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Flavio Quintana - One of the best experts on this subject based on the ideXlab platform.
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Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise?
Waterbirds, 2017Co-Authors: Walter S. Svagelj, Flavio QuintanaAbstract:Abstract. Cormorants and shags (Phalacrocoracidae) are sexually monomorphic in plumage but dimorphic in size with males larger and heavier than females. Such size dimorphism has been capitalized upon for several species in the family to sex adults by using discriminant analysis applied on the morphometric measurements. Despite that, few studies have analyzed the development of sexual size dimorphism during chick growth. In this study, sexspecific growth was assessed in chicks of the Imperial Cormorant (Phalacrocorax atriceps) by analyzing the development of body mass, bill length, head length, tarsus length and wing length measured on 80 chicks sexed by DNA-based technics. Fieldwork was performed during the 2004 breeding season at Punta Leon, Patagonia, Argentina. In addition, discriminant analyses were performed to obtain functions to determine the sex of fledglings. Males had higher asymptotic values and growth rates than females for all measurements considered, even though the arising of dimorphism var...
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Phylogeography and genetic structure of two Patagonian shag species (Aves: Phalacrocoracidae).
Molecular phylogenetics and evolution, 2014Co-Authors: Luciano Calderón, Flavio Quintana, Gustavo S. Cabanne, Stephen C. Lougheed, Pablo L. TubaroAbstract:We compared the phylogeographic and genetic structure of two sympatric shag species, Phalacrocorax magellanicus (rock shag) and Phalacrocorax atriceps (imperial shag), from Patagonia (southern South America). We used multilocus genotypes of nuclear DNA (microsatellite loci) from 324 individuals and mitochondrial DNA sequences (ATPase) from 177 individuals, to evaluate hypotheses related to the effect of physical and non-physical barriers on seabird evolution. Despite sharing many ecological traits, the focal species strongly differ in two key aspects: P. magellanicus has a strong tendency to remain at/near their breeding colonies during foraging trips and the non-breeding season, while P. atriceps exhibits the converse pattern. Both species showed similar mtDNA genetic structure, where colonies from the Atlantic Coast, Pacific Coast and Fuegian region were genetically divergent. We also found similarities in the results of Bayesian clustering analysis of microsatellites, with both species having four clusters. However population differentiation (e.g. Fst, Φst) was higher in P. magellanicus compared to P. atriceps, and average membership probabilities of individuals to specific clusters (Q-values) were also higher in the former. Phalacrocorax magellanicus has strong phylogeographic structure, consistent with the impact of Pleistocene glaciations, with diagnostic haplotypes associated with each of the three mentioned regions. The same pattern was not as evident for P. atriceps. Migration rate estimators were higher for P. atriceps than for P. magellanicus; however both species followed an n-island-like model of gene flow, this implies that dispersal occurs across the continental land mass that separates Atlantic and Pacific Oceans. Our results supported the hypothesis that non-physical barriers are important drivers of the genetic and phylogeographic structure in seabirds, and also that physical barriers constitute effective but not absolute impediments to gene flow.
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No evidence of extra-pair paternity or intraspecific brood parasitism in the Imperial Shag Phalacrocorax atriceps
Journal of Ornithology, 2011Co-Authors: Luciano Calderón, Flavio Quintana, Stephen C. Lougheed, Walter S. Svagelj, Pablo L. TubaroAbstract:In long-lived birds with significant paternal care contribution, as the case of seabirds, extra-pair paternity (EPP) is an infrequent phenomenon. Intriguingly, and in contrast to the general pattern exhibited by seabirds, EPP rates appear relatively high in the two species of cormorants and shags (Phalacrocoracidae family) analyzed so far. We test for EPP in the Imperial Shag Phalacrocorax atriceps, a medium-sized colonial seabird, using four DNA microsatellites originally developed for Great Cormorants P. carbo, and successfully cross-amplified in our focal species. We assessed the parentage of 110 chicks from 37 broods sampled at Punta Leon, Argentina, during the 2004 and 2005 breeding seasons. We found no evidence of EPP or intraspecific brood parasitism (IBP). Given our sample sizes, the upper 95% confidence limits for both EPP and IBP were estimated at 3.3% for the chicks and 8.4% for the broods. Our results did not agree with the previous reports of EPP within the family, probably as consequence of different copulation and courtship behaviours, mostly related to male’s solicitation display and females active search for extra pair copulations.
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Diving Behavior of the Red-Legged Cormorant in Southeastern Patagonia, Argentina
The Condor, 2002Co-Authors: Esteban Frere, Flavio Quintana, Patricia GandiniAbstract:Abstract We studied the diving behavior of Red-legged Cormorants (Phalacrocorax gaimardi) in Patagonia, Argentina, using VHF radio-transmitters deployed during incubation. Red-legged Cormorants made foraging trips in inshore waters less than 15 m deep. Mean dive duration was 26.8 ± 2.0 sec while mean time at surface was 9.2 ± 0.9 sec (n = 2217 dives). The birds spent 74% of their foraging time underwater. Diving efficiency was different among individuals, and was among the highest reported for the Phalacrocoracidae. Dive variables were correlated with the height of the tide, suggesting that the birds forage on the seabed. Red-legged Cormorants were efficient divers, investing most of their feeding time underwater and foraging in shallow waters, maximizing bottom time. Our results are consistent with the hypothesis that Red-legged Cormorant diving behavior is strongly influenced by a combination of environmental variables (bottom heterogeneity and high tide width) characteristic of the south coast of Patagonia. Comportamiento de Buceo del Phalacrocorax gaimardi en la Patagonia Sudoriental, Argentina Resumen. Se estudió el comportamiento de buceo del Phalacrocorax gaimardi en Patagonia, Argentina, usando transmisores VHF instalados durante el periodo de la incubación. P. gaimardi realizó sus viajes de alimentación en áreas costeras poco profundas (<15 m). La duración media del buceo fue 26.8 ± 2.0 seg y el tiempo medio en superficie de 9.2 ± 0.9 seg (n = 2217). Las aves pasaron bajo el agua un 74% de su tiempo de alimentación, mostrando una de las eficiencias de buceo más altas mencionadas para los Phalacrocoracidae. Los parámetros de buceo se correlacionaron con la altura de la marea, sugiriendo que las aves se alimentaron en el fondo marino. Los individuos de P. gaimardi fueron eficientes buceadores, invirtiendo la mayoría de su tiempo de alimentación debajo del agua en aguas someras, maximizando el tiempo en el fondo marino. Nuestros resultados apoyan la hipótesis que P. gaimardi tiene un comportamiento de buceo que responde a las características ambientales de la costa sur de la Patagonia (heterogeneidad del fondo marino y grandes amplitudes de marea).
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DIVING BEHAVIOR OF THE RED-LEGGED CORMORANT IN SOUTHEASTERN PATAGONIA, ARGENTINA
The Condor, 2002Co-Authors: Esteban Frere, Flavio Quintana, Patricia GandiniAbstract:Abstract We studied the diving behavior of Red-legged Cormorants (Phalacrocorax gaimardi) in Patagonia, Argentina, using VHF radio-transmitters deployed during incubation. Red-legged Cormorants made foraging trips in inshore waters less than 15 m deep. Mean dive duration was 26.8 ± 2.0 sec while mean time at surface was 9.2 ± 0.9 sec (n = 2217 dives). The birds spent 74% of their foraging time underwater. Diving efficiency was different among individuals, and was among the highest reported for the Phalacrocoracidae. Dive variables were correlated with the height of the tide, suggesting that the birds forage on the seabed. Red-legged Cormorants were efficient divers, investing most of their feeding time underwater and foraging in shallow waters, maximizing bottom time. Our results are consistent with the hypothesis that Red-legged Cormorant diving behavior is strongly influenced by a combination of environmental variables (bottom heterogeneity and high tide width) characteristic of the south coast of Patag...
Fabiana B. Drago - One of the best experts on this subject based on the ideXlab platform.
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First record of Neodiplostomum travassosi (Digenea: Diplostomidae) in Argentina
2011Co-Authors: Lía I. Lunaschi, Fabiana B. DragoAbstract:NEODIPLOSTOMUM TRAVASSOSI DUBOIS, 1937 (DIPLOSTOMIDAE, DIPLOSTOMINAE) IS REDESCRIBED AND ILUSTRATED BASED ON THE STUDY OF SPECIMENS COLLECTED FROM THE INTESTINE OF POLYBORUS PLANCUS (MILLER) (FALCONIDAE) AND PHALACROCORAX BRASILIANUS (GMELIN) (Phalacrocoracidae), CAPTURED IN FORMOSA PROVINCE, ARGENTINA. THE ORIGINAL DESCRIPTION OF THIS SPECIES WAS BASED ON SPECIMENS COLLECTED FROM STRIGIFORMES AND PICIFORMES IN BRAZIL. MORPHOLOGY AND DIMENSIONS OF SPECIMENS DESCRIBED IN THIS PAPER AGREE WITH THE ORIGINAL DESCRIPTION. THESE REPRESENT TWO NEW HOST RECORDS AND A NEW GEOGRAPHICAL RECORD.
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Primer registro de Neodiplostomum travassosi (Digenea: Diplostomidae) en Argentina First record of Neodiplostomum travassosi (Digenea: Diplostomidae) in Argentina
Universidad Nacional Autónoma de México, 2005Co-Authors: Lía I. Lunaschi, Fabiana B. DragoAbstract:Se redescribe e ilustra a Neodiplostomum travassosi Dubois, 1937 (Diplostomidae: Diplostominae) con base en ejemplares recolectados del intestino de Polyborus plancus (Miller) (Falconidae) y Phalacrocorax brasilianus (Gmelin) (Phalacrocoracidae), capturados en la provincia de Formosa, Argentina. La descripción original de esta especie está basada en ejemplares recolectados de Strigiformes y Piciformes de Brasil. La morfología y dimensiones de los ejemplares estudiados en este trabajo concuerdan con la descripción original. Este hallazgo permite acrecentar la lista de hospederos y efectuar un nuevo registro geográfico para esta especie.Neodiplostomum travassosi Dubois, 1937 (Diplostomidae, Diplostominae) is redescribed and ilustrated based on the study of specimens collected from the intestine of Polyborus plancus (Miller) (Falconidae) and Phalacrocorax brasilianus (Gmelin) (Phalacrocoracidae), captured in Formosa province, Argentina. The original description of this species was based on specimens collected from Strigiformes and Piciformes in Brazil. Morphology and dimensions of specimens described in this paper agree with the original description. These represent two new host records and a new geographical record
David Grémillet - One of the best experts on this subject based on the ideXlab platform.
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Behavioural strategies of cormorants (Phalacrocoracidae) foraging under challenging light conditions
Ibis, 2008Co-Authors: Craig R. White, Patrick J. Butler, David Grémillet, Graham R. MartinAbstract:Diving is indicative of foraging in cormorants (Phalacrocoracidae). We have investigated a range of parameters associated with diving in Great Cormorants Phalacrocorax carbo to provide insight into the bases of cormorant predatory strategies. We hypothesize that if vision is important in cormorant foraging behaviour, and if they are not constrained by the position of their prey in the water column, then diving behaviour will be modulated primarily in response to the diel variation in ambient light levels. Specifically, we propose that cormorants forage at shallower depths when light levels are low, and more deeply when light levels are high. We provide evidence that this is the case. We recorded the occurrence of cormorant diving behaviour using implanted data loggers and recorded ambient light levels and water temperature using leg-mounted loggers in a sample of free-living Great Cormorants in Greenland. Our results show that dives are shallower at the beginning and end of each day when light levels are lower. We suggest that these data support the hypothesis that cormorant foraging is visually-guided even though recent evidence has shown that their underwater visual acuity is poor.
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A tropical bird in the Arctic (the cormorant paradox)
Marine Ecology Progress Series, 1999Co-Authors: David Grémillet, Rory P. Wilson, Sarah Wanless, G. PetersAbstract:Seabirds, like all marine endotherms, have to compensate for the extensive cooling effect of water when diving. Alone among them, cormorants (Phalacrocoracidae) have a wettable plumage and are predicted to require disproportionately large amounts of food to balance heat losses. These piscivorous birds are thus thought to have a detrimental impact on fish stocks. However, we show here that even in great cormorants from Greenland, which dive in water at 3 to 7°C, daily food intake is lower than for well-insulated European seabirds. Despite their wettable plumage, cormorants thus appear to manage their energy budgets in a remarkably efficient way. Nevertheless, the specific foraging strategies which enable this performance make cormorants dependent on high prey density areas, a feature that should be taken into account by future management plans.
G. Peters - One of the best experts on this subject based on the ideXlab platform.
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A tropical bird in the Arctic (the cormorant paradox)
Marine Ecology Progress Series, 1999Co-Authors: David Grémillet, Rory P. Wilson, Sarah Wanless, G. PetersAbstract:Seabirds, like all marine endotherms, have to compensate for the extensive cooling effect of water when diving. Alone among them, cormorants (Phalacrocoracidae) have a wettable plumage and are predicted to require disproportionately large amounts of food to balance heat losses. These piscivorous birds are thus thought to have a detrimental impact on fish stocks. However, we show here that even in great cormorants from Greenland, which dive in water at 3 to 7°C, daily food intake is lower than for well-insulated European seabirds. Despite their wettable plumage, cormorants thus appear to manage their energy budgets in a remarkably efficient way. Nevertheless, the specific foraging strategies which enable this performance make cormorants dependent on high prey density areas, a feature that should be taken into account by future management plans.
Gerald Mayr - One of the best experts on this subject based on the ideXlab platform.
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With 3 Text-figures
2016Co-Authors: Aves Pelecaniformes Phalacrocoracidae, Gerald MayrAbstract:A foot of a cormorant (Aves, Pelecaniformes, Phalacrocoracidae) is described from the Late Oligocene of the locality Enspel near Bad Marienberg, Germany (MP 28). The specimen is tentatively assigned to the genus Oligocorax LAMBRECHT 1933 which is shown to be morphologically distinct from the Recent genus Phalacrocorax. The find from Enspel is the earliest fossil record of the Phalacrocoracidae described so far
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A new skeleton of the late Oligocene “Enspel cormorant”—from Oligocorax to Borvocarbo, and back again
Palaeobiodiversity and Palaeoenvironments, 2015Co-Authors: Gerald MayrAbstract:A new specimen of the cormorant species from the late Oligocene (MP 28) fossil site Enspel in Germany—the third to be discovered at this site—is described. Previously unknown or controversial features bearing on the taxonomic and phylogenetic affinities of this bird are identified, which do not support the assignment of the Enspel cormorant to the taxon Borvocarbo . The species is therefore here, tentatively, transferred back to Oligocorax , in which it was first placed. The new osteological data confirm that ? Oligocorax stoeffelensis is a stem group representative of Phalacrocoracidae, and the species exhibits a previously unrecognised derived morphology of the pectoral girdle bones in that the furcula is fused with the apex carinae of the sternum, a feature absent in modern cormorants. A phylogenetic analysis revealed two alternative positions for ? O. stoeffelensis relative to other stem group Phalacrocoracidae, supporting a sister group relationship either to the clade including Nambashag , Nectornis and crown group Phalacrocoracidae or to a clade including ? O. stoeffelensis and crown group Phalacrocoracidae to the exclusion of Nambashag and Nectornis .
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A dwarf species of the Phalacrocoracoidea (cormorants and anhingas) from the early Miocene of
2015Co-Authors: Gerald MayrAbstract:A tarsometatarsus of a diminutive representative of the Phalacrocoracoidea, the clade including the Phalacrocoracidae (cormorants) and Anhingidae (anhingas), is described from the early Miocene of Germany. The fossil is assigned to a new species Limicorallus (?) carbunculus, and closely resembles the tarsometatarsus of extant Phalacrocoracidae in overall morphology. Limicorallus (?) carbunculus is the smallest representative of the Phalacrocoracoidea, reaching only two-thirds the size of the extant Pygmy Cormorant Phalacrocorax pygmeus. By significantly lowering the minimum size of the Phalacrocorac-oidea, this new species adds to our knowledge of the early diversity of this clade
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A dwarf species of the Phalacrocoracoidea (cormorants and anhingas) from the early Miocene of Germany
Ibis, 2009Co-Authors: Gerald MayrAbstract:A tarsometatarsus of a diminutive representative of the Phalacrocoracoidea, the clade including the Phalacrocoracidae (cormorants) and Anhingidae (anhingas), is described from the early Miocene of Germany. The fossil is assigned to a new species Limicorallus (?) carbunculus, and closely resembles the tarsometatarsus of extant Phalacrocoracidae in overall morphology. Limicorallus (?) carbunculus is the smallest representative of the Phalacrocoracoidea, reaching only two-thirds the size of the extant Pygmy Cormorant Phalacrocorax pygmeus. By significantly lowering the minimum size of the Phalacrocoracoidea, this new species adds to our knowledge of the early diversity of this clade.
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A Small Representative of the Phalacrocoracoidea (Cormorants and Anhingas) from the Late Oligocene of Germany
The Condor, 2007Co-Authors: Gerald MayrAbstract:AbstractI describe a skeleton of a cormorant-like bird from Enspel, a late Oligocene (24.7 mya) fossil site in Germany, which is assigned to a new species, ?Borvocarbo stoeffelensis, sp. nov. The specimen constitutes the earliest described and most completely preserved fossil record of the Phalacrocoracoidea, the clade including Anhingidae (anhingas) and Phalacrocoracidae (cormorants). ?B. stoeffelensis shares derived features with cormorants that are absent in anhingas. Despite its cormorant-like overall morphology, an assignment to the stem lineage of Phalacrocoracidae is not straightforward, because the new species is also distinguished from crown group representatives of the clade (Anhingidae + Phalacrocoracidae) by presumably plesiomorphic features. The morphology displayed by ?B. stoeffelensis places a caveat on the assignment to the Phalacrocoracidae of other less completely known Paleogene and early Neogene taxa. Plesiomorphic features shared by ?B. stoeffelensis and extant “microcormorants” (sensu Siegel-Causey 1988) support a sister group relationship between “Microcarbo” spp. and all other extant Phalacrocoracidae.