Recovery records of Great Cormorants banded in Southern Kanto, Japan

2020 ◽  
Vol 32 (1_2) ◽  
pp. 53-64
Author(s):  
Michio FUKUDA
Keyword(s):  
Great Cormorants

scholarly journals Nesting of Great Cormorants (Phalacrocorax carbo) on man-made structures in Ukraine

2016 ◽  
Vol 24 (2) ◽  
Author(s):  
A. I. Sidorenko ◽  
V. D. Siokhin
Keyword(s):  
National Level ◽  
Field Work ◽  
Current Data ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Breeding Sites ◽  
Breeding Territory ◽  
Wide Range ◽  
Maintenance Work ◽  
Great Cormorants

In Ukraine the Great Cormorant (Phalacrocorax carbo Linnaeus, 1758) uses a rather wide range of habitats for nesting: islands, trees and shrubs, reedbeds and a variety of man-made structures. In general, the strategy of nesting on man-made structures is uncommon both in Ukraine and Europe, and Cormorantsdo this only in the absence of other sites suitable for nesting. Special research onCormorant colonies on technogenic constructions was carried out during the field expeditions by the Research Institute of Biodiversity of Terrestrial and Aquatic Ecosystems of Ukraine in 2002–2003 and 2012–2016. Besides this, we used retrospective and current data from the literature and Internet resources. Most of the field work was carried out by making surveys by boat and on foot. As a result, we found 8 Cormorant colonies on technogenic constructions in Ukraine: gas platforms in the Sea of Azov (near the village Strilkove, Henichesk district of Kherson region); sunken ships – targets for bombing training near the Arabat Spit (these are also known as «ship islands»); electricity pylons of the high-voltage Enerhodar Dnipro Power Line where it crosses the Kakhovka Reservoir; the dock in Yahorlyk Bayk, used in the past as a target for bombing training bombing; artificial island-platforms on Lake Chernine (Kinburn Peninsula); an artificial island on the Sasyk Lagoon (Odessa region); artificial islands, made as navigation markers on the Kremenchuk and Kiev reservoirs. The study found that in most cases the accompanying species was the CaspianGull (Larus cachinnans Pallas, 1811), which actively destroys the Cormorants’ nests and eats their eggs and chicks. The number of nests in the colonies varied greatly (5–30 nests on the navigation marker islands and ca. 2 000–2 300 on the «ship-islands» and gas platforms). This is due, primarily, to the area of the breeding territory. The research found that fierce territorial competition was observed in most of the colonies both with Caspian Gulls and between Cormorants. In addition, we observed anthropogenic interference in the colonies by fishermen and workers conducting routine maintenance work (as happened in the case of electricity pylons and gas platforms). The benefit of this study is that it is the first research in Ukraine conducted at national level onthis type of nesting by Cormorants. Moreover, the study examines the history of emergence of these nesting territories and population dynamics of the Great Cormorant from the time of initial settlement of the breeding sites till the present.

scholarly journals Flock-fishing deep-diving piscivores (Great Crested Grebe Podiceps cristatus, Great Cormorant Phalacrocorax carbo, Common Merganser Mergus merganser) at Lake Vombsjön, southern Sweden, and those that exploit them

Ornis Svecica ◽  
2018 ◽  
Vol 28 (1) ◽  
Author(s):  
Hans Källander
Keyword(s):  
Great Cormorant ◽  
Southern Sweden ◽  
Phalacrocorax Carbo ◽  
Herring Gulls ◽  
Deep Diving ◽  
Large Numbers ◽  
Ardea Cinerea ◽  
Mergus Merganser ◽  
Podiceps Cristatus ◽  
Great Cormorants

Lake Vombsjön in southern Sweden is visited by large numbers of Great Crested Grebes Podiceps cristatus (>2000), Great Cormorants Phalacrocorax carbo (sometimes >1000) and Common Mergansers Mergus merganser (up to 2000) in late autumn and early winter. Different species exploit them. Great Crested Grebes are used especially by commensal Common Gulls Larus canus; the gulls take advantage of fish that flee towards the surface. Common Gulls also use cormorants and mergansers in the same way but also try to kleptoparasitize them. Both Herring Gulls Larus argentatus and Great Black-backed Gulls Larus marinus kleptoparasitize these two species, while Red Kites Milvus milvus, Grey Herons Ardea cinerea and Carrion Crows Corvus corone use them commensally. White-tailed Eagles Haliaeetus albicilla seem to use both methods to obtain fish. On 50% of one hundred visits during November to March, eagles were seen flying low over the fishing flocks. They would fly a metre or so above the flocks and then accelerate and attack a bird holding a fish. The bird would then either try to escape by a rush or by diving, dropping the fish which the eagle seized. Interestingly, the flock-fishing birds showed no fear reactions towards the eagles but appeared to regard them similarly to large gulls.

scholarly journals Great cormorant (Phalacrocorax carbo) predation on pikeperch (Sander lucioperca L.) in shallow eutrophic lakes in Poland

2017 ◽  
Vol 25 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Piotr Traczuk ◽  
Andrzej Kapusta
Keyword(s):  
Length Distribution ◽  
Bird Species ◽  
Fish Populations ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Sander Lucioperca ◽  
Eutrophic Lakes ◽  
Breeding Colony ◽  
Great Cormorants

AbstractIncreases in the population abundance of the piscivorous great cormorant (Phalacrocorax carbo) has led to conflicts with fisheries. Cormorants are blamed for decreased fish catches in many lakes in Poland. The aim of this paper is to describe to role of pikeperch (Sander lucioperca) in the diet of cormorants nesting in a colony on the island in Lake Warnołty. Since the breeding colony is located in the vicinity of Lake OEniardwy, the largest lake in Poland, the cormorants use the resources in this lake. In 2009-2016, 18,432 regurgitated fish were collected, of which 593 were pikeperch. The share of pikeperch among fish collected in 2009-2012 did not exceed 2%, but from 2013 this increased substantially to maximum of 38.2% in 2015. The smallest pikeperch had a standard length of 8.4 cm, and the largest 42.5 cm. Pikeperch mean length differed by year, and the length distribution was close to normal. The sizes of the regurgitated pikeperch indicate that cormorants prey almost exclusively on juvenile specimens. The results of the present study indicate that cormorant predation has a significant impact on pikeperch populations in lakes in the vicinity of the colony, and the great cormorants are possibly a significant factor in the effectiveness of pikeperch management. When planning for the management of fish populations in lakes subjected to cormorant predation pressure, it should be borne in mind that predation by this piscivorous bird species impacts the abundance and size-age structure of fish populations.

Levels of infection of gastric nematodes in a flock of great cormorants (Phalacrocorax carbo) from Lake Biwa, Japan

2011 ◽  
Vol 86 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Kh.M. El-Dakhly ◽  
E. El-Nahass ◽  
S. Uni ◽  
H. Tuji ◽  
H. Sakai ◽  
...  
Keyword(s):  
Lake Biwa ◽  
Single Species ◽  
Phalacrocorax Carbo ◽  
Connective Tissues ◽  
Inflammatory Reactions ◽  
Large Numbers ◽  
Mucosal Surfaces ◽  
Contracaecum Rudolphii ◽  
High Prevalence ◽  
Great Cormorants

AbstractA high prevalence (86.7%) of various species of nematodes was observed in the stomach of great cormorants living in Lake Biwa, Japan. There were varying numbers of adults belonging to two common genera, Eustrongylides Jagerskiold 1909 (Nematoda: Dioctophymatidae) and Contracaecum Railliet & Henry 1912 (Nematoda: Anisakidae). The first included common adenophorean nematodes comprising a single species, Eustrongylides tubifex and the second comprised ascaroid nematodes that contained four named species: Contracaecum rudolphii Hartwich, 1964, Contracaecum microcephalum Yamaguti, 1961, Contracaecum multipapillatum Drasche, 1882 and Contracaecum chubutensis Garbin, 2008. After the prevalence and intensity of the infection had been noted, both types of nematodes were frequently observed to penetrate the mucosa and intrude into the wall of the glandular stomach, where they caused gross haemorrhage and ulceration. The Eustrongylides sp. was predominantly found in a nodular lesion of the proventricular wall, while Contracaecum spp. were observed either free in the lumen of the proventriculus or, on occasion, deeply penetrating its wall. Of the Contracaecum spp., C. rudolphii was the most prevalent. Grossly, large numbers of nematodes were present in infected stomachs (for C. rudolphii intensity was 1–34 and 3–57 nematodes in male birds and 1–21 and 1–32 in females; for C. microcephalum 1–2 and 1 in male birds and 1–2 in females; for C. multipapillatum 2 in male cormorants and no infection in females; for C. chubutensis 1–2 and 1 in male birds and 1–5 and 1 in females and for E. tubifex 1–5 nematodes in male birds and 2–8 in females). Ulcerative inflammation and hyperaemia were the most common pathological presentations, especially in areas that had been invaded by parasites. Microscopically, varying degrees of granulomatous inflammatory reactions were seen, in addition to degenerated nematodes which appeared to have deeply penetrated mucosal surfaces and were surrounded by fibrous connective tissues.

scholarly journals Diet of harbour seals and great cormorants in Limfjord, Denmark: interspecific competition and interaction with fishery

2007 ◽  
Vol 64 (6) ◽  
pp. 1235-1245 ◽  
Author(s):  
Signe M. Andersen ◽  
Jonas Teilmann ◽  
Pernille B. Harders ◽  
Else H. Hansen ◽  
Dorthe Hjøllund
Keyword(s):  
Interspecific Competition ◽  
Prey Species ◽  
Water System ◽  
Open Water ◽  
Diet Analysis ◽  
Atlantic Herring ◽  
Harbour Seals ◽  
Closed Water ◽  
Great Cormorants ◽  
Seal Diet

Abstract Andersen, S. M., Teilmann, J., Harders, P. B., Hansen, E. H., and Hjøllund, D. 2007. Diet of harbour seals and great cormorants in Limfjord, Denmark: interspecific competition and interaction with fishery. – ICES Journal of Marine Science, 64: 1235–1245. Comparative studies on seasonal and regional variation in the diet of harbour seals and great cormorants were conducted in Limfjord, a semi-closed water system in northwest Denmark. To compare harbour seal diet from an open water system containing similar prey species, a small diet analysis from the western Baltic is included. Seal diet during spring reflected the abundance of Atlantic herring entering Limfjord to spawn (90% of the weight consumed), whereas during summer and autumn, seal diet was rather more mixed. The diet of seals in the Rødsand area and cormorants in Limfjord showed no marked seasonal trends. During spring, there was little overlap between seal and cormorant diets in Limfjord because seals fed almost exclusively on Atlantic herring, and they consumed significantly larger herring than did the cormorants. During summer and autumn, seal and cormorant diets overlapped markedly, although the fish items consumed by seals were generally larger. Few commercially targeted species were found in the stomachs and scats of seals and casts of great cormorants, but Atlantic herring were taken by the seals at a size greater than that allowed by the fishery.

Annual Variation in Diet of Breeding Great Cormorants: Does it Reflect Varying Recruitment of Gadoids?

Waterbirds ◽  
2004 ◽  
Vol 27 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Svein-Håkon Lorentsen ◽  
David Grémillet ◽  
Geir Håvard Nymoen
Keyword(s):  
Annual Variation ◽  
Great Cormorants

scholarly journals Cormorants dive through the Polar night

2005 ◽  
Vol 1 (4) ◽  
pp. 469-471 ◽  
Author(s):  
David Grémillet ◽  
Grégoire Kuntz ◽  
Caroline Gilbert ◽  
Antony J Woakes ◽  
Patrick J Butler ◽  
...  
Keyword(s):  
Visual Cues ◽  
Significant Proportion ◽  
Dive Depth ◽  
Day Length ◽  
The Arctic ◽  
High Latitudes ◽  
Phalacrocorax Carbo ◽  
Polar Night ◽  
Light Levels ◽  
Great Cormorants

Most seabirds are visual hunters and are thus strongly affected by light levels. Dependence on vision should be problematic for species wintering at high latitudes, as they face very low light levels for extended periods during the Polar night. We examined the foraging rhythms of male great cormorants ( Phalacrocorax carbo ) wintering north of the Polar circle in West Greenland, conducting the first year-round recordings of the diving activity in a seabird wintering at high latitudes. Dive depth data revealed that birds dived every day during the Arctic winter and did not adjust their foraging rhythms to varying day length. Therefore, a significant proportion of the dive bouts were conducted in the dark (less than 1 lux) during the Polar night. Our study underlines the stunning adaptability of great cormorants and raises questions about the capacity of diving birds to use non-visual cues to target fish.

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