DOCSLIB.ORG

Phylogenetic Patterns of Size and Shape of the Nasal Gland Depression in Phalacrocoracidae

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Phylogenetic Patterns of Size and Shape of the Nasal Gland Depression in Phalacrocoracidae PHYLOGENETIC PATTERNS OF SIZE AND SHAPE OF THE NASAL GLAND DEPRESSION IN PHALACROCORACIDAE DOUGLAS SIEGEL-CAUSEY Museumof NaturalHistory and Department of Systematicsand Ecology, University of Kansas, Lawrence, Kansas 66045-2454 USA ABSTRACT.--Nasalglands in Pelecaniformesare situatedwithin the orbit in closelyfitting depressions.Generally, the depressionsare bilobedand small,but in Phalacrocoracidaethey are more diversein shapeand size. Cormorants(Phalacrocoracinae) have small depressions typical of the order; shags(Leucocarboninae) have large, single-lobeddepressions that extend almost the entire length of the frontal. In all PhalacrocoracidaeI examined, shape of the nasalgland depressiondid not vary betweenfreshwater and marine populations.A general linear model detectedstrongly significant effectsof speciesidentity and gender on size of the gland depression.The effectof habitat on size was complexand was detectedonly as a higher-ordereffect. Age had no effecton size or shapeof the nasalgland depression.I believe that habitat and diet are proximateeffects. The ultimate factorthat determinessize and shape of the nasalgland within Phalacrocoracidaeis phylogenetichistory. Received 28 February1989, accepted1 August1989. THE FIRSTinvestigations of the nasal glands mon (e.g.Technau 1936, Zaks and Sokolova1961, of water birds indicated that theseglands were Thomson and Morley 1966), and only a few more developed in species living in marine studies have focused on the cranial structure habitats than in species living in freshwater associatedwith the nasal gland (Marpies 1932; habitats (Heinroth and Heinroth 1927, Marpies Bock 1958, 1963; Staaland 1967; Watson and Di- 1932). Schildmacher (1932), Technau (1936), and voky 1971; Lavery 1972). othersshowed that the degree of development Unlike most other birds, Pelecaniformes have among specieswas associatedwith habitat. Lat- nasal glands situated in depressionsfound in er experimental studies (reviewed by Holmes the anteromedialroof of the orbit (Siegel-Cau- and Phillips 1985) established the role of the sey 1988). In specieswith extra- or supraorbital nasal gland as an extrarenal excretory organ nasal glands, glandular tissue can enlarge by that maintainselectrolyte homeostasis and water growth outward from the skull (Owen and Kear balanceduring conditionsof salt-loading. 1972)and by increasein width (Bock1958), but The size of the nasalgland and its degree of rarely by increase in length (Staaland 1967, function varies alsowithin species.Marine pop- Peaker and Linzell 1975). Becausecranial bone ulations have larger glands and greater func- is membranous, mesenchymal, and nonintus- tional activity than do freshwater populations susceptive,and becauseit grows very slowly of a given species(Schmidt-Nielsen 1959, 1960, if at all after ossification and maturation (de 1965; Peaker and Linzell 1975). Experimental Beer 1937,Bellairs and Jenkin 1960),change in studies with captive wild and domestic birds bony outline of the gland depressionmust oc- indicate that gland size (i.e. mass)and function cur slowly. Thus, functionally inducedgrowth increasedquickly in individuals of somespecies of the nasal gland in the orbit is constrainedin when subjectedto high electrolytestress or low Pelecaniformesbecause substantial thickening water intake (Holmes et al. 1961, Ellis et al. 1963, of the gland without osteologicalaccommoda- Peaker and Linzell 1975). tion could distort the eye. In other species,accommodation to salt-load- I have shown qualitatively (Siegel-Causey ing is less effective (Skadhauge 1981). Devel- 1988) that the size and shape of the nasal gland opment and growth rate in captive Mallards depression is variable within shags and cor- (Anasplatyrhynchos) that were fed 1%solutions morants (Phalacrocoracidae).In this study, I of sodiumchloride were reducedcompared with surveyedthe variation in size and shape of the development and growth of birds fed fresh nasalgland depressionin the orbit of selected water (Schmidt-Nielsen and Kim 1964). Data members of this family. I examined its pre- from field populationsof wild birds are uncom- sumptive associationwith gland size relative to 110 The Auk 107: 110-118. January 1990 January1990] PhalacrocoracidaeNasal Glands 111 Fig. 1. Outlinesof the ventral view of the frontal bone and nasalgland depressionin selectedPelecani- formes.All views representthe area indicated in Figure 2: lower; shadedareas represent the nasal gland depression:(a) GreatFrigatebird; (b) White Pelican;(c) Red-footedBooby; (d) Northern Gannet;(e) Anhinga; (f) Little Pied Cormorant;(g) OlivaceousCormorant (left, freshwater;right, marine); (h) Double-crested Cormorant (left, freshwater;right, marine); (i) Pied Cormorant;(j) Little Black Cormorant;(k) Brandt'sCor- morant;(1) Black-facedCormorant; (m) SocotraShag; (n) CapeShag; (o) Imperial Shag,marine (left, e; right, •); (p) Imperial Shag,freshwater (left, e; right, •); (q) RockShag; (r) PelagicShag; (s) Red-leggedShag. collectionhabitat, age (measuredby size of bur- I measuredcranium length and frontal width by sa of Fabricius),size, and speciesidentity. dial calipersto a 95% replicated accuracy(RA) of 0.1 mm. The least frontal width was the minimum width METHODS measuredon the frontal (Fig. 2: upper). Length and width of the bursa of Fabricius were measured in the All skeletal measurements were done on museum field to nearestmm with dial calipers,but determi- specimens.Scientific names and sample sizes of species nations of RA were not made. usedin this studyare in parentheses:Reed Cormorant I classified collection localities as freshwater and (Microcarboafricanus; 15), Little Pied Cormorant (M. marine (saltwater) habitats; ambiguous caseswere melanoleucos;21), Brandt's Cormorant (Compsohalieus classifiedas missing. Species identity, gender,and age penicillatus;4), Black-facedCormorant (C. fuscescens;were determined at the time of collection or, in the 2), OlivaceousCormorant (Hypoleucus olivaceus; 50), caseof museumspecimens, from the label. Unknown Double-crested Cormorant (H. auritus;57), Little Black genderwas coded as missing. I codedthose specimens Cormorant (H. sulcirostris;3), Pied Cormorant (H. var- without agedeterminations as adults unless there was ius; 4), Great Cormorant (Phalacrocoraxcarbo; 11), So- evidence(e.g. partly ossifiedbone) to indicatejuve- cotra Shag (Leucocarbonigrogularis; 3), Cape Shag (L. nile status. capensis;4), Imperial Shag(Notocarbo atriceps; 12), Ant- I approximatedthe areaof the nasalglands in species arcticShag (N. bransfieldensis;19), Kerguelen Shag(N. with fusedlobes by the productof the greatestlength verrucosus;2), South GeorgianShag (N. georgianus;2), and width of the nasalgland depressionin the cra- Rock Shag(Stictocarbo magellanicus; 73), PelagicShag nium. For specieswith bilobed nasal glands, I used (S. pelagicus;10), and Red-legged Shag (S. gaimardi; the product of the greatestlength of the medial lobe 30). See Siegel-Causey(1988) for details on system- and the greatestcombined width of both lobes.Mea- atics and nomenclature. surements(see Fig. 2: lower) were made by dial cal- For comparativepurposes, depression outlines for ipers(+ 0.2 mm RA). Theseapproximations may over- Great Frigatebird (Fregataminor; 2), American White estimatethe actualarea of the nasalgland depression, Pelican (Pelecanuserythrorhyncos; 4), Red-looted Boo- especiallyin cormorants,which have lessrectangular by (Sulasula; 2), Northern Gannet (Morusbassanus; 2), depressionsthan do shags.All analyseswere done and Anhinga (Anhingaanhinga; 5) are illustrated(Fig. using log-transformeddata. 1). The nasalglands of tropicbirds(Phaethon spp.) do ! performedmultivariate analyses using the BMDP not occur within the orbit and are not illustrated. A statisticalprograms (Dixon [Ed.] 1988). Becauseof the list of specimensand data are available from the au- sensitivity of the analysisof covariance(ANCOVA) thor. program to small samples,I excluded cells with sam- 112 DOUGLAS$IEGEL-CAUSEY [Auk, Vol. 107 sion surfacesof all specimensI examined were composedof smooth, densebone. There was no osteologicalevidence of vascularization or in- complete ossificationas is seen in speciesthat have extra- or supraorbitalglands (e.g. Procel- lariiformes and Charadriiformes). Phalacrocoracidaeare unique within Pele- caniformes and show intrafamiliar variation in depression shape. Four qualitative characters varied within the cormorantsand shags(char- acters 12-15 in Siegel-Causey1988), but only the shape of the lateral edge of the depression Fig. 2. Generalizedphalacrocoracid cranium and showed intraspecificvariation. This feature is gland depression-relatedmeasurements. Upper: dor- sal view (LFW = least frontal width, CL = cranium influenced by the width of the frontal and the length).Lower: ventral view with palatinesremoved length of the cranium (e.g. the lateral curvature (rectanglerepresents view in Figure 1, DW = depres- increases as the least frontal width decreases sion "width," DL = depression"length"). relative to cranium length). This variation in lateral curvature was evident in Double-crested and Olivaceous cormorants collected from dif- ple sizesof <3. I excludedall caseswith missingdata ferent habitats (Fig. 1: g, h), but it was most for the variables under analysis. Equality of slopes pronounced in comparisonsbetween freshwa- (parallelism)of the regressionsof the dependentvari- ables on the covariatecranium length was testedby ter and marine Imperial Shags(Fig. 1: o, p). The ANOVA, and no significant differences (P
Load more

Recommended publications
  • Birds of Centre Island 105
    BIRDSs-OFCENTRE ISLAND By W. J. COOPER Centre Island lies in Foveaux Strait 7 km south of the South Island, 40 km west-southwest of Invercargill and 16 km southwest of Riverton, at 46O27' 30' ' S, 167O50' 30' ' E (Figure 1). The island is about 89 ha and rises FIGURE 1 - Centre Island Most of the island is covered with exotic pasture grasses, club rush (Scirpus nodosus), water-fern (Histiopteris incisa), Carex appressa, and bush lawyer (Rubus cissoides) in varying quantities with clumps of gorse (Ulex europaeus), especially on the northern slopes, and at the eastern end, flax (Phormium colensoi). Some scattered, stunted, wind-shorn macrocarpa trees (Cupressus macrocarpa) are near the houses. The steeper slopes to the south and west have an interesting mat of saltmarsh vegetation with Selleria radicans, Samolus repens, the shore gentian (Gentiana saxosa), Scirpus cemuus, native celery (Apium prostraturn), and Crassula moschata as predominant species. The cliffs, drier soils and rock outcrops feature the blue shore tussock (Poa astonii), Hebe elliptica, and scattered muttonbird scrub (Senecw reirwldii) as dominant species. Some taupata (Coprosma repens) is on coastal banks. 104 COOPER NOTORNIS 38 The dunes backing the beaches to the north and east are dominated by marram (Ammophila arenaria). Pingao (Desmoschoenus spiralis) dominates a small part of the dunes on the northern shore. The island was reserved as "a site for a lighthouse and Premises connected therewith" in 1875 and was occupied by lighthouse keepers from 1878 until 1989, when the lighthouse was automated. Known scientific visits have been few and brief. Maida and Olga Sansom visited Kuru-kuru, a rocky pinnacle below the lighthouse, on 21 November 1955 (Sansom M.L.
    [Show full text]
  • Energetics of Free-Ranging Seabirds
    University of San Diego Digital USD Biology: Faculty Scholarship Department of Biology 2002 Energetics of Free-Ranging Seabirds Hugh I. Ellis University of San Diego Geir Wing Gabrielsen Follow this and additional works at: https://digital.sandiego.edu/biology_facpub Part of the Biology Commons, Ecology and Evolutionary Biology Commons, Ornithology Commons, and the Physiology Commons Digital USD Citation Ellis, Hugh I. and Gabrielsen, Geir Wing, "Energetics of Free-Ranging Seabirds" (2002). Biology: Faculty Scholarship. 20. https://digital.sandiego.edu/biology_facpub/20 This Book Chapter is brought to you for free and open access by the Department of Biology at Digital USD. It has been accepted for inclusion in Biology: Faculty Scholarship by an authorized administrator of Digital USD. For more information, please contact [email protected]. Energetics of Free-Ranging Seabirds Disciplines Biology | Ecology and Evolutionary Biology | Ornithology | Physiology Notes Original publication information: Ellis, H.I. and G.W. Gabrielsen. 2002. Energetics of free-ranging seabirds. Pp. 359-407 in Biology of Marine Birds (B.A. Schreiber and J. Burger, eds.), CRC Press, Boca Raton, FL. This book chapter is available at Digital USD: https://digital.sandiego.edu/biology_facpub/20 Energetics of Free-Ranging 11 Seabirds Hugh I. Ellis and Geir W. Gabrielsen CONTENTS 11.1 Introduction...........................................................................................................................360 11.2 Basal Metabolic Rate in Seabirds........................................................................................360
    [Show full text]
  • Red-Footed Booby Helper at Great Frigatebird Nests
    264 SHORT COMMUNICATIONS NECTS MEANS ECTS MEANS ICATE SAMPLE SIZE S.D. SAMPLE SIZE 70 IN DAYS FIGURE 2. Culmen length against age of Brown FIGURE 1. Weight against age of Brown Noddy Noddy chicks on Manana Island, Hawaii in 1972. chicks on Manana Island, Hawaii in 1972. about the thirty-fifth day; apparently Brown Noddies on Christmas Island grow more rapidly than those on 5.26 g/day (SD = 1.18 g/day), and chick growth rate Manana. More data are required for a refined analysis and fledging age were negatively correlated (r = of intraspecific variation in growth rates of Brown -0.490, N = 19, P < 0.05). Noddy young. Seventeen of the chicks were weighed both at the This paper is based upon my doctoral dissertation age of fledging and from 3 to 12 days later; there was submitted to the University of Hawaii. I thank An- no significant recession in weight after fledging (t = drew J. Berger for guidance and criticism. The 1.17, P > 0.2), as suggested for certain terns (e.g., Hawaii State Division of Fish and Game kindly LeCroy and LeCroy 1974, Bird-Banding 45:326). granted me permission to work on Manana. This Dorward and Ashmole (1963, Ibis 103b: 447) mea- study was supported by the Department of Zoology sured growth in weight and culmen length of Brown of the University of Hawaii, by an NSF Graduate Noddies on Ascension Island in the Atlantic; scatter Fellowship, and by a Mount Holyoke College Faculty diagrams of their data indicate growth functions very Grant.
    [Show full text]
  • Hemosporidian Blood Parasites in Seabirds—A Comparative Genetic Study of Species from Antarctic to Tropical Habitats
    Naturwissenschaften (2010) 97:809–817 DOI 10.1007/s00114-010-0698-3 ORIGINAL PAPER Hemosporidian blood parasites in seabirds—a comparative genetic study of species from Antarctic to tropical habitats Petra Quillfeldt & Javier Martínez & Janos Hennicke & Katrin Ludynia & Anja Gladbach & Juan F. Masello & Samuel Riou & Santiago Merino Received: 21 May 2010 /Revised: 7 July 2010 /Accepted: 7 July 2010 /Published online: 23 July 2010 # The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Whereas some bird species are heavily affected by ranging from Antarctica to the tropical Indian Ocean. We did blood parasites in the wild, others reportedly are not. Seabirds, not detect parasites in 11 of these species, including one in particular, are often free from blood parasites, even in the Antarctic, four subantarctic, two temperate, and four tropical presence of potential vectors. By means of polymerase chain species. On the other hand, two subantarctic species, thin- reaction, we amplified a DNA fragment from the cytochrome billed prions Pachyptila belcheri and dolphin gulls Larus b gene to detect parasites of the genera Plasmodium, scoresbii, were found infected. One of 28 thin-billed prions Leucocytozoon,andHaemoproteus in 14 seabird species, had a Plasmodium infection whose DNA sequence was identical to lineage P22 of Plasmodium relictum, and one of 20 dolphin gulls was infected with a Haemoproteus lineage which appears phylogenetically clustered with parasites P. Quillfeldt (*) : K. Ludynia : A. Gladbach : J. F. Masello Max-Planck-Institut für Ornithologie, Vogelwarte Radolfzell, species isolated from passeriform birds such as Haemopro- Schlossallee 2, teus lanii, Haemoproteus magnus, Haemoproteus fringillae, 78315 Radolfzell, Germany Haemoproteus sylvae, Haemoproteus payevskyi,andHae- e-mail: [email protected] moproteus belopolskyi.
    [Show full text]
  • Imperial Shag (Heard Island)
    RECOVERY OUTLINE Imperial Shag (Heard Island) 1 Family Phalacrocoracidae 2 Scientific name Leucocarbo atriceps nivalis Falla, 1937 3 Common name Imperial Shag (Heard Island) 4 Conservation status Vulnerable: D1+2 5 Reasons for listing The subspecies has a small population (Vulnerable: D1) found at a single location (D2). Estimate Reliability Extent of occurrence 60 km2 high trend stable high Area of occupancy 3 km2 high trend stable high No. of breeding birds 500 medium trend fluctuating medium No. of sub-populations 1 high Generation time 15 years low 10 Threats 6 Infraspecific taxa The species is considered threatened because the L. a. purpurascens (Macquarie I.) is also Vulnerable. The population is small and variable. However, fluctuations other 6 subspecies on remote subantarctic islands are in population size and breeding success can be more numerous and widespread. Globally, the species attributed to frequently inclement weather (Pemberton is Least Concern. and Gales, 1987) or cycles of abundance over resource availability (E. Woehler). The subspecies could be 7 Past range and abundance adversely affected by offshore fishing or the effects of Endemic to Heard I. and not recorded from nearby climate change on sea temperature and food supply. McDonald or Shag Is. Breeding confined to three sites on north-western coast, Stephenson Lagoon, Saddle 11 Information required Point and Sydney Cove. Roosting sites are more None. widespread (Pemberton and Gales, 1987, Woehler, 1991, Green, 1997a). Population has varied between 12 Recovery objectives 40 and 100 breeding pairs over the last 40 years 12.1 Persistence of existing population. (Woehler, 1991, Green, 1997b, Green and Williams, 1997).
    [Show full text]
  • Kachemak Bay Birds Checklist
    LEGEND SPECIES Sp Su F W Status SPECIES Sp Su F W Status SPECIES Sp Su F W Status __Greater Scaup C C C C rmb __Red-tailed Hawk C C C - sb Laridae - Gulls & Terns C Common - Easily found in small to large numbers in __Lesser Scaup U - U - m __Rough-legged Hawk U U U - sb __Franklin’s Gull - A - - v appropriate habitat. __Steller’s Eider C R C C w __Golden Eagle R R R A s __Black-headed Gull - A - - v __Spectacled Eider - - - A v Falconidae - Falcons __Bonaparte’s Gull C C C R sb U Uncommon - Occasionally, but not always, found in small __King Eider R R R R w __American Kestrel R R R - m __Black-tailed Gull - A - - v numbers with some effort in appropriate habitat. __Common Eider C C C U rb __Merlin U C R R sb __Mew Gull C C C C rb __Harlequin Duck C C C C rb __Gyrfalcon R R R R w __Ring-billed Gull A - - A v R Rare - occurs in very small numbers or in a very limited __Surf Scoter C C C C rm __Peregrine Falcon U U R R sb __California Gull - - A - v number of sites and may not be found every year or even with __White-winged Scoter C C C C rm Rallidae - Rails, Coots & Gallinules __Herring Gull C C C C r concentrated effort. There are more than a few records of __Black Scoter C C C C rmb __American Coot - - A - v __Heermann’s Gull - A - - v these species in appropriate habitats.
    [Show full text]
  • Kendall Birds
    Kendall-Frost Reserve Breeding Common Name Scientific Name Regulatory Status Status Waterfowl - Family Anatidae Brant Branta bernicla W Special Concern Gadwall Ana strepera W American Wigeon Anas americana W Mallard Anas platyrhynchos Y Cinnamon Teal Anas cyanoptera W Northern Shoveler Anas clypeata W Northern Pintail Anas acuta W Green-winged Teal Anas crecca W Redhead Aythya americana W Lesser Scaup Aythya affinis W Bufflehead Bucephala albeola W Red-breasted Merganser Mergus serrator W Ruddy Duck Oxyura jamaicensis W Loons - Family Gaviidae Common Loon Gavia immer W Special Concern Grebes - Family Podicipedidae Pied-billed Grebe Podilymbus podiceps W Horned Grebe Podiceps auritus W Eared Grebe Podiceps nigricollis W Western Grebe Aechmophorus occidentalis W Clark's Grebe Aechmophorus clarkii W Pelicans - Family Pelecanidae Brown Pelican Pelecanus occidentalis Y Endangered Frigatebirds - Family Fregatidae Magnificent Frigatebird Fregata magnificens X Cormorants - Family Phalacrocoracide Double-crested Cormorant Phalacrocorax auritus Y Herons and Bitterns - Family Ardeidae Great Blue Heron Ardea herodias Y Great Egret Ardea alba Y Snowy Egret Egretta thula Y Little Blue Heron Egretta caerulea Y Green Heron Butorides virescens Y Black-crowned Night Heron Nycticorax nycticorax Y Hawks, Kites and Eagles - Family Accipitridae Osprey Pandion haliaetus Y White-tailed Kite Elanus leucurus W Northern Harrier Circus cyaneus W Special Concern Cooper's Hawk Accipiter cooperii Y Red-shouldered Hawk Buteo lineatus Y Red-tailed Hawk Buteo jamaicensis
    [Show full text]
  • Recent Establishments and Extinctions of Northern Gannet Morus Bassanus Colonies in North Norway, 1995-2008
    Recent establishments and extinctions of Northern Gannet Morus bassanus colonies in North Norway, 1995-2008 Robert T. Barrett Barrett, R.T. 2008. Recent establishments and extinctions of Northern Gannet Morus bassanus colonies in North Norway, 1995-2008. – Ornis Norvegica 31: 172-182. Since the last published review of the development of the Northern Gannet Morus bassanus population in Norway (Barrett & Folkestad 1996), there has been a general increase in numbers breeding in North Norway from ca. 2200 occupied nests in 1995 to ca. 2700 in 2008. In Lofoten and Vesterålen, however, numbers have decreased from 1500 occupied nests in 1989 to 500 in 2008, and what were the two largest colonies on Skarvklakken and Hovsflesa have been abandoned. Small colonies have, in the meantime, been established in the region, but these are all characteristically unstable. A new colony established in Troms in 2001 increased to 400 occupied sites in 2007, but the population dropped to 326 in 2008. Harassment by White-tailed eagles Haliaeetus albicilla is mooted as the main cause of the decline in Lofoten and Vesterålen. Robert T. Barrett, Dept. of Natural Science, Tromsø University Museum, N-9037 Tromsø, Norway. INTRODUCTION the well-established colonies, Skarvklakken and Hovsflesa in the north of the country, there were Apart from perhaps the Great Skua Catharacta even signs of declines between 1991 and 1995. skua, there is no species whose establishment as a This paper documents the subsequent fate of the breeding bird in Norway and subsequent popula- North Norwegian colonies, including the extinc- tion development has been so well documented tion of some and the establishment of others.
    [Show full text]
  • A Guide to the Birds of Barrow Island
    A Guide to the Birds of Barrow Island Operated by Chevron Australia This document has been printed by a Sustainable Green Printer on stock that is certified carbon in joint venture with neutral and is Forestry Stewardship Council (FSC) mix certified, ensuring fibres are sourced from certified and well managed forests. The stock 55% recycled (30% pre consumer, 25% post- Cert no. L2/0011.2010 consumer) and has an ISO 14001 Environmental Certification. ISBN 978-0-9871120-1-9 Gorgon Project Osaka Gas | Tokyo Gas | Chubu Electric Power Chevron’s Policy on Working in Sensitive Areas Protecting the safety and health of people and the environment is a Chevron core value. About the Authors Therefore, we: • Strive to design our facilities and conduct our operations to avoid adverse impacts to human health and to operate in an environmentally sound, reliable and Dr Dorian Moro efficient manner. • Conduct our operations responsibly in all areas, including environments with sensitive Dorian Moro works for Chevron Australia as the Terrestrial Ecologist biological characteristics. in the Australasia Strategic Business Unit. His Bachelor of Science Chevron strives to avoid or reduce significant risks and impacts our projects and (Hons) studies at La Trobe University (Victoria), focused on small operations may pose to sensitive species, habitats and ecosystems. This means that we: mammal communities in coastal areas of Victoria. His PhD (University • Integrate biodiversity into our business decision-making and management through our of Western Australia)
    [Show full text]
  • How Seabirds Plunge-Dive Without Injuries
    How seabirds plunge-dive without injuries Brian Changa,1, Matthew Crosona,1, Lorian Strakerb,c,1, Sean Garta, Carla Doveb, John Gerwind, and Sunghwan Junga,2 aDepartment of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061; bNational Museum of Natural History, Smithsonian Institution, Washington, DC 20560; cSetor de Ornitologia, Museu Nacional, Universidade Federal do Rio de Janeiro, São Cristóvão, Rio de Janeiro RJ 20940-040, Brazil; and dNorth Carolina Museum of Natural Sciences, Raleigh, NC 27601 Edited by David A. Weitz, Harvard University, Cambridge, MA, and approved August 30, 2016 (received for review May 27, 2016) In nature, several seabirds (e.g., gannets and boobies) dive into wa- From a mechanics standpoint, an axial force acting on a slender ter at up to 24 m/s as a hunting mechanism; furthermore, gannets body may lead to mechanical failure on the body, otherwise known and boobies have a slender neck, which is potentially the weakest as buckling. Therefore, under compressive loads, the neck is po- part of the body under compression during high-speed impact. In tentially the weakest part of the northern gannet due to its long this work, we investigate the stability of the bird’s neck during and slender geometry. Still, northern gannets impact the water at plunge-diving by understanding the interaction between the fluid up to 24 m/s without injuries (18) (see SI Appendix, Table S1 for forces acting on the head and the flexibility of the neck. First, we estimated speeds). The only reported injuries from plunge-diving use a salvaged bird to identify plunge-diving phases.
    [Show full text]
  • Bird Vulnerability Assessments
    Assessing the vulnerability of native vertebrate fauna under climate change, to inform wetland and floodplain management of the River Murray in South Australia: Bird Vulnerability Assessments Attachment (2) to the Final Report June 2011 Citation: Gonzalez, D., Scott, A. & Miles, M. (2011) Bird vulnerability assessments- Attachment (2) to ‘Assessing the vulnerability of native vertebrate fauna under climate change to inform wetland and floodplain management of the River Murray in South Australia’. Report prepared for the South Australian Murray-Darling Basin Natural Resources Management Board. For further information please contact: Department of Environment and Natural Resources Phone Information Line (08) 8204 1910, or see SA White Pages for your local Department of Environment and Natural Resources office. Online information available at: http://www.environment.sa.gov.au Permissive Licence © State of South Australia through the Department of Environment and Natural Resources. You may copy, distribute, display, download and otherwise freely deal with this publication for any purpose subject to the conditions that you (1) attribute the Department as the copyright owner of this publication and that (2) you obtain the prior written consent of the Department of Environment and Natural Resources if you wish to modify the work or offer the publication for sale or otherwise use it or any part of it for a commercial purpose. Written requests for permission should be addressed to: Design and Production Manager Department of Environment and Natural Resources GPO Box 1047 Adelaide SA 5001 Disclaimer While reasonable efforts have been made to ensure the contents of this publication are factually correct, the Department of Environment and Natural Resources makes no representations and accepts no responsibility for the accuracy, completeness or fitness for any particular purpose of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of or reliance on the contents of this publication.
    [Show full text]
  • The Behaviour of the Gannet by J
    The behaviour of the Gannet By J. B. Nelson (Concluded from page 2 88) EGG LAYING THE ECOLOGY OF the egg laying of the Gannet Sula bassana (effect of density, age and nest position on the onset and synchronisation of laying) is discussed elsewhere (Nelson 1964a and in preparation). The act of deposition was observed on five occasions on all of which the tail was depressed and guided the egg into the nest—important in view of the Gannet's poorly developed retrieving ability. The one accurately timed laying took two minutes. Eggs may be laid at any time of day, and possibly also at night. INCUBATION Gannets (and apparently all Sulidae) lack brood patches and incubate their single egg beneath their webs, which become highly vascularised and hot during incubation. Non-breeding birds caught during the breeding season had cool webs, but no known breeders were caught off the nest, so it was not known whether webs remain hot. Howell and Bartholomew (1962) showed that the mean internal temperature of incubated eggs of the Red-footed Booby S. sula was 36° C. and the foot temperature 3 5.8° C, and suggested that the feet do not provide the main source of heat for incubation. They were vague in their alternative and the difference in the temperatures they recorded would seem too small to disprove the conventional view. The egg tempera­ ture achieved by this method compares favourably with that of brood- spot incubation (e.g. 36.6° C. for the surface temperature of Herring Gulls' eggs: Baerends 1959).
    [Show full text]