird-sightingsdatabase, which containedanecdotal sightings starting in 1967 that were submittedby ForestService employees and forestvisitors. We also used other unpublishedadministrative studies and miscellaneous fileslocated at the SRNF supervisor'soffice in Eureka.As part of another study (Hunter et al. 1997), 5563 point countswere conductedat 189 randomsites in late matureand old-growthDouglas-fir (mean 29 counts/ site)between late April andearly August during 1995 and 1996. Eachpoint countlasted 10 minutesand all individualsdetected were tallied.Peregrine Falconprey remainswere collectedfrom nest siteswithin the MRRD and were identifiedby N. JohnSchmitt of the WesternFoundation of Vertebrate Zoology.We alsoinclude some previously published records from American Birds (AB), National Audubon Society Field Notes (NASFN), Harris (1991, 1996) and other sources. We usedthe followingterms to describethe statusof a species:Resident-- presentthroughout the year,although turnover of individualsor populations (includingsubspecies) may occur.Transient--occurs during migrationor dispersal;modified by seasonif abundancesdiffer. Breeder--breeding has beenconfirmed, unless prefixed by "probable"or "possible."Determination of breedingstatus (i.e., confirmed,probable, or possible)generally follows criteriaused by Robersonand Tenney(1993). Visitor--presentduring only part of the year, not includingmigration or dispersal;modified by seasonif abundancesdiffer. More than one term may be usedto describea species, e.g., someindividuals of a speciesmay be residentwhile others are transient. Abundanceestimates assume reasonable effort by a competentobserver in appropriatehabitat and properseason during a 24-hourperiod. Abundant-- alwayspresent, usually encountered in very large (>500) numbers.Com- mon-always present,usually encountered in large (100-500) numbers. Fairly common--alwayspresent, usuallyencountered in small (10-100) numbers.Uncommon--usually present, usually encountered in very small (<10) numbers.Rare--unlikely to be encountered,and only in very small (< 10) numbers.Casual--few records but reasonably expected again, unlikely to be encountered.Accidental--few records and very unpredictable,very unlikelyto be encountered.Hypothetical--all reports are "unconfirmed."We consideredrecords from observersknown by usto be competent,and records from other observerswhen accompaniedby convincingdetails, as "con- firmed."All otherreports were consideredunconfirmed. Species for whichall reportsare from PeregrineFalcon prey remainswere alsoconsidered hypo- theticalbecause falcons may foragelong distances from nestsites. We chose not to excludeunconfirmed reports because doing so couldpreclude or delay detectionof emergingpatterns of birddistribution. Reports were not included, however,if availabledetails were unconvincing. All recordsare from Trinity County unlessotherwise specified. When pertinent, we includedsome recordsfrom outsidethe MRRD; locations outsidethe MRRD are precededby an asterisk(*). All locationsmentioned can be foundon U.S. GeologicalSurvey 71/2-minute quadrangles or on 68 BIRDS OF THE MAD RIVER RANGER DISTRICT, CALIFORNIA nationalforest visitor's maps. Codes used for Californiacounties are HUM, Humboldt;MEN, Mendocino;TRI, Trinity. Other abbreviationsused