15 results on '"Zarco, Agustín"'
Search Results
2. Proximity to corridors benefits bird communities in vegetated interrow vineyards in Mendoza, Argentina
- Author
-
Goijman, Andrea Paula and Zarco, Agustín
- Published
- 2024
- Full Text
- View/download PDF
3. Evidence of nest abandonment in Grass Wrens Cistothorus platensis suggest that non-breeding nests are not structures that differ in function from breeding nest
- Author
-
Llambías, Paulo E., Jefferies, María M., Zarco, Agustín, Garrido, Paula S., and Arrieta, Ramiro S.
- Published
- 2022
- Full Text
- View/download PDF
4. The barn owl as an accumulator of bone remains in central western Argentina: multi-taxa neo-taphonomic approach and implications for Holocene contexts.
- Author
-
Rubini, Facundo Sesto, Mignino, Julián, Guardia, Nicolás M, Zarco, Agustín, Teta, Pablo, Ojeda, Agustina A, and López, José Manuel
- Subjects
OWLS ,PALEONTOLOGICAL excavations ,BIOTIC communities ,BIRD pellets ,HOLOCENE Epoch ,BARN owl ,REPTILES - Abstract
Barn owls are the most widely distributed group of owls in the world and are among the most common accumulators of small vertebrate remains at archeological and paleontological sites. Despite its importance as a bone remains accumulator and predictor of paleoenvironmental conditions due to its generalist habits, the vertebrate prey of this raptor has been scarcely studied from an ecological community perspective, especially considering the diverse range of prey it captures. Archeological, paleontological, and taphonomic studies typically reveal taxon-specific patterns, focusing primarily on small rodents. In order to overcome this problem, we studied an assemblage of vertebrate bones from barn owl pellets in the central Monte Desert of Argentina. Our analysis included the full range of prey taxa, including rodents, marsupials, birds, and reptiles, addressed from both an ecological and neo-taphonomic perspective. We compare the taxonomic and taphonomic findings with those from regional small vertebrate records obtained from various sampling types over the past 50 years to explore recent environmental changes within the Anthropocene. The assemblage of small vertebrate prey presented here comprises five species of cricetids, one species from the Caviidae family, and at least one ctenomyid rodent species. Additionally, the assemblage includes one species of didelphid marsupial, one reptile species, and at least six passeriform bird species that belong to separate families. The overall taphonomic trends are consistent with the typical barn owl pattern. However, our analysis identified a larger percentage of postcranial elements exhibiting signs of digestion compared to pellet-derived vertebrate bone assemblages previously documented. Furthermore, it is important to note that a significant proportion of avian bone fragments exhibit distinct signs of digestion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Diet switching of seed-eating birds wintering in grazed habitats of the central Monte Desert, Argentina
- Author
-
Marone, Luis, Olmedo, Matías, Valdés, Daniela Y., Zarco, Agustín, de Casenave, Javier Lopez, and Pol, Rodrigo G.
- Published
- 2017
6. Plausible causes of seed preferences and diet composition in seed‐eating passerines.
- Author
-
Marone, Luis, Cueto, Víctor R., Lopez de Casenave, Javier, Zarco, Agustín, and Camín, Sergio R.
- Subjects
PASSERIFORMES ,COEXISTENCE of species ,DESERT ecology ,SEEDS ,ANIMAL nutrition ,FOOD habits ,FOOD preferences - Abstract
We evaluated whether seed mass, handling time, handling efficiency and profitability account for (a) preferences in controlled experiments and (b) field‐diet composition of four bird species of the Monte desert, Argentina. The question of whether birds maximise their energy intake rates while feeding on seeds is assessed. We used feeding experiments with six native seed species of 0.07–0.75 mg (i.e. the seed‐size range consumed in nature), which account for 0.59–0.84 of the field diet of the four birds. We measured seed‐handling times and used published information on bird preferences and diets, and on seed chemistry, for further calculations. Bird preferences were always positively related to seed mass and also to seed profitability in the two intermediate‐sized birds. Diet composition correlated positively with seed mass and negatively with seed profitability in three species, but some birds also showed a flexible behaviour eating the most attractive seeds according to their availability. This behaviour is not genuinely opportunistic because it only focuses on a restricted fraction of the total seed species present in the field. Contrary to expectations of species coexistence due to resource partitioning, small and large birds showed similar feeding efficiencies when eating the smaller and the larger seeds. The positive association between seed mass and profitability in several studies suggests that most birds can maximise their energy reward, on average and in the long‐term, by preferring the larger seeds. A combination of potential feeding optimisation with certain flexibility in the field may characterise the feeding ecology of desert seed‐eating birds. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. Feeding habits of the Asiatic red-bellied squirrel Callosciurus erythraeus introduced in Argentina
- Author
-
Zarco, Agustín, Benitez, Verónica Victoria, Fasola, Laura, Funes, G., and Guichon, Maria Laura
- Subjects
purl.org/becyt/ford/1 [https] ,Ciencias Biológicas ,INVASIVE SQUIRREL ,BEHAVIOUR ,FAECES ANALYSIS ,Ecología ,purl.org/becyt/ford/1.6 [https] ,CIENCIAS NATURALES Y EXACTAS ,DIET - Abstract
Knowledge of food habits of invasive species is necessary to predict invasion success and potential interactions in the invaded community. The Asiatic red-bellied squirrel Callosciurus erythraeus has been introduced in Asia, Europe and South America. We studied feeding habits of red-bellied squirrels in Argentina in two sites 600 km apart where wild populations have become established. We used both faecal microhistological analysis and behavioural records to describe diet composition and feeding habits. We also analysed diet selection and the potential role of the squirrels as seed disperser. Squirrels consumed items from 35 species of exotic trees and shrubs and one native tree species; fruits and seeds represented the bulk of the diet in all seasons (faeces analysis: >44%; behavioural observations: >38%). Squirrels also consumed epiphytic and climbing plants, ferns, invertebrates, fungi, lichens, mosses and bird eggs. Diet composition varied throughout the year according to food availability. We did not find evidence of endozoochoric dispersal but we observed squirrels carrying and dropping nuts and acorns during transport. The consumption of a wide range of food items and species, the ability to modify the diet according to food availability, and the capacity to hoard food indicate that feeding habits of red-bellied squirrels favour their invasive potential. Fil: Zarco, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Benitez, Verónica Victoria. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ecología y Desarrollo Sustentable; Argentina Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina Fil: Funes, G.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Guichon, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Provincia del Neuquén. Subsecretaría de Producción y Recursos Naturales. Centro de Ecología Aplicada del Neuquén; Argentina
- Published
- 2018
8. Building multiple nests is associated with reduced breeding performance in a south temperate population of Grass Wrens Cistothorus platensis platensis.
- Author
-
Llambías, Paulo Emilio, Jefferies, María Milagros, Cáceres Apaza, Daniel Pascual, Garrido, Paula Sabrina, Zarco, Agustín, Arrieta, Ramiro Santiago, and Bender, José Benjamin
- Subjects
NEST building ,ANIMAL clutches ,NEST predation ,BROOD parasitism ,NESTS ,GRASSES - Abstract
Grass Wrens Cistothorus platensis build two types of non‐breeding nest structures: platforms and dummy nests. Platforms are rudimentary accumulations of grasses concealed between vegetation. Dummy and breeding nests are dome‐shaped with a similar structural layer. We used a nest‐removal experiment and observational data to evaluate several hypotheses regarding the adaptive significance of building multiple nests in a south temperate population of Grass Wrens. Building non‐breeding nests was not a strategy of males to attract additional females, as most of these nests were built after pair formation and both sexes collaborated during building. Building non‐breeding nests was not a post‐pairing display as the presence of multiple nests did not increase female investment in the breeding attempt: clutch size and female provisioning to nestlings did not differ between experimental and control territories where no non‐breeding nests were removed. Similarly, in non‐manipulated territories, clutch size and female provisioning were not correlated with the number of non‐breeding nests or with males' nest‐building effort. Contrary to this hypothesis, the number of non‐breeding nests was associated with delayed clutch initiation and reduced hatching success. The presence of non‐breeding nests did not reduce nest predation and brood parasitism, which did not differ between experimental and control territories. We did not detect differences in concealment between non‐breeding and breeding nests, suggesting that non‐breeding nests were not the result of abandonment before egg‐laying to reduce subsequent nest predation. Dummy nests did not provide shelter; they were not used frequently for roosting over the breeding season and were not maintained during the non‐breeding season. We suggest that building non‐breeding nests may be an attempt by males to manipulate the decision of females to breed with a mate they might otherwise reject or to start reproduction earlier than optimal for the females. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. Plasma Cholinesterase Activity in Wild Birds from Undisturbed Woodlands in the Central Monte Desert.
- Author
-
Quero, Arnoldo Ángel Martín, Zarco, Agustín, Landa, Florencia Belén, and Gorla, Nora Bibiana María
- Subjects
- *
BIRDS , *CHOLINESTERASE reactivators , *ENGLISH sparrow , *FORESTS & forestry , *DESERTS , *FOREST birds , *SONGBIRDS - Abstract
Plasma cholinesterase activity is a biomarker sensitive to the effect of organophosphate and carbamate pesticides, and its enzymatic levels have been previously unknown for most of the wild birds analyzed in the present study. Our objectives were to establish plasma acetylcholinesterase levels in songbirds of 2 undisturbed sites in the central Monte Desert (Argentina). We also examined the influence on cholinesterase activity of age, sex, body condition, feeding and migratory habits, and species. One hundred and sixty‐five wild birds belonging to 26 species were studied. The values obtained for acetylcholinesterase activity provide a good estimate of the normal values in free‐living individuals of the species Zonotrichia capensis, Molothrus bonariensis, Passer domesticus, Diuca diuca, Poospiza ornata, Saltator aurantiirostris, Gryseotyrannus aurantioatrocristatus, and Columbina picui, with interspecies differences. The median enzymatic levels ± standard error of the mean ranged from 546.31 ± 17.97 μmol min–1 L–1 in P. domesticus to 3439.90 ± 173.92 μmol min–1 L–1 in Tyrannus melancholicus. No significant differences were detected between different sexes or ages. Birds that migrate (which are also insectivores) showed higher levels of cholinesterase than residents (mainly granivores). It is recommended that in cases of bird poisoning, plasma cholinesterase activity can be used as a diagnostic tool only if pre‐exposure levels obtained in the same species are available, and ideally evaluated in individuals from the same biogeographical region. Environ Toxicol Chem 2019;38:1692–1700. © 2019 SETAC [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
10. Predation by invasive rainbow trout on the critically endangered Pehuenche spiny‐chest frog.
- Author
-
Zarco, Agustín, Corbalán, Valeria, and Debandi, Guillermo
- Subjects
- *
FROGS , *PREDATION , *INTRODUCED species , *RAINBOW trout , *RARE birds - Abstract
The Pehuenche spiny‐chest frog Alsodes pehuenche is an endemic species from the Andes of Argentina and Chile and is considered to be critically endangered. Its population has been declining over the past 10 years, principally as a consequence of the paving of a road that crosses the streams the frog inhabits. Until recently, exotic fish species had not been recorded in these streams. This study documents the presence of rainbow trout (Oncorhynchus mikyss) in one of these streams and predation on the endangered frog species. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
11. Erythrocyte micronucleus cytome assay of 17 wild bird species from the central Monte desert, Argentina.
- Author
-
Quero, Arnoldo, Ferré, Daniela, Zarco, Agustín, Cuervo, Pablo, and Gorla, Nora
- Subjects
BIRDS -- Environmental aspects ,ERYTHROCYTES ,NUCLEOLUS ,ENVIRONMENTAL impact analysis ,POLLUTANTS - Abstract
Birds have the potential to be considered valuable bioindicators of the quality of ecosystems and the environmental impact of pollutants. The aims of this study were to determine the micronuclei frequency and other nuclear abnormalities in erythrocytes by analyzing a wild bird community from central Monte desert (Argentina) and to clarify if there were any differences among certain species. Frequencies of nuclear abnormalities were determined in 73 wild birds belonging to 17 species and two orders (Passeriformes and Columbiformes). A high proportion of individuals, 90.4 and 80.9 %, had erythrocytes with micronuclei and nuclear buds, respectively. Notched nuclei, binucleated cells, nuclear tails, and nucleoplasmic bridges were also recorded. Certain species appeared to be more informative than others with regard to the possibility of being used as bioindicators of genetic damage. Saltator aurantiirostris and Columbina picui were the only species that showed significantly different frequencies of nuclear alterations, in comparison with the other species. The frequencies here presented are the first reported for these bird species from the orders Passeriformes and Columbiformes. This research supports the notion that the use of these biomarkers could be effectively applied to evaluate spontaneous or induced genetic instability in wild birds. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
12. First record of Dot-winged Crake, Porzana spiloptera, Durnford, 1877 (Rallidae) for the central Andes in Argentina.
- Author
-
Zarco, Agustín, Cuervo, Pablo F., and Llambías, Paulo E.
- Subjects
- *
SPECIES distribution , *PORZANA (Genus) - Abstract
Porzana spiloptera, the Dot-wing Crake, has a patchy distribution in southern South America and has previously been considered as inhabiting exclusively lowland wetlands. Here we present evidence of a new population inhabiting a high-elevation site in the Central Andes of Argentina. This record suggests not only a broader distribution but greater tolerance of the species to higher elevation and lower temperatures than has previously been assumed. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
13. Gastropoda, Pulmonata, Lymnaeidae, Pseudosuccinea columella (Say, 1817): First record in Córdoba province, central Argentina.
- Author
-
Zarco, Agustín, Fantozzi, M. Cecilia, and Cuervo, Pablo F.
- Subjects
- *
GASTROPODA , *PULMONATA , *LYMNAEIDAE , *BOTANICAL gardens - Abstract
Pseudosuccinea columella (Say, 1817) is a lymnaeid snail with great invasive capabilities, and has, at present, a worldwide distribution. So far, the presence of this lymnaeid snail in Argentina was restricted to a few provinces in the northeastern region, such as Misiones, Corrientes, Entre Ríos and some botanical gardens in Buenos Aires, but the recent discovery of specimens in central Argentina (Córdoba) not only represents the first record for the region, but also the southernmost confirmed record in the wild for the Neotropical region and the westernmost for the country. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
14. Winter Flock Structure in the Central Monte Desert, Argentina
- Author
-
Zarco, Agustín and Cueto, Víctor R.
- Published
- 2017
- Full Text
- View/download PDF
15. Predicting how seed-eating passerines respond to cattle grazing in a semi-arid grassland using seed preferences and diet.
- Author
-
Sagario, M. Cecilia, Cueto, Víctor R., Zarco, Agustín, Pol, Rodrigo, and Marone, Luis
- Subjects
- *
GRAZING , *GRASSLANDS , *ROTATIONAL grazing , *RANGE management , *SOIL seed banks , *PASSERIFORMES , *SHRUBS - Abstract
Unveiling the mechanisms that act as causal links between habitat alteration and bird abundance conciliates results often interpreted as unpredictable or irreproducible. • We modeled the main effects of cattle grazing on vegetation variables. • And used seed preferences of birds to predict their numerical response to grazing. • Grass seed specialists responded to the reduction of large grass seeds only. • Some expanding specialists responded to the reduction of all kinds of seeds. • Natural history knowledge conciliates results often interpreted as unpredictable. Numerical responses of animals to habitat perturbation often seem inconsistent, spreading skepticism about the predictive capacity of applied ecology. Domestic grazing changes several habitat variables that can affect seed-eating birds. Birds, in turn, show adaptations (e.g. in their feeding behavior) that could allow them to overcome habitat perturbations. Here we modelled habitat variables (e.g. cover of different plants, panicles, soil seed bank) in grazed and ungrazed (or lightly grazed) habitats of the central Monte desert, Argentina, to detect those affected by grazing activity. There was no effect of grazing on shrub and tree cover, but grazing reduced the abundance mostly of large grass seeds but also of small grass and forb seeds. Then, we used model's outputs and knowledge of feeding preferences of the five most common seed-eating passerines in the Monte to make species-specific predictions: changes in abundance of grass seed specialists (Saltatricula multicolor , Microspingus torquatus and Porphyrospiza carbonaria) due to grazing activity should be consistent and should depend on large grass seeds (i.e. preferred seeds), whereas changes in abundance of more generalist species (Zonotrichia capensis and Diuca diuca) should be less consistent and explained also by the abundance of other seeds. The abundance of large grass seeds was sufficient to predict the abundances of S. multicolor , M. torquatus and P. carbonaria. The best model for predicting the abundance of Z. capensis included large grass seeds as well as small grass or forb seeds. No model including the abundance of seeds predicted the abundance of D. diuca. Therefore, feeding behavior explained the abundance of four out of the five bird species. A review of the literature showed that feeding behavior is also a good predictor of habitat use in other desert grasslands. Conservative range management should consider, and even manipulate, the level of the seeds preferred by wildlife. Grazed grasslands should be rested from grazing on a rotational basis so that grasses, especially those whose seeds are preferred by birds, can seed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.