Pablo Yorio

• Doctor
• Investigador Superior at Centro para el Estudio de Sistemas Marinos - CONICET

Las aves marinas son uno de los grupos de aves más amenazados a nivel global. Sin embargo, varias actividades humanas también proveen recursos que estas aves pueden utilizar en su beneficio. Se presenta una síntesis del conocimiento sobre el uso de recursos antrópicos por parte de las aves marinas que se reproducen en el litoral patagónico argentin...

The European green crab (Carcinus maenas) is one of the most extensively studied decapod species worldwide, and it currently inhabits every continent except Antarctica. Its effects are observed across various spatio-temporal scales, impacting a wide range of taxa and environments. While extensive research has been conducted in the Northern Hemisphe...

El Golfo San Jorge (GSJ) fue incluido como una de las áreas geográficas prioritarias en el marco de la Iniciativa Pampa Azul por ser una de las regiones más productivas y con mayor diversidad del Mar Argentino. La región es clave en el ciclo de vida de los recursos pesqueros más importantes de Argentina y cuenta con áreas protegidas destinadas a la...

CAPÍTULO 10. El Golfo San Jorge como área prioritaria de investigación, manejo y conservación en el marco de la Iniciativa Pampa Azul. El Golfo San Jorge (GSJ) fue incluido como una de las áreas geográficas prioritarias en el marco de la Iniciativa Pampa Azul por ser una de las regiones más productivas y con mayor diversidad del Mar Argentino. La...

Rationale Understanding the migration of marine animals is hindered by the limitations of traditional tracking methods. It is therefore crucial to develop alternative methods. Stable isotope‐based tracking has proven useful for this task, although it requires detailed isoscapes in the focal area. Here, we present predator‐based isoscapes of the coa...

The genetic identification of evolutionary significant units and information on their connectivity can be used to design effective management and conservation plans for species of concern. Despite having high dispersal capacity, several seabird species show population structure due to both abiotic and biotic barriers to gene flow. The Kelp Gull is...

El desarrollo urbano e industrial puede tener un impacto negativo sobre las poblaciones de aves marinas, aunque muchas veces las aves pueden aprovechar estructuras artificiales que podrían proporcionarles condiciones más estables para la reproducción y/o con una menor presión de depredación. Este trabajo actualiza la distribución de colonias de ave...

Waste associated with human activities can benefit opportunistic species at the individual and population levels but could also expose them to pathogens or toxins. We provide information on unreported foraging habits of White‐faced ibis ( Plegadis chihi ) and Black‐faced ibis ( Theristicus melanopis ) in the Chubut River Valley, an urban and agricu...

Monofilament fishing lines lost or discarded during recreational fishing activities often result in negative impacts on marine organisms. We assessed the interactions between Kelp and Olrog's gulls (Larus dominicanus and L. atlanticus, respectively) and recreational fishing at Bahía San Blas, Argentina. Monofilament lines constituted 61 and 29 % of...

Predictable anthropogenic food subsidies attract species with generalist and opportunistic feeding habits, often resulting in conflicts with human populations. We assessed the spatio-temporal distribution and abundance of Kelp Gulls (Larus dominicanus) during the annual cycle at anthropogenic food sources located along 70 km of urban and agricultur...

Many seabirds show sexual differences in different aspects of their trophic ecology. The Imperial Cormorant (Leucocarbo atriceps) presents sexual size dimorphism, with males being larger and heavier than females. They show sexual differences in feeding behaviour, but no studies have yet comprehensively quantified the sexual segregation in the use o...

El conocimiento de la biología reproductiva de las aves es relevante para entender aspectos de sus historias de vida e interpretar cómo responden a los crecientes cambios que enfrentan a nivel global. Se evaluó la biología reproductiva de la Gaviota Cocinera (Larus dominicanus) en el Área Natural Protegida Punta Tombo, Chubut, sitio de una de las m...

Wildlife populations are dynamic and changes in their spatial distribution and/or abundance at different loca�tions may potentially change the scenarios under which conservation efforts should be allocated. To maximize success in management and/or conservation actions, regular monitoring and dynamic frameworks to re-adapt strategies are needed. F...

Anthropogenic debris is used as nesting material by many seabirds and may result in negative impacts. We assessed the frequency of occurrence of debris (>5 mm) in Kelp Gull (Larus dominicanus) nests at six locations along 2400 km of the Argentine coast, at different distances from urban centres, and in nests of other seven seabird species nesting s...

El Golfo San Jorge (GSJ) fue incluido como una de las áreas geográficas prioritarias en el marco de la Iniciativa Pampa Azul por ser una de las regiones más productivas y con mayor diversidad del Mar Argentino. La región es clave en el ciclo de vida de los recursos pesqueros más importantes de Argentina y cuenta con áreas protegidas destinadas a la...

As marine ecosystems are harvested or modified by anthropogenic or natural factors, there is an increasing demand for indicators of trophic web health or status. The Magellanic Penguin (Spheniscus magellanicus) is a widely distributed species that forages in the Patagonian Shelf. During breeding, this species is a central-place forager that feeds m...

Sexual segregation in feeding strategies has been widely reported in seabirds. Most seabirds occupy wide breeding distributional ranges, and dissimilar ecological settings may result in distinct environmental pressures on males and females leading to geographical differences in sexual segregation. Using GPS loggers and stable isotope analysis of wh...

Monitoring programmes are essential for detecting population changes, but data series are difficult to sustain over time. Additionally, wide-scale monitoring is needed to adequately interpret demographic behaviour given the metapopulation dynamics characteristics of most seabird species and to understand the underlying factors, such as anthropogeni...

The Olrog’s Gull Larus atlanticus is an endemic and threatened species of the south-western Atlantic. Little is known about its movements during the non-breeding period. The objective of this study was to analyse the migration of the species by tracking adults from Bahía San Blas (Buenos Aires province, Argentina) with geolocators and using informa...

Seabirds often have wide distribution ranges and may travel relatively long distances to breeding grounds, often crossing jurisdictional boundaries. When engaged in foraging behaviour, seabirds are prone to interact with different fisheries and suffer incidental mortality. We assessed the spatial use of foraging Magellanic penguins Spheniscus magel...

The assessment of the relevance of forage fish in seabird diet and how different species partition food resources is fundamental to understand predator–prey relationships. We assessed the importance of forage fish in the diet of Royal (Thalasseus maximus maximus) and Cayenne (T. sandvicensis eurygnathus) terns and their partitioning of food resourc...

Este artículo no cuenta con un resumen.

Royal Terns (Thalasseus maximus) and Cayenne Terns (Thalasseus sandvicensis eurygnathus) breed sympatrically in Patagonia, and very little is known about their breeding foraging patterns. Simultaneous information on the foraging patterns of both species using VHF radio-telemetry is presented from a mixed species colony in the Punta León Protected A...

Many closely related seabirds nest in mixed colonies, and this association may result in interspecific interactions such as competition for common resources and kleptoparasitism. Trophic interactions were evaluated between the Kelp Gull (Larus dominicanus Lichtenstein, 1823) and Royal and Cayenne terns (Thalasseus maximus maximus (Boddaert, 1783) a...

The Magellanic Penguin (Spheniscus magellanicus) is the most abundant and widely distributed seabird breeding on the Patagonian Coast of Argentina. We combined conventional stomach content and stable isotope analysis to assess Magellanic Penguin diet during the chick rearing stage at the two northernmost colonies in an area subject to fisheries. In...

Prey use by male and female Magellanic Penguins (Spheniscus magellanicus) was quantified during chick rearing in northern Golfo San Jorge, Argentina and the dietary niches and diet composition of each sex were assessed and compared. A total of 67 males and 45 females were flushed during the chick stages of 2011 and 2012. Argentine Anchovy (Engrauli...

Year-round foraging strategies are key determinants of bird population dynamics. However, trophic ecology studies during the non-breeding period rarely focus on individuals from a known breeding colony, precluding links to demographic aspects of the target population or metapopulation. Using stable isotope analysis (δ¹⁵N, δ¹³C) of primary feathers...

Persistent organic pollutants (POPs) are of great concern for the environment. In this study we (a) determine levels and distribution of OCPs, PCBs, and PBDEs in sediments and two crab species (Neohelice granulata and Cyrtograpsus altimanus), (b) assess bioaccumulation in crabs, and (c) explore the occurrence of POPs in the Near Threatened Olrog's...

Kelp Gull (Larus dominicanus) foraging patterns were studied by deploying GPS loggers on 20 incubating individuals at their colony in the Bahía San Blas protected area, Argentina. Mean number of trips per day was 1.5 ± 0.5, and mean trip duration was 272.6 ± 165.2 min. Mean maximum distance from the colony was 19.6 ± 24.4 km. Incubating Kelp Gulls...

We assessed Kelp Gull (Larus dominicanus) diet composition complementing conventional and stable isotope methods to determine the relevance of food derived from recreational fisheries. To achieve this goal, we quantified Kelp Gull diet composition breeding at the Bahía San Blas protected area, Argentina, between 2012 and 2014, assessing differences...

Esta subregión se extiende a lo largo de más de 5.000 km. Debido a su extensión, se conjugan en ella diversas unidades ecológicas. La aridez del clima en el sector continental determina ambientes terrestres adaptados a las condiciones de escasez de agua, caracterizados por arbustos xerofíticos achaparrados, con hojas redu-cidas. La comunidad climáx...

We assessed differences in diet composition between Imperial Cormorants (Phalacrocorax atriceps) breeding at Isla Arce and Isla Vernaci Este, Golfo San Jorge, Argentina. Both colonies are located within the Patagonia Austral marine park, and commercial trawl fisheries operate in adjacent waters, thus knowledge of their food requirement is fundament...

Penguins are the most threatened group of seabirds after albatrosses. Despite being regularly captured in fishing gear, the threat to penguins, as a group, has not yet been assessed. We reviewed both published and grey literature to identify the fishing gear types that penguins are most frequently recorded in, the most impacted species and, for the...

Resumen ∙ El consumo del descarte pesquero en el mar es actualmente un importante componente en la ecología alimentaria de muchas especies de gaviotas. Los estudios de dieta son clave para evaluar la contribución relativa del descarte en su ecología trófica, así como empezar a comprender los potenciales efectos de la actividad pesquera sobre sus pa...

Several studies have applied induced regurgitations to characterize the diet of cormorants, but none have presented quantitative information indicating complete stomach contents were obtained. Our goal was to test the value of induced regurgitations for the assessment and monitoring of Imperial Cormorant (Phalacrocorax atriceps) diet. Stomach sampl...

We quantified the trophic niche of Magellanic penguins (Spheniscus magellanicus) breeding and moulting in Golfo San Jorge, Argentina, through conventional stomach content and stable isotope analysis. A total of 112 adults were flushed during the early and late chick stages of 2011 and 2012 at Isla Vernacci Norte, and at least 15 prey taxa were foun...

Conventional dietary studies combined with stable isotope analysis allowed the characterisation of the trophic niche of South American Terns (Sterna hirundinacea) breeding in Argentina. Direct observation of prey deliveries during mate- and chick-provisioning showed that the diet of South American Terns comprised at least 18 prey items, mainly pela...

In South America, Kelp Gulls (Larus dominicanus) breed from Chilean Tierra del Fuego north to Río de Janeiro, Brazil, on the Atlantic coast and to Piura, Peru, on the Pacific coast. This review presents the first synthesis of information on the distribution and size of Kelp Gull colonies at the country level in coastal environments of Uruguay, Chil...

The dispersal of individuals among breeding sites is considered to be one of the key processes in seabird population dynamics. The kelp gull (Larus dominicanus) is the most abundant gull in coastal Argentina, although its population dynamics in the region remains poorly understood. This article aims to address aspects of kelp gull demography along...

Although several studies have reported basic information about the size of eggs of Kelp Gulls (Larus dominicanus), no attention has been paid to the comparison of patterns of intra-clutch variation at different breeding sites. Here, the variation in egg size of Kelp Gulls at two colonies from Patagonia, Argentina, was analyzed. The objectives were...

The Kelp Gull (Larus dominicanus), a common seabird in coastal Patagonia, has recently increased in overall abundance and distribution, creating some concerns for the protection and conservation of other native, threatened species. We combined genetic and demographic data of four large Kelp Gull colonies distributed along 1800 km of the northern Pa...

The knowledge of seabird breeding distribution and abundance is important for their management and conservation. We present information on the breeding of gulls and terns gathered between 2006–2013 at the Reserva Natural de Usos Múltiples Bahía San Blas, Buenos Aires Province. We recorded the nesting of eight species, in most cases in mixedspecies...

We quantified the causes and rate of nest desertions in Magellanic Penguins (Spheniscus magellanicus) during the egg stage at Punta Tombo, Argentina. Incubating Magellanic Penguins rarely deserted. The average desertion rate during seven years was 11% (SD = 9.2%). Desertions were poorly correlated with the length of the incubation spell and only 25...

Among marine debris, monofilament fishing lines often result in negative impacts on marine organisms. We characterized marine debris and incidence of lost and discarded monofilament lines along beaches used by recreational fishers, and report the impact of lines on Kelp Gulls (Larus dominicanus) at the Bahía San Blas protected area, site of one of...

Understanding the processes involved in the establishment and persistence of new seabird colonies is important for improving conservation and management strategies. Over the past few decades, kelp gull Larus dominicanus numbers have increased in Patagonia, Argentina, and new colonies have been reported. We studied a recently established colony to a...

The Olrog's Gull (Larus atlanticus) is a species that feeds almost exclusively on intertidal crabs. The influence of feeding technique, food source, and habitat characteristics on the feeding rate of breeding individuals was examined at Bahía San Blas, Argentina, from September to December 2007. Olrog's Gulls used four feeding techniques, with more...

The knowledge of seabird breeding distribution and abundance is important for their management and conservation. We present information on the breeding of gulls and terns gathered between 2006-2013 at the Reserva Natural de Usos Múltiples Bahía San Blas, Buenos Aires Province. We recorded the nesting of eight species, in most cases in mixed-species...

The first information on the morphometry and sexual size dimorphism of the sympatric South American (Sterna hirundinacea), Cayenne (Thalasseus sandvicensis eurygnathus) and Royal (T. maximus maximus) terns from the Patagonia region in Argentina is provided, and a discriminant analysis to sex the three species is used. Morphological characters were...

We assessed the potential overlap in diet composition of the kelp gull Larus dominicanus and the threatened Olrog’s gull L. atlanticus breeding syntopically at Bahía San Blas, Argentina, during two breeding seasons (2006 and 2007). Diet was studied using regurgitated pellets (180 per species and year) and chick stomach samples obtained through the...

2000. Age-related feeding behaviour and foraging efficiency in Kelp Gulls Larus dominicanus attending coastal trawlers in Argentina. Ardea 88(2): 207-214. We studied age-related differences in feeding behaviour and foraging suc-cess of Kelp Gulls Larus dominicanus feeding on fishery discards at trawl vessels in northern Patagonia, Argentina. Kelp G...

Olrog’s Gull Larus atlanticus breeds only in Argentina and is currently categorized as “Vulnerable”. Knowledge of the location of colonies and an updated understanding of human activities that may impact their breeding populations are crucial to the development of adequate conservation and management actions. In this paper we update the breeding di...

Olrog’s Gull Larus atlanticus is a threatened species which feeds during the breeding season almost exclusively on crabs. We studied the use of foraging areas and its relationship with prey resources in Olrog’s Gulls breeding at Bahı´a San Blas, Argentina. Feeding areas were identified by radio-tracking 10 and 12 birds in 2006 and 2007, respectively...

Seabirds are facing a growing number of threats in both terrestrial and marine habitats, and many populations have experienced dramatic changes over past decades. Years of seabird research have improved our understanding of seabird populations and provided a broader understanding of marine ecological processes. In an effort to encourage future rese...

We evaluated seabird attendance and incidental mortality at coastal trawl vessels targeting Argentine red shrimp (Pleoticus muelleri) in the Isla Escondida fishing area, Argentina, during 2006–2007 and 2007–2008. Eight seabird species attended vessels, and the most frequent and abundant seabird (percent occurrence, mean number per haul) in the two...

We evaluated discard consumption by Kelp Gulls (Larus dominicanus) and Black-browed Albatrosses (Thalassarche melanophrys) associated with trawlers operating at Golfo San Jorge, Argentina, and assessed differences in their feeding behaviour, prey size preferences and foraging efficiency. Observations were made onboard hake (January 2007) and shrimp...

Many populations of seabird species with opportunistic or generalist feeding habits have expanded worldwide, possibly because they are using additional food resources provided by human activities. The Kelp Gull (Larus dominicanus) is a generalist feeder that often feeds on urban and fish waste and its populations have been expanding in several regi...

Many populations of seabird species with opportunistic or generalist feeding habits have expanded worldwide, possibly because they are using additional food resources provided by human activities. The Kelp Gull (Larus dominicanus) is a generalist feeder that often feeds on urban and fish waste and its populations have been expanding in several regi...

Many seabirds are attracted to trawl vessels to make use of fishery waste, and often this attraction results in increased incidental mortality. We assessed seabird attendance and associated incidental mortality at the Argentine red shrimp Pleoticus muelleri trawl fishery in Golfo San Jorge, Argentina. Information on seabird numbers was gathered in...

We examined temporal changes in diet composition and prey selection in the threatened Olrog’s gull Larus atlanticus breeding at Bahía San Blas, Argentina. Diet was assessed through pellet analysis (N = 360) and chick stomach samples (N = 120) during 2006 and 2007. Prey availability was sampled in 2,084 1m2 quadrats distributed throughout Olrog’s gu...

Sources of information used to estimate total number of marine species for different taxa of the Patagonian Shelf region of South America. (0.06 MB DOC)

Summary of literature sources on marine biodiversity for the non-coastal Brazilian deep-sea marine realms: (1) slope, (2) seamounts and oceanic islands, and (3) abyssal plains. (0.09 MB DOC)

Diversity, state of knowledge, and expertise of all taxonomic groups within the Tropical West Atlantic region of South America. Sources of the reports: databases, scientific literature, books, field guides, technical reports. State of knowledge classified as: 5 = very well known (>80% described, identification guides <20 years old, and current taxo...

Diversity, state of knowledge, and expertise of all taxonomic groups within the Humboldt Current region of South America. Sources of the reports: databases, scientific literature, books, field guides, technical reports. State of knowledge classified as: 5 = very well known (>80% described, identification guides <20 years old, and current taxonomic...

Diversity, state of knowledge, and expertise of all taxonomic groups within the Patagonian Shelf region of South America. Sources of the reports: databases, scientific literature, books, field guides, technical reports. State of knowledge classified as: 5 = very well known (>80% described, identification guides <20 years old, and current taxonomic...

Sources of information used to estimate total number of marine species for different taxa of the Tropical East Pacific region of South America. (0.05 MB DOC)

Diversity, state of knowledge, and expertise of all taxonomic groups within the Tropical East Pacific region of South America. Sources of the reports: databases, scientific literature, books, field guides, technical reports. State of knowledge classified as: 5 = very well known (>80% described, identification guides <20 years old, and current taxon...

Diversity, state of knowledge, and expertise of all taxonomic groups within the Brazilian region of South America. Sources of the reports: databases, scientific literature, books, field guides, technical reports. State of knowledge classified as: 5 = very well known (>80% described, identification guides <20 years old, and current taxonomic experti...

Major Brazilian cruises that have taken samples in the deep sea, including seamounts and abyssal plains. (0.06 MB DOC)

The marine areas of South America (SA) include almost 30,000 km of coastline and encompass three different oceanic domains--the Caribbean, the Pacific, and the Atlantic--ranging in latitude from 12∘N to 55∘S. The 10 countries that border these coasts have different research capabilities and taxonomic traditions that affect taxonomic knowledge. This...

The study of temporal patterns in diet composition is crucial to interpret adequately several aspects of seabird ecology and life history. The variation in prey composition and prey size in relation to chick age were evaluated in a South American Tern (Sterna hirundinacea) colony at Punta Loma, Argentina, during the 2006 breeding season. The diet o...

This paper describes nocturnal, marine feeding behaviour in the Brown-hooded Gull (Larus maculipennis) in November 2009. The gulls assembled at night at the end of a long pier, running 800 m offshore into the Golfo Nuevo, at Puerto Madryn, Chubut Province, Argentina. Powerful lights predictably lighted the water around the end of the pier and attra...

This study investigated the level of seabird mortality caused by the domestic trawl fleet (freshies) for hake (among other less important targets) operating in waters off central Patagonia (37–48°S), analyzing the effect of environmental and operational variability on the level of seabird interactions. With a total of 135 vessels, the fleet is one...

Assessing human activities and understanding their interaction with seabirds constitute important steps in the development of adequate conservation planning schemes. We evaluated the spatial use of the marine environment by foraging Magellanic Penguins Spheniscus magellanicus and Imperial Cormorants Phalacrocorax atriceps breeding at a newly design...

Diets of breeding Imperial Cormorants Phalacrocorax atriceps were studied at two breeding colonies, Islas Blancas and Isla Arce, located approximately 30 km apart in an area subject to increasing fishing pressure off Central Patagonia, Argentina. The goal was to assess differences between locations and diet variation among stages of the breeding cy...

Nest site selection of Kelp gulls Larus dominicanus breeding in Conejo and Bridges islands, Tierra del Fuego, Argentina, was assessed between 14 and 30 December 2005 to describe variability in nest site features and determine variables affecting nest choice. Fourteen microhabitat variables were quantified at 40 nest sites and at 40 random points in...

This paper describes nocturnal, marine feeding behaviour in the Brown-hooded Gull (Larus maculipennis) in November 2009. The gulls assembled at night at the end of a long pier, running 800 m offshore into the Golfo Nuevo, at Puerto Madryn, Chubut Province, Argentina. Powerful lights predictably lighted the water around the end of the pier and attra...

We studied the predation by Kelp Gull (Larus domimcanus) upon Royal and Cayenne terns (Thalasseus maximus and T. sandvicensis euygnathus, respectively) at the Punta Leon Protected Area, Argentina, during the 2005 and 2006 breeding seasons to assess changes in the predator-prey interaction with respect to that observed at the same location in the ea...

Infanticide and nonfatal aggression by adults toward unfamiliar chicks have been widely reported in colonial birds, and can be an important cause of chick mortality. We studied intraspecific aggression by adults toward chicks at a South American Tern (Sterna hirundinacea) colony in Patagonia, Argentina, during 2005 to characterize this behavior, ev...

Conflicts between habitat use and conservation are inherent to the management of wetlands. A major challenge for their management is to preserve habitat while addressing the demands from multiple users. In southern Patagonia (Argentina), a growing aquaculture activity based on rainbow trout introductions in shallow lakes is generating concerns abou...

We studied the diet of Imperial Cormorants (Phalacrocorax atriceps) and Rock Shags (P. magellanicus) at Bahía Bustamante, Argentina, between 1992 and 1994. We analyzed pellet casts (1887 from Imperial Cormorants and 799 from Rock Shags) and regurgitations of stomach contents (260 from Imperial Cormorants and 24 from Rock Shags). Imperial Cormorants...

The Neotropic Cormorant (Phalacrocorax brasilianus) is a widespread and abundant species distributed throughout the Neotropics. We report on diving behavior and foraging areas of Neotropic Cormorants in inshore marine waters of Patagonia, Argentina. Mean dive duration was 18.9 ± 5.3 sec and differed significantly among birds. Maximum dive duration...

Wetlands are critical foraging areas for many waterbird species, and their relatively high productivity often determines the coexistence of several species using food resources for breeding and/or refueling during migration. Between 18 October and 20 December 2000, we gathered information on foraging habitat use and feeding techniques of sixteen wa...

The Strobel Plateau is a conspicuous and representative basaltic plateau ("meseta") in the Patagonian steppe, Argentina. This plateau is dotted with more than 1500 shallow lakes, which are regularly used by waterbirds and support one of the main breeding populations of the near threatened Hooded Grebe (Podiceps gallardoi). We collected data on bird...