DOCSLIB.ORG

Sex Determination of Adult Humboldt Penguins Using

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Sex Determination of Adult Humboldt Penguins Using J. Field Ornithol., 68(1):102-112 SEX DETERMINATION OF ADULT HUMBO•T PENGUINS USING MORPHOMETRIC CHARACTERS CAgLOS B. ZAVALAGA 1 AND ROSANA PAREDES ProyectoConservaci6n de Punta SanJuan WildlifeConservation Society ParqueJosg de Acosta187 Lima 17 Perd Abstract.-•TheHumboldt Penguin (Spheniscushumboldti) is one of the most endangered and least-studiedspecies of penguins.Studies of its breedingecology are needed to develop managementplans for its conservation,and sex determination is essentialto measurecertain reproductiveparameters. Humboldt Penguins,like other speciesof penguins,showed sexual sizedimorphism, with malesbeing heavierand larger than females.One discriminantfunc- tion wasderived from externalmeasurements of 297wild adult HumboldtPenguins of known sex (146 femalesand 151 males) at Punta SanJuan, Peru. The sex of 95% of these birds could be correctlydetermined using the discriminantfunction D• -- -38.98 + 3.16(WH) + 3.69(BL) where WH is width of the head and BL is bill length. In addition, the sexof 91% of the birdswere correctly classified by meansof the bill lengthusing the univariatefunction D,= -6.31 + BL. In both equations,if D > 0 the bird was classifiedas male, if D < 0 it was a female, and if D = 0, the sex could not be identified. The discriminant function D 1 wasnot accurateto sexa groupof captiveHumboldt Penguins (71% successfullyclassified) becausethere were differencesin sizeof the head betweenwild and captivebirds. However, weobtained 83% of casessuccessfully classified using the functionD 2 as bill lengthwas similar betweenwild and captivebirds. The discriminantfunction may not be applicableto other wild and captivepopulations of Humboldt Penguins. DETERMINACION DEL SEXO EN ADULTOS DE SPHENISCUS HUMBOLDTI UTILIZANDO CARACTERISTIC• MORFOM•TRICAS Sinopsis.--Dentrode las 17 especiesde pingtinos,el de Humboldt (Spheniscushumboldti) es uno de los m•s amenazadosy menos estudiados.Para 11evara cabo planes de manejo dirigidosa su conservaci6n,son necesariosestudios sobre su ecologiareproductiva, siendo la determinaci6ndel sexoesencial para medir algunosde susparimetros reproductivos. Los pingtinos de Humboldt son sexualmentedim6rficos en susmedidas corporales, siendo los machosmils pesados y grandesque las hembras.Una funci6n discriminantefue obtenidaa partir de lasmedidas de 297 adultosde sexoconocido (146 hembrasy 151machos) en Punta SanJuan, Per6. E1sexo de estasaves pudo ser identificadocorrectamente en un 95% de los casosutilizando la funci6n discriminante D 1 = -38.98 + 3.16 (WH) + 3.69 (BL), donde WH esel anchode la cabezay BL la longituddel pico. De igual manerase identific6 el sexo del 91% de los pingtinos por medio de la ecuaci6nunivariada D2 = -6.31 + BL. Para ambasecuaciones, si D > 0 el ave fue clasificadacomo macho,si D < 0 como hembray si D = 0, el ave no era clasificada. La funci6n discriminante D• no fue tan exitosa en la determinaci6ndel sexode pingtinos cautivos(s61o el 71% de los casosfue correctamente clasificado)debido a que estasaves exhibieron cabezas mils grandes que aquellasmedidas en el campo.Sin embargo,el sexodel 83% de lospinguinos pudo ser identificado utilizando la ecuacionD,debido a que la longituddel pico fue similarentre los ping/iinossilvestres y los cautivos.La funci6n discriminantedesarrollada no necesariamentepudiera aplicarsea otraspoblaciones de pingtinos de Humboldt ya seasilvestres o cautivos. The Humboldt Penguin (Spheniscushumboldti) is one of the most threatened and least-studiedspecies of penguins (Boersma 1991, Hays Currentaddress: Apartado Postal 180606, Lima 18, Perd. 102 Vol.68, No. I SexingHumboldt Penguins [ 103 1984). Becauseof a sharp decline in the wild population (Hays 1984), studiesof their ecologyand behavior are needed for developingeffective conservationplans. To achieve most of these studies,the ability to deter- mine the sex of individuals is essentialfor investigatingsex-specific be- havior (Davis 1988) or measuring certain reproductive parameters (CCAMLR 1994). Determining sex of captiveHumboldt Penguinsin zoos is also important in order to maximize successfulreproduction in captive birds (Cheney 1990, McGill and Perkins 1993, Steveson1993). Humboldt Penguins,like most seabirdspecies, lack plumage characters by which sexesmay be recognized. However, small differences in mor- phometric parameters reveal sufficient dimorphism to distinguishsexes (Murphy 1936:452,Scholten 1987). Charactersused to determinesex in penguinsinclude vent measurements(Boersma and Davies1987), sexual behavior (Davis 1988, Edgington 1989, Scholten 1992), morphometric differences in mated pairs (Edgington 1989) and temporal attendance during incubation (Kerry et al. 1993). Some of thesemethods have been used successfullyin the wild and in captivity,but only on reproductive individualsduring early parts of the breeding season.Cloacal examination has been used in wild Adfilie Penguins (Pygoscelisadeliae,, Lishman 1985, Sladen 1978), ChinstrapPenguins, (Pygoscelis antarctica; Lishman 1985) and captive Humboldt Penguins (Yamazaki et al. 1994). However, this technique requires trained researchers and specialized equipment to complete with minimal stressto the animal. Other methods,such as chro- mosome analysis,hormone analysis,and laparoscopyare effective but time-consumingand expensive (Edgington 1989). Sex determination by discriminant analysisof external measurements has been used successfullyin the wild in severalpenguin speciessuch as MagellanicPenguin (Spheniscusmagellanicus, Scolaro et al. 1983), Yellow- eyed Penguin (Megadyptesantipodes, Darby and Seddon 1990), all pygos- celid penguins (Amat et al. 1993, Kerry et al. 1992, Williams 1990), Little Blue Penguin (Eudyptulaminor novaehollandiae,Gales 1988), and others. Discriminant analysis uses morphometric differences between known male and female birds to calculate a function that predicts the sex of unknown individuals. This technique is reliable, practical, fast, inexpen- sive,non-invasive, and can be used outside of the breeding season. The objectivesof this studywere (1) to determine discriminantfunc- tion(s) using external measurementswith which to determine the sex of wild adult Humboldt Penguins at Punta San Juan, Peru and (2) to test the applicabilityof these functions on captiveHumboldt Penguins. MATERIALS AND METHODS Measurementsof wild penguins.--BetweenSeptember 1992 and June 1993, the bodies of 223 dead adult Humboldt Penguinswere recovered from the port of San Juan de Marcona, 3 km north of Punta San Juan (15ø22'S,75ø12'W), a 54-ha guano bird reserveon the southerncoast of Peru. This reserve holds one of the largest populations of Humboldt Penguinsin the country (Hays 1984). The birds were accidentallycaught 104] c. B. Zavalagaand R. Paredes j. FieldOrnithol. Winter 1997 and drowned in the nets of small boatsin the courseof normal fishing operationsbased at Punta SanJuan along 50-60 km of the coast (within 5 km offshore).Thus, the penguinscaught may originatefrom Punta San Juan as well as from neighboring colonies such as Sombrerillo, San Ni- colils, and San Fernando. Immediatelyafter collection,carcasses were weighedto the nearest100 g with a 10-kg Pesolaspring balance. Head and bill were measuredwith vernier calipersto the nearest0.1 mm and the flipper wasmeasured with a ruler to the nearest 0.1 cm. The measurementsincluded: total length of the head (LH) from supraoccipitalto the tip of the bill; width of the head (WH) in a crevicejust posteriorto the bulge behind the eyes;bill length (BL) from the edge of implantationof feathersto the tip of the culmen;bill depth (BD) measureddorso-ventrally at the nostrilsand flip- per length (FL), maximumflattened chord, from the humero-radialjoint to the tip of the flipper (Fig. 1). The sex of each individual was deter- mined by gonad examination after dissection. Discriminant functions were derived from the measurements taken from the 223 carcasses(analysis sample). These data were analyzedby stepwisediscriminant function analysiswith the SPSS/PC + 4.0.1 statis- tical package (Norusis 1990). The Wilks' lambda ratio was used as a cri- terion for variable selection.All other statisticalanalysis were carried out using the SYSTAT5.0 statisticalpackage (Wilkinson 1991). To test the accuracyof our results,we measured74 breedingwild pen- guins of known sex (validation sample). These animalswere banded and measuredbetween 1992 and 1994 at Punta San Juan as part of a long- term studyof the breeding ecologyof this species.The sex of thesebirds was identified from their position during copulation. Body masswas excluded from the discriminantanalysis because there was a significantamount of seasonalvariability (CV = 13.6%). Also, the majority of dead penguins were wet and their lungs were full of water (due to drowning) at the time of weighing, which would bias this mea- surement(Table 1). These penguinswere 4.8% heavierthan a sampleof 288 living penguins of known sex (the sex of these individualswas deter- mined from the discriminantfunction reported below) weighedat the sametime at Punta SanJuan (males:• -- 4711.06 g, SE -- 31.55, range -- 3450-6000, n = 165; females:• = 4047.39 g, SE -- 35.15, range = 2950-5400, n = 123; pooled:• = 4427.62 g, SE = 30.42, range = 2950- 6000, n -- 288). These differences were significant (z-test, z = 98, P < 0.05). All measurementswere normallydistributed (Kolmogorov-Smirnov one sample test, P > 0.05 in all tests)with some overlap between sexes.In order to determine a discriminant function, we established the same cri- FIGURE1. Variablesmeasured
Load more

Recommended publications
  • Humboldt Penguin Spheniscus Humboldti Population in Chile: Counts of Moulting Birds, February 1999–2008
    Wallace & Araya: Humboldt Penguin population in Chile 107 HUMBOLDT PENGUIN SPHENISCUS HUMBOLDTI POPULATION IN CHILE: COUNTS OF MOULTING BIRDS, FEBRUARY 1999–2008 ROBERTA S. WALLACE1 & BRAULIO ARAYA2 1Milwaukee County Zoo, 10001 W. Blue Mound Road, Milwaukee, WI 53226, USA ([email protected]) 2Calle Lima 193. Villa Alemana, V Región, Chile Received 19 August 2014, accepted 9 December 2014 SUMMARY WALLACE, R.S. & ARAYA, B. 2015. Humboldt Penguin Spheniscus humboldti population in Chile: counts of moulting birds, February 1999–2008. Marine Ornithology 43: 107–112 We conducted annual counts of moulting Humboldt Penguins roosting on the mainland coast and on offshore islands in north and central Chile during 1999–2008. The census area included the known major breeding colonies in Chile, where many penguins moult, as well as other sites. Population size was relatively stable across years, with an average of 33 384 SD 2 372 (range: 28 642–35 284) penguins counted, but the number of penguins found at any individual site could vary widely. Shifting penguin numbers suggest that penguins tend to aggregate to moult where food is abundant. While many of the major breeding sites are afforded some form of protected status, two sites with sizable penguin populations, Tilgo Island and Pájaros-1 Island, have no official protection. These census results provide a basis upon which future population trends can be compared. Key words: penguin, Spheniscus humboldti, census, Chile INTRODUCTION penguin taking less than three weeks to moult (Paredes et al. 2003). Penguins remain on land during moult, and they return to The Humboldt Penguin Spheniscus humboldti is a species endemic sea immediately after moulting (Zavalaga & Paredes 1997).
    [Show full text]
  • A New Home for Penguins a New Front Door to the Zoo
    A New Home for Penguins A New Front Door to the Zoo A new, state-of-the-art exhibit draws visitors directly into our mission, educating them about ennis Conner the plight of these enchanting, flightless birds and the actions people can take to save them. D Ryan Hawk AT A GLANCE HABITAT They are the zoo’s natural comedians, a delightful must- natural home. The exhibit also enhances the penguins’ lives Humboldt penguins live along the rugged see animal for visitors of all ages. Yet the penguins’ current with a state-of-the-art biofiltration and rain water harvest- coastline of Peru and Chile exhibit — originally built for seals and sea lions 60 years ing system that dramatically minimizes water loss. Because ago — is well below today’s standards for animal care and Humboldt penguins reside in coastal habitats, the new NUMBER conservation education. penguin exhibit will tell a compelling conservation story Only 10,000-12,000 remain in the wild that resonates with the marine-savvy, Pacific Northwest You can help build a stunning new, naturalistic home OPPORTUNITY specifically designed for penguins, inspiring our guests to community. A new state-of-the art, environmentally take conservation actions on their behalf! With a glass- And, what better way to meet the penguins than through friendly home for breeding endangered Humboldt penguins helps visitors learn wall, underwater viewing is a cornerstone of this signature a new entry to the zoo! Revolutionizing how we welcome how to make choices that keep marine exhibit,COMPLETED allowing guests to see these aquatic acrobats fly and serve our guests, this new “front door” will provide environments healthy while immersing visitors through water at up to 20 m.p.h.
    [Show full text]
  • Classroomsecrets.Com
    Penguins King Penguin Galapagos Penguin Penguins live in both hot and cold places in the This penguin species is the This penguin is the only Southern Hemisphere, the bottom half of the world, second largest. They have penguin to breed near the below the equator. They have wings but they can orange cheeks and look equator. They feed on not fly, so they use them as flippers. There are 17 similar to Emperor small fish like sardines. different species of penguin. penguins. King penguins do The Galapagos Penguin not make a nest, instead lays its eggs in crevices, All penguins forage for food in the sea. They have the female lays a single egg caves or a burrow to spines in their mouths to stop their prey (fish, squid which the male keeps warm protect them from getting and krill) from swimming away. in a pouch in his belly and too much heat from the balances it on his feet. sun. There are only 1000 Baby penguins are called chicks, born with very fluffy They live around the edges breeding pairs of these feathers and unable to go into the water until they of Antarctica and live on a penguins and so they are have grown their adult feathers. The parents hunt diet of mainly lanternfish at risk of extinction. for food, swallow it down and then bring it back up and squid. to feed to their chicks. Yellow-eyed Penguin Rockhopper Penguin Chinstrap Penguin This type of penguin can be There are three types of Chinstrap penguins have found in New Zealand and Rockhopper Penguin: Northern a black line across their has a band of yellow Rockhopper, Eastern cheeks that looks like a feathers on its head as well Rockhopper and Southern chinstrap.
    [Show full text]
  • Sentinels of the Ocean the Science of the World’S Penguins
    A scientific report from The Pew Charitable Trusts April 2015 Sentinels Of the Ocean The science of the world’s penguins Contents 1 Overview 1 Status of penguin populations 1 Penguin biology Species 3 22 The Southern Ocean 24 Threats to penguins Fisheries 24 Increasing forage fisheries 24 Bycatch 24 Mismatch 24 Climate change 25 Habitat degradation and changes in land use 25 Petroleum pollution 25 Guano harvest 26 Erosion and loss of native plants 26 Tourism 26 Predation 26 Invasive predators 26 Native predators 27 Disease and toxins 27 27 Protecting penguins Marine protected areas 27 Ecosystem-based management 29 Ocean zoning 29 Habitat protections on land 30 31 Conclusion 32 References This report was written for Pew by: Pablo García Borboroglu, Ph.D., president, Global Penguin Society P. Dee Boersma, Ph.D., director, Center for Penguins as Ocean Sentinels, University of Washington Caroline Cappello, Center for Penguins as Ocean Sentinels, University of Washington Pew’s environmental initiative Joshua S. Reichert, executive vice president Tom Wathen, vice president Environmental science division Becky Goldburg, Ph.D., director, environmental science Rachel Brittin, officer, communications Polita Glynn, director, Pew Marine Fellows Program Ben Shouse, senior associate Charlotte Hudson, director, Lenfest Ocean Program Anthony Rogers, senior associate Katie Matthews, Ph.D., manager Katy Sater, senior associate Angela Bednarek, Ph.D., manager Acknowledgments The authors wish to thank the many contributors to Penguins: Natural History and Conservation (University of Washington Press, 2013), upon whose scholarship this report is based. Used by permission of the University of Washington Press The environmental science team would like to thank Dee Boersma, Pablo “Popi” Borboroglu, and Caroline Cappello for sharing their knowledge of penguins by writing and preparing this report.
    [Show full text]
  • Changes in Abundance and Distribution of Humboldt Penguin Spheniscus Humboldti
    Vianna et al.: Abundance and distribution of Humboldt Penguin 153 CHANGES IN ABUNDANCE AND DISTRIBUTION OF HUMBOLDT PENGUIN SPHENISCUS HUMBOLDTI JULIANA A. VIANNA1, MARITZA CORTES2, BÁRBARA RAMOS3, NICOLE SALLABERRY-PINCHEIRA1,3, DANIEL GONZÁLEZ- ACUÑA4, GISELE P.M. DANTAS5, JOÃO MORGANTE6, ALEJANDRO SIMEONE3 & GUILLERMO LUNA-JORQUERA2 1Pontifícia Universidad Católica de Chile, Facultad de Agronomía e Ingeniería Forestal, Departamento de Ecosistemas y Medio Ambiente, Vicuña MacKenna, 4860, Macul, Santiago, Chile ([email protected]) 2Universidad Católica del Norte, Coquimbo, Chile 3Universidad Andrés Bello, Facultad de Ecología y Recursos Naturales, Santiago, Chile 4Universidad de Concepción, Facultad de Ciencias Veterinarias, Chillán, Chile 5Pontificia Universidade Católica de Minas Gerais, Belo Horizonte, Brazil 6Universidade de São Paulo, Instituto de Biociencias, São Paulo, Brazil Received 26 July 2013, accepted 15 May 2014 SUMMARY VIANNA, J.A., CORTES, M., RAMOS, B., SALLABERRY-PINCHEIRA, N., GONZÁLEZ-ACUÑA, D., DANTAS, G.P.M., MORGANTE, J., SIMEONE, A. & LUNA-JORQUERA, G. 2014. Changes in abundance and distribution of Humboldt Penguin Spheniscus humboldti. Marine Ornithology 42: 153–159. Patterns of species abundance distribution (SAD) are driven by a given species’ physiology, life history attributes and environmental variables, and this is true of the Humboldt Penguin Spheniscus humboldti. Climate variability such as El Niño Southern Oscillation (ENSO) has impacted this species and other marine fauna in the eastern South Pacific Ocean. After reviewing manuscripts and reports, we identified 80 Humboldt Penguin breeding colonies, distributed from La Foca Island (05°12′S, 81°12′W) in Peru to Metalqui Island (42°12′S, 74°09′W) in Chile, but reduced the number to 73 after fieldwork surveys in northern Chile.
    [Show full text]
  • Field Studies of Spheniscus Penguins DAVID CAMERON Duffy
    SPN August, 1991 Spheniscus Penguin Newsletter vol. 4, number 1 In this Issue The British and Irish Humboldt Studbook, 1990 1 Planning for the Future of North American Humboldts 1 Hand-rearing Humboldts at Sea World, San Diego 2 Building Better Nesting Sites for Spheniscus Penguins 8 A Survey of Spheniscus Field Studies 10 A Selected Bibliography of Spheniscus Penguins 16 This issue of SPN : The major articles in this issue, with the exception of 'Nesting Sites for Spheniscus Penguins/" are from papers presented at the Spheniscus Workshop held at the AAZPA Regional Conference in Sacramento, California, in March 1990. Other papers presented at that workshop were included in the November, 1990 SPN, and it was intended to include all remaining papers in this issue. Unforhmate realities of printing costs/ however, forced a change in plan (see below for information on contributing toward production costs of this publication). Papers remaining, for our next issue, are: "Avian Malaria/" "Incubation Behavior Patterns in Adelies/" "Molt Patterns of Black-footed Penguins," and "Diet, Feeding Regimen, and Growth Rates in Hand-reared Magellanic Chicks." Thanks to the authors and to the American Association of Zoological Parks and Aquariums, for permission to reprint these papers. Publication information: SPN Spheniscus Penguin Newsletter ISSN # 1045-0076 Indexed in Wildlife Review SPN is published twice aIUlUally, with financial support from the Portland Chapter of the American Association ofZoo Keepers, and the Metro Washington Park Zoo. Subscription is free, to those with a serious interest in Spheniscus penguins. Contributions toward printing and postage costs arewelcome (and tax-deductible in the US) ;please make checks payable to "Portland Chapter, AAZK," and send to the Editor at the address below.
    [Show full text]
  • Spheniscus Humboldti): Implications for Habitat Conservation
    PLOS ONE RESEARCH ARTICLE Effects of nest type and sex on blood saccharide profiles in Humboldt penguins (Spheniscus humboldti): Implications for habitat conservation 1 2 3 David J. Schaeffer , Jeffrey M. Levengood , Michael J. AdkessonID * 1 Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana- Champaign, Urbana, Illinois, United States of America, 2 Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, Illinois, United States of America, 3 Chicago Zoological Society, Brookfield Zoo, Brookfield, Illinois, United States of America a1111111111 * [email protected] a1111111111 a1111111111 a1111111111 Abstract a1111111111 Reproductive success of endangered Humboldt penguin (Spheniscus humboldti) colonies in Peru has been associated with nesting habitat type, presumably due to differences in environmental exposure and activity patterns that may affect energy demands and metabo- OPEN ACCESS lism. Gas chromatography and mass spectrometry were used to determine serum concen- trations of 19 saccharides from 30 Humboldt penguins nesting at Punta San Juan, Peru in Citation: Schaeffer DJ, Levengood JM, Adkesson MJ (2020) Effects of nest type and sex on blood order to evaluate differences in metabolic state between penguins nesting in a sheltered saccharide profiles in Humboldt penguins burrow or crevice (n = 17) and those in exposed surface nests (n = 13). Univariate and multi- (Spheniscus humboldti): Implications for habitat variate statistical analyses identified serum saccharides (arabinose, maltose, glucose-6- conservation. PLoS ONE 15(5): e0233101. https:// phosphate, and levoglucosenone in particular) that were nest-dimorphic with substantial dif- doi.org/10.1371/journal.pone.0233101 ferences between surface- and sheltered-nesting penguins.
    [Show full text]
  • First Gps-Tracks of Peruvian Diving-Petrels and Inca Terns in Souterhn Peru*
    FIRST GPS-TRACKS OF PERUVIAN DIVING-PETRELS AND INCA TERNS IN SOUTERHN PERU* Report presented to the Pacific Seabird Group Conservation Small-grant Program Carlos B. Zavalaga1, Joanna Alfaro-Shigueto2, Giacomo Dell’Omo3 1Graduate School of Environmental Studies, Nagoya University. Sonoyama house 105, Sonoyama-cho 2-21- 1, Chikusa-ku, Nagoya 464-0812, Japan. e-mail: [email protected] 2Asociación Pro-Delphinus, Octavio Bernal 572-5, Lima 11, Peru. University of Exeter, Center of Ecology and Conservation, Penryn, Cornwall, TR10 9EZ, UK. 3Ornis italica, Piazza Crati 15, 00199, Rome, Italy. March 2010 * Original Project Title: At-sea movements of Peruvian-Diving Petrels in Peru: Interaction with the commercial fisheries? Background Peruvian Diving-petrels (Pelecanoides garnotii, PDP) are endemic seabirds to the Humboldt Current breeding on islands off Peru and northern Chile (Murphy 1936). Habitat loss, human disturbance and poaching have been well-documented causes of population decline over the last 100 years (Coker 1919, Murphy 1936, Hays 1989, Jahncke and Goya 1998). In the last decades, it has been speculated that interactions between PDP and the commercial fishery is a main factor of PDP’s population decline through incidental by-catch (Garcia-Godos and Goya 2006, Birdlife International 2008). This species is essentially confined to the inshore islands of La Vieja and San Gallan, on the central coast of Peru (Fig.1), with approximately 13,000 breeding pairs in 1995-96 (Jahncke and Goya 1998). Recent estimates have revealed that the breeding population size in these two islands has increased to approximately 36,500 breeding pairs (Zavalaga and Alfaro 2009).
    [Show full text]
  • Penguins As Marine Sentinels Author(S): P
    Penguins as Marine Sentinels Author(s): P. Dee Boersma Source: BioScience, Vol. 58, No. 7 (July/August 2008), pp. 597-607 Published by: University of California Press on behalf of the American Institute of Biological Sciences Stable URL: http://www.jstor.org/stable/10.1641/B580707 . Accessed: 10/10/2013 14:13 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. University of California Press and American Institute of Biological Sciences are collaborating with JSTOR to digitize, preserve and extend access to BioScience. http://www.jstor.org This content downloaded from 205.175.116.25 on Thu, 10 Oct 2013 14:13:07 PM All use subject to JSTOR Terms and Conditions Articles Penguins as Marine Sentinels P. DEE BOERSMA From the tropics to Antarctica, penguins depend on predictable regions of high ocean productivity where their prey aggregate. Increases in precipitation and reductions in sea ice associated with climate warming are affecting penguins. The largest breeding colony of Patagonian (Magellanic) penguins, at Punta Tombo, Argentina, had approximately 200,000 breeding pairs in October 2006—a decline of 22% since 1987. In the 1980s and 1990s, petroleum pollution was a major source of Patagonian penguin mortality.
    [Show full text]
  • The Humboldt Penguin in Peru Coppelia Hays
    The Humboldt penguin in Peru Coppelia Hays Numbers of Humboldt penguins Humboldt penguins are endemic to the area Spheniscus humboldti, which live on the associated with the cold, nutrient-rich Humboldt coast and islands of Chile and Peru, have Current which sweeps up the coast of Chile and Peru. During historical times their numbers have been declining since the mid-1800s. Ex- diminished, although no factual data are avail- tracting guano for fertiliser has damaged able to estimate the magnitude of the decline. their breeding sites; they have been ex- Evidence for historical decline is based solely on ploited for food and skins and captured anecdotal accounts. Murphy's (1936) Oceanic for pets or zoos; they are incidentally Birds of South America remains the primary source of information on the general biology of caught in fishing nets and recent over- the Humboldt penguin. Even as early as the fishing may have caused a food shortage. 1930s, Murphy mentioned the vast diminution of The author surveyed the Humboldt pen- penguins on the islands of Peru. Because little is guins in Peru in 1981 and here discusses known of this species in the wild, a preliminary the conservation measures that are being survey was initiated to assess the present distri- taken. bution of the Humboldt penguin and to provide a 92 OryxVoll8No2 Downloaded from https://www.cambridge.org/core. IP address: 170.106.35.229, on 26 Sep 2021 at 08:57:02, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605300018767 quantitative estimate of population numbers only be entered when the sea was calm.
    [Show full text]
  • Questions and Answers: 90-Day Petition Finding for 12 Species of Penguins
    Questions and Answers: 90-day Petition Finding for 12 Species of Penguins Q: What action is being taken today? A: On November 29, 2006, the U.S. Fish and Wildlife Service received a petition from the Center for Biological Diversity to list 12 species of penguins under the Endangered Species Act. The 12 proposed species live in a range of habitats in the Antarctic, sub- Antarctic, and southern oceans and include the Emperor Penguin, the largest penguin species, smaller species with circumpolar range, such as the rockhopper, several species endemic to New Zealand and Australia and coastal species of Peru, Chile and South Africa. The petition asks that seven of the species be listed as endangered and five as threatened. Section 4 of the Endangered Species Act requires that the Service make a finding on whether a petition to list, delist or reclassify a species, contains substantial information indicating that the petitioned action may be warranted. That finding is to be made within 90 days, to the maximum extent practicable, after receipt of the petition and is to be published in the Federal Register. Findings are based on information included in or referenced by the petition. The Service conducted a preliminary review of the information provided in the petition and issued a 90-day finding that for 10 of the 12 petitioned species, the petition provided substantial information to indicate that listing may be warranted. Today’s finding is called a positive 90-day finding for these ten species under the provisions of the Endangered Species Act. Q: What happens next? A: The Service is initiating a more thorough status review of the species and will issue a second finding, called a 12-month finding, indicating whether the petitioned action is warranted.
    [Show full text]
  • Foraging Trip Duration Increases for Humboldt Penguins Tagged with Recording De7ices
    Griffiths, R., Double, M. C., Orr, K. and Dawson, R. J. G. Piersma, T. 1997. Do global patterns of habitat use and 1998. A DNA test to sex most birds. – Mol. Ecol. 7: migration strategies co-evolve with relative investments in 1071–1075. immunocompetence due to spatial variation in parasite Hamilton, W. D. and Zuk, M. 1982. Heritable true fitness and pressure? – Oikos 80: 623–631. bright birds: a role for parasites? – Science 218: 384–386. Poulin, R. 1996. Sexual inequalities in helminth infections: a Harper, D. G. C. 1999. Feather mites, pectoral muscle condi- cost of being a male? – Am. Nat. 147: 287–295. tion, wing length and plumage coloration of passerines. – Price, P. W. 1980. Evolutionary biology of parasites. – Prince- Anim. Behav. 58: 553–562. ton University Press, Princeton. Hudson, P. J. and Dobson, A. P. 1997. Host-parasite pro- Proctor, H. and Owens, I. 2000. Mites and birds: diversity, cesses and demographic consequences. – In: Clayton, D. parasitism and coevolution. – Trends Ecol. Evol. 15: 358– H. and Moore, J. (eds). Host-parasite evolution: general 364. principles and avian models. Oxford University Press, Ox- Rosen, S., Hadani, A. and Perlstein, Z. 1988. The occurrence ford, pp. 128–154. of Megninia hologastra (Analgidae Gaud, 1974) on poultry in Israel. – Avian Pathol. 17: 921–924. Kirkpatrick, C. E., Robinson, S. K. and Kitron, U. D. 1991. Rozsa, L. 1997. Wing-feather mite (Acari: Proctophyllodidae) Phenotypic correlates of blood parasitism in the common abundance correlates with body mass of passerine hosts: A grackle. – In: Loye, J. E. and Zuk, M. (eds). Bird-parasite comparative study.
    [Show full text]