Reproduction du Grand Cormoran (Phalacrocorax carbo) et du Cormoran à aigrettes (P. auritus) aux îles de la Madeleine, Québec

1983 ◽  
Vol 61 (3) ◽  
pp. 524-530 ◽  
Author(s):  
Christian Pilon ◽  
Jean Burton ◽  
Raymond McNeil
Keyword(s):  
Mortality Rate ◽  
Clutch Size ◽  
Hatching Success ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Different Types ◽  
Nesting Sites ◽  
The Mean ◽  
Great Cormorants ◽  
La Madeleine

The Great Cormorant (Phalacrocorax carbo) and the Double-crested Cormorant (P. auritus) on the Magdalen Islands (Québec) nest in different types of habitat; all Great Cormorants nest on the ground either on cliff ledges or on the flat tops of rocky islands, while all Double-crested Cormorants nest in coniferous trees. No mixed colonies were seen in 1977 and 1978. Most Great Cormorants laid their eggs some 10 days before the Double-crested Cormorants. The mean clutch size was 4.4 for the Great Cormorant in 1978 and 3.2 and 3.6 for the Double-crested Cormorant in 1977 and 1978. The hatching success was similar for both species, 69.2% for the Great Cormorant in 1978 and 74.5 and 71.8% for the Double-crested Cormorant in 1977 and 1978. Great Cormorant chicks had a higher mortality rate mainly during their first 2 weeks of like. This resulted in a similar ratio of young fledged for both species of cormorant, about 2.0 fledglings per clutch for the Great Cormorant and 2.1 and 2.4 fledglings per clutch for the Double-crested Cormorant in 1977 and 1978. The greater mortality rate of young Great Cormorants reflects differences in nesting sites' conditions.

Distribution of pair quality in a tree-nesting waterbird colony: central-periphery model vs. satellite model

2012 ◽  
Vol 90 (7) ◽  
pp. 861-867 ◽  
Author(s):  
Piotr Minias ◽  
Krzysztof Kaczmarek ◽  
Tomasz Janiszewski
Keyword(s):  
Clutch Size ◽  
Theoretical Models ◽  
Predation Rate ◽  
Site Quality ◽  
Laying Date ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Fledging Success ◽  
Heterogeneous Habitats ◽  
Nesting Sites

The spatial distribution of pair quality within waterbird colonies has been suggested to follow one of three theoretical models: central-periphery, satellite, or random. The central-periphery pattern occurs in homogeneous habitats, where good-quality pairs occupy better protected, central nesting sites. In contrast, the satellite and random patterns are associated with heterogeneous habitats and they assume that good-quality pairs occupy the most attractive nesting sites irrespectively of their location within the colony. Spatial patterns of laying date, clutch size, and fledging success were analysed with geostatistical tools in the colony of tree-nesting subspecies of Great Cormorant ( Phalacrocorax carbo sinensis (Blumenbach, 1798)) in central Poland. There was support for the random or satellite model in the distribution of clutch size, which was considered a reliable proxy of pair quality. We also found a positive correlation of clutch size with nest height. These results implicate that the habitat of tree-nesting colonial waterbirds may produce sufficient variation in the nesting-site quality to disrupt the central-periphery gradients of pair-quality distribution. In contrast, distribution of fledging success within the colony followed a clear central-periphery pattern, which was suggested to reflect an increased predation rate at the edges of the colony, rather than the intrinsic quality of breeding birds.

Summer food of the Great and Double-crested Cormorants on the Magdalen Islands, Quebec

1983 ◽  
Vol 61 (12) ◽  
pp. 2733-2739 ◽  
Author(s):  
Christian Pilon ◽  
Jean Burton ◽  
Raymond McNeil
Keyword(s):  
Clupea Harengus ◽  
Great Cormorant ◽  
Pseudopleuronectes Americanus ◽  
Phalacrocorax Carbo ◽  
Nesting Sites ◽  
Capelin Mallotus Villosus ◽  
Great Cormorants ◽  
Clupea Harengus Harengus ◽  
Associated Species ◽  
Magdalen Islands

This study of the food of the Great Cormorant (Phalacrocorax carbo) and the Double-crested Cormorant (P. auritus) on the Magdalen Islands, Quebec, is based on regurgitations and pellets collected on nesting sites during the summers of 1977 and 1978. Both species generally ate flatfishes (especially the winter flounder, Pseudopleuronectes americanus), American sand lances (Ammodytes americanus) and cunners (Tautogolabrus adspersus). Relatively more Great Cormorants than Double-crested Cormorants ate flatfishes and cunners during both summers, while relatively more Double-crested Cormorants fed on American sand lances during the summer of 1977. These fishes and other prey taken in lesser extent were mostly bottom-associated species; however both cormorants, especially the Double-crested Cormorant, take advantage of Capelin (Mallotus villosus) and Atlantic Herring (Clupea harengus harengus) schools which come spawning close to the seashore. Great and Double-crested cormorants appear to be opportunistic feeders since their diet varies with the availability of prey.

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.

scholarly journals Pathology associated with Contracaecum rudolphii (Nematoda: Anisakidae) infection in the great cormorant Phalacrocorax carbo (L. 1758)

2011 ◽  
Vol 48 (1) ◽  
pp. 29-35 ◽  
Author(s):  
J. Rokicki ◽  
Z. Sołtysiak ◽  
J. Dziekońska-Rynko ◽  
J. Borucińska
Keyword(s):  
Monitoring Program ◽  
Great Cormorant ◽  
Potential Contribution ◽  
Secretory Product ◽  
Phalacrocorax Carbo ◽  
European Continent ◽  
Associated Lesions ◽  
Contracaecum Rudolphii ◽  
Gun Shot ◽  
Great Cormorants

AbstractThis is a report of lesions associated with the nematode Contracaecum rudolphii (Nematoda: Anisakidae) from the proventriculus of the great cormorant, Phalacrocorax carbo (L. 1758). The study was undertaken as part of a health monitoring program for P. carbo, which is endangered and thus protected within the European continent. Cormorants were collected by gun-shot from north-eastern Poland in the spring of 2006, four birds were necropsied on site and the gastrointestinal tract was examined for the presence of nematodes. The birds came from a region with noted increases in the cormorant population over the last decade. Esophageal and gastric sections with parasites in situ were fixed in formalin and processed routinely for paraffin embedding, stained with H&E and examined by brightfield microscopy. Parasite associated lesions consisted of severe, ulcerative gastritis at the attachment sites, and diffuse granulomatous gastritis in adjacent areas. Eosinophilic material speculated to be the parasite-derived excretory-secretory product was consistently forming the parasite-host boundry at the attachment points. Although the parasite-associated gastric lesions were focally severe, all examined birds appeared in good body condition. Because only four birds were investigated in this study, the potential contribution of C. rudolphii to morbidity and mortality in great cormorants needs to be examined further.

scholarly journals Breeding biology of Bengal eyed turtle Morenia petersi (Anderson 1879) in Bangladesh

2015 ◽  
Vol 42 (2) ◽  
pp. 169-181
Author(s):  
Md Lokman Hossain ◽  
Shorab Uddin Sarker ◽  
Noor Jahan Sarker
Keyword(s):  
Incubation Period ◽  
Clutch Size ◽  
Breeding Season ◽  
Gravid Female ◽  
Gonad Development ◽  
Egg Laying ◽  
Nesting Sites ◽  
Fallow Lands ◽  
The Mean ◽  
Second Clutch

This study was conducted to determine the breeding season, gonad development, egg laying period, clutch size and other biological aspects of Bengal Eyed Turtle, Morenia petersi of Bangladesh. The egg-laying period was found between November and February. The nesting sites were elevated fallow lands in secluded areas. The female turtle laid all the mature eggs at a time for each clutch at night. A gravid female turtle laid two clutches of eggs in each breeding season and the mean clutch size was 9.7 ± 1.5 eggs and mean weight of each egg was 8.9 ± 1.3 g. The eggs are elongated in shape and whitish in colour. The mean incubation period was 119 ± 30 days. The incubation period of first clutch was the longer than the second clutch. The hatchlings emerged out between April and May. Hatchery success was found 56.8%. The percentage of weight gain and specific growth rate (SGR) by weight of hatchlings in the first year was greater than second and third year. Present investigation was made to explore the possibility to raise turtle farming in captive condition.Bangladesh J. Zool. 42(2): 169-181, 2014

scholarly journals Genetic diversity of Great Cormorants Phalacrocorax carbo in the eastern Baltic region

Biologija ◽  
2016 ◽  
Vol 62 (3) ◽  
Author(s):  
Dalius Butkauskas ◽  
Kristina Chaika ◽  
Saulius Švažas ◽  
Gennady Grishanov ◽  
Algimantas Paulauskas ◽  
...  
Keyword(s):  
Haplotype Network ◽  
Great Cormorant ◽  
Baltic Region ◽  
Phalacrocorax Carbo ◽  
The Baltic Sea ◽  
Continental Part ◽  
Kaliningrad Region ◽  
Great Cormorants ◽  
The Baltic ◽  
Eastern Baltic

A rapid expansion of the continental subspecies of the Great Cormorant (Phalacrocorax carbo sinensis) has been recorded in Europe since the 1980s. Evaluation of genetic variability of the  Great Cormorant using molecular markers is necessary for investigation of the mechanisms of formation of the newly established breeding populations in the  eastern Baltic region (in the Kaliningrad region of Russia and in Lithuania). The  samples for molecular investigation were collected in the largest breeding colonies of Great Cormorants located on the coast of the Curonian Lagoon of the Baltic Sea and in their smaller, later formed breeding colonies located in the continental part of Lithuania. After sequencing and alignment of partial fragments of mtDNA control region, 21 different haplotypes, including 8 new haplotypes never identified before, and 13 haplotypes described earlier were found. They were distributed with different frequency in different sampling sites. The haplotype network constructed using 342 bp D-loop sequences identified during the  current study and all available sequences of Great Cormorants deposited in GenBank by previous investigators revealed haplotypes attributed to subspecies P. c. sinensis being distinguished from haplotypes of subspecies P. c. carbo in the separate part of haplotype network. The newly described haplotypes did not form a phylogenetically uniform group indicating possible colonization of the Kaliningrad region and the continental part of Lithuania by individuals descending from the  largest breeding colonies spread at the  coast zone of the  Baltic Sea. A  high level of genetic population diversity in different breeding colonies recorded in the Kaliningrad region and in eastern Lithuania confirms the formation of a highly variable and well-adapted population of the Great Cormorant participating in the process of colonization of new breeding areas in the Baltic region.

scholarly journals Nestling Development of Jackdaws Corvus monedula in Agricultural Landscape

2015 ◽  
Vol 39 (1) ◽  
pp. 4-23
Author(s):  
Piotr Kamiński ◽  
Leszek Jerzak ◽  
Joerg Boehner
Keyword(s):  
Mortality Rate ◽  
Ambient Temperature ◽  
Clutch Size ◽  
Agricultural Landscape ◽  
Hatching Success ◽  
Egg Laying ◽  
Point Of View ◽  
Ne Poland ◽  
Temperature And Precipitation ◽  
Nestling Development

Abstract A Jackdaw colony of over 200 nests, built in cavities of old willow trees along 3 km of a small road running through meadows next to the river Narew in an agricultural landscape (15 km southwest of Białystok, NE Poland), was studied to determine nest locations and construction, onset of egg laying, incubation period, egg parameters, clutch size and hatching success, nestling growth and mortality, breeding success as well as predation. The onset of laying and clutch size were correlated with ambient temperature and precipitation (p < 0.001). Hatching success was also determined by these environmental factors as well as by the degree of predation (p < 0,001). There was a statistically significant correlation between clutch size and hatching success (p < 0.001) as well as fledging success (p < 0.001). Nestlings hatching first or second grew faster, reached a higher body weight, and had a lower mortality rate than those hatching last or second to last. There was also a statistically significant correlation between nestling survival and clutch size as well as ambient temperature (p < 0.001 each). Nestling mortality caused by predators, i. e. mainly by martens Martes foina and domestic cats Felis domestica, was high in periods of intensive burning of the meadows surrounding the Jackdaw colony. However, mortality rate of the youngest nestlings was almost 100% lower in periods of high predation compared to times of low predatory activity. Several groups of insects constituted a high amount of nestling food, e. g. 60% of all Orthoptera occurring in the meadows next to the breeding colony. In that area the total dry body mass of phytophagous invertebrates amounted to 1.4-2.0 g per m2, of which 0.3 g were fed to the nestlings. The percentage of zoophagous invertebrates delivered to the offspring was high with about 30-35%. From an economical point of view, Jackdaws during the breeding season are advantageous in an agricultural landscape because they reduce pest insects significantly while consuming only an insignificant amount of all seeds applied.

scholarly journals Pied-Billed Grebe Nesting Ecology on Squaw Creek National Wildlife Refuge,1996–2007

2008 ◽  
Vol 42 (2008) ◽  
pp. 23-29
Author(s):  
Jessica F. Lee ◽  
Francis E. Durbian ◽  
Ron Bell ◽  
Michael Voltz
Keyword(s):  
Clutch Size ◽  
Water Depth ◽  
Vegetation Type ◽  
Hatching Date ◽  
National Wildlife Refuge ◽  
Nesting Ecology ◽  
Wildlife Refuge ◽  
Nesting Sites ◽  
The Mean ◽  
Nest Initiation

Pied-billed Grebes (Podilymbus podiceps) are secretive water-birds that build floating nests in smaller wetlands. Our study focused on the nesting ecology, including phenology, of Pied-billed Grebes at Squaw Creek National Wildlife Refuge in northwest Missouri during an 11 year period. We located 956 Pied-billed Grebe nests in wetlands from April to July 1996–2007 and documented the number of eggs in the nest, water depth at the nest, and surrounding vegetation. Using this information, the mean clutch size, mean nest initiation date, mean hatching date, mean water depth at nesting sites, and most common vegetation types surrounding nests were determined and analyzed for differences among years. The mean clutch size for all nests was 7.18 eggs/nest (SE = 0. 09, n = 249) although clutch size significantly varied among years (F=3.51, df=7, P=0.0013). Mean nest initiation date from 414 nests was 18 May while the mean hatching date was 11 June. Both dates were significantly different among years (F=31.86, df=11, P&lt;0.0001 and F=31.93, df=11, P&lt;0.0001). Mean water depth at nest sites was 62.03 cm (SE=0.45, n=561) and varied significantly across years (F=46.50, df= 7, P&lt;0.0001). River bulrush (Schoenoplectus fluviatilis) was the most common vegetation type found at 72.2% of 573 nesting sites followed by arrowhead (Sagitarria latifolia) (23.2%), smartweed (Polygonum sp.) (20.8%), and American lotus (Nelumbo lutea) (19.5%). All Pied-billed Grebe nesting data from Squaw Creek NWR falls within the ranges reported in other nesting studies. It appears current management on the refuge is adequate to support quality Pied-billed Grebe nesting habitat.

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