DOCSLIB.ORG

Biology and Conservation of American

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Biology and Conservation of American Biology and Conservation of American Oystercatchers on the Outer Banks of North Carolina - 20 years of collaborative focal species research and management Ted Simons USGS Cooperative Fish and Wildlife Research Unit Department of Applied Ecology, NC State University Outline • Overview of American Oystercatcher Biology • AMOY Research on the Outer Banks – Changes in Distribution and Abundance – Factors affecting reproductive success • History of American Oystercatcher Working Group Oystercatchers of the Americas Haematopus palliatus Taxonomic Status • Generally recognized as separate species from Haematopus ostralegus • Five subspecies are currently recognized • The subspecies galapagensis, endemic • Regularly hybridizes with to the Galapagos H. bachmani, and hybrids islands, may be a with H. ater are known separate species H. palliatus subspecies • palliatus - Atlantic and Caribbean coasts North America, Central America, South America to southern Brazil, West Indies, and Pacific Central America • durnfordi - Argentina (and Uruguay?) • frazari - W. Mexico • galapagensis - Galapagos Is. • pitanay - W. South America to Chiloe Island, Chile palliatus subspecies Habitats: Diverse, but Strictly Coastal Feeding • Food: almost exclusively shellfish and other marine invertebrates that inhabit intertidal areas. • Foraging microhabitat: restricted to intertidal sand or mud flats, oyster or mussel reefs or shoals; less commonly, rocky shorelines Breeding Biology • Strong mate and nest site fidelity • In North America, the nesting season begins in late March- early May • Oystercatchers lay 2-4 eggs in a shallow scrape • Incubation takes 27 days, during which time the eggs are vulnerable to nest predators, flooding, and exposure • Precocial chicks, 35-45 days to develop flight capability • Unlike most other shorebirds young fed by adults up to 6 weeks after fledging Conservation Status • Globally: Least Concern (IUCN 2007) • US and Canada: Species of Greatest Concern • El Salvador and Mexico: Endangered • Guatemala: Near Threatened • Brazil: Considered Vulnerable in São Paulo state Population estimates: palliatus Distribution Season Individuals Coasts E & S Non-breeding 11,000 USA Mexico Breeding 500 Caribbean Breeding 550 Non-breeding 550 Central Breeding 1751-2450 America Non-breeding 275-600 N South Breeding 200 America Brazil Breeding 6500 palliatus total - 21,326 Clay et al. in Ens, B.J. and L.G. Underhill. 2014. Conservation Status of Oystercatchers around the World. International Wader Studies Number 20. US SHOREBIRD CONSERVATION PLAN SHOREBIRDS OF CONSERVATION CONCERN – 2016 LIST ESA-listed • Black-necked Stilt (knudseni) • Snowy Plover (nivosus [Pacific Coast]) • Piping Plover • Eskimo Curlew • Red Knot (rufa) Greatest Concern • American Oystercatcher (North America breeding palliatus) • Snowy Plover (nivosus [Interior/Gulf Coast] and tenuirostris) • Wilson’s Plover (North America breeding wilsonia) • Mountain Plover • Bristle -thighed Curlew • Bar-tai led Godwit (baueri) • Red Knot (roselaari) Oystercatcher Research in North Carolina • Research began on the Outer Banks in 1997 • Collaborative effort with the NC Wildlife Resources Commission, NPS, USFWS, NC Audubon • Studies of breeding biology now include data from over ~3,000 nesting attempts (~325 breeding pairs) Focal Species Conservation • Widespread along Atlantic and Gulf Coasts • Sensitive to a variety of factors affecting coastal resources – Habitat loss, coastal development – Pressure from human recreation – Pollution – Non -native predators • Large, charismatic, easily identified • Long-lived, amenable to long term mark-resight studies Research Methods • Demographic Studies – Oystercatchers are easily marked, allowing us to identify individuals from year to year and track survival and movement – Each banded Oystercatcher has a unique code engraved on a plastic band that can be read with binoculars or a spotting scope Capture Methods • Adult oystercatchers are captured with a decoy and noose carpet or a “Whoosh” net • Juveniles are captured just before fledging AMOY noose trapping.mov Telemetry • Small chicks tagged with 2g glue-on transmitters • Fledglings and adults are tracked with larger transmitters glued to a leg band • Argos and GPS tags now feasible. Reproductive Success • The breeding season is divided into two distinct periods: nesting and chick rearing • Oystercatcher chicks are mobile shortly after hatch and do not remain in the nest • Nest survival is variable among sites and years, but is generally low; ~25% of all nests survive to hatch • 0.39 (SE 0.02) chicks produced per breeding pair (n = 2,985 nesting attempts, 1995 – 2014) Sources of Nest Failure During Incubation Avian Ghost Crab 5% Human 3% 3% Abandonment 6% Mammal 54% Storm/Tides 29% N = 478 Source of failure could not be determined for 52% of failed nests (N = 518) Sources of Nest Failure – Cape Hatteras Chick Survival • Oystercatcher chicks are camouflaged and highly mobile, which makes them difficult to monitor • We used radio tags to track chicks and identify sources of mortality Chicks Fledged per Breeding Pair 1.4 Cape Hatteras National Seashore Cape Lookout National Seashore 1.2 1 0.8 Productivity 0.6 0.4 0.2 0 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Year Sources of Chick Mortality Human 16% Environmental 30% Predators 54% N = 37 Source of mortality can not be determined for ~ 50% of chick mortalities 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Cumulative survival probability survival Cumulative 0.1 Schulte, S.A. and T.R. Simons. 2015. Factors affecting the reproductive success of American Oystercatchers 0 (Haematopus palliatus) on the Outer Banks of North 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 Carolina. Marine Ornithology 43: 37-47. Days observed Vehicles and Chick Survival • Humans have direct and indirect effects on chick survival • Oystercatcher chicks are highly mobile • Small chicks use truck ruts and beach debris for hiding • Fledglings collide with vehicles at night • 13 chicks killed by vehicles on Hatteras and Lookout from 2003- 2007 • Cape Lookout closed beach sections with oystercatcher broods after two chicks were killed in 2005 • No mortality from vehicles documented on CALO after the policy was implemented Chick Survival and Vehicle Closures 0.6 N=146 0.5 0.4 N=120 0.3 0.2 Survival probability 0.1 0.267 0.476 0 Partial beach Full Beach Closure type Daily survival rates (DSR) for American Oystercatcher broods on beaches with and without off-road vehicles. 1 0.99 0.98 0.97 0.96 DSR 0.95 0.94 0.93 No vehicles present 0.92 Vehicles present 0.91 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Age (days) Vehicles, Chick Behavior, and Habitat Use FullFull beach beach closures closures Partial beach closures Below tide line Open beach Dunes 22% 26% 39% Chick habitat use Open beach 39% Dunes 74% FullFull beach beach closuresclosures Partial beach closures Resting Resting 24% 31% Out of sight 43% Chick behavior Foraging Out of sight 4% 56% Foraging Moving 10% 16% Getting fed Moving Getting fed 1% 15% 0% Chick Survival - Access to Foraging Sites 1 0.99 0.98 0.97 0.96 DSR 0.95 0.94 0.93 Forage access 0.92 No forage access 0.91 0 3 6 9 12 15 18 21 24 27 30 33 36 39 Age (days) Hurricane Effects • Hurricane Isabel made landfall on the Outer Banks in 2003 • Overwash and sand movement improved habitat and reduced predator populations • Large improvement in reproductive success in areas affected by the storm 0.9 0.8 Hurricane Isabel 0.7 0.6 0.5 0.4 0.3 0.2 Chicks fledged/breeding pair 0.1 0 1999 2000 2001 2002 2003 2004 2005 2006 2007 Hurricane Isabel Overwash Fans 1998 2004 Demographic Model Insights • Hurricanes can have strong positive effects on nest survival • “Bonanza” years may be very important for population stability • Oystercatchers are long-lived birds, so a single strong cohort can have long term effects on the population • Periodic depression of nest predator populations may be an effective management tool for inducing bonanza years Schulte and Simons. 2016. Waterbirds. Predator Management • Gathered baseline data on the ecology of raccoons South Core Banks in 2007 and 2008 – Population size – Home range size – Movement patterns – Population parameters • Age distribution • Survival • Recruitment • Evaluated the response of raccoon, shorebird, and turtle populations to an experimental removal of raccoons in 2008 - 2009 Parsons, A. W., T. R. Simons, A. F. O’Connell, Jr., and M. K. Stoskopf. 2012. Demographics, diet, movements, and survival of an isolated, unmanaged raccoon Procyon lotor (Procyonidae, Carnivora) population on the Outer Banks of North Carolina. Mammalia 77: 21–30. Camera Trapping Results • Total of 1,299 camera “captures” over 5 trapping periods from May 2007 to June 2008 • Total of 532 recaptures • Average population estimate based on photo- recaptures over five camera-trapping periods = 228 animals (SE 20) • Density ~ 10 raccoons per square mile Parsons et al. 2015. Journal of Wildlife Management. Chicks Fledged per Breeding Pair 149 raccoons were trapped and euthanized on South Core Banks in December 2008 and April 2009 Chicks fledgedbreeding per pair Effects of Human Disturbance Objectives: • To assess if military overflights, vehicles, and recreational activities affect the behavior, reproductive success, and survival rates of breeding American Oystercatchers on Cape Lookout National Seashore in 2011 and 2012 Methods: • Baseline audio monitoring of ground noise level across the entire Park • 24- hour continuous audio and video monitoring of American Oystercatcher nests (48,000 hours) • Heart- rate monitoring of incubating Borneman, T.E., E.T. Rose, and T.R. Simons. 2014. Minimal changes in the heart rate of incubating American Oystercatchers individuals (12,000 hours) (Haematopus palliatus) in response to human activity. The Condor 116: 493-503. Behavior of American Oystercatchers Before and During Human Activities * * * * Heart Rate of American Oystercatchers Before and During Human Activities * Limitations of Observational Studies - Lack of true replication, randomization, and controls Table 1.
Load more

Recommended publications
  • American Oystercatcher
    Maine 2015 Wildlife Action Plan Revision Report Date: January 13, 2016 Haematopus palliatus (American Oystercatcher) Priority 3 Species of Greatest Conservation Need (SGCN) Class: Aves (Birds) Order: Charadriiformes (Plovers, Sandpipers, And Allies) Family: Haematopodidae (Oystercatchers) General comments: First nesting record in Maine - 1994. 4 - 8 breeding pairs in Maine, range expansion, Northern Atlantic population 11,000 and considered stable. Listed as Critical risk category because of high vulnerability to climate change - Gilbrathe et al. 2014. Species Conservation Range Maps for American Oystercatcher: Town Map: Haematopus palliatus_Towns.pdf Subwatershed Map: Haematopus palliatus_HUC12.pdf SGCN Priority Ranking - Designation Criteria: Risk of Extirpation: NA State Special Concern or NMFS Species of Concern: Haematopus palliatus is listed as a species of Special Concern in Maine. Recent Significant Declines: NA Regional Endemic: NA High Regional Conservation Priority: United States Shorebird Conservation Plan: Species of High Concern North Atlantic Regional Shorebird Plan: Highly Imperiled United States Birds of Conservation Concern: Bird of Conservation Concern in Bird Conservation Regions 14 and/or 30: Yes High Climate Change Vulnerability: Vulnerability: 3, Confidence: High, Reviewers: Decided in Workshop (W) Understudied rare taxa: NA Historical: NA Culturally Significant: NA Habitats Assigned to American Oystercatcher: Formation Name Cliff & Rock Macrogroup Name Rocky Coast Formation Name Intertidal Macrogroup Name Intertidal
    [Show full text]
  • Black Oystercatcher
    Alaska Species Ranking System - Black Oystercatcher Black Oystercatcher Class: Aves Order: Charadriiformes Haematopus bachmani Review Status: Peer-reviewed Version Date: 08 April 2019 Conservation Status NatureServe: Agency: G Rank:G5 ADF&G: Species of Greatest Conservation Need IUCN: Audubon AK: S Rank: S2S3B,S2 USFWS: Bird of Conservation Concern BLM: Final Rank Conservation category: V. Orange unknown status and either high biological vulnerability or high action need Category Range Score Status -20 to 20 0 Biological -50 to 50 11 Action -40 to 40 -4 Higher numerical scores denote greater concern Status - variables measure the trend in a taxon’s population status or distribution. Higher status scores denote taxa with known declining trends. Status scores range from -20 (increasing) to 20 (decreasing). Score Population Trend in Alaska (-10 to 10) 0 Suspected stable (ASG 2019; Cushing et al. 2018), but data are limited and do not encompass this species' entire range. We therefore rank this question as Unknown. Distribution Trend in Alaska (-10 to 10) 0 Unknown. Habitat is dynamic and subject to change as a result of geomorphic and glacial processes. For example, numbers expanded on Middleton Island after the 1964 earthquake (Gill et al. 2004). Status Total: 0 Biological - variables measure aspects of a taxon’s distribution, abundance and life history. Higher biological scores suggest greater vulnerability to extirpation. Biological scores range from -50 (least vulnerable) to 50 (most vulnerable). Score Population Size in Alaska (-10 to 10) -2 Uncertain. The global population is estimated at 11,000 individuals, of which 45%-70% breed in Alaska (ASG 2019).
    [Show full text]
  • CHAPTER 1 General Introduction 1.1 Shorebirds in Australia Shorebirds
    CHAPTER 1 General introduction 1.1 Shorebirds in Australia Shorebirds, sometimes referred to as waders, are birds that rely on coastal beaches, shorelines, estuaries and mudflats, or inland lakes, lagoons and the like for part of, and in some cases all of, their daily and annual requirements, i.e. food and shelter, breeding habitat. They are of the suborder Charadrii and include the curlews, snipe, plovers, sandpipers, stilts, oystercatchers and a number of other species, making up a diverse group of birds. Within Australia, shorebirds account for 10% of all bird species (Lane 1987) and in New South Wales (NSW), this figure increases marginally to 11% (Smith 1991). Of these shorebirds, 45% rely exclusively on coastal habitat (Smith 1991). The majority, however, are either migratory or vagrant species, leaving only five resident species that will permanently inhabit coastal shorelines/beaches within Australia. Australian resident shorebirds include the Beach Stone-curlew (Esacus neglectus), Hooded Plover (Charadrius rubricollis), Red- capped Plover (Charadrius ruficapillus), Australian Pied Oystercatcher (Haematopus longirostris) and Sooty Oystercatcher (Haematopus fuliginosus) (Smith 1991, Priest et al. 2002). These species are generally classified as ‘beach-nesting’, nesting on sandy ocean beaches, sand spits and sand islands within estuaries. However, the Sooty Oystercatcher is an island-nesting species, using rocky shores of near- and offshore islands rather than sandy beaches. The plovers may also nest by inland salt lakes. Shorebirds around the globe have become increasingly threatened with the pressure of predation, competition, human encroachment and disturbance and global warming. Populations of birds breeding in coastal areas which also support a burgeoning human population are under the highest threat.
    [Show full text]
  • Trophic Facilitation by the Oystercatcher Haematopus Palliatus Temminick on the Scavenger Snail Buccinanops Globulosum Kiener in a Patagonian Bay
    Journal of Experimental Marine Biology and Ecology 325 (2005) 27–34 www.elsevier.com/locate/jembe Trophic facilitation by the oystercatcher Haematopus palliatus Temminick on the scavenger snail Buccinanops globulosum Kiener in a Patagonian bay Pedro Daleoa,b,*, Mauricio Escapab,c, Juan Pablo Isaccha,b, Pablo Ribeiroa,b, Oscar Iribarnea,b aDepartamento de Biologı´a (FCEyN), Universidad Nacional de Mar del Plata, Funes 3250, CC 573 Correo Central, B7600WAG, Mar del Plata, Argentina bConsejo Nacional de Investigaciones Cientı´ficas y Te´cnicas (CONICET), Argentina cInstituto Argentino de Oceanografı´a (IADO), Argentina Received 25 August 2004; received in revised form 4 April 2005; accepted 7 April 2005 Abstract This study investigated the role of the American oystercatcher (Haematopus palliatus) as a resource subsidizer for the scavenger snail Buccinanops globulosum in a northern Patagonian bay (40845VS, 64856VW, San Antonio Bay, Argentina). The most frequent food item for the snails was dead crabs Cyrtograpsus angulatus Dana, and the snails preferred this item. In the field, most dead crabs (78%) resulted from oystercatcher predation. Field densities of dead crabs were within the 95% confidence limits of the estimated densities produced by oystercatcher foraging activity, suggesting that a large proportion of carrion available for snails is a byproduct of oystercatcher predation. Dead crabs with injuries were more rapidly detected and consumed by snails, probably because injuries produced by oystercatchers increase leakage of body fluids and facilitate penetration of the proboscis of the snails. Our results suggest that oystercatcher predation subsidize this scavenger snail by increasing availability of food, decreasing variability in their provision and facilitating their consumption.
    [Show full text]
  • List of Shorebird Profiles
    List of Shorebird Profiles Pacific Central Atlantic Species Page Flyway Flyway Flyway American Oystercatcher (Haematopus palliatus) •513 American Avocet (Recurvirostra americana) •••499 Black-bellied Plover (Pluvialis squatarola) •488 Black-necked Stilt (Himantopus mexicanus) •••501 Black Oystercatcher (Haematopus bachmani)•490 Buff-breasted Sandpiper (Tryngites subruficollis) •511 Dowitcher (Limnodromus spp.)•••485 Dunlin (Calidris alpina)•••483 Hudsonian Godwit (Limosa haemestica)••475 Killdeer (Charadrius vociferus)•••492 Long-billed Curlew (Numenius americanus) ••503 Marbled Godwit (Limosa fedoa)••505 Pacific Golden-Plover (Pluvialis fulva) •497 Red Knot (Calidris canutus rufa)••473 Ruddy Turnstone (Arenaria interpres)•••479 Sanderling (Calidris alba)•••477 Snowy Plover (Charadrius alexandrinus)••494 Spotted Sandpiper (Actitis macularia)•••507 Upland Sandpiper (Bartramia longicauda)•509 Western Sandpiper (Calidris mauri) •••481 Wilson’s Phalarope (Phalaropus tricolor) ••515 All illustrations in these profiles are copyrighted © George C. West, and used with permission. To view his work go to http://www.birchwoodstudio.com. S H O R E B I R D S M 472 I Explore the World with Shorebirds! S A T R ER G S RO CHOOLS P Red Knot (Calidris canutus) Description The Red Knot is a chunky, medium sized shorebird that measures about 10 inches from bill to tail. When in its breeding plumage, the edges of its head and the underside of its neck and belly are orangish. The bird’s upper body is streaked a dark brown. It has a brownish gray tail and yellow green legs and feet. In the winter, the Red Knot carries a plain, grayish plumage that has very few distinctive features. Call Its call is a low, two-note whistle that sometimes includes a churring “knot” sound that is what inspired its name.
    [Show full text]
  • Black Oystercatcher Foraging ­ Hollenberg and Demers 35
    Black Oystercatcher foraging ­ Hollenberg and Demers 35 Black Oystercatcher (Haematopus bachmani) foraging on varnish clams (Nuttallia obscurata) in Nanaimo, British Columbia Emily J. R. Hollenberg 1 and Eric Demers 2 1 406­3905 Quadra St., Victoria, B.C., V8X 1J1; email: [email protected] 2 Corresponding author: Biology Department, Vancouver Island University, 900 Fifth St., Nanaimo, B.C., V9R 5S5; email: [email protected] Abstract: In this study, we investigated whether Black Oystercatchers (Haematopus bachmani) feed on the recently intro­ duced varnish clam (Nuttallia obscurata), and whether they selectively feed on specific size classes of varnish clams. Sur­ veys were conducted at Piper’s Lagoon and Departure Bay in Nanaimo, British Columbia, between October 2013 and February 2014. Foraging oystercatchers were observed, and the number and size of varnish clams consumed were recor­ ded. We also determined the density and size of varnish clams available at both sites using quadrats. Our results indicate that Black Oystercatchers consumed varnish clams at both sites, although feeding rates differed slightly between sites. We also found that oystercatchers consumed almost the full range of available clam sizes, with little evidence for size­selective foraging. We conclude that Black Oystercatchers can successfully exploit varnish clams and may obtain a significant part of their daily energy requirements from this non­native species. Key Words: Black Oystercatcher, Haematopus bachmani, varnish clam, Nuttallia obscurata, foraging, Nanaimo. Hollenberg, E.J.R. and E. Demers. 2017. Black Oystercatcher (Haematopus bachmani) foraging on varnish clams (Nuttallia obscurata) in Nanaimo, British Columbia. British Columbia Birds 27:35–41. Campbell et al.
    [Show full text]
  • Business Plan for the Conservation of the American Oystercatcher
    Business Plan for the Conservation of the American Oystercatcher A 10-Year Plan to Secure a Coastal Keystone Species American Oystercatcher Working Group National Fish and Wildlife Foundation October 26, 2008 i WHAT IS A BUSINESS PLAN? A business plan serves two broad, primary functions. First, it provides specific information to those (e.g., prospective investors) not familiar with the proposed or existing business, including its goals and the management strategy and financial and other resources necessary to attain those goals. For outside individuals, it is imperative that the business plan offer a clear rationale for why the goals represent a good investment and why the strategy for achieving those goals is the best one possible. Second, a business plan provides internal guidance to those who are active in the operation of the business, allowing all individuals to understand where the business is headed and the means by which it will get there. The plan helps keep the business from drifting away from its goals and key actions through careful articulation of a strategy. In the context of the National Fish and Wildlife Foundation’s conservation efforts, business plans represent the strategies necessary to meet the goals of Keystone and other initiatives. At its core, each business plan emphasizes the type(s) and magnitude of the impacts (benefits) that will be realized through the initiative, the monetary costs involved, and the potential obstacles (risks) to achieving those gains. Readers of the business plan must be able to see the strength of the relationship between the activities identified within the strategy and the anticipated outcomes.
    [Show full text]
  • AFRICAN Black OYSTERCATCHER
    1 1 2 2 3 3 4 African Black Oystercatcher 4 5 5 6 6 7 7 8 Between 8 9 9 10 10 11 the tides 11 12 Text by Phil Hockey 12 13 13 14 he African Black Oystercatcher’s 14 15 15 first entry into the scientific ‘led- 16 16 17 ger’ happened only 141 years 17 18 T 18 19 ago, when a specimen collected at the 19 20 Cape of Good Hope was described by 20 21 21 22 Bonaparte. Bonaparte named the bird 22 23 moquini after the French botanist, 23 24 24 25 Horace Benedict Alfred Moquin Tandon, 25 26 director of the Toulouse Botanical 26 27 27 28 Gardens. Its first entry into the litera- 28 29 29 ture, however, predates this by more 30 30 31 than 200 years. 31 32 32 33 In 1648, Étienne de Flacourt, the 33 34 Governor-General of Madagascar, 34 35 35 36 visited Saldanha Bay. He wrote: ‘There 36 37 are birds like blackbirds, with a very shrill 37 38 38 39 and clear cry, as large as partridges, with 39 40 40 a long sharp beak and red legs: they are 41 41 42 very good to eat and when young they 42 43 43 44 taste like Woodcock’. The first descrip- 44 45 tions of the bird’s biology date from the 45 46 46 47 late 19th century – much of what was 47 48 written then was culled from knowledge 48 49 49 50 of the European Oystercatcher, and much 50 51 51 of it was wrong! 52 52 53 Now, at the end of the 20th century, it 53 54 54 55 seems as though this striking bird may 55 56 be moving from a confused past into an 56 57 57 58 uncertain future.
    [Show full text]
  • IDENTIFYING HYBRID OYSTERCATCHERS in SOUTHERN CALIFORNIA WALTER WEHTJE, 2286 Barbara Drive, Camarillo, California 93012; [email protected]
    FEATURED PHOTO IDENTIFYING HYBRID OYSTERCATCHERS IN SOUTHERN CALIFORNIA WALTER WEHTJE, 2286 Barbara Drive, Camarillo, California 93012; [email protected] The photo featured on the back cover of this issue was taken on 26 May 2005 on the south side of San Nicolas Island, Ventura County, California. Its subject appears to be a rather dark American Oystercatcher (Haematopus palliatus). A large shorebird of sandy beaches, tidal mudflats and rocky shores, along the Pacific coast this species ranges from central Chile to central Baja California. In central Baja California it is replaced by the Black Oystercatcher (H. bachmani), a bird of rocky shorelines that ranges north to the Aleutian Islands. For a 300-mile stretch along the Baja California peninsula the two species interbreed, forming a stable hybrid zone (Jehl 1985). Any pied oystercatcher observed north of the international border had probably wandered north from Baja California and has to be examined closely. Of the 35 documented sightings of “American” Oystercatchers in southern California, 11 have proved to be of hybrids (Cole and McCaskie 2004). So what constitutes a “good” American Oystercatcher? Jehl posed this question more than 20 years ago. Using techniques developed for studying hybrid popula- tions devised by Charles Sibley and his students (e.g., Sibley and Short 1959), Jehl established a hybrid index for black and pied oystercatchers. Specifically, he scored the uppertail coverts, tail, chest, undertail coverts, thighs, greater secondary coverts, extent of white wing stripe, underwing coverts, and axillaries from 0 (black, as in H. bachmani) to 4 (white, as in H. palliatus). The character score for the belly ranged from 0 to 6.
    [Show full text]
  • British Birds |
    VOL. LU JULY No. 7 1959 BRITISH BIRDS WADER MIGRATION IN NORTH AMERICA AND ITS RELATION TO TRANSATLANTIC CROSSINGS By I. C. T. NISBET IT IS NOW generally accepted that the American waders which occur each autumn in western Europe have crossed the Atlantic unaided, in many (if not most) cases without stopping on the way. Yet we are far from being able to answer all the questions which are posed by these remarkable long-distance flights. Why, for example, do some species cross the Atlantic much more frequently than others? Why are a few birds recorded each year, and not many more, or many less? What factors determine the dates on which they cross? Why are most of the occurrences in the autumn? Why, despite the great advantage given to them by the prevail­ ing winds, are American waders only a little more numerous in Europe than European waders in North America? To dismiss the birds as "accidental vagrants", or to relate their occurrence to weather patterns, as have been attempted in the past, may answer some of these questions, but render the others still more acute. One fruitful approach to these problems is to compare the frequency of the various species in Europe with their abundance, migratory behaviour and ecology in North America. If the likelihood of occurrence in Europe should prove to be correlated with some particular type of migration pattern in North America this would offer an important clue as to the causes of trans­ atlantic vagrancy. In this paper some aspects of wader migration in North America will be discussed from this viewpoint.
    [Show full text]
  • SHOREBIRDS (Charadriiformes*) CARE MANUAL *Does Not Include Alcidae
    SHOREBIRDS (Charadriiformes*) CARE MANUAL *Does not include Alcidae CREATED BY AZA CHARADRIIFORMES TAXON ADVISORY GROUP IN ASSOCIATION WITH AZA ANIMAL WELFARE COMMITTEE Shorebirds (Charadriiformes) Care Manual Shorebirds (Charadriiformes) Care Manual Published by the Association of Zoos and Aquariums in association with the AZA Animal Welfare Committee Formal Citation: AZA Charadriiformes Taxon Advisory Group. (2014). Shorebirds (Charadriiformes) Care Manual. Silver Spring, MD: Association of Zoos and Aquariums. Original Completion Date: October 2013 Authors and Significant Contributors: Aimee Greenebaum: AZA Charadriiformes TAG Vice Chair, Monterey Bay Aquarium, USA Alex Waier: Milwaukee County Zoo, USA Carol Hendrickson: Birmingham Zoo, USA Cindy Pinger: AZA Charadriiformes TAG Chair, Birmingham Zoo, USA CJ McCarty: Oregon Coast Aquarium, USA Heidi Cline: Alaska SeaLife Center, USA Jamie Ries: Central Park Zoo, USA Joe Barkowski: Sedgwick County Zoo, USA Kim Wanders: Monterey Bay Aquarium, USA Mary Carlson: Charadriiformes Program Advisor, Seattle Aquarium, USA Sara Perry: Seattle Aquarium, USA Sara Crook-Martin: Buttonwood Park Zoo, USA Shana R. Lavin, Ph.D.,Wildlife Nutrition Fellow University of Florida, Dept. of Animal Sciences , Walt Disney World Animal Programs Dr. Stephanie McCain: AZA Charadriiformes TAG Veterinarian Advisor, DVM, Birmingham Zoo, USA Phil King: Assiniboine Park Zoo, Canada Reviewers: Dr. Mike Murray (Monterey Bay Aquarium, USA) John C. Anderson (Seattle Aquarium volunteer) Kristina Neuman (Point Blue Conservation Science) Sarah Saunders (Conservation Biology Graduate Program,University of Minnesota) AZA Staff Editors: Maya Seaman, MS, Animal Care Manual Editing Consultant Candice Dorsey, PhD, Director of Animal Programs Debborah Luke, PhD, Vice President, Conservation & Science Cover Photo Credits: Jeff Pribble Disclaimer: This manual presents a compilation of knowledge provided by recognized animal experts based on the current science, practice, and technology of animal management.
    [Show full text]
  • The Factors Affecting Productivity and Parental
    THE FACTORS AFFECTING PRODUCTIVITY AND PARENTAL BEHAVIOR OF AMERICAN OYSTERCATCHERS IN TEXAS by Amanda N. Anderson, B.S. THESIS Presented to the faculty of The University of Houston-Clear Lake in partial fulfillment of the requirements for the degree MASTERS OF SCIENCE THE UNIVERSITY OF HOUSTON CLEAR LAKE December, 2014 ACKNOWLEDGEMENTS I would first like to give thanks and love to my parents, Lisa and Eddie for their ongoing support. You have been my rock in all circumstances and helped me persevere through life’s obstacles. I would not be the independent, hard-working, or accomplished woman I am today without you two. I want to recognize my brother, grandparents, and extended family. I have always cherished our time together during my visits back home. Thanks to my significant other, Sean Stewart for helping me get through these last few months. To my advisor, George Guillen, thank you for your guidance, support, and the opportunity to work on an amazing project. My intention for completing a research thesis was to intimately study waterbirds, and you helped me do so. I would also like to thank Jenny Oakley for providing logistical support. To my mentor and sidekick, Susan Heath, I am immensely grateful for your support, advice, and patience over the last two years. You taught me so much and helped me along the path to my avian career. I admire your passion for birds and hope I’m as bad ass as you are when I’m fifty something! I would like to thank Felipe Chavez for his ornithological expertise and always helping when called upon.
    [Show full text]