DOCSLIB.ORG

Distribution and Abundance Patterns of the Palila on Mauna Kea, Hawaii

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Distribution and Abundance Patterns of the Palila on Mauna Kea, Hawaii DISTRIBUTION AND ABUNDANCE PATTERNS OF THE PALILA ON MAUNA KEA, HAWAII CHARLESVAN RIPER, III, TMJ. MICHAEL SCOTT,2 AND DAVID M. WOODSIDE3 'Departmentof Zoology,University of Hawaii, Honolulu, Hawaii 96822 USA, 2PatuxentWildlife Research Center, U.S. Fish and WildlifeService, P.O. Box 44, Hawaii VolcanoesNational Park, Hawaii 96718 USA, and 3Hawaii Departmentof Land and Natural Resources, 1151 Punchbowl Street, Honolulu, Hawaii 96813 USA ABSTP•CT.--Censuses of the known geographicalrange of the rare and endangeredPalila were conductedin January (nonbreedingseason) and September(breeding season)1975. The habitat (mamane and naio forest of Mauna Kea, Hawaii) was divided into five major areas, with each analyzed for vegetationalcomposition, phenology of the predominanttree species,and Palila density.Using a line transectcensus technique, we determinedthat: 1) the Palila occupied5,560 ha, approximately 10% of its former range; 2) Palila populations were more restricted in the nonbreedingseason, possibly reflecting their flocking tendency;3) Palila densitieswere 38 birds per km2 in the breedingseason and 36 birdsper km2 in the nonbreedingseason; 4) Palila population movementswere small, and apparently were correlatedwith patternsof food availability; and 5) all methodsof analysisyielded a projected population of approximately 1,600 birds. These low numbers, coupled with its restricted range, make the Palila one of the most vulnerable endangered species.Received 10 May 1977, accepted16 November 1977. THE Palila (Psittirostra bailleui) is a finch-billed member of the endemic Hawaiian honeycreeperfamily Drepanididae, and is presentlyconsidered rare and endangered. We have extrapolated the pre-19th century distribution from analysis of specimens in museums and literature references(Fig. 1). Historically, its range included the mamane (Sophora chrysophylla) and mamane~naio (Myoporum sandwicense)eco- systemsof Mauna Kea, Hualalai, as well as the southwesternslope of Mauna Loa. Mamane fruit is the primary food source of the Palila, although there are no records of the bird occurring in the mamane forest on the eastern slope of Mauna Loa. It was apparently limited to the upper forest regions, as Perkins (1903) found it only from 1,220 to 1,830 m on Hualalai. Wilson and Evans (1890-1899) also reported it as being confined to the upland districts of Hualalai and Mauna Kea. Palila range has been greatly reduced since the turn of the century. Perkins noted indicationsof its declinewhen he reportedthat in Kona in August 1894he saw only two males, whereas in 1892 he had observed it "in numbers" (Munro 1960). This was apparently the last recordedsighting of a Palila in this area. The specieswas found to be locally common in 1943, 1948-49, and 1950 between 2,360 and 2,530 m on the western and northeastern slopes of Mauna Kea (Richards and Baldwin 1953). The last recorded sighting of a bird on the northern slope of Mauna Kea is that of Walker (1968), who observed three individuals above Puu Mali. Berger (1972) found the Palila on Mauna Kea common from 2,135 m to nearly tree line, rarely descendingas low as 1,980 m. Despite a much wider distribution in the past, all information available indicates that today the Palila is found only in parts of the mamane and naio ecosystemsof Mauna Kea. In order to document the distribution and abundance of the species, censusesof its entire known geographical range were conducted during January 1975 (nonbreedingseason) and again during September 1975 (breeding season). 4 Presentaddress: Cooperative National Park ResourcesStudies Unit, P.O. Box 54, Hawaii Volcanoes National Park, Hawaii 96718 USA. 518 The Auk 95: 518-527. July 1978 July 1978] Palila Distributionand Abundance 5 19 N Kailuc 0 5 10 15 20 25 I•ilo•eters 0 5 10 15 ISLAND of HAWAII Miles --- PresentPalila Range i'•...•i" '• Farmer Palila Range Fig. 1. Map of Ha•vaii indicating historicalrange and presentdistribution of the Palila. METHODS Seventeenpeople representing the Ha•vaii StateForestry and Fish and Gamedivisions, U.S. Fish and Wildlife and Forestservices, and Universityof Ha•vaii participatedin t•vo S-daycensuses. The non- breedingseason census •vas conductedfrom 13-17 January 1975, •vhile the breedingseason count •vas made from 15-19 September 1975. Five repeat censusesinvolving five observers•vere conductedfrom 22-26 Septemberto confirmthe reliability of the censustechnique. Total counts•vere made in the 80-ha enclosureat Puu Laau utilizing 16 observerson 17 and 23 September 1975. Information •vas gathered on Palila populationnumbers and density,geographical range and movements•vithin the range,as •vell as vegetationalphenology (flo•vering and fruiting densities)of mamane and naio in September. All the high mamane and naio forest on Mauna Kea was studied, •vith most of the transects being •vithin the fence-lineof the Mauna Kea Game Management District. Natural featuressuch as roads, gulches, and areas lacking trees •vere used to divide the mountain into five survey sections(Fig. 2). Section One •vas further divided into t•vo smaller units for the first census and into three on the second (Puu Nanaha to Kemole •vascovered only on the first count). Within this sectionthe Palila •vascensused from tree line at 2,815 m to 2,195 m on Parker Ranch. SectionsThree, Four, and Five •vere all covered on a single day in each survey, as each containedonly a small relict of mamane forest. Sections•vere divided into transectsalong either 60 or 30 m contours, except for the eight transects from Puu Laau to Puu O Kauha, •vhich •vere run from high to low elevationsduring the first census. Elevations •vere initially measured in feet and the numbers later converted to meters and rounded. Observersused altimeters, topographic maps, and compassesto maintain correctcontours. Each section 520 VANRIPER, SCOTT, AND WOODSIDE [Auk,Vol. 95 z000 % 15LAND of Hawaii Fig. 2. Map of Mauna Kea, Hawaii indicating sectionscensused. was walkedfrom oneend to the other,except Section Two duringthe secondcensus. During this count, observersstarted simultaneously from a mid-linepoint on eachtransect, and walked both directionsto respectiveedges of the forest.The changein techniquewas to reducepossible bias in the data, as during the first countobservations extended well into the afternoon.All othercensusing was done during the first4 h after sunrise,when birds were mostconspicuous. The initial day of eachcensus period was spent refamiliarizing participants with the Palila,and the remainderof the weekcensusing different forested areas. Each observerwalked at slowspeeds and recordedage, sex,and socialgrouping. To minimizedouble registrations, time of the observationalong with directionof flightwas recorded. Besides observations of Palila,all endangeredspecies were noted. Observationsmade by eachobserver were recordedas audio when a bird was heard but not seen, audio-visualwhen it washeard first then seen, or visualif observedfirst. No "squeaking"or othersounds were usedto lure birds. The right angle distanceof the sightingfrom the transectline was determined with a rangefinderor by pacing.Occurrences of the threeobservational types were plotted against the 276 distanceobservations for whichdetection type was noted.This indicatedthat Palila were detected by audio(or audio-visual)and visualstimuli in approximatelyequal numbers at distancesup to 25 m. However,as the distancefrom observerincreased beyond 25 m therewas an increasingreliance on audio stimuli;observations beyond 37 m werealmost entirely the resultof auraldetection. Screening effect of the mamanecanopy was probablyresponsible for the sharpdecline in visualdetections at greaterdis- tances. The effectivearea surveyed on eachside of the observerwas determined by poolingall sightingsand findingthat distancewhere the numberof sightingsfirst decreased dramatically (Emlen 1971). It was 15 m for the firstcount and 6 m for the second.This gavea coefficientof detectability(Emlen 1971)for the Palilaof 0.21 duringthe nonbreedingseason (January) and 0.11 duringthe breedingseason (September). Thesedetectability values are relativelylow, and reflectthe quietnessof the speciesand its habit of remainingwithin the canopy.Palila appeared to vocalizeand fly lessfrequently during the breeding season, and thus we found the difference in distribution of observational distances between the two censuseshighly significant (X 2 = 38.7; df = 10;P < 0.005). July 1978] Palila Distributionand Abundance 5 2 1 Density and total numbers of Palila were determined for each sectionusing the following formulas: D = P/A T• =D'O where D = density of Palila; Tj - total number of Pallia; P = number of Pallia tallied within effective detection area; A = hectares surveyed within effective detection area; and O = number of hectares bounded by Palila observations (effective habitat). The effective detection area was calculated for each section using the formula: A = M'L'C where L = total length of all transectsbounded by outermost Palila sightings;C = subjectively derived correction factor of either 1.1 or 1.2 for deviation from transect due to roughnessof terrain; and M = maximum probable detectability distance from the transect (January = 15 m, September = 6 m) mul- tiplied by 2. Population and densityestimates were developedfor each survey using: r=rj j=0 D= T/O where T = total number of Palila; D - density of Palila; O - number of hectares bounded by Palila observations; andj = section number. In order to measurediscontinuity of Palila distribution,a clear acetatesheet
Load more

Recommended publications
  • Hulu the Palila, Activity 4
    ACTIVITY 3: Find my favorite things! Hi! It’s Hulu again. I’m a Palila, a finch-billed Hawaiian honeycreeper. We only live in Hawai‘i. Would you like to know a little more about me? My favorite food: seeds from the māmane tree. This plant has beautiful yellow flowers, is in the pea and bean family, and is only found in Hawaii (endemic to Hawaii). Other foods I like: naio berries, caterpillars. Where I live: on the upper slopes of Mauna Kea on Hawai‘i Island. I like to live where the māmane tree can be found. Unfortunately, there aren’t so many of these trees left because the dryland forest got destroyed! Some places where my family used to live: not only Mauna Kea, but also on Mauna Loa and Hualālai; my family used to live in an area 10X bigger than now! Nesting materials: I used grasses, stems, roots, lichen and branch bark from the māmane tree to build my nest. And usually I raise two eggs at a time. My favorite place to visit: the Keauhou Bird Conservation Center Discovery Forest. Check out the next page to see if you can find words about me. Till next time, A hui hou! Hulu P.S. Watch your inbox. I’ll see you again soon! © 2020. Hawai‘i Forest Institute. All rights reserved. Things you learned about me this time Things you learned about me last time - Find the words! and this time – Find the words! g w r f m v c n e u h i c d e s h e e p m u a g v l z h e e j c h a l i f a a w s a x y f u v n t u j o q l c q a i n n j h n a m o d e x g t l t b j j h d u n q z s x i b p l d a k e p e o o w b g e h a c l l t d i i g o n r q i l u o a
    [Show full text]
  • BIRDCONSERVATION the Magazine of American Bird Conservancy Fall 2016 BIRD’S EYE VIEW a Life Shaped by Migration
    BIRDCONSERVATION The Magazine of American Bird Conservancy Fall 2016 BIRD’S EYE VIEW A Life Shaped By Migration The years have rolled by, leaving me with many memories touched by migrating birds. Migrations tell the chronicle of my life, made more poignant by their steady lessening through the years. still remember my first glimmer haunting calls of the cranes and Will the historic development of of understanding of the bird swans together, just out of sight. improved relations between the Imigration phenomenon. I was U.S. and Cuba nonetheless result in nine or ten years old and had The years have rolled by, leaving me the loss of habitats so important to spotted a male Yellow Warbler in with many memories touched by species such as the Black-throated spring plumage. Although I had migrating birds. Tracking a Golden Blue Warbler (page 18)? And will passing familiarity with the year- Eagle with a radio on its back Congress strengthen or weaken the round and wintertime birds at through downtown Milwaukee. Migratory Bird Treaty Act (page home, this springtime beauty was Walking down the Cape May beach 27), America’s most important law new to me. I went to my father for each afternoon to watch the Least protecting migratory birds? an explanation of how I had missed Tern colony. The thrill of seeing this bird before. Dad explained bird “our” migrants leave Colombia to We must address each of these migration, a talk that lit a small pour back north. And, on a recent concerns and a thousand more, fire in me that has never been summer evening, standing outside but we cannot be daunted by their extinguished.
    [Show full text]
  • Palila Loxioides Bailleui
    Forest Birds Palila Loxioides bailleui SPECIES STATUS: Federally Listed as Endangered State Listed as Endangered State Recognized as Endemic NatureServe Heritage Rank G1—Critically Imperiled IUCN Red List Ranking—Critically Endangered Photo: DOFAW Revised Recovery Plan for Hawaiian Forest Birds —USFWS 2006 Critical Habitat Designated 1977 SPECIES INFORMATION: The palila is a finch-billed Hawaiian honeycreeper (Family: Fringillidae) whose life history and survival is linked to māmane (Sophora chrysophylla), an endemic dry-forest tree in the legume family. Males and females are similar, with a yellow head and breast, greenish wings and tail, a gray back, and white underparts. Males have a black mask, and females have less yellow on the back of their heads and a gray mask. Approximately 90 percent of the palila’s diet consists of immature māmane seeds; the remainder consists of māmane flowers, buds, leaves, and naio (Myoporum sandwicense) berries. Caterpillars and other insects comprise the diet of nestlings, but also are eaten by adults. Māmane seeds have been found to contain high levels of toxic alkaloids, and palila use particular trees for foraging, suggesting that levels of alkaloids may vary among trees. Individuals will move limited distances in response to the availability of māmane seeds. Palila form long-term pair bonds, and males perform low advertisement flights, sing, chase females, and engage in courtship feeding prior to breeding. Females build nests, usually in māmane trees, and males defend a small territory around the nest tree. Females mostly incubate eggs, brood nestlings and feed young with food delivered by male. First-year males sometimes help a pair by defending the nest and feeding the female and nestlings.
    [Show full text]
  • Observations on the Breeding of the Palila Psitt1rostra
    462 C. VAN RIPER 111 IBIS122 OBSERVATIONS ON THE BREEDING OF THE PALILA PSITTIROSTRA BAILLEUI OF HAWAII CHARLESVAN RIPER111 Received 2 June 1979 The Palila Psittirostra bailleui, one of six species of its genus (Amadon 1950), was first collected in the Kona District of Hawaii by Bailleu in 1876 (Oustalet 1877). Historically the Palila was confined to the mamane Sophora chrysophylla and mamane-naio Myoporum sandwicense forests at high elevations on the mountains of Mauna Kca, Hualalai and Mauna Loa (Wilson & Evans 1890-1899, Perkins 1893, Rothschild 1893-1900). This range has been greatly reduced since the turn of the century. The bird is now found only on c. 5560 ha of Mauna Kea, occupying merely 10% of its former range. The present population is estimated to be 1500-1700 individuals at densities of approximately 37 birds per 100 ha (van Riper, Scott & Woodside 1978). Habitat degradation has been extensive in Hawaii, yet little work has been carried out concerning the effects of habitat alteration on the endemic organisms. The Palila is specialized in its feeding habits, being totally reliant upon the mamane ecosystem, which is rapidly diminishing (Warner 1960). This study was undertaken to define thc basic breeding parameters of the remaining population on Mauna Kea, and to identify reasons why the bird is today so rare. METHODS The study extended from 1970 through 1975, with 757 days spent in the field. During the last three years data were collected in every month, Study sites were at 1980, 2130 and 2290m in the Kaohe and Mauna Kea Game Management areas at Puu Laau on the southwestern slope of Mauna Kea, Hawaii (Fig.
    [Show full text]
  • Palila Restoration Research, 1996−2012 Summary and Management Implications
    Technical Report HCSU-046A PALILA RESTOratION RESEarch, 1996−2012 SUMMARY AND MANAGEMENT IMPLIcatIONS Paul C. Banko1 and Chris Farmer2, Editors 1 U.S. Geological Survey, Pacific Island Ecosystems Research Center, Kīlauea Field Station, P.O. Box 44, Hawaii National Park, HI 96718 2 American Bird Conservancy, Kīlauea Field Station, P.O. Box 44, Hawaii National Park, HI 96718 Hawai‘i Cooperative Studies Unit University of Hawai‘i at Hilo 200 W. Kawili St. Hilo, HI 96720 (808) 933-0706 October 2014 Citation: Banko, P. C., and C. Farmer, editors. 2014. Palila restoration research, 1996–2012: summary and management implications. Hawai‘i Cooperative Studies Unit Technical Report HCSU-046A. University of Hawai‘i at Hilo. 70 pages. This product was prepared under Cooperative Agreements CA03WRAG0036-3036WS0012, CA03WRAG0036-3036WS0032, and CAG09AC00041 for the Pacific Island Ecosystems Research Center of the U.S. Geological Survey. This article has been peer reviewed and approved for publication consistent with USGS Fundamental Science Practices (http://pubs.usgs.gov/circ/1367/). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. PALILA RESTORATION RESEARCH, 1996–2012: SUMMARY AND MANAGEMENT IMPLICATIONS A palila (Loxioides bailleui) selects a seedpod from a māmane (Sophora chrysophylla) tree high on the western slope of Mauna Kea, Hawai‘i. The palila’s ecology and existence are inextricably linked to green māmane seeds, their critically important food. Chronic shortfalls in the supply of māmane seedpods could lead to the extinction of the palila. Photo by Jack Jeffrey (http://www.jackjeffreyphoto.com/).
    [Show full text]
  • Hawaii's 'Alalā
    VOL. 2 | 2018 SAN DIEGO ZOO GLOBAL INSTITUTE FOR CONSERVATION RESEARCH While the ‘alalā is the flagship species for the breeding and release program managed by our Hawaii Endangered Bird Conservation Program and its partners, many of the state’s birds are close to Hawaii’s ‘Alalā: extinction. Hawaii is home to more than one-third of federally listed Recovering an Iconic Species endangered bird species, and the race is on to save them. 1 “Withthe‘alalāvirtuallyextinctinthewild,the breedingprogramhasbecomecriticalandthefateof thespecieshangsonitssuccess.” – RON SWAISGOOD, Ph.D. PARTNERING TO SAVE HAWAII’S NATIVE BIRDS \\ Allison Alberts, Ph.D., Chief Conservation and Research Officer, San Diego Zoo Global ringing species back from the brink of extinction is the goal of San Diego Zoo Global, and our Bpartners are essential to this critical endeavor. In the 25-year history of the Hawaii Endangered Bird Conservation Program, the focus has been on husbandry, breeding, and reintroducing Hawaiian bird species back into native habitat. At the Keauhou and Maui Bird Conservation Centers, we care for the ‘alala¯, or Hawaiian crow, as well as the puaiohi, palila, kiwikiu, ‘akeke‘e, and ‘akikiki. Since 1993, we are proud to say that the collaborative effort has reared more than 1,130 birds from 16 species, with 810 birds successfully released into protected or restored habitat throughout Hawaii. The work is ongoing and involves collaborating with partners to protect forests, remove invasive predators, restore the native plants and trees these birds need to survive, and monitor released birds. We are grateful to government agencies and NGOs; individual, corporate, and foundation donors; local landowners, communities, and schools; and our dedicated staff who are committed to saving Hawaii’s iconic bird species.
    [Show full text]
  • Palila (Loxioides Bailleui)
    Hawaiian Bird Conservation Action Plan Focal Species: Palila (Loxioides bailleui) Synopsis: The Palila is a specialized Hawaiian honeycreeper with a population of only 1,263 birds that are restricted to 45 km2 of remnant high elevation māmane forest on Mauna Kea. Palila numbers have declined annually since 2003 because of long-term drought and habitat degradation by feral sheep introduced for hunting. Lawsuits resulted in Federal court orders in 1979, 1987, and 1998 that mandated removal of feral ungulates from Palila Critical Habitat, but a substantial number of feral sheep remain. Following a settlement agreement in 2009, fencing efforts are underway and sheep eradication is expected to follow, but natural forest regeneration and active restoration will take time. Greater public and local government support are needed. Māmane forest, Mauna Kea. Photo David Leonard. Adult male Palila. Photo Eric VanderWerf. Population Size and Trend: Range-wide Geographic region: Hawaiian Islands population surveys have been conducted annually Group: Forest Birds since 1980 (Johnson et al. 2006, Leonard et al. Federal Status: Endangered 2008, Banko et al. in press). Population estimates State status: Endangered fluctuated between 2,000 and 7,000 birds from IUCN status: Critically endangered 1980 to 2004, but no statistically significant Conservation score, rank: 20/20, At-risk trends were detected (Johnson et al. 2006). Watch List 2007 Score: Red However, Leonard et al. (2008) documented a Climate Change Vulnerability: High significant decline beginning in 2003 that has continued through 2011. From 2003 to 2011, population estimates declined each year by an average of 586 ± 106 birds for a mean annual loss of 17% ± 3.5 or 79% overall (Banko et al.
    [Show full text]
  • Foraging Ecology of the Hawaiian Crow, an Endangered Generalist’
    TheCondor88:211-219 0 The Cooper Ornithological Society 1986 FORAGING ECOLOGY OF THE HAWAIIAN CROW, AN ENDANGERED GENERALIST’ HOWARD F. SAKAI~ USDA Forest Service,Pacific SouthwestForest and Range Experiment Station, Institute of Pacific Islands Forestry Honolulu, HA 96813 C. JOHN RALPH~ USDA Forest Service,Pacific SouthwestForest and Range Experiment Station, Institute of Pacific Islands Forestry, Honolulu, HA 96813 C. D. JENKINS Department of Wildhfe Ecology,Russell Laboratory, Universityof Wisconsin,Madison, WI 53706 Abstract. The hypothesis that food was limiting the population of the endangeredHawaiian Crow (Corvus hawaiiensis)was investigated by observing its foraging habits. This crow was an omnivore, feeding on a wide variety of items including fruits, invertebrates, flower nectar, mam- mals, plant parts, and passerineeggs and nestlings.It was also an opportunistic feeder, shifting to readily available resources.The crow was adept at finding passerinenests, using this high protein diet of nestlingsand eggsduring the passerinebreeding season.Oha kepau (Clermontia spp.) and olapa (Cheirodendrontrigynum) comprised the bulk of the fruits taken. Arachnida and Isopoda were the predominant invertebrates found in droppings. Crows used the upper half of the canopy of mature trees,especially ohia (Metrosideroscollina) and koa (Acaciakoa), for their daily activities. Although the sample size was small, in the study area food seemed to be reasonably plentiful, and the crows were adaptable. Therefore, other factors probably are restricting the population. Efforts to maintain present habitat of the Hawaiian Crow need to be increased,with emphasis on ensuringa temporally continuous sourceof food. Key words: Hawaiian Crow; Corvus hawaiiensis;Hawaii; feeding strategy. INTRODUCTION pensis)in South Africa (Skead 1952); various The endangered Hawaiian Crow (Corvus ha- Australian crows and ravens, C.
    [Show full text]
  • Endangered Species Act a Record of Success Table of Contents
    AMERICAN BIRDS 2016 ENDANGERED SPECIES ACT A RECORD OF SUCCESS TABLE OF CONTENTS RECOVERY OF ESA-LISTED BIRDS .......................................................................................................................3 ESA Recovery Success Rate: Results ...........................................................................................................6 How Birds Benefit from ESA Listing ............................................................................................................7 History and Impact of the ESA .....................................................................................................................9 The ESA and Landowners ............................................................................................................................ 11 ABC’s ESA Actions .........................................................................................................................................12 SPECIES ACCOUNTS .............................................................................................................................................13 SPOTLIGHT ON HAWAIIAN BIRDS .....................................................................................................................27 Population Trends of Island Species Since Listing ................................................................................ 28 ABC’S STANCE ON THE ESA ..............................................................................................................................
    [Show full text]
  • Breeding Biology and Nesting Success of Palila’
    TheCondor92:1012-1021 0 The Cooper olnitholcgical society 1990 BREEDING BIOLOGY AND NESTING SUCCESS OF PALILA’ SANDRA M. PLETSCHET*,~ AND JEFFREYF. KELLY~ U.S. Fish and Wildlife Service,Patuxent Wildli$eResearch Center, Laurel, MD 20709 Abstract. We studied the breeding biology of Palila (Loxioidesbailleui) at 85 nests from 20 April to 14 September 1988. Eggswere laidover a 139&y period and incubationaveraged 16.6 davs. The female incubated 85.2% of davliaht hours and males fed incubating females. Modal clutch size was 2 (X = 2.0) and an averageof 1.4 nestlingsfledged per succe&fulnest. Nestlings were in the nest an average of 25.3 days. Both females and males fed nestlings with the rate of feeding decreasingas the nestlingsgrew older. Palila nesting successwas 25%, reduced primarily by hatching failure and depredation of nestlings.Hatching failure, due to inviable eggsor desertion, occurredin 4 1% of nestswith eggs(55% of nest mortality). Egg depredation was rare (5% of nest mortality). Inbreeding and low food availability are postulated as the major causesfor poor hatching success. Twenty-one percent of nests with nestlingswere depredated(35% of nest mortality). Brood reduction was observed in 47% of nests with two nestlings.Nest successdecreased signifi- cantly late in the breeding season, from 46.4% to 12.8%. During this same period, the abundanceof mamane (Sojhora chrysophylla)pods, the Palila’s primary food, also decreased significantly.Stepwise discriminant analysiscorrectly classified the fate of 79% of nestsusing e&laying date,hest-tree area, and d&ance between the nest tree and adjacent trees ai variables. Key words: Palila; Loxioides bailleui; Hawaii; endangeredspecies;nestingsuccess; hatch- ing success;brood reduction.
    [Show full text]
  • Revised Recovery Plan for Hawaiian Forest Birds
    U.S. Fish & Wildlife Service Revised Recovery Plan for Hawaiian Forest Birds Cover photographs (clockwise from upper right): 1. Maui parrotbill, 2. Palila, 3. Captive puaiohi with fledglings, 4. O`ahu `elepaio at nest, 5. `Akiapõlã`au, 6. Po`ouli. 1, 4, 5 ©Eric A. VanderWerf, U.S. Fish and Wildlife Service; 2, 3 ©Jack Jeffrey, U.S. Fish and Wildlife Service; 6 by Paul Baker, Maui Forest Bird Recovery Project. All photographs used with permission. Dedication To the naturalists and scientists who have contributed to our understanding of the biology and ecology of Hawaiian forest birds. Revised Recovery Plan for Hawaiian Forest Birds i GUIDE TO RECOVERY PLAN ORGANIZATION This recovery plan provides individual species accounts and actions needed Statewide for the recovery of 21 taxa of forest birds in Hawai`i. The plan covers a group of species for which the threats and limiting factors are similar, and for which similar actions are needed for recovery. Many of the recovery actions apply across the identified recovery areas for each species. In other cases the plan identifies specific land parcels where a particular recovery action is needed. Section I, the Introduction, provides an overview of the causes for decline of the Hawaiian forest birds and the current threats, ongoing conservation efforts, and general recovery strategies for the species covered by this plan. The Species Accounts in Section II summarize the available information on the taxonomy, life history, habitat requirements, current and historical ranges, population status, reasons for decline and current threats, and species-specific conservation efforts and recovery strategies.
    [Show full text]
  • The Endangered Species Act and Birds of Old-Growth Forest
    William & Mary Environmental Law and Policy Review Volume 14 (1989-1990) Issue 1 Environmental Practice News Article 2 October 1989 The Endangered Species Act and Birds of Old-Growth Forest Sean Skaggs Follow this and additional works at: https://scholarship.law.wm.edu/wmelpr Part of the Environmental Law Commons Repository Citation Sean Skaggs, The Endangered Species Act and Birds of Old-Growth Forest, 14 Wm. & Mary Envtl. L. & Pol'y Rev. 2 (1989), https://scholarship.law.wm.edu/wmelpr/vol14/iss1/2 Copyright c 1989 by the authors. This article is brought to you by the William & Mary Law School Scholarship Repository. https://scholarship.law.wm.edu/wmelpr The Endangered Species Act and Birds of Old-Growth Forest By Sean Skaggs The Red-cockaded Woodpecker and the Spotted Owl are two bird species whose existence is closely tied to habitat known as old- growth forest. Current levels of destruction of old-growth forest suggest that both species will be in danger of extinction in the near future. Both species have figured prominently in recent challenges of U.S. Forest Service management practices in national forests. Practices which cause the destruction of old-growth forest have been challenged in Washington, on behalf of the Spotted Owl, and in Texas, on behalf of the Red-cockaded Woodpecker. Both challenges have relied, in part, on the Endangered Species Act of 1973.1 This article will examine the courts' interpretation of the Endangered Species Act and the impact of their decisions on the continued survival of the Red-cockaded Woodpecker and the Spotted Owl.
    [Show full text]