Ignacio Roesler

Universidad de Buenos Aires | UBA · Department of Ecology, Genetics and Evolution

La única población estable de huillines en agua dulce conocida de Argentina se encuentra en el Parque Nacional Nahuel Huapi. Se recorrieron 14 sitios lineales (50–600 m) costeros aguas abajo de la confluencia de los ríos Limay y Traful para evaluar la situación del huillín en el embalse Alicurá. Se detectó la especie en un sector que se encuentra b...

La provincia de Santa Cruz es la segunda en superficie de Argentina continental. Su tamaño, baja densidad poblacional y la inaccesibilidad de gran parte de su territorio generan que su fauna sea mayormente desconocida. Desde 2009 hasta 2021, en el marco del Proyecto Macá Tobiano/Programa Patagonia, hemos realizado monitoreos de aves casi ininterrum...

La Torcaza Ala Blanca (Zenaida meloda) fue mencionada por primera vez en Argentina en 2007, y desde entonces se ha se expandido por todo el oeste y ciertos sectores del centro del país. En este trabajo presentamos nuevos registros de Torcaza Ala Blanca para Santa Cruz, Argentina, siendo este uno de los registros más australes conocidos hasta el mom...

La Codorniz de California (Callipepla californica) fue introducida en Argentina en diferentes ocasiones desde la década de 1920’s hasta 1970’s. Hasta el presente, el límite sur de su distribución en Argentina se situaba en la provincia del Chubut. Aquí presentamos el primer registro de la Codorniz de California para la provincia de Santa Cruz. Este...

Citizen science data are increasingly used for biodiversity monitoring. However, concerns are often raised over the accuracy of species identifications in citizen science databases, as data are collected mostly by non‐professionals. Misidentifications can simultaneously generate two error types: false positives (erroneous reports of a species) and...

El Piojito Trinador (Serpophaga griseicapilla) es un pequeño tiránido migratorio que completa su ciclo anual en el sur de Sudamérica, siendo aparentemente un endémico de cría de Argentina. Sin embargo, al ser una especie recientemente descripta carece de registros históricos, por lo que diversos aspectos de su ecología migratoria aún resultan poco...

Optimising conservation efforts requires an accurate record of the extant species as well as their geographic distributions. Nevertheless, most current conservation strategies start from an incomplete biodiversity inventory. Argentina has an extraordinary diversity of species, however, until now an updated inventory of its fauna has not been carrie...

Formulating effective management plans for addressing the impacts of invasive non-native species (INNS) requires the definition of clear priorities and tangible targets, and the recognition of the plurality of societal values assigned to these species. These tasks require a multi-disciplinary approach and the involvement of stakeholders. Here, we d...

Un inventario biológico enumera, ordena, cataloga y/o cuantifica ecorregiones, ecosistemas o especies. Es una herramienta básica y fundamental de gestión ambiental, que, al mismo tiempo, constituye la primera medida de conservación, dado que no se puede cuidar aquello que es ignorado. El presente Inventario Biológico Argentino es el esfuerzo de un...

Effective long-term management is needed to address the impacts of invasive alien species (IAS) that cannot be eradicated. We describe the fundamental characteristics of long-term management policies for IAS, diagnose a major shortcoming, and outline how to produce effective IAS management. Key international and transnational management policies co...

Effective long-term management is needed to address the impacts of invasive alien species (IAS) that cannot be eradicated. We describe the fundamental characteristics of long-term management policies for IAS, diagnose a major shortcoming, and outline how to produce effective IAS management. Key international and transnational management policies co...

Migratory sheldgeese (continental Upland Goose Chloephaga picta, Ashy-headed Goose C. poliocephala, and continental Ruddy-headed Goose C. rubidiceps) are endemic birds of southern South America. They are currently threatened by illegal hunting, overgrazing, and invasive predators. Because their breeding area is intensely grazed by sheep and cows, w...

Invasive Alien Species (IAS) threaten biodiversity, ecosystem functions and services, modify landscapes and impose costs to national economies. Management efforts are underway globally to reduce these impacts, but little attention has been paid to optimising the use of the scarce available resources when IAS are impossible to eradicate, and therefo...

Three migratory species of sheldgeese (Chloephaga spp.) make seasonal movements across a large portion of the Argentine territory. All three of these species have been affected by anthropogenic actions which have caused dramatic population drops, especially for the Ruddy-headed Goose (Chloephaga rubidiceps). Although telemetry techniques have rapid...

RESUMEN Presentamos el registro de un adulto y dos cachorros de puma en un nido de cauquén común, monitoreado con una trampa cámara en la provincia de Santa Cruz, República Argentina. Los felinos permanecieron en el nido 15 minutos, retiraron los huevos pero no los consumieron. Posiblemente, los huevos de aves formen parte de la dieta de este carní...

Imberti, S., H. Casañas, and I. Roesler (2020). Hooded Grebe (Podiceps gallardoi), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.hoogre1.01

The population of the critically endangered hooded grebe ( Podiceps gallardoi ) has decreased drastically during recent decades. The effects of climate change on their reproductive area (Southern Patagonia) have been proposed as one of the potential causes of their critical situation. However, there is much uncertainty about climate variability and...

Pesticide use has been suggested as one of the major drivers of the global amphibian decline. Laboratory and mesocosm studies have addressed several questions to understand the mechanism by which pesticides cause detrimental effects on amphibians. However, the extrapolation of those results to natural populations may not be adequate to predict envi...

Since its rediscovery in 1998, two major threats have been mentioned for the enigmatic Austral Rail Rallus antarcticus : cattle management by burning grass and rushes and predation by American mink Neovison vison . Added to the lack of a protocol to monitor this secretive bird, ever-growing threats make it necessary to study its global situation in...

ABSTRACT—The Upland Goose (Chloephaga picta) is a ground-nesting bird that has suffered a precipitous population decline in the last 60 years. We monitored Upland Goose nests with camera traps in Santa Cruz province, Argentina, to study nest disturbances that could reduce reproductive success. We studied female behavior following nest disturbance b...

Biodiversity loss in shallow lakes is associated to several factors among which water level decrease and fish introduction are indicated as potential stressors. The Patagonian basaltic plateaus, located in one of the most arid regions of South America, hold thousands of shallow lakes and ponds and some large lakes, where vegetated lakes are the pri...

Invasive American mink is a severe threat to endangered waterbird populations. In Europe and South America, control efforts have been increasing in the last decades. Mink has a proven acute impact on the Hooded Grebe, a critically endangered specialist of highland plateau lakes in Patagonia where a single mink attack can deplete up to 4% of the glo...

Northwestern Buenos Aires province is located within the Pampas region of Argentina. Agricultural practices have extensively modified native grasslands in a relatively short period, leaving no intact pristine areas. Based on data collected between 2006 and 2015 at 153 ponds in agricultural landscapes, we compiled an annotated list of the amphibians...

Understanding the demography of an invasive species is crucial to better guide managers seeking to slow the spread of the invader. Habitat differences can affect demographic rates, which may in turn impact the speed of the invasion, but this has been rarely addressed. We studied the demography of invasive North American beavers (Castor canadensis)...

In 2011, the invasive American mink Neovison vison became the most acute threat to the globally critically endangered Hooded Grebe Podiceps gallardoi (global population <800 individuals) when mink killed over 4 % of their global population. The Hooded Grebe is endemic to the Argentinean Austral Patagonia. In 2014, we established a control program i...

Summary The Ruddy-headed Goose Chloephaga rubidiceps has two separate and genetically distinct populations, one sedentary that inhabits the Malvinas/Falklands Islands and another migratory, which inhabits continental southern South America. New information suggests that these populations should be considered as different evolutionarily significant...

Aquaculture in arid Patagonia is potentially affecting the hooded grebe (Podiceps gallardoi), a critically endangered endemic waterbird. Exotic rainbow trout (Oncorhynchus mykiss) were stocked from 1994 in naturally fishless lakes, the primary reproductive habitat of this grebe. Trout and grebes are visual predators, whose diets overlap. Consequent...

The critically endangered hooded grebe Podiceps gallardoi has suffered a population reduction of 80% in the last 25 years. Although climatic conditions are suggested to be important causes of this decline, invasive species are also having a large impact. Hooded grebes have the lowest recruitment rate within the Podicepodiformes, but this is usually...

Existen pocas áreas verdes y reservas urbanas en la ribera del Área Metropolitana de Buenos Aires (AMBA), por lo que resulta imprescindible conservarlas. La Reserva Ecológica Costanera Norte (RECN, 18 ha) es una de las dos reservas de la Ciudad de Buenos Aires que se formó por terrenos ganados al río. Fue declarada Reserva Ecológica en diciembre de...

Information on Nearctic shorebirds is scarce for inland South America. This work presents information on abundance and habitat use of the species that inhabit water bodies in the highlands of western Santa Cruz province, Argentina. Surveys were conducted during four austral summers (January to March) from 2010 to 2013, with annual data collected at...

The status of the Hooded Grebe in Chile has been uncertain since it was first mentioned for the country 25 years ago. Since the first observation, a new set of records has been published elsewhere, but none of them has comprehensively assessed the status of the species in Chile. These publications hypothesize that the species is either a breeding r...

Invernada de Pandion haliaetus en Argentina: Perspectivas a Partir de Nuevos Registros Entre 1993–2008 La subespecie migratoria Pandion haliaetus carolinensis se reproduce a través de la mayor parte de América del Norte. La mayoría de estos individuos invernan al norte del Ecuador, aunque números significativos de individuos de esta especie viajan...

During ornithological studies in the provinces of Jujuy, Salta, and San Juan, we recorded the Andean Swallow Orochelidon andecola at 40 localities. These are the first records in Argentina, and also represent the southernmost for the species. Some of these localities are up to 1500 m lower than the previously known elevational limit (now 800 masl),...

Santa Cruz province is the second largest province in Argentina, and also the least populated. This province makes up the southern tip of continental Argentina. Althought it has low population density and is remote from big cities, in the past it received well-deserved attention from researchers. This was probably due to the presence of many intere...

We analyzed all known records from Argentina of the Little Blue Heron (Egretta caerulea). We report the first breeding record and 13 new localities for the species, which is now known from 30 records from 28 localities in 10 provinces. Most records come from valleys and wetlands in northern and northwestern Argentina, where the species apparently b...

We present the results of searches for the Austral Rail Rallus antarcticus in Argentine and Chilean Patagonia between January 1998 and February 2006 and from subsequent visits. We surveyed 58 localities and found the rail in 22, which collectively cover approximately 85 km2 of habitat. A maximum of 175 individuals were detected. This poorly known s...

The Hooded Grebe Podiceps gallardoi has been uplisted to globally Endangered' recently mainly because of the rapid population decline suffered within the last 20 years due to factors such as nest depredation by Kelp Gull Larus dominicanus as well as destruction of colonies by wind and lake desiccation. During a census of Hooded Grebes during the 20...

We estimated the present population size of the Hooded Grebe Podiceps gallardoi and compared it with the population in 1985. During the breeding seasons 2009/2010 and 2010/2011 we monitored 251 lakes on the main plateaus of Santa Cruz province, southern Patagonia, Argentina, where the entire population of Hooded Grebes spends the breeding season. D...

We present new records of the little-known White-chested Swift Cypseloides lemosi from northern Peru and north-west Bolivia; photographic documentation is available for one of the Peruvian records, whilst the sight-only Bolivian records represent the species' first mention for the country. We also present a photographically documented record of the...

This paper presents novelty information about the distribution of Scinax granulatus in Argentina. These records were made ca. 300 km from the closest known locality. Here we propose that the species is expanding its range following the tree implantation in a former treeless habitat like the Pampas. Scinax granulatus (Peters, 1871) ranges from south...

The diverse genus Sporophila has a complex systematic history. A new dark-collared form of Sporophila seedeater, herein described on the basis of three adult males, resembles male S. ruficollis but has a dark nape and rufous back. We informally name the new form 'caraguata' for its preferred habitat. We tested four hypotheses regarding the systemat...

Barn Swallow Hirundo rustica was first recorded nesting in Argentina in the early 1980s, when just a few pairs were found in central-east Buenos Aires province. Since then, the species appears to have spread. Here we present new records from a locality in central Buenos Aires province, providing further evidence of the extension of its breeding ran...

We provide the first confirmation of the Sooty Swift (Cypseloldes fumigatus) in Argentina. The species was found breeding at four small to large waterfalls (7 to 60 m in height) in the departments of Oberá and Cainguás, Misiones province, north eastern Argentina. Within this relatively small breeding range the maximum distance between localities wa...

The status, distribution and natural history of the Subtropical Doradito Pseudocolopteryx acutipennis has long been misunderstood. Only recently has new information concerning its distri- bution in the Pampas become available, yet still almost nothing is known about its biology. Here I present data on breeding biology, voice and behaviour, as well...

The status, distribution and natural history of the Subtropical Doradito Pseudocolopteryx acutipennis has long been misunderstood. Only recently has new information concerning its distribution in the Pampas become available, yet still almost nothing is known about its biology. Here I present data on breeding biology, voice and behaviour, as well as...

We present the first record of the Masked Tityra (Tityra semifasciata) in Argentina. We observed and photographed a male on 17 January 2008 in Parque Nacional Iguazú, Misiones. The bird was in the canopy, in a mixed-species flock that included the other two species in the genus, the Black-tailed Tityra (Tityra cayana) and the Black-crowned Tityra (...

We present the first record of the Masked Tityra (Tityra semifasciata) in Argentina. We observed and photographed a male on 17 January 2008 in Parque Nacional Iguazú, Misiones. The bird was in the canopy, in a mixed-species flock that included the other two species in the genus, the Black-tailed Tityra (Tityra cayana) and the Black-crowned Tityra (...

The Bobolink (Dolichonyx oryzivorus) breeds in temperate North America and migrates in winter to southern South America. During the non-breeding season, this species occupies grasslands, marshes, and rice fields in Paraguay, Bolivia, Brazil and Argentina. Since the 1960's, a population decrease has been noted, largely due to modification of the bre...

Descripción de un nido, de pichones y de aspectos de la dieta y comportamiento del Milano de Corbata (Harpagus diodon).

Se presentan nuevos registros de la Cachirla Trinadora (Anthus chacoensis) en Argentina para las provincias de Córdoba, Buenos Aires, San Luis, La Pampa, Santa Fe y Entre Ríos. La información obtenida muestra que resulta más común que lo que previamente se pensaba, y sugiere que su área reproductiva estaría en la región de las Pampas del centro de...

El Aguilucho Alas Anchas (Buteo platypterus) es una rapaz migratoria que nidifica en América del Norte y pasa la temporada no reproductiva en el norte de América del Sur, extendiéndose hacia el sur por los Andes. Hasta ahora, el único registro documentado para Argentina correspondía a un individuo observado en el Parque Nacional Calilegua, provinci...

La presencia del Aguilucho Cola Corta (Buteo brachyurus) en la Región Chaqueña argentina es muy poco conocida y está basada en pocos datos concretos. En este trabajo se presentan nueve registros nuevos para las provincias de Chaco, Formosa y Santiago del Estero, siendo este último el primero para la provincia. Buteo brachyurus parece no ser tan rar...