DOCSLIB.ORG

Monitoring Least Bell's Vireo (Vireo Bellii Pusillus) and Comparing

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Monitoring Least Bell's Vireo (Vireo Bellii Pusillus) and Comparing Monitoring Least Bell’s Vireo (Vireo bellii pusillus) and comparing breeding landbird populations at the Dos Rios Ranch restoration site and San Joaquin River National Wildlife Refuge 2015-2016 Report prepared for River Partners, in support of habitat restoration work funded by the Central Valley Project Conservation Program. Final Report in fulfillment of grant agreement R12AP20047. November 2016 Kristen E. Dybala, Robert G. Walsh, and Nathaniel E. Seavy Monitoring Least Bell’s Vireo (Vireo bellii pusillus) and comparing breeding landbird populations at the Dos Rios Ranch restoration site and San Joaquin River National Wildlife Refuge 2015-2016 November 2016 Point Blue Conservation Science Kristen E. Dybala, Robert G. Walsh, and Nathaniel E. Seavy Acknowledgements This project was made possible by funding from the Central Valley Project Conservation Program. Suggested Citation Dybala KE, Walsh RG, Seavy NE. 2016. Monitoring Least Bell’s Vireo (Vireo bellii pusillus) and comparing breeding landbird populations at the Dos Rios Ranch restoration site and San Joaquin River National Wildlife Refuge 2015-2016. Point Blue Conservation Science, Petaluma, CA. This is Point Blue Contribution No. 2101. Point Blue Conservation Science – Point Blue’s 140 staff and seasonal scientists conserve birds, other wildlife and their ecosystems through scientific research and outreach. At the core of our work is ecosystem science, studying birds and other indicators of nature’s health. Visit Point Blue on the web www.pointblue.org. Cover photo credit: Robert G. Walsh Table of Contents EXECUTIVE SUMMARY .................................................................................................................... 1 INTRODUCTION ............................................................................................................................... 2 MONITORING OBJECTIVES .............................................................................................................. 3 METHODS AND RESULTS ................................................................................................................. 4 Study areas and sampling design ................................................................................................ 5 Bird surveys and vegetation monitoring at point count stations ............................................... 5 Riparian landbird response to restoration ................................................................................. 6 Least Bell’s Vireo monitoring .................................................................................................... 11 RECOMMENDATIONS ................................................................................................................... 15 PROJECT DATA .............................................................................................................................. 17 Data management .................................................................................................................... 17 Other products .......................................................................................................................... 17 REFERENCES .................................................................................................................................. 18 APPENDICES .................................................................................................................................. 22 Appendix A. Point count coordinates ....................................................................................... 22 Appendix B. Vegetation data and metadata ............................................................................ 22 Appendix C. Least Bell’s Vireo media and coordinates ............................................................ 22 Appendix D. PowerPoint slides of key results .......................................................................... 22 Appendix E. Annotated bird list, 2016 ...................................................................................... 23 P a g e | 1 EXECUTIVE SUMMARY This report describes the results of our 2015-2016 efforts to (1) document any evidence of colonization by Least Bell’s Vireo on Phase 1 of the Dos Rios Ranch restoration or recolonization on the adjacent San Joaquin River National Wildlife Refuge (SJRNWR), Stanislaus County, California, and (2) assess the response of the overall breeding landbird community to the Dos Rios Ranch restoration phase 1 and how it compares to the breeding bird community using the older restored riparian habitat in the SJRNWR. During spring of 2015 and 2016, we surveyed birds at 39 point count stations distributed across restoration sites at Dos Rios Ranch and SJRNWR, including 2 visits per year to each station for a total of 156 point count surveys. Vegetation was surveyed at each point count station in each year, and an additional 107 hours were spent on targeted searches for, and monitoring of, Least Bell’s Vireos. A single territorial male Least Bell’s Vireo was observed at the SJRNWR for two weeks in June of 2016. To our knowledge, this was the only record of the species from the entire Central Valley for the 2016 breeding season. A search for all Bell’s Vireo records from all of Central and Northern California produced an estimated average of just 1.3 individual vireos detected per year over the past several decades. Thus, in addition to requiring suitable riparian habitat, successful colonization of Dos Rios Ranch and SJRNWR by Least Bell’s Vireo will depend on whether more birds disperse out of southern California. We compared the species richness and breeding densities of landbirds at the Dos Rios Ranch restoration Phase 1 (1-2 years old) to restoration sites at SJRNWR, grouped into sites that were 3-6 years old and 9-12 years old. Species richness and the breeding densities of six Central Valley Join Venture (CVJV) riparian focal species at Dos Rios Ranch were already similar to that of the 3-6 year old SJRNWR sites. Further, Dos Rios Ranch has already achieved the CVJV breeding density objective for Song Sparrows. Using the data from SJRNWR and Dos Rios together, we found that bird species richness was correlated with tree, shrub, and ground cover, as well as canopy height, suggesting that species richness will continue to increase as restoration plantings mature. Finally, we make several recommendations: (1) Continue to evaluate restoration success using a broad suite of riparian species, which can provide broad insights into changes in the overall condition of riparian habitat. (2) Maximize the chances of vireo colonization by ensuring that restored sites are maturing into the vegetation structure most suitable for Least Bell’s Vireo. (3) Develop a plan for monitoring any future vireo nest attempts, including obtaining and maintaining permits. (4) Consider providing habitat for Tricolored Blackbirds at Dos Rios Ranch. (5) Consider monitoring black rats, Brown-headed cowbirds, or other species that could have negative impacts on riparian restoration success. (6) Evaluate whether current restoration designs are climate-smart and capable of adapting to projected climate conditions. (7) Continued to restore riparian vegetation and improve floodplain connectivity to provide important habitat for riparian-dependent species, as well as to provide the many other benefits of improved riparian ecosystem function, such as reducing flood risk, sequestering carbon, and contributing to local economies. P a g e | 2 INTRODUCTION Riparian ecosystems are hotspots of avian diversity in the western United States (Knopf et al. 1988; Knopf and Samson 1994). The Central Valley of California in particular provides essential breeding and wintering habitat, migration stopover areas, and corridors of dispersal for riparian- associated birds (Humple and Geupel 2002; Latta et al. 2012; Cormier et al. 2013; Dybala et al. 2015). Sixty-two species of landbirds have regularly bred in Central Valley riparian forests over the last two decades (Point Blue Conservation Science unpublished data) and many others use riparian areas during portions of their life cycle. Loss of riparian habitat may be the most important cause of population declines among landbird species in western North America (DeSante and George 1994), including the decline and extirpation of many riparian species once common in the Central Valley (RHJV 2004; CVJV 2006; Dybala et al. In press). While the populations of many riparian songbirds have declined in the Central Valley, the extirpation of the Least Bell’s Vireo (Vireo bellii pusillus) is one of the most dramatic examples (Howell et al. 2010). The Least Bell’s Vireo was once common in riparian habitat of coastal Southern California and the Central Valley (Goldman 1908; Grinnell and Miller 1944). However, by the late 1970s, the species had declined dramatically; extensive surveys in the Central Valley failed to detect a single individual (Goldwasser et al. 1980). As a result, the Least Bell’s Vireo was listed as state endangered in 1980 and federally endangered in 1986. In 1986, only 300 pairs remained with the majority in San Diego, Riverside, and Santa Barbara counties and eight or fewer pairs or territorial males within each of San Bernardino, Riverside, Orange, Los Angeles, Ventura, Inyo, and Monterey counties (USFWS 1998). More recently, the outlook for the Least Bell’s Vireo has been improved by extensive efforts to restore habitat and boost reproductive success. As a result of these
Load more

Recommended publications
  • Wildlife of the North Hills: Birds, Animals, Butterflies
    Wildlife of the North Hills: Birds, Animals, Butterflies Oakland, California 2005 About this Booklet The idea for this booklet grew out of a suggestion from Anne Seasons, President of the North Hills Phoenix Association, that I compile pictures of local birds in a form that could be made available to residents of the north hills. I expanded on that idea to include other local wildlife. For purposes of this booklet, the “North Hills” is defined as that area on the Berkeley/Oakland border bounded by Claremont Avenue on the north, Tunnel Road on the south, Grizzly Peak Blvd. on the east, and Domingo Avenue on the west. The species shown here are observed, heard or tracked with some regularity in this area. The lists are not a complete record of species found: more than 50 additional bird species have been observed here, smaller rodents were included without visual verification, and the compiler lacks the training to identify reptiles, bats or additional butterflies. We would like to include additional species: advice from local experts is welcome and will speed the process. A few of the species listed fall into the category of pests; but most - whether resident or visitor - are desirable additions to the neighborhood. We hope you will enjoy using this booklet to identify the wildlife you see around you. Kay Loughman November 2005 2 Contents Birds Turkey Vulture Bewick’s Wren Red-tailed Hawk Wrentit American Kestrel Ruby-crowned Kinglet California Quail American Robin Mourning Dove Hermit thrush Rock Pigeon Northern Mockingbird Band-tailed
    [Show full text]
  • California Towhee Responses to Chick Distress Calls
    The Condor 109:79–87 # The Cooper Ornithological Society 2007 OFFSPRING DISCRIMINATION WITHOUT RECOGNITION: CALIFORNIA TOWHEE RESPONSES TO CHICK DISTRESS CALLS LAURYN BENEDICT1 Museum of Vertebrate Zoology, 3101 Valley Life Sciences Building, University of California, Berkeley, CA 94720 Abstract. Accurate offspring discrimination improves parental fitness by ensuring appropriate parental investment. In colonial avian species, offspring discrimination is often mediated by recognition of individual offspring vocalizations, but spatially segregated species do not necessarily need sophisticated recognition abilities if parents can use alternative information to distinguish offspring from nonoffspring. I experimen- tally tested the hypothesis that territorial California Towhee (Pipilo crissalis) parents use a location-based decision rule, instead of true vocal recognition of offspring, when deciding whether to respond to chick distress calls. Accurate responses to offspring distress calls should be favored by natural selection because they can have large fitness benefits if parents succeed in chasing away potential nest predators. Responses to nonoffspring, in contrast, may be costly and should not be favored by natural selection. Towhee parents were presented with a series of three playback experiments in which I manipulated the identity of the vocalizing chick, the age of resident chicks, and the location of the distress call broadcast. Parents showed no evidence of individual vocal recognition and no pattern of differential response to distress calls when offspring age differed from that of the calling chick. Parents did, however, exhibit a significant tendency to approach distress calls originating near their offspring more often than distress calls originating elsewhere on their territory. These results provide support for the evolution of an offspring discrimination strategy based on a simple location-based decision rule instead of true vocal recognition.
    [Show full text]
  • Bird Checklist
    Gray-cheeked Thrush Catharus minimus Blackburnian Warbler Dendroica fusca Field Sparrow Spizella pusilla Swainson’s Thrush Catharus ustulatus American Redstart Setophaga ruticilla Swamp Sparrow Melospiza georgiana National Park Service Hermit Thrush Catharus guttatus Pine Warbler Dendroica pinus American Tree Sparrow Spizella arborea U.S. Department of the Interior Veery Catharus fuscescens Prairie Warbler Dendroica discolor Grasshopper Ammodramus savannarum Wood Thrush Hylocichla mustelina Palm Warbler Dendroica palmarum Sparrow New River Gorge National River Blue-winged Warbler Vermivora pinus Fox Sparrow Passeralla iliaca Mockingbird and Thrasher Family Yellow Warbler Dendroica petechia Song Sparrow Melospiza melodia (Mimidae) Swainson’s Warbler Limnothlypis swainsonii Vesper Sparrow Pooecetes gramineus Brown Thrasher Toxostoma rufum Worm-eating Helmitheros vermivorus Savannah Sparrow Passerculus sandwichensis Bird Checklist Gray Catbird Dumetella carolinensis Warbler Dark-eyed (“Slate-colored”) Junco hyemalis Northern Mockingbird Mimus polyglottos Tennessee Warbler Vermivora peregrina Junco Wilson’s Warbler Wilsonia pusilla Crow and Jay Family (Corvidae) Hooded Warbler Wilsonia citrina Blackbird and Oriole Family (Icteridae) Blue Jay Cyanocitta cristata Golden-winged Vermivora chrysoptera Rusty Blackbird Euphagus carolinus American Crow Corvus brachyrhynchos Warbler Common Grackle Quiscalus quiscula Common Raven Corvus corax Nashville Warbler Vermivora ruficapilla Red-winged Blackbird Agelaius phoeniceus Kentucky Warbler Oporornis
    [Show full text]
  • A COMPARATIVE ANALYSIS of SONG and RESPONSES to SONG PLAYBACK University of Colorado at Denver
    FINAL REPORT A COMPARATIVE ANALYSIS OF SONG AND RESPONSES TO SONG PLAYBACK IN THE AVIAN GENUS PIPILO Peter S. Kaplan Department of Psychology University of Colorado at Denver Abstract An experiment was undertaken to characterize the responses of Green-tailed Towhees (Pipilo chlorura) and Rufous-sided Towhees (P. erythophthalmus) to each others' songs and to the songs of five other towhee species, plus one hybrid form. A total of 12 Green-Tailed Towhees and 10 Rufous-sided Towhees from Boulder and Gilpin counties were studied at three field sites: the Doudy Draw Trail, the National Center for Atmospheric Research (NCAR), and on private land at the mouth of Coal Creek Canyon. In May, each bird was mist-netted and banded to facilitate individual identification. During the subsequent playback phase in June and July, each individual received one three-part playback trial on each of 7 consecutive or near-consecutive days. A 9-min playback trial consisted of a 3-min "pre-play" period, during which the bird was observed in the absence of song playback, a 3-min "play" period, in which tape recorded song was played to the subject from a central point in his territory, and a 3-min "post-play" period when the bird • was again observed in the absence of song playback. Order of presentation of song exemplars from different towhee species were randomized across birds. The main dependent measure was the change in the number of songs produced by the subject bird during song playback, relative to the pre-play period. Results showed that Green-tailed Towhees responded by significantly increasing their rate of singing, but only in response to Green-tailed Towhee songs.
    [Show full text]
  • Buckingham Trails Preserve Wildlife Species List
    Wildlife Species List for Buckingham Trails Preserve Designated Status Scientific Name Common Name FWC FWS FNAI MAMMALS Family: Dasypodidae (armadillos) Dasypus novemcinctus nine-banded armadillo * Family: Leporidae (rabbits and hares) Sylvilagus floridanus eastern cottontail Family: Felidae (cats) Felis silvestris domestic cat * Family: Procyonidae (raccoons) Procyon lotor raccoon Family: Suidae (old world swine) Sus scrofa feral hog * Family: Mephitidae (skunks) Spilogale putorius eastern spotted skunk BIRDS Family: Anatidae (swans, geese and ducks) Subfamily: Anatinae Aix sponsa wood duck Anas fulvigula mottled duck Family: Odontophoridae (new world quails) Colinus virginianus northern bobwhite Family: Ciconiidae (storks) Mycteria americana wood stork E E G4/S2 Family: Anhingidae (anhingas) Anhinga anhinga anhinga Family: Ardeidae (herons, egrets, bitterns) Ardea herodius great blue heron Ardea alba great egret G5/S4 Egretta thula snowy egret SSC G5/S3 Egretta caerulea little blue heron SSC G5/S4 Egretta tricolor tricolored heron Bubulcus ibis cattle egret Butorides virescens green heron Family: Threskiornithidae (ibises and spoonbills) Subfamily: Threshiornithinae Eudocimus albus white ibis Family: Cathartidae (new world vultures) Coragyps atratus black vulture Cathartes aura turkey vulture Family: Accipitridae (hawks, kites, accipiters, harriers, eagles) Elanoides forficatus swallow-tailed kite G5/S2 Rostrhamus sociabilis plumbeus Everglades snail kite E E G4G5T3Q/S2 Accipiter cooperii Cooper's hawk G5/S3 Hailaeetus leucocephalus
    [Show full text]
  • Life History Account for California Towhee
    California Wildlife Habitat Relationships System California Department of Fish and Wildlife California Interagency Wildlife Task Group CALIFORNIA TOWHEE Melozone crissalis Family: EMBERIZIDAE Order: PASSERIFORMES Class: AVES B484 Written by: D. Dobkin, S. Granholm Reviewed by: L. Mewaldt Edited by: R. Duke Updated by: CWHR Program Staff, November 2014 DISTRIBUTION, ABUNDANCE, AND SEASONALITY The former brown towhee recently has been split into the California towhee and the canyon towhee, M. fusca (American Ornithologists' Union 1989). The California towhee is a common, characteristic resident of foothills and lowlands in most of cismontane California. Frequents open chaparral and coastal scrub, as well as brush-land patches in open riparian, hardwood hardwood-conifer, cropland, and urban habitats. Commonly uses edges of dense chaparral and brushy edges of densely wooded habitats. Also occurs in lowest montane habitats of similar structure in southern California, and locally in Siskiyou and western Modoc cos. Local on coastal slope north of southern Humboldt Co., and apparently absent from western San Joaquin Valley (Grinnell and Miller 1944, McCaskie et al. 1979, Garrett and Dunn 1981). The Inyo California towhee, M. c. eremophilus, occurs only in the Argus Mountains of southwestern Inyo Co. SPECIFlC HABITAT REQUIREMENTS Feeding: Feeds on seeds, insects, and some fruits. Gleans and scratches in litter, picks seeds and fruits from plants, and rarely flycatches (Davis 1957). Prefers to forage on open ground adjacent to brushy cover. Insects are important in breeding season, often constituting a third of the diet (Martin et al. 1961). Cover: Shrubs in broken chaparral, margins of dense chaparral, willow thickets, and brushy understory of open wooded habitats provide cover.
    [Show full text]
  • Warbling Vireo (Vireo Gilvus)
    Warbling Vireo (Vireo gilvus) NMPIF level: Species Conservation Concern, Level 2 (SC2) NMPIF assessment score: 14 NM stewardship responsibility: Low National PIF status: No special status New Mexico BCRs: 16, 34, 35 Primary breeding habitat(s): Mixed Conifer Forest, Montane Riparian Other habitats used: Spruce-Fir Forest, Ponderosa Pine Forest, Middle Elevation Riparian Summary of Concern Warbling Vireo is a generally stable and widespread species, but local population trends are uncertain. In New Mexico, it is associated with highland riparian and aspen communities which may be sensitive to disturbance or changes in forest structure. It may also be sensitive to nest parasitism by cowbirds and loss of winter habitat. Associated Species Dusky Grouse (BC2), Northern Goshawk (BC2), Red-naped Sapsucker (SC2), Purple Martin, Violet-green Swallow (SC2), American Robin, Orange-crowned Warbler, Black-headed Grosbeak Distribution Warbling Vireo is very broadly distributed across almost the entire United States and western Canada, excluding the southeast and Gulf Coast regions. Breeding populations also extend south in the Sierra Madre Occidental to central Mexico. The species winters along the Pacific slope of Mexico (Gardali and Ballard 2000). In New Mexico, Warbling Vireos breed in upper elevation forests and woodlands statewide, and also occur in lowland riparian areas. Ecology and Habitat Requirements Across its large range, this species occupies many different woodland and forest vegetation types. It is generally associated with riparian areas and mature, mixed deciduous woodlands. In many locations, it is strongly associated with cottonwood-dominated riparian forests, which provide favored habitat structure of large trees with a semi-open canopy. In New Mexico, it also shows a preference for aspen and spruce-aspen communities.
    [Show full text]
  • Red-Eyed Vireo Vireo Olivaceus
    Red-eyed Vireo Vireo olivaceus Folk Name: Preacher, Hanger, Red-eyed Swinging Bird Status: Breeder Abundance: Common to Very Common Habitat: Hardwood forests and mixed pine hardwood forests The Red-eyed Vireo is our most common and best known member of the vireo family. It is also the largest of our vireos, averaging 6 inches in length. Adults have a blue-gray head with a distinctive bright red eye and a white eyebrow outlined in black. Its body is olive green above and white below and it has no wing bars. Like our other vireos, this bird is more often heard than seen. It repeats its song over and over all day long, often while perched high up in a tree. This is why many local folk have called it “Preacher” or the “Preacher Bird.” One early interpretation of this bird’s call was: “You see it, you know it, do you hear me? Do you believe it?” last bird leaving during fall migration on 18 September of In June 1919, Charlotte businessman and birder C. M. that year. McIlwaine had two arrive in Charlotte on April Carson published this poem with a different interpretation 14, 1930, and his last was seen on 24 September. Charlie of the song of the Red-eyed Vireo: Sellers reported a departure date of 13 October in 1939 and an early return date of 11 April in 1941. What little bird is it that’s up so soon, from early Grace Anderson of Statesville published this morn to sleepy moon? He is calling his dearie all anthropomorphic but eloquent account of the nesting day long, as he hops from limb with his pretty song.
    [Show full text]
  • Common Birds of the Estero Bay Area
    Common Birds of the Estero Bay Area Jeremy Beaulieu Lisa Andreano Michael Walgren Introduction The following is a guide to the common birds of the Estero Bay Area. Brief descriptions are provided as well as active months and status listings. Photos are primarily courtesy of Greg Smith. Species are arranged by family according to the Sibley Guide to Birds (2000). Gaviidae Red-throated Loon Gavia stellata Occurrence: Common Active Months: November-April Federal Status: None State/Audubon Status: None Description: A small loon seldom seen far from salt water. In the non-breeding season they have a grey face and red throat. They have a long slender dark bill and white speckling on their dark back. Information: These birds are winter residents to the Central Coast. Wintering Red- throated Loons can gather in large numbers in Morro Bay if food is abundant. They are common on salt water of all depths but frequently forage in shallow bays and estuaries rather than far out at sea. Because their legs are located so far back, loons have difficulty walking on land and are rarely found far from water. Most loons must paddle furiously across the surface of the water before becoming airborne, but these small loons can practically spring directly into the air from land, a useful ability on its artic tundra breeding grounds. Pacific Loon Gavia pacifica Occurrence: Common Active Months: November-April Federal Status: None State/Audubon Status: None Description: The Pacific Loon has a shorter neck than the Red-throated Loon. The bill is very straight and the head is very smoothly rounded.
    [Show full text]
  • Stephens Forest
    Field Checklist for Stephens Forest ___Warbling Vireo* ___Kentucky Warbler* * = confirmed or likely area breeder ___Red-eyed Vireo* ___Common Yellowthroat* Iowa Wildlife Action Plan Migratory Species of Greatest ___Hooded Warbler* Stephens Forest Conservation Need ___Blue Jay* ___American Redstart* Iowa Wildlife Action Plan Nesting Species of Greatest ___American Crow* ___Cerulean Warbler* Conservation Need ___Northern Parula* ___Horned Lark* ___Magnolia Warbler ___Greater White-fronted Goose ___Ring-billed Gull ___Bay-breasted Warbler Bird Conservation ___Snow Goose ___Purple Martin* ___Blackburnian Warbler ___Cackling Goose ___Rock Pigeon* ___Tree Swallow* ___Yellow Warbler* ___Canada Goose* ___Eurasian Collared-Dove* ___N. Rough-winged Swallow* ___Chestnut-sided Warbler* Area ___Wood Duck* ___Mourning Dove* ___Bank Swallow* ___Blackpoll Warbler ___Gadwall ___Cliff Swallow* ___Yellow-rumped Warbler ___American Wigeon ___Yellow-billed Cuckoo* ___Barn Swallow* ___Yellow-throated Warbler ___Mallard ___Black-billed Cuckoo* ___Black-throated Green Warbler ___Blue-winged Teal ___Black-capped Chickadee* ___Canada Warbler ___Northern Shoveler ___Barn Owl ___Tufted Titmouse* ___Wilson’s Warbler ___Hooded Merganser ___Yellow-breasted Chat* Belted Kingfisher ___Common Merganser ___Eastern Screech-Owl* ___Red-breasted Nuthatch USFWS ___Great Horned Owl* ___White-breasted Nuthatch* ___Eastern Towhee* ___Northern Bobwhite* ___Barred Owl* ___American Tree Sparrow ___Ring-necked Pheasant* ___Long-eared Owl ___Brown Creeper ___Chipping Sparrow* ___Ruffed
    [Show full text]
  • California Rare & Endagered Birds
    California brown pelican Pelecanus occidentalis californicus State Endangered 1971 Fully Protected Federal Endangered 1970 General Habitat: The California brown pelican uses a variety of natural and human-created sites, including offshore islands and rocks, sand spits, sand bars, jetties, and piers, for daytime loafing and nocturnal roosting. Preferred nesting sites provide protection from mammalian predators and sufficient elevation to prevent flooding of nests. The pelican builds a nest of sticks on the ground, typically on islands or offshore rocks. Their nesting range extends from West Anacapa Island and Santa Barbara Island in Channel Islands National Park to Islas Los Coronados, immediately south of and offshore from San Diego, and Isla San Martín in Baja California Norte, Mexico. Description: The brown pelican is one of two species of pelican in North America; the other is the white pelican. The California brown pelican is a large, grayish-brown bird with a long, pouched bill. The adult has a white head and dark body, but immature birds are dark with a white belly. The brown pelican weighs up to eight pounds and may have a wingspan of seven feet. Brown pelicans dive from flight to capture surface-schooling marine fishes. Status: The California brown pelican currently nests on West Anacapa Island and Santa Barbara Island in Channel Islands National Park. West Anacapa Island is the largest breeding population of California. In Mexico, the pelicans nest on Islas Los Coronados and Isla San Martín. Historically, the brown pelican colony on Islas Los Coronados was as large as, or larger than, that of recent years on Anacapa Island.
    [Show full text]
  • Voice in Communication and Relationships Among Brown Towhees
    THE CONDOR VOLUME 66 SEPTEMBER-OCTOBER, 1964 NUMBER 5 VOICE IN COMMUNICATION AND RELATIONSHIPS AMONG BROWN TOWHEES By JOET.MARSHALL,JR. This paper seeks to answer two questions: (1) What is the function of each song and call in brown towhees; that is, what information does a bird communicate to its fellows vocally, o’r how does it regulate their behavior by its voice? (2) What evi- dence does voice offer for understanding relationship by descent within the closely-knit group of brown towhee species? For the first, I would extend the analysis of Quain- tance (1938,194l) to all members of the group. As to the second question, an ingenious evolutionary reconstruction, based on museum and habitat studies, has been developed by Davis (1951). Do vocal attributes agree with his scheme? The three speciesof brown towhees, genus Pipdo, are the same size and general color and are more similar to each other than any one of them is to other ground-inhabiting finches in the same genus and in the genus Melozorte. Indeed, so close is their relation- ship that the same calls can easily be discerned in each species; although differing in timbre, similarity in form and usage proclaims them to be homologous. The Abert Towhee (Pipdo abed) occupies dense riparian woodland and mesquite thickets of the Colorado River and Gila River drainages, mostly in Arizona. The Brown Towhee proper (Pip20 fuscus) lives in brushy margins of openings in the southwestern United States and Mexico. The White-throated Towhee (Pipilo aZbicoZZis)inhabits brushy slopes, often with tree yuccas, in Puebla and Oaxaca, MCxico.
    [Show full text]