Common Birds of Foothill Horizons Compiled by Pam “Tenaya” Hardy, Updated and Amended by Dan Webster

Total Page:16

File Type:pdf, Size:1020Kb

Common Birds of Foothill Horizons Compiled by Pam “Tenaya” Hardy, Updated and Amended by Dan Webster Common Birds of Foothill Horizons Compiled by Pam “Tenaya” Hardy, updated and amended by Dan Webster Acorn Woodpecker This is the most common woodpecker seen at Foothill Horizons. It has a black back with white wing bars. In flight, it is most easily identified by white patches on the underside of its black wings. On the top of its head is the classic bright red woodpecker patch. This is the marking that will most easily distinguish it from any of the other woodpeckers likely to be seen at Foothill. The other two likely to be seen are the downey or hairy woodpeckers. Both of these species have the red stripe around the back of their head rather than on top of it. Males, females, and juveniles are very similar. The female has a bit less red on her head. Acorn woodpeckers have some of the most interesting habits of any of the birds around Foothill. They collect acorns in the fall and then dig holes into the soft bark of the ponderosa pines to store them in for the winter. If you look carefully around the property, you will find trees riddled with these acorn-size holes. These trees are called granary trees, and are used by the same birds year after year. It is obviously important for this bird to live in an area with both oaks and some sort of soft barked tree. On the coast, they prefer the redwood trees. They live on the west coast of the U.S. from the middle of Oregon down to Baja California, and in the Southwest down into Mexico. Anna's Hummingbird The most obvious field mark on the male Anna's hummingbird is its bright pink iridescent head. Sometimes you won't see the bright pink on its head. You have to be at just the right angle with the sun to see it. Usually the best angle is looking at it straight on. If you don't see the color, the head feathers may look black. If you look carefully, you may be able to see a white eye stripe. The female throat may show just some red flecks of color. The rest of the bird is the same, the under parts are grayish, and the upper parts are a dusky metallic green. Juveniles look very similar to the female, but the male may show a few red specks on the head as well as the throat. Anna's hummingbirds are very territorial. There is usually only one in a well-defined area. If you see a hummer at a feeder three or four times in an hour it is probably the same hummer. These birds will fight endlessly until one goes away to another territory. They do this because flowers can only produce so much nectar at a time and food is fairly scarce. So, when a hummer finds a good territory he wants to keep it. When a female shows up, the male in the territory will try to fight her off too. You can usually tell a bird is a female in this situation because she will just sit and listen to the male squawk and scream, whereas another male would fight back. Eventually, the male will stop trying to fight her off, she will nest in the male's territory and mate with him. The male will then protect the territory for the both of them while she raises the young. Anna's hummingbirds only live on the west coast of North America, but within that range they live in all sorts of habitats from mountains to deserts. On the west coast, the Anna's is the most common hummingbird. Due to its size and territorial nature, it can be difficult to see it in the wild. Recognizing its song helps. Anna's don't migrate far. There are only a few places at the extremes of their range that they are only seasonal. If they do migrate it is more likely to be simply uphill or downhill depending on local conditions. Hummingbirds eat both flower nectar and insects. Occasionally, you may see them doing what looks like flying around in dizzy circles in the air. They are catching flying bugs. Black-Headed Grosbeak This large finch is named for its very large, triangular bill and its black head. The male has cinnamon-orange colored under parts with black upper parts and white wing bars. The female is the same size and shape but with more yellow under parts, brown upper parts and the same wing bars. The female also has a strong distinguishing eye stripe, which makes for remarkable camouflage when on the nest. During its first season the male looks very similar to the female. This colorful bird is most commonly seen in the dense foliage of trees and is frequently seen in the bird blind in spring. The black-headed grosbeak is only in the western U.S. in the summer months. It winters in southern Mexico and Central America. The large size of its beak shows that the black-headed grosbeak is mainly a seedeater. Black Phoebe This little flycatcher is almost entirely black with a white belly and white tail covers. The male and the female are virtually identical, but the juvenile is browner with cinnamon-colored wing bars. This bird is most commonly seen around water flying out from the bank or a branch, catching an insect, and coming back. The black phoebe is mainly a Mexican bird whose range extends north into Arizona, New Mexico, and along the temperate coast of California. Being a flycatcher, this bird feeds mostly on insects. Brown-Headed Cowbird At first glance, the male of this species looks like a black bird. With a closer look, you can distinguish a duller dark brown head from a black body which shows an almost metallic green color in the right light. The female is the same size and shape, and is gray-brown above and paler below. The juvenile male resembles the female, but it is a bit more streaked. Cowbirds have a very interesting behavioral adaptation; they lay their eggs in the nests of other birds. The other birds then raise the cowbird chicks as their own young. The cowbird eggs are only slightly larger, and hatch more quickly than most birds' eggs, so when the young cowbirds hatch, they often out-compete the other babies in the nest for the mother's attention and food. Over 270 species of birds have been documented as victims of cowbird parasitism. Brown-headed cowbirds are found year-round in the eastern U.S. and in parts of California. Over the rest of the U.S. they are only found during the summer months. Bushtit The bushtit is one of the smallest birds on campus. It is gray above, and paler below, with a long tail. It is distinguished from the plain titmouse by its smaller size, differing behavior, and lack of a crest. Bushtit behavior is probably one of their most important identifying characteristics. They are most commonly seen in groups of 5 - 15 birds moving from bush to bush making a chattering sound together. Bushtits live in Mexico and the western parts of the U.S. at lower elevations where they can find woodlands and chaparral. California Towhee (Formerly "Brown Towhee") The California towhee is the closest bird we have to the classic "little brown bird." Its upper parts are brown, and it is a bit paler below. It is brown all over with a short triangular shaped bill made for eating seeds off the ground. It is just a bit bigger than the spotted towhee. This bird varies a bit in different parts of its range, but for the most part it is the same for male, female, and juvenile. Behavior is probably the best identifier of this bird. It is found in the same places behaving virtually the same as the spotted towhee. That is, it digs around in the leaves for seeds and bugs. Often it can be found by listening for its repetitive high-pitched "chink" call that it makes even when on the ground digging around for seeds. Again, it is very similar to the spotted towhee. It likes streamside thickets in woodlands and forests where it can find plenty of seeds and insects. The California towhee is less widely distributed than the spotted towhee. Foothill Horizons' climate is just about the coldest, most northern area that it is found in. It does not migrate and lives year-round on the west coast and in the warmer areas of the Southwest and Mexico. Dark-Eyed Junco Dark-eyed juncos are also informally called executioner birds. This is because they have what looks like a black hood. This is their most obvious field mark. They have a short, thick, triangular-shaped bill made for eating seeds. They have brown backs and wings with no wing bars. Their belly is white. Their tail is black and when they flick open their tail you can get a glimpse of the white tail feathers on the outside edges. Males and females are very similar. The only difference is that females are just a bit more faded looking, as if someone may have washed them on the hot cycle one too many times. Juncos usually travel in fairly large flocks of ten to twenty birds. They are primarily a seed eating bird so they are often seen on the ground scratching around in the dirt. Juncos are very comfortable in this habitat and are found all over campus and down to Phoenix Lake.
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]
  • Bird Species Checklist
    6 7 8 1 COMMON NAME Sp Su Fa Wi COMMON NAME Sp Su Fa Wi Bank Swallow R White-throated Sparrow R R R Bird Species Barn Swallow C C U O Vesper Sparrow O O Cliff Swallow R R R Savannah Sparrow C C U Song Sparrow C C C C Checklist Chickadees, Nuthataches, Wrens Lincoln’s Sparrow R U R Black-capped Chickadee C C C C Swamp Sparrow O O O Chestnut-backed Chickadee O O O Spotted Towhee C C C C Bushtit C C C C Black-headed Grosbeak C C R Red-breasted Nuthatch C C C C Lazuli Bunting C C R White-breasted Nuthatch U U U U Blackbirds, Meadowlarks, Orioles Brown Creeper U U U U Yellow-headed Blackbird R R O House Wren U U R Western Meadowlark R O R Pacific Wren R R R Bullock’s Oriole U U Marsh Wren R R R U Red-winged Blackbird C C U U Bewick’s Wren C C C C Brown-headed Cowbird C C O Kinglets, Thrushes, Brewer’s Blackbird R R R R Starlings, Waxwings Finches, Old World Sparrows Golden-crowned Kinglet R R R Evening Grosbeak R R R Ruby-crowned Kinglet U R U Common Yellowthroat House Finch C C C C Photo by Dan Pancamo, Wikimedia Commons Western Bluebird O O O Purple Finch U U O R Swainson’s Thrush U C U Red Crossbill O O O O Hermit Thrush R R To Coast Jackson Bottom is 6 Miles South of Exit 57.
    [Show full text]
  • L O U I S I a N A
    L O U I S I A N A SPARROWS L O U I S I A N A SPARROWS Written by Bill Fontenot and Richard DeMay Photography by Greg Lavaty and Richard DeMay Designed and Illustrated by Diane K. Baker What is a Sparrow? Generally, sparrows are characterized as New World sparrows belong to the bird small, gray or brown-streaked, conical-billed family Emberizidae. Here in North America, birds that live on or near the ground. The sparrows are divided into 13 genera, which also cryptic blend of gray, white, black, and brown includes the towhees (genus Pipilo), longspurs hues which comprise a typical sparrow’s color (genus Calcarius), juncos (genus Junco), and pattern is the result of tens of thousands of Lark Bunting (genus Calamospiza) – all of sparrow generations living in grassland and which are technically sparrows. Emberizidae is brushland habitats. The triangular or cone- a large family, containing well over 300 species shaped bills inherent to most all sparrow species are perfectly adapted for a life of granivory – of crushing and husking seeds. “Of Louisiana’s 33 recorded sparrows, Sparrows possess well-developed claws on their toes, the evolutionary result of so much time spent on the ground, scratching for seeds only seven species breed here...” through leaf litter and other duff. Additionally, worldwide, 50 of which occur in the United most species incorporate a substantial amount States on a regular basis, and 33 of which have of insect, spider, snail, and other invertebrate been recorded for Louisiana. food items into their diets, especially during Of Louisiana’s 33 recorded sparrows, Opposite page: Bachman Sparrow the spring and summer months.
    [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]
  • Song Variations and Singing Behavior in the Rufous-Sided Towhee, Pipilo Erythrophthalmus Oregonus
    SONG VARIATIONS AND SINGING BEHAVIOR IN THE RUFOUS-SIDED TOWHEE, PlPlLO ERYTHROPHTHALMUS OREGONUS \ DONALD E. KROODSMA Department of Zoology Oregon State University Corvallis, Oregon 97331 The singing behavior and vocalizations of the total song length. To the human ear this in- Rufous-sided Towhee ( Pipilo erythrophthal- troductory phrase was often inaudible and the mus) have been described recently by several song appeared to consist of a trill alone. authors (e.g., Davis 1958; Borror 1959; Roberts Each sonagram in figure 2 represents a song 1969). All have recognized variation in the type, i.e., one of the distinctive songs repeated song repertoire of both individuals and popu- in a consistent manner in the repertoire of an lations, yet only the variation in songs sampled individual. The male towhees sang a given from the eastern subspecies (Borror 1959) has song type at the rate of 8-15 songs per min for received extensive sonagraphic analysis. Here up to 15 min; at times, however, especially I discuss 1) the song variations observed in during early morning, males alternated two the repertoires of four neighboring males of song types, singing first one and then the other the race 2.’ e. oregonus, 2) the similarities of in sequence for several minutes at a time. Re- variations among these birds, and 3) the use gardless of the pattern of singing behavior, in of variations in the singing behavior of the successive renditions of a song type the struc- individual. ture of the introductory phrase and the trill syllables were unaltered; only the number of METHODS syllables in the trill varied.
    [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]
  • A WHITE-EYED SPOTTED TOWHEE OBSERVED in NORTHWESTERN NEBRASKA RICK WRIGHT, 128 Evans Road, Bloomfield, New Jersey 07003; [email protected]
    NOTES A WHITE-EYED SPOTTED TOWHEE OBSERVED IN NORTHWESTERN NEBRASKA RICK WRIGHT, 128 Evans Road, Bloomfield, New Jersey 07003; [email protected] Towhees visually—and in rare cases vocally—resembling the Eastern Towhee (Pipilo erythrophthalmus) have been reported at least eight times this century in the Nebraska Panhandle (Silcock and Jorgensen 2018), far to the west of that taxon’s expected range. As a result of the resplitting of the Eastern Towhee and Spotted Towhee (P. maculatus) (AOU 1995), observers have begun to once again pay close attention to the appearance and vocalizations of the region’s towhees, a practice that had declined following the species’ earlier taxonomic lumping (AOU 1954). On 20 and 21 May 2018, I observed a Spotted Towhee (presumptively P. m. arcticus, which breeds in the area) with white irides in the campground at the Gilbert- Baker Wildlife Area (42° 46.02' N, 103° 55.67' W) in the extreme northwest of the Nebraska Panhandle, 10 km north of Harrison, Sioux County. I photographed the bird on the first date (Figure 1). The deep saturated black of the head indicated that this individual was a male; the browner primaries were presumably retained juvenile feathers, contrasting with the rest of the formative plumage, identifying this as an individual in its second calendar year. When I returned on the second date, the towhee was accompanied by a female Spotted Towhee of unknown age; her plumage and soft-part colors were unremarkable. Silent the day before, on this occasion the male sang several times, a series of loud ticking notes followed by a lower-pitched, buzzy trill indistinguishable to my ear from the vocalizations of other nearby Spotted Towhees.
    [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]
  • 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]
  • 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]
  • Song Variations and Singing Behavior in the Rufous-Sided Towhee, Pipilo Erythrophthalmus Oregonus
    SONG VARIATIONS AND SINGING BEHAVIOR IN THE RUFOUS-SIDED TOWHEE, PlPlLO ERYTHROPHTHALMUS OREGONUS \ DONALD E. KROODSMA Department of Zoology Oregon State University Corvallis, Oregon 97331 The singing behavior and vocalizations of the total song length. To the human ear this in- Rufous-sided Towhee ( Pipilo erythrophthal- troductory phrase was often inaudible and the mus) have been described recently by several song appeared to consist of a trill alone. authors (e.g., Davis 1958; Borror 1959; Roberts Each sonagram in figure 2 represents a song 1969). All have recognized variation in the type, i.e., one of the distinctive songs repeated song repertoire of both individuals and popu- in a consistent manner in the repertoire of an lations, yet only the variation in songs sampled individual. The male towhees sang a given from the eastern subspecies (Borror 1959) has song type at the rate of 8-15 songs per min for received extensive sonagraphic analysis. Here up to 15 min; at times, however, especially I discuss 1) the song variations observed in during early morning, males alternated two the repertoires of four neighboring males of song types, singing first one and then the other the race 2.’ e. oregonus, 2) the similarities of in sequence for several minutes at a time. Re- variations among these birds, and 3) the use gardless of the pattern of singing behavior, in of variations in the singing behavior of the successive renditions of a song type the struc- individual. ture of the introductory phrase and the trill syllables were unaltered; only the number of METHODS syllables in the trill varied.
    [Show full text]