DOCSLIB.ORG

The Practiced

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Practiced ogmzed.Haines are even more vari- KennKaufman able: About a dozen races are found in North America,with a couple THEPRACTICED EYE more in the Bahamas and another 7•xtand Illustrations byKenn Kaufman five or so in Mexico and Central America.These subspecies were de- scribedoriginally on the basis of dif- ferences visible in the hand, but manyof the differencesare obvious in the field aswell. Althoughbird guidesgive one precisesize measurement for each Identifyingthe species,these birds actually show a lot ofregional variation. (This is a worri- somethought, since size is also a ma- jor fieldmark for separatingthem). HairyWoodpeckerFortunately, the two vary in tandem. The largestforms of bothspecies are found at the northern limits of their range,across Canada and Alaska, and thebirds get generally smaller farther south.In both species,the largest birdsare those with thelargest bills, sothe appearance of bill size (relative to the size of the bird) does not changevery muchfrom placeto In tryingto make "PracticedEye" compares the two, place.But some Downy Woodpeck- and looksat the variationin Hairy ers from the Northwest Territories general comparisons Woodpeckersthat can compoundare aboutas largeas someHairy theproblem. Woodpeckersfrom Guatemala,im- betweenHairy and TheHairy is the bigger species, of plyingthat size alone is a shakyfield course,but sizealone has little value mark for observerson unfamiliar ter- Downywoodpeckers, for identification unless the two are ritory. seenside by side. More helpful is the Anotheraspect in whichthe birds we encounter an differencein bill proportions.The varytogether is wing pattern. Hairies obstacle: Both Downy'sbill is truly tiny for a wood- and Downies acrossthe far north and pecker,barely extending beyond the in the easternstates and provinces speciesshow a lot of tuftsof feathersat itsbase. The typi- (theones that are usually illustrated) cal Hairy hasa muchlonger, more haveprominent white spots on the geographicvariation. chisel-likebill (seeFigure I). But it's coverts,especially the lesser and me- importantto notethat in the latter dian coverts, which seem to show BIRDERS SELDOM WANT TO TALK species,males have larger bills than morewhite than black; they also have aboutthe fieldidentification of very females.If your mentalimage of numerouswhite spots on the flight commonbirds. This would be espe- "typical"in Hairiesis based on males, feathers. In the west, however, from ciallytrue for suchwidespread and femalesmay not be soobvious. The the Rockiesto the PacificCoast, the familiarbirds as the Hairy Wood- occasionalsmall-billed female Hairy whitespots on the coverts largely dis- pecker(Picoides villosus) and Downy maytake a secondor third look to appear.Some Hairies in the Rocky Woodpecker(Picoides pubescens). identify. Mountainshave wings almost com- The implicationseems to be that In tryingto make general compar- pletelyblack, with onlya fewsmall everyoneshould already know these isonsbetween Hairy and Downy whitespots in theprimaries and sec- species.But thesetwo woodpeckers woodpeckers, we encounteran ob- ondaries. areastonishingly similar in plumage,stacle: Both species show a lotof geo- Colorof theunderparts also varies and they sometimesgive pause to graphicvariation. About seven dis- White is the usualcolor, but in the even experiencedobservers. This tinctsubspecies of Downies are rec- PacificNorthwest both woodpeckers Volume 47, Number 2 ß$11 Figure1. Portraitsof Hairyand Downywoodpeckers, mainly to comparebill shapes.Top left: typicaladult mall HairyWoodpecker. Center left: typical adultfemale HairyWoodpecker. Aitbeugh the speciesvaries in bodysize and bill sizein different parts of its range,females average shorter-billed than maleseverywhere. Bottom: an ntypicallyshort-billed adult female HairyWoodpecker. Top right: adult female DownyWoodpecker. Center right: adult male DownyWoodpecker. In this species,the sexdifference in bill sizeis slightand inconsistent,not noticeablein the field. In comparingthe two species,their different facial "expressions"seem to be causedmainly by the smaller bill and rounderhead of the Downy,and actual differencesin markingsare hard to find. In someregions of NorthAmerica I get the impressionthat the whitespot on the sideof the napeis moreconspicuous on the Downy,more invaded by blackon the Hairy,but I wouldn'twant to suggestthat this holdsup everywhere. havethe white of the underparts,fa- theyare prevalent in a fewareas (see the birdsin the QueenCharlotte Is- cial stripes,and backreplaced by a nextparagraph). So the presenceor lands,off the coastof British Colum- palesmoky brown. absenceof tailspots is not a totallyre- bia.This isolated island group (which Beyondthese variations, in which canalso boast avery distinctive popu- Hairyand Downy woodpeckers par- lation of Northern Saw-whetOwl) alleleach other, there are some slight holdsa raceof HairyWoodpecker, P. changesin tail pattern.The white The typicalHairy v.picoideus, that looks almost differ- outer tail feathersare usuallyun- has a much longer, entenough to bea differentspecies. I markedin the Hairy Woodpecker, havenot seenthese woodpeckers in andusually marked with a fewblack more chisel-like bill life(though the Queen Charlottes are bars in the Downy Woodpecker. gettinghigher on my list of future des- However, Downies in somenorthern tinations),but lookingat a seriesof and westernregions may havethe liablefield mark everywhere. specimensat theAmerican Museum blackbarring reduced, occasionally The HairyWoodpecker offers fur- of NaturalHistory, I wasimpressed to thepoint where these feathers ap- thersurprises in maridmeregions of with theirstriking appearance, and pear unmarked.And someHairies Canada, both east and west. Hairies with their variability.Most were havea fewblack spots or barson the found in Newfoundland often have washedwith pale brown on the breast. outertail feathers.Such birds may "extra"dark markings on the flanks Most had some dark bars on the cropup in variouspopulations, but and back. Even more distinctive are flanks,streaks or spotson thesides of 312-American Birds, Summer 1993 the chest,and blackspots or bars samequality as the "pick" call, start- one could almost count the notes in within the whiteon the back.Many ingat the same pitch as that call and theDowny's rattle (not quite, but al- had black barson the white outer tail thendescending. The Hairy'srattle most),while the notes in theHairy's feathers--andon some(mainly juve- rapid-fireburst are much too rapid niles?)these tail barswere more exten- to count. I realize that written de- sivethan on themost heavily marked scriptionsofsounds are hardly useful DownyWoodpecker. When bird by themselves,but you might think Whenbird species are very similar about thesedescriptions the next in appearance,voice often provides a speciesare timeyou listen to recordings,or to majorclue for separating them. So it verysimilar in thewoodpeckers themselves. iswith Downy and Hairy woodpeck- So far we'vebeen comparing the ers.Each species has two common appearance,voice HairyWoodpecker only to the Dow- calls that could be described as a ny (andto itsown variable self), as "pick"note and a "rattle,"but the often provides if there were no other serious con- qualityof thesevocalizations is dif- a majorclue for tenders.But a differentkind of prob- ferent.The Downy reallydoes say lemcan arise in springand summer, pick,with a flator chirpingsound. separatingthem. whenjuvenile Hairies are on the The Hairy'snote is a sharp,ringing loose.Many juveniles are very similar peek/Wecould say that the Downy to adults on a casualview. But others sounds conversational, while the doesnot soundany longer,but it (ashinted at in thediscussion of geo- Hairysounds urgent. packsin morenotes and stays more graphicvariation) can give a different There is even more difference in or lesson one pitch--often a slightly impression. theirrattle calls. The Downygives a lowerpitch than that of the "pick" On adult Hairies,red showsup short seriesof notes with about the note.One getsthe impressionthat onlyon the nape, and only on males. Figure2.Some examples ofgeographic variation inHairy Woodpeckers. Left:middle Atlantic coastal reg'mn ofthe eastern United States. The underparts arewhite, and the white spots inthe wings are large and numerous. Second from left: Pacific Northwest. These birds have fewer white spots on the wings, andthe white areas on the body and head are largely replaced bysmoky brown. Third from left: central Rocky Mountains. Although the underparts are as whiteas on eastern birds, the wings are mostly black. Right: Queen Charlotte Islands, off British Columbia. Variable, but most are strikingly patterned. Theyregularly have prominent black spots and bars on the back, sides, and flanks; their underparts areusually washed with pale brown; many have black barson the outer tail feathers (on many juveniles, much more conspicuous than shown on this adult). Volume 47, Number 2- 313 Figure3. Somepoints regarding juvenile Hairy Woodpeckers. Left: two variations ontypical head patterns. The rod patch is on the crown, not on the nape,an it maybe present in females as well as males. It's my impression that the darker-faced juvenile Hairies occur in those populations that have fewerwhite spots on the wings, but I havenot checked this thoroughly. Center:. avariant juvenile Hairy Woodpecker from Newfoundland. Thisbird might easilybe mistaken for a Three-toedWoodpecker, asit hasbarring on the back, barring on the flanks, and a yellowcrown patch. All three of
Load more

Recommended publications
  • Purple Martin Monitoring After a Wildfire in the Lincoln
    PURPLE MARTIN MONITORING AFTER A WILDFIRE IN THE LINCOLN NATIONAL FOREST, NEW MEXICO – 2007 RESULTS Submitted To: Prepared By: USDA Forest Service Hawks Aloft, Inc. Danney Salas P.O. Box 10028 Sacramento Ranger District Albuquerque, New Mexico 87184 1101 New York Avenue (505) 828-9455 Alamogordo, New Mexico 87571 Website: www.hawksaloft.org E-mail Contact: [email protected] Purple Martin Conservation Association John Tautin 301 Peninsula Dr., Suite 6 Erie, Pennsylvania 16505 15 February 2008 Purple Martins in the Lincoln National Forest TABLE OF CONTENTS EXECUTIVE SUMMARY .................................................................................................1 INTRODUCTION ...............................................................................................................2 STUDY AREA ....................................................................................................................3 METHODS ..........................................................................................................................4 RESULTS ............................................................................................................................7 DISCUSSION......................................................................................................................9 ACKNOWLEDGMENTS .................................................................................................13 LITERATURE CITED ......................................................................................................13
    [Show full text]
  • 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]
  • European Corn Borer, Ostrinia Nubilalis (Hübner) (Insecta: Lepidoptera: Crambidae)1 John L
    EENY156 European Corn Borer, Ostrinia nubilalis (Hübner) (Insecta: Lepidoptera: Crambidae)1 John L. Capinera2 Distribution flights and oviposition typically occur in May, late June, and August. In locations with four generations, adults are active First found in North America near Boston, Massachusetts in April, June, July, and August-September. in 1917, European corn borer, Ostrinia nubilalis (Hübner), now has spread as far west as the Rocky Mountains in both Egg Canada and the United States, and south to the Gulf Coast Eggs are deposited in irregular clusters of about 15 to 20. states. European corn borer is thought to have originated in The eggs are oval, flattened, and creamy white in color, Europe, where it is widespread. It also occurs in northern usually with an iridescent appearance. The eggs darken Africa. The North American European corn borer popula- to a beige or orangish tan color with age. Eggs normally tion is thought to have resulted from multiple introductions are deposited on the underside of leaves, and overlap like from more than one area of Europe. Thus, there are at least shingles on a roof or fish scales. Eggs measure about 1.0 two, and possibly more, strains present. This species occurs mm in length and 0.75 m in width. The developmental infrequently in Florida. threshold for eggs is about 15°C. Eggs hatch in four to nine days. Life Cycle and Description The number of generations varies from one to four, with only one generation occurring in northern New England and Minnesota and in northern areas of Canada, whereas three to four generations occur in Virginia and other southern locations.
    [Show full text]
  • Roosevelt Wild Life Bulletins the Roosevelt Wild Life Station
    SUNY College of Environmental Science and Forestry Digital Commons @ ESF Roosevelt Wild Life Bulletins The Roosevelt Wild Life Station 1926 Roosevelt Wild Life Bulletin Charles C. Adams SUNY College of Environmental Science and Forestry Follow this and additional works at: https://digitalcommons.esf.edu/rwlsbulletin Part of the Animal Sciences Commons, Biodiversity Commons, Ecology and Evolutionary Biology Commons, and the Natural Resources and Conservation Commons Recommended Citation Adams, Charles C., "Roosevelt Wild Life Bulletin" (1926). Roosevelt Wild Life Bulletins. 23. https://digitalcommons.esf.edu/rwlsbulletin/23 This Book is brought to you for free and open access by the The Roosevelt Wild Life Station at Digital Commons @ ESF. It has been accepted for inclusion in Roosevelt Wild Life Bulletins by an authorized administrator of Digital Commons @ ESF. For more information, please contact [email protected], [email protected]. VOLUME 4 OCTOBER, 1926 NUMBER 1 Roosevelt Wild Life Bulletin OF THE Roosevelt Wild Life Forest Experiment Station OF The New York State College of Forestry AT Syracuse University RELATION OF BIRDS TO WOODLOTS CONTENTS OF ROOSEVELT WILD LIFE BULLETIN (To obtain these publications see announcement on back of title page.) Roosevelt Wild Life Bulletin, Vol. i, No. i. December, 192 1. 1. Foreword Dr. George Bird Grinnell. 2. Roosevelt Wild Life State Memorial Dr. Charles C. Adams. 3. Appropriateness and Appreciation of the Roosevelt Wild Life Memorial Dr. Charles C. Adams. 4. Suggestions for Research on North American Big Game and Fur- Bearing Animals Dr. Charles C. Adams. 5. Theodore Roosevelt Sir Harry H. Johnston. 6. Roosevelt's Part in Forestry Dr.
    [Show full text]
  • Hairy Woodpecker Dryobates Villosus Kingdom: Animalia FEATURES Phylum: Chordata the Hairy Woodpecker Averages Nine and One-Half Class: Aves Inches in Length
    hairy woodpecker Dryobates villosus Kingdom: Animalia FEATURES Phylum: Chordata The hairy woodpecker averages nine and one-half Class: Aves inches in length. The feathers on its back, outer tail Order: Piciformes feathers, belly, stripes on its head and spots on its wings are white. The head, wing and tail feathers Family: Picidae are black. The male has a small, red patch on the ILLINOIS STATUS back of the head. Unlike the similar downy woodpecker, the hairy woodpecker has a large bill. common, native BEHAVIORS The hairy woodpecker is a common, permanent resident statewide. Nesting takes place from March through June. The nest cavity is dug five to 30 feet above the ground in a dead or live tree. Both sexes excavate the hole over a one- to three-week period. The female deposits three to six white eggs on a nest of wood chips. The male and female take turns incubating the eggs during the day, with only the male incubating at night for the duration of the 11- to 12-day incubation period. One brood is raised per year. The hairy woodpecker lives in woodlands, wooded areas in towns, swamps, orchards and city parks. Its call is a loud “peek.” This woodpecker eats insects, seeds and berries. adult at suet food ILLINOIS RANGE © Illinois Department of Natural Resources. 2021. Biodiversity of Illinois. Unless otherwise noted, photos and images © Illinois Department of Natural Resources. © Illinois Department of Natural Resources. 2021. Biodiversity of Illinois. Unless otherwise noted, photos and images © Illinois Department of Natural Resources. © Illinois Department of Natural Resources. 2021.
    [Show full text]
  • The Generic Distinction of Pied Woodpeckers
    THE GENERIC DISTINCTION OF PIED WOODPECKERS M. RALPH BROWNING, 170 JacksonCreek Drive, Jacksonville,Oregon 97530 ABSTRACT: The ten speciesof New World four-toedwoodpeckers (scalaris, nuttallii, pubescens, villosus, stricklandi, arizonae, borealis, albolarvatus, lignarius,and m ixtusand the two borealthree-toed species (arcticus and tridactylus), currentlycombined in the genusPicoides, differ, in additionto the numberof toes,in modificationsof the skull,ribs, the belly of the pubo-ischio-femoralismuscle, head plumage,and behavior. I recommendthat the genericname Dryobates be reinstituted for the New World four-toedwoodpeckers. There are three generalmorphological groups of pied woodpeckers,a groupof nine four-toedspecies of the New World, a groupof 22 four-toed speciesof the Old World, and a groupof two three-toedspecies straddling bothregions. ! referto thesegroups of piedwoodpeckers beyond as the New World,Old World,and three-toedgroups. The three-toedspecies have long beenin the genusPicoides Lac•p•de, 1799, but the four-toedgroups have been combinedat the genericlevel in differentways. All four-toedpied woodpeckerswere long includedin the genusDryobates Boie, 1826, later changed to Dendrocopos Koch, 1816 an earlier name (Voous 1947, A.O.U. 1947, Peters 1948). Despite the differencein number of toes, Dendrocoposwas combined with Picoidesbecause of generalsimilarities in anatomy (Delacour 1951, Short 1971a), plumage and behavior (Short 1974a), and vocalizations(Winkler and Short 1978). The A.O.U (1976) followedthis mergerof the genera.On the basisof skeletalcharacters Rea (1983) was skepticalof the merger,but he did not providedetails. On the otherhand, Ouellet(1977), concludingthat the two generadiffer in external morphologyand some behaviors and vocalizations, separated the Old World four-toedwoodpeckers in Dendrocoposand three-toedand New World four-toedwoodpeckers in Picoides.The A.O.U.
    [Show full text]
  • Picoides Arcticus Swainson Black-Backedblack-Backed Woodpecker Woodpecker, Page 1
    Picoides arcticus Swainson black-backedblack-backed woodpecker woodpecker, Page 1 State Distribution Best Survey Period Photo courtesy Mike Danzenbaker Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Status: Special Concern Counties in the Upper Peninsula. Breeding is probable in Houghton, Keweenaw, Luce and Ontonagon Counties Global and state ranks: G5/S2 (Evers 1991, Michigan Natural Features Inventory 2002). Winter records of wandering individuals are Family: Picadae (woodpeckerzs) known south to Kalamazoo and Wayne counties (Wood 1951), although most southern Lower Peninsula obser- Total range: Black-backed woodpeckers are year- vations are prior to the mid 1900s (Zimmerman and Van round residents within boreal and montane forests Tyne 1959). Michigan is at the southern edge of this across northern North America. They breed from species range. central Alaska and northern Canada to montane areas of California and New England. Although the black- Recognition: This relatively large woodpecker has a backed woodpecker does not migrate south in winter, wingspan of 16 inches and length of 9.5 inches. It is individuals may move infrequently to areas south of the larger than the hairy woodpecker. Black-backed wood- regular breeding range in response to local insect peckers appear large-headed and short-tailed. Adults outbreaks. Movements can vary from a few wandering are all black with a bluish gloss above and a dis- individuals to irruptions involving many birds. Winter tinct white malar stripe. The belly and breast are records have occurred as far south as southern white but the sides and flanks are barred with Saskatchewan, Iowa, central Illinois, northern Indiana, black.
    [Show full text]
  • Hairy Woodpecker Body Has a Number of Nuts, Sometrees Andshrubs
    Artwork by John Thompson HAIRY WOODPECKER SCIENTIFIC NAME Picoides villosus COMMON NAME Spanish Woodpecker, Sook DESCRIPTION The Hairy Woodpecker is a mostly black and white bird that is approximately 8 – 9 inches in length. The male has a red patch on the back of the head, with black upper- parts and white underparts. The head has a black eyeline and mustache stripe on an otherwise white face. The sub-species on Abaco and Grand Bahama has black spots on the tail feathers; otherwise the outer tail feathers are white and unbarred. The female looks like the male but lacks a red head patch. Birds of the Bahamian Pine Forest DIET Woodpeckers play a special role in the food chain. They drill into trees to uncover insect food, to create nesting shelters and to communicate with other woodpeckers. While they do punch holes in trees, these trees are rarely healthy ones. By stripping the bark from dead or dying trees and cleaning up the resident wood borers or carpeneter ants, they prevent these pests from spreading to nearby healthy trees. Woodpeckers feed mainly on wood-boring grubs, insects, insect eggs and pupae. They also consume sap, nuts, and the fruit of some trees and shrubs. The Hairy Woodpecker has a number of body adaptations, which make it ideally suited for its unique place in the food chain. It has a sharp stout bill with a chisel-like tip for chipping and digging into tree trunks and branches. Bones between the beak and the unusually thick skull are not as rigidly joined as they are in other birds.
    [Show full text]
  • The Hairy Woodpecker in Central America
    THE HAIRY WOODPECKER IN CENTRAL AMERICA BY ALEXANDER F. SKUTCH HE Hairy Woodpecker (Dendrocopos villosus) , familiar to nearly every T observant person who frequents the woods and fields of temperate North America, is found in the highlands of the warmer parts of the con- tinent as far south as western Panama. The forms of the species that breed in the mountains of Central America are distinct from those resident farther north, yet all are so similar in plumage and voice that the naturalist who knows any race of the Hairy Woodpecker will at once greet a member of any other race as an old friend. Only after the first warmth of recognition has passed will he begin to think about the differences between the southern bird and its northern relatives. The Central American forms are smaller than the more boreal forms and have the under parts, and sometimes also the white central band along the back, more or less strongly tinged with brown. In both Guatemala and Costa Rica Hairy Woodpeckers occupy a broad altitudinal belt extending from about 4,000 to at least 11,000 feet above sea-level. At the lowermost of the elevations mentioned they appear to occur only where the mountain slopes are exposed to the prevailing winds and hence unusually cool and humid for the altitude. In the valleys and on the more sheltered slopes they are rarely met lower than 6,000 feet. Near Vara Blanca, on the northern or windward slope of the Cordillera Central of Costa Rica, an excessively humid region exposed to the full sweep of the northeast trade-winds and subject to long-continued storms of wind-driven mist and rain, I found Hairy Woodpeckers abundant at 5,500 feet.
    [Show full text]
  • Hairy Woodpecker (Picoides Villosus)
    Hairy Woodpecker (Picoides villosus) Paul Cotter Traits of the hairy woodpecker—contrasting black and white (sometimes smoky) coloration, distinctive undulating flight, loud drumming, and willingness to come to feeders—are familiar to many observers in North American forests and woodlands (Fig 1). This species characteristically probes trees for insects, its primary food item, but also feeds on fruit and seeds. A charismatic year-round resident of Southeastern Alaska (Southeast), the hairy woodpecker can be observed in all forested areas of the Tongass National Forest (Gabrielson and Lincoln 1959). In the Tongass, as elsewhere, hairy woodpeckers are primary excavators; they hollow out their nests in trees, often in the trunk or upper regions of snags. These nests are later available for use by other wildlife species. The hairy woodpecker is associated with the varied structure of mature and old-growth forests (Jackson et al. 2002). Because the species is strongly affiliated with old-growth forest habitats, population trends of the hairy woodpecker may serve as indicators of old- growth forest health. Further, because other bird species are at least partly dependent on abandoned hairy woodpecker cavities, declines in hairy woodpecker populations may foreshadow declines in other avian species. Recently, the U.S. Fish and Wildlife Service (USFWS) has expressed interest in developing a monitoring strategy for hairy woodpeckers (M. Kissling, USFWS, Juneau, AK, FIG 1. A male hairy woodpecker at a feeding site in personal communication 2004). The reliance of this southeastern Alaska. (Bob Armstrong) species on old-growth forest habitats for breeding and wintering makes it a logical choice for a Management Indicator Species (MIS) for measuring old-growth forest health in the Tongass.
    [Show full text]
  • Black-Backed Woodpecker (Picoides Arcticus) Status Review Under the California Endangered Species Act
    Black-backed Woodpecker (Picoides arcticus) Status Review under the California Endangered Species Act John Muir Project of Earth Island Institute and Center for Biological Diversity February 11, 2013 Prepared by Chad Hanson, Ph.D. TABLE OF CONTENTS Introduction 1 Executive Summary 1 I. Habitat Essential to the Continued Existence of the Species 4 A. Range of Subspecies 4 B. Suitable Habitat 8 1. Nesting Habitat 9 2. Foraging Habitat 14 3. Home-range Size 17 II. Listing the Black-backed Woodpecker is Warranted Because the Continued Existence of the Black-backed Woodpecker in California is in Serious Danger or is Likely to Become So in the Foreseeable Future Due to One or More Listing Factors 19 A. Present or Threatened Modification or Destruction of the BBWO’s Habitat 19 1. BBWO Habitat Loss Relative to Historic Extent 19 2. Extreme Scarcity of Moderate and High Quality Suitable Habitat 22 3. Destruction of Habitat and Lack of Regulatory Mechanisms to Protect the Species or Its Habitat 28 a. Post-disturbance Salvage Logging 28 b. Ongoing Fire Suppression 32 c. Forest Thinning—Suppression of Natural Tree Mortality 32 4. Current Laws and Regulations Do Not Protect BBWO Habitat 34 a. Public Land 34 i. U.S. Forest Service’s Elimination of the Wildlife Viability Requirement 34 ii. Sierra Nevada Forest Plan Amendment 2001 and 2004 36 iii. Northwest Forest Plan 1994 Record of Decision 39 b. Private Lands 40 i. California Forest Practices Rules 40 ii. Oregon Forest Practices Act 42 5. Significant Post-fire Salvage Logging is Occurring on Public and Private Lands 42 a.
    [Show full text]
  • Interspecific Social Dominance Mimicry in Birds
    bs_bs_banner Zoological Journal of the Linnean Society, 2014. With 6 figures Interspecific social dominance mimicry in birds RICHARD OWEN PRUM1,2* 1Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520-8150, USA 2Peabody Natural History Museum, Yale University, New Haven, CT 06520-8150, USA Received 3 May 2014; revised 17 June 2014; accepted for publication 21 July 2014 Interspecific social dominance mimicry (ISDM) is a proposed form of social parasitism in which a subordinate species evolves to mimic and deceive a dominant ecological competitor in order to avoid attack by the dominant, model species. The evolutionary plausibility of ISDM has been established previously by the Hairy-Downy game (Prum & Samuelson). Psychophysical models of avian visual acuity support the plausibility of visual ISDM at distances ∼>2–3 m for non-raptorial birds, and ∼>20 m for raptors. Fifty phylogenetically independent examples of avian ISDM involving 60 model and 93 mimic species, subspecies, and morphs from 30 families are proposed and reviewed. Patterns of size differences, phylogeny, and coevolutionary radiation generally support the predic- tions of ISDM. Mimics average 56–58% of the body mass of the proposed model species. Mimics may achieve a large potential deceptive social advantage with <20% reduction in linear body size, which is well within the range of plausible, visual size confusion. Several, multispecies mimicry complexes are proposed (e.g. kiskadee- type flycatchers) which may coevolve through hierarchical variation in the deceptive benefits, similar to Müllerian mimicry. ISDM in birds should be tested further with phylogenetic, ecological, and experimental investigations of convergent similarity in appearance, ecological competition, and aggressive social interactions between sympatric species.
    [Show full text]