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HomeMy WebLinkAbout3184; CANNON ROAD WEST; RESULTS OF 1993 LEAST BELL'S VIREO SURVEYS; 1993-09-22P&D Environmental Services September 22, 1993 A Division of P&D Technologies 1100 Town & Country Road Suite 300 - Orange, CA 92668 P.O. Box 5367 Orange, CA 92613-5367 FAX 714/953-6989 714/835-4447 An Employee-Owned Company Mr. Frank Jimeno City of Carlsbad 2075 Las Palmas Drive Carlsbad, California 92000-4859 SUBJECT: Results of 1993 least Bell's vireo surveys in Macario Canyon Dear Mr. Jimeno: Focused surveys to determine the presence or absence of the federal and state endangered least Bell's vireo (Vireo -bellii pusillus) were-conducted in Macario Canyon, in the City of Carlsbad. The area was surveyed by a P&D Technologies biologist to assess the potential for impacts to occupied least Bell's vireo habitat resulting from the extension of Cannon Road. The survey area is located at the mouth of Macario Canyon, immediately southeast of Agua Hedionda Lagoon. Introduction Loss and degradation of breding habitat on a regional level, in addition to nest parasitism by the brown-headed 6owbird (Molothrus tE)', have résülfed-in ,a severe decline in the least Bell's vire6 population in California. Throughout thisspecies range, habitat conversion for agricultural purposes have removed much of the original riparian woodlands required for nesting by this vireo. Flood éontrol measures and channelization have further depleted the riparian habitats used by the vireo and other birds. Cattle grazing has also impacted habitat by removing the understory vegetation necessary for nesting birds- : The significant reduction in the population size and range of the vireo resulted in its listing as federally endangered in May 1986. The least Bell's vireo prefers mature riparian habitat with a dense understory of young willows (Salix spp), mulefat (Baccharis sahcifoha), California rose (Rosa californica), and a variety of other' shrubby species. The vireo is generally found in areas that include trees such as willow, sycamore (Platanus racemosa), or cottonwood (Populus spp.), particularly where the canopy is within or immediately adjacent to an understory layer of vegetation (Salata 1983). A recent analysis indicates that this species prefers stratified vegetation, with low amounts of aquatic and herbaceous cover (RECQN .1990). Another significant ecological variable is the width of the willQw. riparian woodland. The vireo shows a strong' preference for wide woodlands, which typically exhibit more stratification of vegetation. A marked increase in occupied habitat occurs Mr. Frank Jimeno September 22, 1993 City of Carlsbad Page 2 as the width of the willow riparian woodland exceeds 50 meters wide versus 10 meters or less (RECON 1990). Methods A series of twelve surveys was conducted by P&D biologist Doug Willick according to the following schedule: April 15 and 23; May 4, 14, and 21; June 2, 15, and 22; July 8, 19, and 29; and August 5. The surveys entailed walking slowly along the riparian habitat and carefully recording all bird species observed or heard in the vicinity. The riparian habitat quickly ends just downstream from the proposed Cannon Road crossing. All riparian habitat within a 1/4 mile of the proposed crossing was covered during the survey. The timing and frequency of the surveys followed guidelines provided by the United States Fish and Wildlife Service. Twelve surveys were performed during morning hours (generally between 0700 and 1030 hours), under optimal weather conditions. They were accomplished by an ornithologist with demonstrated experience and competence in working with the least Bell's vireo. Results The section of Macario Creek that was surveyed supports a willow riparian system that is generally considered high quality vireo habitat. The dominate tree species include black willow (Salix goodingii) and arroyo willow (, lasiolepsis). The area near the mouth of the canyon (where the Cannon Road bridge is proposed) has the highest potential to support breeding vireos. The riparian habitat in general is utilized frequently by human transients for shelter, and, consequently, some of the understory vegetation has been removed or is disturbed. However, fairly extensive areas of mulefat and younger willows still exist. One male least Bell's vireo was found during the April 23 visit. It was first detected as it began singing from an elderberry on a small slope immediately east of the riparian habitat. It soon moved into the dense willow woodland near the mouth of Macario Canyon. Excellent views were obtained of the vireo, which generally foraged through the riparian vegetation, often in close proximity to a dirt road that cuts through the eastern edge of the habitat. It sang occasionally through the rest of the survey, although was conspicuously quiet for long periods of time. The bird was unbanded, and apparently unpaired. It covered at least 500 feet of the riparian corridor while conducting the survey. This bird was not found, however, on any of the subsequent visits. Consequently, no vireos were found to be on territory, and no evidence of nesting was observed. An indication of the quality of the riparian habitat is the presence of sensitive riparian bird species. Bird species observed onsite are included as Attachment 1. In addition to the least Mr. Frank Jimeno September 22, 1993 City of Carlsbad Page 3 Bell's vireo that was present during one survey visit, two pairs of territorial yellow-breasted chats were located in the survey area, with one of these being in the same area as the vireo. One or two recently fledged chats were observed here on May 21. As the yellow-breasted chat has habitat requirements very similar to the vireo, their presence is considered an indicator of vireo quality habitat. Other noteworthy occurrences included a pair of California gnatcatchers (Polioptila californica) in coastal sage scrub and riparian scrub immediately east of the willow riparian habitat at the mouth of Macario Canyon. Two issues possibly affecting the use of this area by the vireo include disturbance by transients and cowbirds. Occasional disturbances from transients living in the vicinity of the habitat (e.g., the discharging of firearms and removal or degradation of the understory vegetation) may have been a factor in the bird's disappearance. Brownheaded cowbirds were observed frequently on the study site. Approximately 10 to 15 individuals per day were typically seen in the area of the vireo observation, especially after early May. The presence of cowbirds may impact the reproductive success for vireos attempting to breed in this area. If you have any questions or require additional information, please call me at (714) 835-4447. Sincerely, P&D ENVIRONMENTAL SERVICES Doug Willick Biologist Attachments References Cited RECON Regional Environmental Consultants, 1990. Draft Comprehensive Species Management Plan for the Least Bell's Vireo. Prepared for the San Diego Association of Governments. Salata, L.R. 1983. Status of the Least Bell's Vireo on Camp Pendleton, California: Report on Research Done in 1983. US Fish and Wildlife Service pubi., Laguna Niguel, California. I ATTACHMENT 1 MACARIO CANYON AVIFAUNAL SPECIES LIST Family Ardeidae Great Blue Heron Ardea herodias Great Egret Casmerodius albus Green-backed Heron Butorides striatus Family Cathartidae Turkey Vulture Cathartes aura Family Accipitridae Black-shouldered Kite Elanus caeruleus Cooper's Hawk Accipiter cooperi Red-tailed Hawk Buteo jamaicensis Red-shouldered Hawk Buteo lineatus Family Falconidae American Kestrel Falco sparverius Family Phasianidae California Quail Callipepla californica Family Rallidae Virginia Rail Rallus limicola Family Cuculidae Greater Roadrunner Geococcyx californianus Family Columbidae Rock Dove Columba lii Mourning Dove Zenaida macroura Family Trochilidae Black-chinned Hummingbird Archilochus alexandri Anna's Hummingbird Calypte anna Rufous/Allen's Hummingbird Selasphorus sp. Family Picidae Nuttall' s Woodpecker Picoides nuttallii Downy Woodpecker Picoides pubescens Northern Flicker Colaptes auratus S • Family Tyrannidae Western Wood-Pewee Contopus sordidulus Willow Flycatcher Empidonax traillii Pacific-slope Flycatcher Empidonax difficilis Black Phoebe Sayornis nigricans Cassin's Kingbird Tyrannus vociferans Western Kingbird Tyrannus verticalis Family Hirundinidae Northern Rough-winged Swallow Stelgidopteryx serripennis Cliff Swallow Hirundo pvrrhonota Barn Swallow Hirundo rustica Family Corvidae Scrub Jay Aphelocoma coerulescens American Crow Corvus brachyrhynchos Common Raven Corvus corax Family Aegithalidae Bushtit Psaltriparus mini mus Family Troglodytidae Bewick's Wren Thrvomanes bewickii House Wren Troglodytes aedon Marsh Wren Cistothorus palustris Family Muscicapidae Ruby-crowned Kinglet Regulus calendula California Gnatcatcher Polioptila californica Swainson' s Thrush Catharus ustulatus Wrentit Chamaea fasciata Family Mimidae Northern Mockingbird Mimus polyglottos California Thrasher Toxostoma redivivum Family Laniidae Loggerhead Shrike Lanius ludovicianus Family Sturnidae European Starling Sturnus vulgaris Family Vireonidae Bell's Vireo Vireo bellii pusillus Warbling Vireo Vireo gilvus Family Emberizidae Orange-crowned Warbler Vermivora celata Yellow Warbler Dendroica petechia Common Yellowthroat Geothlypis trichas Wilson's Warbler Wilsonia pusilla Yellow-breasted Chat Icteria virens Western Tanager Piranga ludoviciana Black-headed Grosbeak Pheucticus melanocephalus Blue Grosbeak Guiraca caerulea California Towhee Pipilo crissalis Rufous-sided Towhee Pipilo erythrophthal mus Song Sparrow Melospiza melodia Red-winged Blackbird Agelaius phoeniceus Western Meadowlark Sternella neglecta Brown-headed Cowbird Molothrus ater Northern Oriole Icterus galbula Hooded Oriole Icterus cucullatus Family Fringillidae House Finch Carpodacus mexicanus Lesser Goldfinch Carduelis psaltria Lawrence's Goldfinch Carduelis lawrencei American Goldfinch Carduelis tristi s RECEIVED JUL 2 0199Z CITY OF CARLSBAD ENGINEERING DEPARTMENT Suite 300 Transportation Orange, CA 92668 Environmental P.O. Box 5367 Economics Orange, CA 92613-5367 Landscape Architecture FAX 714/953-6989 714/835-4447 P&D lèchnologles Planning 1100 Town & Country Road Engineering June 30, 1992 An Employee-Owned Company 'p Lloyd Hubbs, City Engineer City of Carlsbad 2075 Las Palmas Drive Carlsbad, California 92000-4859 Re: Results of 1992 least Bell's vireo surveys in Macãrio Canyon Dear Mr. Hubbs; Focused surveys to determine the presence or absence of the federal and state endangered least Bell's vireo (KtLeo bellii pusillus) were conducted in Macario Canyon, adjacent to Agua Hedionda Lagoon, in the City of Carlsbad. The area was surveyed by P&D Technologies biologists to assess the potential for impacts to occupied least Bell's vireo habitat resulting from the extension of Cannon Road. Introduction Loss and degradation of breeding habitat on a regional level, in addition to nest parasitism by the brown-headed cowbird (Molothrus a), have resulted in a severe decline in the least Bell's vireo population in California. Throughout this species range, habitat converion for agricultural purposes have removed much of the original riparian woodlands required for nesting by this vireo. Flood control measures and channelization have further depleted the riparian habitats used by the vireo and other birds. Cattle grazing has also impacted habitat by removing the understory vegetation necessary for nesting birds. The significant reduction in the population size and range of;the vireo resulted in its listing as federally endangered in May 1986: The least Bell's vireo prefers mattite riparian habitat with a dense understory of young willows (lix spp.), mulefat (Baccharis salicifolia), California rose (Rosa californic), and a variety of other shrubby species. The vireo is generally found in areas that include trees such as willow, sycamore (Platanus racernosa), or cottonwood (Populus spp.), particularly where the canopy is within or immediately adjacent to an understory layer of vegetation (Salata 1983). A recent analysis indicates that this species prefers stratified vegetation, with low amounts of aquatic and herbaceous cover (RECON 1990). Another significant ecological variable is the width of the willow riparian woodland. The vireo shows a strong preference for wide woodlands, which typically exhibit more stratification of vegetation. A marked increase in occupied habitat occurs 2 as the width of the willow riparian woodland exceeds 50 meters wide versus 10 meters or less (RECON 1990). Methods A series of eight surveys was conducted by P&D biologist Doug Willick according to the following schedule: April 13 and 22; May 7, 14, 21, and 27; and June 4 and 26. Zachery Likens assisted in the surveys on April 13. The surveys entailed walking slowly along the riparian habitat and carefully recording all bird species observed or heard in the vicinity. The riparian habitat quickly ends just downstream from the proposed Cannon Road crossing. All riparian habitat within a 1/4 mile of the proposed crossing was covered during the survey. The timing and frequency of the surveys followed guidelines provided by the United States Fish and Wildlife Service. Eight surveys were performed during morning hours (generally between 0700 and 1000 hours), under optimal weather conditions, and were accomplished by ornithologists with demonstrated experience and competence in performing least Bell's vireo surveys. Results The section of Macario Creek that was surveyed supports a willow riparian system that is generally considered high quality vireo habitat. The dominate tree species include black willow (Salix goodingii) and arroyo willow ( lasiolepsis). The area near the mouth of the canyon (where the Cannon Road bridge is proposed) has the highest potential to support breeding vireos. The riparian habitat in general is utilized frequently by human transients for shelter, and, consequently, some of the understory vegetation has been removed or is disturbed. However, fairly extensive areas of mulefat and younger willows still exist. One pair of least Bell's vireos was found during the April 13 and 22 visits. The male was singing consistently, and was presumed to be on territory. The presumed territory was located in the most extensive area of mature willows at the mouth of Macario Canyon. Excellent views were obtained of both birds, which generally foraged through the riparian vegetation in close proximity to each other. Neither of these birds could be found, however, on subsequent visits. It is presumed that the pair abandoned the territory. An indication of the quality of the riparian habitat is the presence of sensitive riparian bird species. Bird species observed onsite are included as an attachment. In addition to the vireos that were present during a portion of the surveys, two pairs of yellow-breasted chats were located, with one of these being in the same area as the vireos. This pair was observed on June 26 with recently fledged young. Other noteworthy occurrences included the presence of a pair of California gnatcatchers (Polioptila californica) in coastal sage scrub and riparian scrub, immediately adjacent to willow riparian habitat. I 3 Two issues possibly affecting the use of this area by the vireo include disturbance by transients and cowbirds Occasional disturbances from transients living in the vicinity of the habitat occupied by the vireos (e.g., shooting with firearms and slingshots) may have been a factor in the birds disappearance. Brown-headed cowbirds were observed frequently on the study site. Approximately 10 to 15 individuals per day were typically seen in the area of the vireo territory, especially after mid May. The presence of cowbirds may impact the reproductive success for vireos attempting to breed in this area. If you have any questions or require additional information, please call me at (714) 835-4447. Sincerely, P&D TECHNOLOGIES &I Wo Doug Willick Biologist 4 Literature Cited RECON Regional Environmental Consultants, 1990. Draft Comprehensive Species Management Plan for the Least Bell's Vireo. Prepared for the San Diego Association of Governments. Salata, L.R. 1983. Status of the Least Bell's Vireo on Camp Pendleton, California: Report on Research Done in 1983. US Fish and Wildlife Service pubi., Laguna Niguel, California. ATTACHMENT 1 MACARIO CANYON AVIFAUNAL SPECIES LIST Family Ardeidae Great Blue Heron Ardea herodias Great Egret Casmerodius albus Green-backed Heron Butorides striatus Family Accipitridae Red-tailed Hawk Buteo jamaicensis Red-shouldered Hawk Buteo lineatus Family Phasianidae California Quail Callipepla californica Family Rallidae Virginia Rail Rallus limicola Family Cuculidae Greater Roadrunner Geococcyx californianus Family Columbidae Mourning Dove Zenaida macroura Family Trochilidae Black-chinned Hummingbird Archilochus alexandri Anna's Hummingbird Calypte anna Family Picidae Nuttall' s Woodpecker Picoides nuttall ii Downy Woodpecker Picoides pubescens Northern Flicker Colaptes auratus Family Tyrannidae Western Wood-Pewee Contopus sordidulus Willow Flycatcher Empidonax traillii Pacific-slope Flycatcher Empidonax difficilis Black Phoebe Savornis nigricans Cassin ' s Kingbird Tyrannus vociferans Western Kingbird Tyrannus verticalis 5 Family Hirundinidae Northern Rough-winged Swallow Stelgidoptervx serripennis Cliff Swallow Hirundo pvrrhonota Family Corvidae Scrub Jay Aphelocoma coerulescens Common Raven Corvus corax Family Aegithalidae Bushtit Psaltriparus minimus Family Troglodytidae Bewick's Wren Thryomanes bewickii House Wren Troglodytes aedon Marsh Wren Cistothorus palustris Family Muscicapidae Ruby-crowned Kinglet Regulus calendula California Gnatcatcher Polioptila californica Wrentit Chamaea fasciata Family Mimidae Northern Mockingbird Mimus polyglottos California Thrasher Toxostoma redivivum Family Laniidae Loggerhead Shrike Lanius ludovicianus Family Sturnidae European Starling Sturnus vulgaris Family Vireonidae Bell's Vireo Vireo bellii pusillus Solitary Vireo Vireo solitarius Warbling Vireo Vireo gilvus Family Emberizidae Orange-crowned Warbler Vermivora celata Yellow Warbler Dendroica petechia Townsend's Warbler Dendroica towndsendi Hermit Warbler Dendroica occidentalis MacGillivray's Warbler Oporornis tolmiei Common Yellowthroat Geothlypis trichas 'Wilson's Warbler Wilsonia pusilla 1.1 .1 .4 4 Yellow-breasted Chat Icteria virens Western Tanager Piranga ludoviciana Black-headed Grosbeak Pheucticus melanocephalus Blue Grosbeak Guiraca caerulea California Towhee Pipilo crissalis Rufous-sided Towhee Pipilo erythrophthal mus Song Sparrow Melospiza melodia Red-winged Blackbird Agelaius phoeniceus Brown-headed Cowbird Molothrus ater Northern Oriole Icterus galbula Family Fringillidae House Finch Carpodacus mexicanus Lesser Goldfinch Carduelis psaltria American Goldfinch Carduelis tristis 7 . I RECEWED -U U U I i r n i 1001 - P&D Technologies Planning - - 401 W A Street Engineering Suite 2500 Transportation CITY San Diego, CA 92101 OF RLSA : EnVlrOnmefltal Economics EGEERING DEPARTMENT - - Landsàape - Architecture 1-i An Employee-Owned Company . July 16, 1991 - Mr. Lloyd Hubbs, City Engineer City of Carlsbad - - 2075 Las Palmas Drive - Carlsbad, California 92000-4859 - - Re: Results of 1991 least Bell's vireo surveys in Macario Canyon Dear Mr. Hubbs; - Focused surveys for the federally endangered least Bell's vireo (Vireo bellii pusillus) were conducted in Macano Canyon adjacent to Agua Hedionda lagoon in the City of Carlsbad (Figure 1) The area was surveyed by P&D Technologies biologists Raymond Vizgirdas (RV) and Douglas Willick (DW) according to the following schedule: - April 23, 0630 to 1030 hours (RV, DW) April 30, 0600 to 1100 hours (RV) May 31, 0600 to 1000 hours (RV) S June 19, 0600 to 1000 hours (RV) - June 25, 0600-to 1000 hours (RV) T..1 1I\If1____ .. JUl IL, VI3U to iuuvnours kKV) Weather conditions for the area varied between overcast, cool to sunny-'breezy days with a tempeiature range of 60 to 80 degrees Fahrenheit. - The riparian habitat on site is described as a riparian woodland dominated by a mixture of tree and shrub willow species. The dominant tree species is the black willow CSalix goodingii), while the most common shrubby willow species is the arroyo willow (, lasiolepsis). The area near the mouth of the canyon (where the Cannon Road bridge is proposed) has the highest potetitial - to support breeding vireos. The riparian habitat in general is heavily utilized by human vagrants (e.g., shelters), and some of the understory has been removed or is very disturbd. 0 • Mr. Lloyd Hubbs July 16, 1991 Page two The surveys entailed walking slowly along the drainage and recording bird species observed or heard in 'the. vicinity (Attachment 1); The entire length of the riparian woodland was surveyed on all six days Some of the species observed/detected were spring, non-breeding migrants and were not detected in the remainder of the surveys These include bird species such as the gray dusky and Hammonds flycatchers, solitary and warbling vireos Other species such as the California gnatcatcher were detected on the upland habitats adjacent to the canyon in coastal sage scrub In excess of twenty cowbirds (Molothrus ater) were observed in the riparian habitat on each of the s!.irvey• days. One additional note, noise produced by low flying aircraft from the nearby Palomar Airport over the study site in conjunction with low cloud cover did hinder hearing birds singing at times Though not proven, excess noise may also prevent least Bell's vireo from establishing nesting territory in the area. In summary, no least Bell's vireo were' observed or detected during these 1991 surveys. Past surveys by RECON (1990) had identified the presence of-least Bell's vireo on site, but the bird did not appear to breed at this location. If you have any questions or require additional information, please call me at (619),232-4466. Sincerely, P&D TECHNOLOGIES fkay •• --'•-•-• Biologist ' Figure 1 on Least Bell's 'eo Survey Site . . - ATTACHMENT! MACARIO CANYON BIRD SPECIES OBSERVED (1991) Common Name Scientific Name Family Ardeidae Great Blue Heron Ardea herodias Family Cathartidae Turkey Vulture Cathartes aura Family Accipitridae - Black-shouldered Kite Elanus caeruleus Northern Hamer Circus cyaneus Cooper's Hawk Accipiter cooperu Red-tailed Hawk Buteo jamaicensis Family Falconidae American Kestrel Falco sparverius Peregrine Falcon Falco peregrinus Family Phasianidae California Quail Callzpepla cal:fornzca Family Ralhdae Virginia Rail Rallus limicola Family Charadnidae Killdeer Charadrius vociferus Family Columbidae - Rock Dove Columba livia Mourning Dove Zenaida rnacroura Family Cucuhdae Greater Roadrunner Geococcyx californianus Family Trochilidae - Black-chinned Hummingbird Archilochus alexandri Anna's Hummingbird Calypte anna Selasphorus hummingbird Selasphorus sp. Family Alcedinidae Belted Kingfisher Ceryle alcyón Family Picidae Nuttalls Woodpecker Picoides nuttallzi Downy Woodpecker Picoides pubescens Northern Flicker Colaptes auratus Family Tyrannidae Western Wood-Pewee Contopus sordidulus Hammond's Flycatcher Empidonax hammondii Dusky Flycatcher Empidonax oberholseri Gray, Flyuchcr Errpidonc ghtt Western Flycatcher Empidonax difficilis Black Phoebe Sayornis nigricans Say's Phoebe Sayornis saya Ash-throated Flycatcher Myiarchus cinerascens Cassin's Kingbird Tyrannus vocferans Family Hirundinidae Northern Rough- Stelgidopteryx serripennis Winged Swallow Family Corvidae Scrub Jay Aphelocoma coerulescens American Crow . Corvus brachyrhynchos Common Raven Corvus corax Family Paridae Plain Titmouse Parus inornatus Family. Acgithaiidat Bushtit Psaltriparus minimus Family Troglodytidae House Wren Troglodytes aedon Family Muscicapidae Ruby-crowned Kinglet Regulus calendula California Gnatcatcher Polioptila californica Swainson's Thrush Catharus ustulatus Hermit Thrush Catharus guttatus Americah. Robin Turdus niigratorius Wrentit . Chamaea fasciata Family Mimidae Northern Mockingbird Mimus polyglottos California Thrasher Toxostoma redivivum Family Ptilogbnatidae Phainopepla Phainopepla nitens Family Laniidae Loggerhead Shrike Lanius ludovicianus Family Sturnidae European Starling Sturnus vulgaris Family Vireonidae Solitary Vireo Vireo solitãrius Warbling Vireo Vireo gilvus I Family Emberizidae Subfamily Parulinae Orange-crowned Warbler Vermivora celata Nashville Warbler Vermivora ruficapilla Yellow Warbler Dendroica petechia Black-throated Gray Dendroica nigrescens Warbler American Redstart Setophaga ruticilla Common Yellowthroat Geothlypis trichas Wilson's Warbler Wilsonia pusilla Yellow-breasted Chat Ictéria virens Subfamily Cardinalinae Black-headed Grosbeak Pheucticus melanocephalus Lazuli Bunting Passerina arnoena Subfamily Emberizinae Rufous-sided Towhee Pipilo erythrophthalmus Brown Towhee Pipilo fuscus Song Sparrow Melospiza melodia LincOln's Sparrow Melospiza lincolnii White-crowned Sparrow Zonotrichia leucophrys Subfamily Icterinae Red-winged Blackbird Agelaius phoeniceus Brewer's Blackbird Euphagus cyanocephalus Brown-headed Cowbird MolOthrus ater N orthern Oriole Icterus galbula .,.• S Family Fringillidae House Finch Carpodacus mexicanus Lesser Goldfinch Carduelis psaltria Family Passeridae House Sparrow Passer domesticus 1. Nomenclature follows American Ornithologist's Union, 1983-Checklist of North American birds. 6th edition. Am. Ornithol. Union, [Washington, D.C.]