Partitioning of Nesting Space Among Seabirds of the Benguela Upwelling Region
Total Page:16
File Type:pdf, Size:1020Kb
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. -
Differential Responses of Boobies and Other Seabirds in the Galapagos to the 1986-87 El Nino- Southern Oscillation Event
MARINE ECOLOGY PROGRESS SERIES Published March 22 Mar. Ecol. Prog. Ser. Differential responses of boobies and other seabirds in the Galapagos to the 1986-87 El Nino- Southern Oscillation event David J. Anderson Department of Biology. University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA ABSTRACT: The impact of the 1986-87 El Nido-Southern Oscillation (ENSO) event on seabirds in the Galapagos Islands was generally less severe than that of the previous ENSO in 1982-83. Sea surface temperatures (SST) rose to levels comparable to those of 4 ENSOs pnor to the 1982-83 event. SST became anomalous approximately in January and had returned to typical levels by July. Blue-footed booby Sula nebouxii reproductive attempts failed throughout the archipelago, and breeding colonies were deserted, shortly after SST became unusually warm in January. Masked boobies S. dactylatra, red- footed boobies S. sula and several other species were apparently unaffected by the anomalous conditions, or temporarily suspended breeding for several months. A gradient in both SST and in the ENSO's impact on some seabirds was evident, with populations nesting in the cooler south of the archipelago affected less than those in the warmer north. At one colony studied both before and during the ENSO, blue-footed booby failure was associated with apparent reductions in both availablllty and body size of their primary prey item. INTRODUCTION 1985 (Valle 1986). The diversity of responses produced seabird assemblages with proportions and reproductive Oceanographic change has a dramatic impact upon performances that were markedly different, over the tropical seabird reproduction and adult mortality on short term at least, from pre-ENS0 assemblages, and both local and regional scales. -
A Suggested Blueprint for the Development of Maritime Archaeological Research in Namibia Bruno E.J.S
Journal of Namibian Studies, 2 (2007): 103–121 ISSN: 1863-5954 A suggested blueprint for the development of maritime archaeological research in Namibia Bruno E.J.S. Werz Abstract During the last few decades, maritime archaeology has developed into an internationally accepted field of specialisation within the discipline of archaeology. It has, however, only gained academic recognition in Southern Africa since the late 1980s, when a lecturing post for maritime archaeology was established at the University of Cape Town. This resulted in initial efforts being focused on South Africa. Now, however, the time has come to expand the development of maritime archaeology to neighbouring countries. Due to various positive factors – including the presence of an important research potential as well as growing interest and positive contributions by some organisations and private individuals – Namibia provides a fertile ground to extend the field of operations. This article first summarises the objectives and methodology of maritime archaeological research in general; then it offers suggestions as to how to establish this research specialisation in Namibia, bearing in mind local circumstances. What is Maritime Archaeology? Maritime archaeology developed by means of an evolutionary process from underwater salvage, treasure hunting, the collecting of antiquities and the kind of archaeological work that was done until the early twentieth century. During the 1960s, the field became an area of specialisation within the discipline of archaeology. This period saw a growing involvement of professional archaeologists, the rudimentary development of research designs, the improvement of diving equipment, and the application of techniques that facilitated work in an underwater environment. The initial emphasis, however, was on the latter.1 As a result, the field did not obtain widespread support from its terrestrial counterparts, where efforts were generally directed at solving specific research problems. -
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. -
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). -
CROWNED CORMORANT | Microcarbo Coronatus (Phalacrocorax Coronatus)
CROWNED CORMORANT | Microcarbo coronatus (Phalacrocorax coronatus) J Kemper | Reviewed by: T Cook; AJ Williams © Jessica Kemper Conservation Status: Near Threatened Southern African Range: Coastal Namibia, South Africa Area of Occupancy: 6,700 km2 Population Estimate: 1,200 breeding pairs in Namibia Population Trend: Stable to slightly increasing Habitat: Coastal islands and rocks, protected mainland sites, artificial structures, inshore marine waters Threats: Disturbance, entanglement in human debris and artificial structures, predation by gulls and seals, pollution from oiling 152 BIRDS TO WATCH IN NAMIBIA DISTRIBUTION AND ABUNDANCE TABLE 2.5: A resident species with some juvenile dispersal, this small Number of Crowned Cormorant breeding pairs at individu- cormorant is endemic to south-west Namibia and west al breeding localities in Namibia (listed north to south), esti- to south-western South Africa. It has a very restricted mated from annual peaks of monthly nest counts at Mercu- ry, Ichaboe, Halifax and Possession islands, and elsewhere range along the coastline (Crawford 1997b), occupying an from opportunistic counts, not necessarily done during peak area of about 6,700 km2 in Namibia (Jarvis et al. 2001). It breeding (Bartlett et al. 2003, du Toit et al. 2003, Kemper et usually occurs within one kilometre of the coast, and has al. 2007, MFMR unpubl. data). not been recorded more than 10 km from land (Siegfried et al. 1975). It breeds at numerous localities in Namibia Number of Date of most and South Africa. In Namibia, it is known to breed at 12 breeding recent reliable islands, five mainland localities and one artificial structure, Breeding locality pairs estimate from Bird Rock Guano Platform near Walvis Bay to Sinclair Bird Rock Platform 98 1999/2000 Island (Table 2.5: Bartlett et al. -
The German Colonization of Southwest Africa and the Anglo-German Rivalry, 1883-1915
University of Nebraska at Omaha DigitalCommons@UNO Student Work 7-1-1995 Doors left open then slammed shut: The German colonization of Southwest Africa and the Anglo-German rivalry, 1883-1915 Matthew Erin Plowman University of Nebraska at Omaha Follow this and additional works at: https://digitalcommons.unomaha.edu/studentwork Recommended Citation Plowman, Matthew Erin, "Doors left open then slammed shut: The German colonization of Southwest Africa and the Anglo-German rivalry, 1883-1915" (1995). Student Work. 435. https://digitalcommons.unomaha.edu/studentwork/435 This Thesis is brought to you for free and open access by DigitalCommons@UNO. It has been accepted for inclusion in Student Work by an authorized administrator of DigitalCommons@UNO. For more information, please contact [email protected]. DOORS LEFT OPEN THEN SLAMMED SHUT: THE GERMAN COLONIZATION OF SOUTHWEST AFRICA AND THE ANGLO-GERMAN RIVALRY, 1883-1915. A Thesis Presented to the Department of History and the Faculty of the Graduate College University of Nebraska In Partial Fulfillment of the Requirements for the Degree Master of Arts University of Nebraska at Omaha by Matthew Erin Plowman July 1995 UMI Number: EP73073 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI Blsaartalibn Publish*rig UMI EP73073 Published by ProQuest LLC (2015). Copyright in the Dissertation held by the Author. -
First Atlantic Records of the Red-Footed Booby Sula Sula and Brown Booby S. Leucogaster in Southern Africa
36 FIRST ATLANTIC RECORDS OF THE RED-FOOTED BOOBY SULA SULA AND BROWN BOOBY S. LEUCOGASTER IN SOUTHERN AFRICA B.M. DYER1 & Y. CHESSELET2 1Marine and Coastal Management, Private Bag X2, Roggebaai 8012, South Africa ([email protected]) 2Ministry of Fisheries and Marine Resources, PO Box 394, Lüderitz, Namibia Received 31 August 2000, accepted 18 April 2002 The Red-footed Booby Sula sula and the Brown Booby S. taken to the Southern African Foundation for the Conservation of leucogaster occur in most tropical seas (Harrison 1983). Both Coastal Birds (SANCCOB) rescue station for treatment, but died species have been recorded previously in the southern African three days later. The corpse was then sent for necropsy to the region (Maclean 1993, Hockey et al. 1992, 1996). Three addi- Regional Veterinary Laboratory, Stellenbosch. Enterobacter coli tional records are reported here for the Red-footed Booby and one and other Enterobacteriae were identified but were considered (the third) for the Brown Booby in southern Africa, all from the unlikely to have caused death. The stomach was empty. The speci- Atlantic coast. men (the first for South Africa) is in the South African Museum (SAM ZO58494). Morphometric details are culmen 79.9 mm, tarsus 237.5 mm, wing 372 mm, and tail 192 mm. RED-FOOTED BOOBY The three records published here are the first for the Atlantic coast A white-morph Red-footed Booby was observed at Ichaboe Island of southern Africa although several records exist for the eastern (26°17'S, 14°56'E) by Y.C., c. 30 km north of Lüderitz, Namibia coast, all from Mozambique (Hockey et al. -
Flight Patterns and Energy Budget of the Cape Gannet
Energy Budget and foraging behaviour of the Cape gannet Morus capensis during the breeding season René Alfredo Navarro-Cañas BSc. Biology - MSc. Zoology Universidad Austral de Chile Thesis presented for the Degree of Doctor of Philosophy in the Department of Zoology University of Cape Town 2010 Supervised by: Professor L.G. Underhill Co-supervised by: Dr. R.J.M. Crawford 2 Declaration I hereby declare that all of the work presented in this thesis, titled “Energy Budget and foraging behaviour of the Cape gannet, Morus capensis, during the breeding season”, is my own, except where otherwise stated in the text. This thesis has not been submitted in whole or in part for a degree at any other university. Signed in Cape Town in July 2010, René Alfredo Navarro-Cañas Date of graduation: December 16th, 2010 3 4 To Henk Visser Whose vision and enthusiasm lead to this project, it’s funding and its beginnings. I am grateful for the trust and opportunity he gave me to conduct this piece of research “Supiste que vencer o ser vencido son caras de un azar indiferente, que no hay otra virtud que ser valiente.” Did you know that to win or to be defeated are faces of an indifferent fate that there is no other virtue that being brave Jorge Luis Borges 5 6 Contents Chapter 1 General introduction 19 Chapter 2 The growth of Cape gannet chicks: intra- and inter- 31 seasonal comparisons of growth performance in relation to adults foraging effort and prey availability Chapter 3 Energy expenditure of free-ranging chicks of the 57 Cape gannet Chapter 4 Water everywhere but not a drop to drink: water flux 89 and water economy of free-ranging Cape gannets Chapter 5 A new look at track sinuosity: using distance-ratio 105 scale for the analysis of animal movement Chapter 6 Unpredictable resources and foraging strategies in 129 Cape gannets Chapter 7 Energy expenditure Cape gannets in relation to 157 foraging behaviour Chapter 8 Synthesis. -
Breeding Seabirds at Dassen Island, South Africa: Chances of Surviving Great White Pelican Predation
Vol. 9: 125–131, 2010 ENDANGERED SPECIES RESEARCH Published online January 11 doi: 10.3354/esr00243 Endang Species Res OPENPEN ACCESSCCESS Breeding seabirds at Dassen Island, South Africa: chances of surviving great white pelican predation Martin M. Mwema1, 2,*, Marta de Ponte Machado1, 2, Peter G. Ryan1 1Percy Fitzpatrick Institute, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa 2Animal Demography Unit, Department of Zoology, University of Cape Town, Rondebosch 7701, South Africa Present address: Box 1019, 00100, GPO, Nairobi, Kenya ABSTRACT: Seabird predation by great white pelicans Pelecanus onocrotalus is an unusual phenom- enon that has become increasingly frequent in the Western Cape, South Africa. We report the scale of pelican predation and its impact on the breeding success of 5 seabird species monitored at Dassen Island in 2006. Pelican predation was observed on chicks of kelp gulls Larus dominicanus, crowned cormorants Phalacrocorax coronatus and Cape cormorants Phalacrocorax capensis. No predation on eggs was seen. Breeding success for 4 of the 5 species studied was low, with the white-breasted cor- morants Phalacrocorax lucidus having the highest breeding success (0.56 fledglings per nest). Cape and bank cormorants Phalacrocorax neglectus did not fledge any chicks, while crowned cormorants had a breeding success of 0.08 fledglings per nest. Kelp gulls had a hatching success of 46%, but only a few chicks fledged, giving a breeding success of 0.06 fledglings per nest. Pelican predation poses a threat to at least 3 of the 5 seabirds studied, all of which are endemic to southern Africa. Three spe- cies are globally Endangered or Near Threatened, and pelican predation places additional pressure on these species. -
A Report on the Guano-Producing Birds of Peru [“Informe Sobre Aves Guaneras”]
PACIFIC COOPERATIVE STUDIES UNIT UNIVERSITY OF HAWAI`I AT MĀNOA Dr. David C. Duffy, Unit Leader Department of Botany 3190 Maile Way, St. John #408 Honolulu, Hawai’i 96822 Technical Report 197 A report on the guano-producing birds of Peru [“Informe sobre Aves Guaneras”] July 2018* *Original manuscript completed1942 William Vogt1 with translation and notes by David Cameron Duffy2 1 Deceased Associate Director of the Division of Science and Education of the Office of the Coordinator in Inter-American Affairs. 2 Director, Pacific Cooperative Studies Unit, Department of Botany, University of Hawai‘i at Manoa Honolulu, Hawai‘i 96822, USA PCSU is a cooperative program between the University of Hawai`i and U.S. National Park Service, Cooperative Ecological Studies Unit. Organization Contact Information: Pacific Cooperative Studies Unit, Department of Botany, University of Hawai‘i at Manoa 3190 Maile Way, St. John 408, Honolulu, Hawai‘i 96822, USA Recommended Citation: Vogt, W. with translation and notes by D.C. Duffy. 2018. A report on the guano-producing birds of Peru. Pacific Cooperative Studies Unit Technical Report 197. University of Hawai‘i at Mānoa, Department of Botany. Honolulu, HI. 198 pages. Key words: El Niño, Peruvian Anchoveta (Engraulis ringens), Guanay Cormorant (Phalacrocorax bougainvillii), Peruvian Booby (Sula variegate), Peruvian Pelican (Pelecanus thagus), upwelling, bird ecology behavior nesting and breeding Place key words: Peru Translated from the surviving Spanish text: Vogt, W. 1942. Informe elevado a la Compañia Administradora del Guano par el ornitólogo americano, Señor William Vogt, a la terminación del contracto de tres años que con autorización del Supremo Gobierno celebrara con la Compañia, con el fin de que llevara a cabo estudios relativos a la mejor forma de protección de las aves guaneras y aumento de la produción de las aves guaneras. -
KELP BLUE NAMIBIA (Pty) Ltd
KELP BLUE NAMIBIA (Pty) Ltd EIA SCOPING & IMPACT ASSESSMENT REPORT AND ENVIRONMENTAL MANAGEMENT PLAN FOR THE PROPOSED KELP CULTIVATION PILOT PROJECT NEAR LÜDERITZ, KARAS REGION Prepared for: Kelp Blue Namibia (Pty) Ltd August 2020 1 DOCUMENT CONTROL Report Title EIA SCOPING & IMPACT ASSESSMENT REPORT FOR THE PROPOSED KELP CULTIVATION PILOT PROJECT NEAR LÜDERITZ, KARAS REGION Report Author Werner Petrick Client Kelp Blue Namibia (Pty) Ltd Project Number NSP2020KB01 Report Number 1 Status Final to MEFT and MFMR Issue Date August 2020 DISCLAIMER The views expressed in the document are the objective, independent views of the author with input from various Environmental and Social Experts (i.e. Specialists). Neither Werner Petrick nor Namisun Environmental Projects and Development (Namisun) have any business, personal, financial, or other interest in the proposed Project apart from fair remuneration for the work performed. The content of this report is based on the author’s best scientific and professional knowledge, input from the Environmental Specialists, as well as available information. Project information contained herein is based on the interpretation of data collected and data provided by the client, accepted in good faith as being accurate and valid. Namisun reserves the right to modify the report in any way deemed necessary should new, relevant, or previously unavailable or undisclosed information become available that could alter the assessment findings. This report must not be altered or added to without the prior written consent of the author. Project Nr: NSP2020KB01 EIA SCOPING & IMPACT ASSESSMENT REPORT AND EMP FOR August 2020 Report number: 1 THE PROPOSED KELP CULTIVATION PILOT PROJECT 2 Table of Contents 1 INTRODUCTION ..................................................................................................................................