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1. Age-related prey selectivity and foraging efficiency of Olrog's Gulls (Larus atlanticus) feeding on crabs in their non-breeding grounds

Author:
María Paula Berón,   et al.   ; Germán O. García; Tomás Luppi; Marco Favero;     Show all 4 Authors
Source:
Emu 2011 v.111 no.2 pp. 172-178
ISSN:
1448-5540
Subject:
Larus; adults; age structure; birds; coastal water; crabs; diet; feeding preferences; foraging; juveniles; life history; males; predator-prey relationships; threatened species; Argentina
Abstract:
... Foraging ecology is an essential component of the life history of a species and a good understanding of foraging ecology is especially important for threatened species where prey populations may be adversely affected by anthropogenic processes. This study examines age-related prey selection and prey-handling efficiency of Olrog's Gulls (Larus atlanticus) during the non-breeding season at the Mar C ...
DOI:
10.1071/MU10053

2. Barn Swallows keep expanding their breeding range in South America

Author:
María Soledad Liébana,   et al.   ; Juan Manuel Grande; Miguel A. Santillán; Paula M. Orozco; Marcos Matías Reyes; Maximiliano Adrián Galmes; Joaquín Ceregheti;     Show all 7 Authors
Source:
Emu 2015 v.115 no.3 pp. 256-260
ISSN:
1448-5540
Subject:
Hirundo rustica; Prosopis caldenia; agricultural land; breeding; forests; habitats; nesting sites; nests; roads; wetlands; Argentina; North America
Abstract:
... Barn Swallows (Hirundo rustica) breeding in North America traditionally wintered in South America. In the 1980s a small breeding population was found in coastal Argentina and since then the breeding range of Barn Swallows in the country has expanded. Our aims here were to examine the north-western limits of the breeding range of Barn Swallows in Argentina, and to analyse the factors that may deter ...
DOI:
10.1071/MU14097

3. Breeding phenology and nest survival of Cinereous (Circus cinereus) and Long-winged (C. buffoni) Harriers in the agricultural landscapes of north-east Patagonia, Argentina

Author:
María S. Bó,   et al.   ; Luciano N. Segura;     Show all 2 Author
Source:
Emu 2018 v.118 no.2 pp. 218-223
ISSN:
1448-5540
Subject:
Circus; agricultural land; breeding; grasslands; habitats; nesting; nests; phenology; population dynamics; survival rate; Argentina
Abstract:
... We present novel data on breeding ecology and nest survival of the Cinereous (Circus cinereus) and Long-winged (C. buffoni) Harriers in modified grasslands of southern Argentina and we evaluate variations in daily nest survival rates (DSR) in relation to temporal and habitat variables. We studied three mixed nesting colonies embedded in agricultural landscapes along a road. We found that DSR decre ...
DOI:
10.1080/01584197.2017.1404431

4. Differing nest-defence behaviour in urban and rural populations of breeding Burrowing Owls

Author:
María Susana Bó,   et al.   ; Matilde Cavalli; Juan Pablo Isacch; Alejandro V. Baladrón; Laura M. Biondi;     Show all 5 Authors
Source:
Emu 2016 v.116 no.4 pp. 428-434
ISSN:
1448-5540
Subject:
Athene cunicularia; aggression; breeding; breeding season; escape behavior; fearfulness; habitats; human-wildlife relations; humans; males; nestlings; nests; reproductive success; rural areas; synanthropes; urban areas
Abstract:
... The behaviour of birds in urban habitats often differs from that of birds in surrounding natural and rural habitats, with the attenuation of fear responses to humans a primary behavioural adaptation to urban life. In breeding birds, fear responses and nest-defence have been linked to reproductive success. We studied the nest-defence behaviour of male Burrowing Owls in rural and urban habitats by m ...
DOI:
10.1071/MU16009

5. Habitat relationships of diurnal raptors at local and landscape scales in southern temperate grasslands of Argentina

Author:
Bó, María Susana,   et al.   ; Pedrana, Julieta; Isacch, Juan Pablo;     Show all 3 Authors
Source:
Emu 2008 v.108 no.4 pp. 301-310
ISSN:
0158-4197
Subject:
Circus; agroecosystems; birds of prey; forests; grasses; grasslands; habitat conservation; habitats; landscapes; models; roads; species diversity; surveys; Argentina
Abstract:
... We evaluated the relationship between an assemblage of diurnal raptors and local- and landscape-scale habitat variables in the eastern portion of South America's temperate grasslands in Argentina (37°32'-37°45'S, 57°19'-57°26'W). The landscape is a mosaic of agroecosystems and natural grasslands. Raptor species were sampled using fixed-distance point-counts, from October 2004 to February 2005. We ...
DOI:
10.1071/MU07075

6. High frequency but low impact of brood parasitism by the specialist Screaming Cowbird on its primary host, the Baywing

Author:
María C. De Mársico,   et al.   ; Juan C. Reboreda;     Show all 2 Author
Source:
Emu 2014 v.114 no.4 pp. 309-316
ISSN:
1448-5540
Subject:
Molothrus; brood parasitism; clutch size; eggs; hatching; hosts; nests; progeny; viability; Argentina
Abstract:
... Brood-parasitic cowbirds (Molothrus spp.) exploit the parental care of other species (hosts) that raise their offspring. Parasitism by cowbirds reduces host reproductive success in several ways and quantifying such costs is an important step to better understand evolutionary interactions in host-parasite associations. We estimated the costs of parasitism by the host-specialist Screaming Cowbird (M ...
DOI:
10.1071/MU14008

7. Nesting habitat of Chubut Steamer Ducks in Patagonia, Argentina

Author:
María Laura Agüero,   et al.   ; J. Pablo García Borboroglu; Dan Esler;     Show all 3 Authors
Source:
Emu 2010 v.110 no.4 pp. 302-306
ISSN:
1448-5540
Subject:
breeding; coasts; ducks; habitat conservation; habitats; islands; nesting; nesting sites; nests; predators; regression analysis; sediments; shrubs; vegetation cover; wind speed; Argentina
Abstract:
... We studied nest-site selection of the flightless Chubut Steamer Duck (Tachyeres leucocephalus) along 292 km of continental coastline and 59 km of island coastline in Patagonia, Argentina, between 2004 and 2006. This area encompasses the main breeding range of the species. Almost all nests were on islands and islets, which ranged in area from 0.5 to 54.4 ha and were 0.01-5.6 km from the mainland. N ...
DOI:
10.1071/MU09096

8. Population size, provisioning frequency, flock size and foraging range at the largest known colony of Psittaciformes: the Burrowing Parrots of the north-eastern Patagonian coastal cliffs

Author:
María Luján Pagnossin,   et al.   ; Juan F. Masello; Christina Sommer; Petra Quillfeldt;     Show all 4 Authors
Source:
Emu 2006 v.106 no.1 pp. 69-79
ISSN:
1448-5540
Subject:
Psittaciformes; adults; aerial surveys; agricultural land; anthropogenic activities; breeding season; burrows; cliffs; flocks; foraging; habitats; monitoring; nesting; nestlings; nests; parrots; population size; reproductive success; sandstone; vegetation; Argentina
Abstract:
... We here describe the largest colony of Burrowing Parrots (Cyanoliseus patagonus), located in Patagonia, Argentina. Counts during the 2001–02 breeding season showed that the colony extended along 9 km of a sandstone cliff facing the Altantic Ocean, in the province of Río Negro, Patagonia, Argentina, and contained 51412 burrows, an estimated 37527 of which were active. To our knowledge, this is larg ...
DOI:
10.1071/MU04047

9. Prey selection and food habits of breeding Burrowing Owls (Athene cunicularia) in natural and modified habitats of Argentine pampas

Author:
María S. Bó,   et al.   ; Matilde Cavalli; Alejandro V. Baladrón; Juan P. Isacch; Guadalupe Martínez;     Show all 5 Authors
Source:
Emu 2014 v.114 no.2 pp. 184-188
ISSN:
1448-5540
Subject:
Athene cunicularia; Coleoptera; arthropods; breeding; diet; food choices; habitats; trapping
Abstract:
... Understanding the way animals respond to novel habitats and fluctuations in food resources can provide insights into the ability of species to settle in modified habitats. We studied the patterns of arthropod selection by Burrowing Owls in natural and modified habitats. We assessed the diet of this owl by means of pellet analysis and, simultaneously, we estimated relative abundance of arthropods i ...
DOI:
10.1071/MU13040

10. Red-backed Hawks supply food to scavenging Chimango Caracaras

Author:
Bó, María S.,   et al.   ; Baladrón, Alejandro V.; Biondi, Laura M.; Malizia, Ana I.; Bechard, Marc J.;     Show all 5 Authors
Source:
Emu 2009 v.109 no.3 pp. 260-264
ISSN:
0158-4197
Subject:
Buteo; agonistic behavior; birds of prey; hawks
Abstract:
... Positive interactions between species of terrestrial vertebrates occur frequently and it is common among birds. However, such interactions have generally been overlooked in raptor field studies. We analysed interactions between Red-backed Hawks (Buteo polyosoma) and Chimango Caracaras (Milvago chimango) in order to determine the characteristics of the association between these two South American r ...
DOI:
10.1071/MU09024

11. The diet of Olrog's Gull (Larus atlanticus) reveals an association with fisheries during the non-breeding season

Author:
María Paula Berón,   et al.   ; Juan Pablo Seco Pon; Germán O. García; Carla A. Paterlini; Rocío Mariano-Jelicich; Marco Favero;     Show all 6 Authors
Source:
Emu 2013 v.113 no.1 pp. 69-76
ISSN:
1448-5540
Subject:
Larus; adults; birds; blood; carbon; coasts; crabs; diet; fisheries; isotope labeling; juveniles; models; nitrogen; pelagic fish; stable isotopes; wintering grounds; Argentina
Abstract:
... In this study, we used stable-isotope analysis to determine the importance of different food resources in the diet of an endemic gull species of the Atlantic coast of southern South America during the non-breeding period. We compared the isotopes ¹⁵N and ¹³C in the blood of Olrog's Gulls (Larus atlanticus) of different ages with those in potential prey of the Gulls. We also determined the abundanc ...
DOI:
10.1071/MU11100

12. The diet of the South American Tern: the Argentine Anchovy as key prey in the non-breeding season

Author:
María P. Silva Rodriguez; María P. Berón,   et al.   ; Rocío Mariano-Jelicich; Sofía Copello; Juan P. Seco Pon; Laura Mauco; Mariela I. Ghys; Marco Favero;     Show all 8 Authors
Source:
Emu 2011 v.111 no.4 pp. 292-296
ISSN:
1448-5540
Subject:
Cynoscion guatucupa; Engraulis anchoita; Sterna; anchovies; breeding sites; coasts; diet; fishery resources; flocks; pellets; predators; seabirds; spring; winter; Argentina; Brazil
Abstract:
... The Argentine Anchovy (Engraulis anchoita) is one of the most important pelagic fishery resources of the Patagonian Shelf and is known to be an important prey item for several seabirds of the northern Argentine coast. The South American Tern (Sterna hirundinacea) is endemic to the Atlantic and Pacific coasts of South America and, on the Atlantic coast, breeds from central Brazil to southern Argent ...
DOI:
10.1071/MU10055

13. The eldest sibling is the lousiest in an obligate brood-reducer seabird

Author:
María Soledad Leonardi,   et al.   ; Walter S. Svagelj; Agustina Gómez Laich; Flavio Quintana;     Show all 4 Authors
Source:
Emu 2018 v.118 no.2 pp. 212-217
ISSN:
1448-5540
Subject:
breeding season; chicks; hatching date; hosts; lice; models; parasitism; parents; seabirds
Abstract:
... Previous studies on vertical transmission of lice on terrestrial birds have shown that the intensity of parasitism can vary within broods in relation to the hatching order of chicks. In species where the hatching order has an important effect on chick survival, lice would benefit from living on the host with the highest survival prospects. In the present work, we test this hypothesis using as mode ...
DOI:
10.1080/01584197.2017.1387028

14. Use of Peninsula Valdes (Patagonia Argentina) by migrating Red Knots (Calidris canutus rufa)

Author:
María de los Ángeles Hernández,   et al.   ; Luciana R. Musmeci; Luis O. Bala; José A. Scolaro;     Show all 4 Authors
Source:
Emu 2012 v.112 no.4 pp. 357-362
ISSN:
1448-5540
Subject:
Calidris canutus; aerial surveys; beaches; censuses; coasts; foraging; tides; winter; Argentina
Abstract:
... Red Knots (Calidris canutus rufa) that winter in southern South America stop on Peninsula Valdes, Patagonian Argentina, on their northern passage. The Peninsula comprises two large gulfs, each of which has two high and two low tides per day; high tides in San José Gulf correspond to low tides in Nuevo Gulf and vice versa. We conducted weekly censuses of Red Knots on several beaches on these gulfs ...
DOI:
10.1071/MU10079

15. Variation in the size of eggs of Chubut Steamer Ducks (Tachyeres leucocephalus)

Author:
María Laura Agüero,   et al.   ; Walter S. Svagelj; Pablo García Borboroglu;     Show all 3 Authors
Source:
Emu 2012 v.112 no.2 pp. 167-172
ISSN:
1448-5540
Subject:
Anatidae; breeding; breeding season; clutch size; coasts; duck eggs; ducks; eggs; genetic variation; islands; latitude; natural history; temporal variation; waterfowl; Argentina
Abstract:
... Although several studies have analysed spatial or temporal variation in the size of eggs in waterfowl (Anseriformes), no study has analysed variation throughout the breeding range of a species. Chubut Steamer Ducks (Tachyeres leucocephalus) are flightless marine waterfowl endemic to a small section of coastline in Patagonia, Argentina. We partitioned and analysed sources of variation in the size o ...
DOI:
10.1071/MU11068