Marcelo Bertellotti - Academia.edu (original) (raw)

Papers by Marcelo Bertellotti

Journal of Ornithology, 2014

Science of The Total Environment, Apr 1, 2023

Los pinguinos de Magallanes son entre las aves marinas, la especie mas afectada por la contaminac... more Los pinguinos de Magallanes son entre las aves marinas, la especie mas afectada por la contaminacion con petroleo en Chubut y Santa Cruz. Una de las consecuencias adversas de la exposicion a hidrocarburos y otros contaminantes es el aumento de los niveles celulares de especies reactivas del oxigeno o estres oxidativo, considerados herramientas utiles como biomarcadores del impacto de la exposicion a contaminantes quimicos peligrosos. El objetivo de este trabajo fue evaluar parametros hematologicos y marcadores de estres oxidativo durante la rehabilitacion de tres pinguinos empetrolados provenientes del Area Natural Protegida Punta Tombo, Chubut, Argentina. Se tomaron tres muestras de sangre por individuo, la primera muestra al arribo de los pinguinos al centro de rehabilitacion, la segunda una semana despues y una ultima muestra antes de ser liberados. Se obtuvo la cantidad total de leucocitos, la razon heterofilos/linfocitos, el hematocrito y las concentraciones de glucosa y de proteinas totales. Se analizo la actividad de la enzima catalasa, responsable de la degradacion del peroxido de hidrogeno, los niveles de tioles totales no proteicos y el dano a lipidos evaluando las especies reactivas al acido tiobarbiturico, como indicadores de estres oxidativo. El estudio se complemento con la obtencion del peso de los pinguinos. En general, los parametros medidos, aumentaron o se mantuvieron constantes desde la primera tomas toma de muestra hasta la ultima. Si bien algunas de las variables para cada pinguino se comportaron diferentes durante el tratamiento, en general se observo una tendencia a normalizarse hacia el momento de su liberacion. Se concluye que los pinguinos se liberaron en buen estado fisico luego de la rehabilitacion.

La Zona Costera Patagónica Argentina, 2015

El valor de las aves marinas como recurso en la zona costera patagónica se basa en su atractivo p... more El valor de las aves marinas como recurso en la zona costera patagónica se basa en su atractivo para la actividad turística y en menor medida en la producción de guano. Si bien numerosas especies de aves se reproducen en la región, el pingüino de Magallanes constituye el principal atractivo turístico y es la especie de ave que genera el mayor ingreso directo. Las otras especies poseen solamente un valor relativo a nivel local o contribuyen a la diversidad de la fauna silvestre que atrae visitantes nacionales y extranjeros. En cuanto a la explotación guanera, si bien se continúa desarrollando en unas pocas localidades, existen limitaciones que la han convertido en una actividad de baja importancia relativa. Otra actividad relacionada con las aves y que debería ser reconsiderada al planificar el uso sostenible de los recursos en la zona costera es la caza deportiva. Las poblaciones involucradas tienen amplia distribución en ambientes terrestres y acuáticos continentales de la Patagonia. Sin embargo, muchas de ellas habitan o utilizan los ambientes costeros durante parte del año, como el cauquén común (Chloephaga picta), el pato maicero (Anas georgica), el pato barcino (Anas flavirostris, la perdiz chica (Notura maculosa), la martineta común (Eudromia elegans) y la paloma torcaza (Zenaida auriculata). Cabe considerar que no existen hasta la fecha estudios que evalúen los efectos de la actividad sobre las especies, ni las consecuencias de la misma para las poblaciones que utilizan los ambientes costeros. Un aspecto poco tenido en cuenta es la importancia que las aves pueden tener como indicadoras de integridad biológica de algunos ecosistemas. Entre otras cosas, se ha señalado el potencial de las aves marinas para el seguimiento de los niveles de contaminantes que se acumulan a lo largo de la cadena trófica y los stocks de peces comerciales, ya que son sensibles a los cambios en la disponibilidad de alimento. Por otro lado, las aves playeras migratorias están consideradas como buenas indicadoras de la calidad ambiental y el estado de los humedales. Esto sugiere que sería conveniente evaluar la utilidad de algunas especies como indicadoras de cambios ambientales.Fil: Bertellotti, Néstor Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: García Borboroglu, Pablo. Wildlife Conservation Society; Estados Unido

Canadian Journal of Zoology, 2022

Migratory shorebirds are of the most threatened avian species due to effects of human activities ... more Migratory shorebirds are of the most threatened avian species due to effects of human activities and climate change. Physiological parameters are useful to evaluate the health status of free-living animals. Here we investigated lymphocytes, heterophils, heterophils/lymphocytes, and glucose for female and male Two-banded plovers (TBPLs), Charadrius falklandicus (Latham, 1790) during nonbreeding (body moult) and breeding (incubation), in coastal areas of northern Patagonia Argentina. We also measured corticosterone for first time for the species during breeding. Nonbreeding TBPLs were more likely to have higher physiological measurements that were not dependent on body moult nor body condition, being similar between sexes. Differences found in glucose are likely related to recent feeding in nonbreeding birds compared with fasting during incubation. The gregarious nonbreeding behaviour in comparison with the isolated breeding pairs, would increase the risk of acquiring parasites and /or pathogens inducing a response of the immune system reflected in higher values of lymphocytes. Baseline corticosterone during breeding was similar between sexes and were lower compared with other values reported for breeding plovers. TBPLs undergo energetically demanding physiological changes during the nonbreeding stage, strengthening the idea that conservation of the environmental resources at these locations may be more important than previously thought.

Península Valdés (Patagonia, Argentina) is considered one of the best places in the world to watc... more Península Valdés (Patagonia, Argentina) is considered one of the best places in the world to watch southern right whales (Eubalaena australis) due to the large number of animals as well as to their predictability and proximity to the coast. The present study describes the spatial and temporal dynamics of whalewatching, and the different groups of whales that were the focus of this activity in Península Valdés during six reproductive seasons (from 2005 to 2008 and from 2012 to 2013). The aim was to generate useful tools to improve whalewatching activity in this area. Data were recorded from 1,816 whalewatching trips operated from Puerto Pirámides. Every trip had several stopovers to watch whales, defined as ‘sightings’. At the beginning of the season, most sightings occurred near Puerto Pirámides port, while at the end of the season, sightings were farther from the port. During the first half of the whale season, trips tended to be coastal and shorter but the groups of whales sighted were more varied, including solitary animals, mating groups and mothers with their recently born calves. In the second half of the season, trips tended to be further from the coast and longer, but the whales sighted were mainly mother-calf pairs, the last group of whales to leave the area. This difference in the characteristics of the sightings as the whale season progressed could be the basis to generate different recreational experience opportunities. Whalewatching has a major impact on the regional economy and whalewatching regulations, if correctly applied, could improve the quality of a conservation plan, considering that both gulfs of Península Valdés (San José and Nuevo) are the main calving areas for this species in the South Atlantic Ocean.Fil: Fazio, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Argüelles, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Bertellotti, Néstor Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Diseases of Aquatic Organisms, Aug 31, 2016

Southern right whales Eubalaena australis from Peninsula Valdés, Argentina, show wounds produced ... more Southern right whales Eubalaena australis from Peninsula Valdés, Argentina, show wounds produced by kelp gulls Larus dominicanus that feed on the whales' dorsal skin and blubber. During the 2013 whale season, several calves were reported showing kelp gull injuries with a swollen area surrounded by rhomboid-shaped raised edges. Samples from 9 calves were taken in order to establish the etiology of these rhomboid-shaped wounds; 2 calves (one living, one dead) showed gull-inflicted injuries with rhomboid-shaped edges. Samples from the dead calf were histologically characterized by the presence of dermal congestion, suppurative dermatitis and panniculitis, necrotizing vasculitis and vascular thrombosis. Erysipelothrix rhusiopathiae was detected by culture and PCR in samples from both calves. In this study we report, for the first time to our knowledge, the isolation of E. rhusiopathiae from wounds produced by gull attacks on southern right whale calves, supplying evidence that these wounds may act as an entry route for pathogens. This work provides new information about the consequences of gull-inflicted injuries for whale health.

Diseases of aquatic organisms, Jan 16, 2015

Poxvirus skin disease has been reported in several species of cetaceans, principally in odontocet... more Poxvirus skin disease has been reported in several species of cetaceans, principally in odontocetes, and a single report in mysticetes. Southern right whales Eubalaena australis in Peninsula Valdes, Argentina, show a variety of skin lesions of unknown etiology, and the number of these lesions has increased in recent years. Samples from dead whales were taken in order to establish the etiology of these lesions. One calf and one adult presented ring-type lesions, characterized by a circumscribed and slightly raised area of skin. Lesions were histologically characterized by the presence of microvesicles and vacuolated cells in the stratum spinosum, along with hyperplasia of the stratum corneum and eosinophilic inclusion bodies in the cytoplasm of the epithelial cells. Transmission electron microscopy showed aggregations of virions with typical poxvirus morphology. PCR of cetacean poxvirus (CPV) DNA polymerase, DNA topoisomerase I and parapoxvirus DNA polymerase gene fragments was done,...

Polar Biology, Nov 26, 2015

Intestinal parasites suppose a cost to hosts as they compete directly for nutritional resources. ... more Intestinal parasites suppose a cost to hosts as they compete directly for nutritional resources. Therefore, hosts must defend themselves against intestinal parasites by mounting an immune response. Many penguin species acquire parasites through their diet and transfer these parasites to their chicks when feeding them. High parasite loads in penguin chicks could have effects on their growth and body condition, and ultimately on their survival. Here, we evaluated the effect of parasites on the cell-mediated immune system in Gentoo penguin (Pygoscelis papua) chicks at Stranger Point (25 de Mayo/King George Island, South Shetland Islands). To this end, 12 chicks were experimentally deparasitized with a mixture of anthelminthic drugs (albendazole and praziquantel), whereas 10 others were kept as control. We measured cutaneous cell-mediated immunity in response to immunization with phytohemagglutinin (PHA). We also analyzed the leukocyte profile in both treated and control groups before and after the treatment. After the treatment, deparasitized birds showed larger foot-web swelling in response to PHA injection than control birds. Deparasitized penguins also showed lower eosinophil and monocyte counts than controls, whereas heterophils, lymphocytes, and total white blood cell counts did not differ between groups. Our results suggest that Gentoo penguin chicks parasitized with intestinal parasites suffer a cost in terms of reduced cell-mediated immune responses that could ultimately affect their survival.

Avian Conservation and Ecology

In coastal Patagonia, Argentina, shorebird breeding habitats overlap with high levels of human re... more In coastal Patagonia, Argentina, shorebird breeding habitats overlap with high levels of human recreational activities, such as dog-walking and driving motorized vehicles. We assessed physiological traits related to body condition, nutritional metabolites, cellular immunity, and stress responses of adult Two-banded Plovers (Charadrius falklandicus) in northern Chubut, Patagonia, Argentina. We examined blood samples from 46 individuals captured at an urban ("disturbed" treatment, n = 28) and a rural beach ("control" treatment, n = 18) between 2016 and 2017. We studied (1) body condition by size-correcting body mass to wing-chord lengths, (2) nutritional metabolites, such as the haematocrit, glucose, and concentrations of triglycerides, cholesterol, and total proteins, (3) cellular immunity by counting total leukocytes, and the percentages of heterophils, lymphocytes, eosinophils, and monocytes, and (4) stress responses by obtaining the heterophil/lymphocyte ratio and quantifications of plasma baseline corticosterone. We determined the overall support of predictor variables: treatment, day of the year (DOY), interaction DOY × treatment, year, and sex on a multivariate assessment using MANOVA. Body condition and triglycerides decreased, and monocytes increased, during the breeding season at the control site (DOY × treatment). Body condition significantly differed by sex, with males exhibiting lower values than females. Triglycerides, cholesterol, and total leukocyte count significantly differed between years, showing higher values in 2017. The multivariate model showed the greatest variation only explanatory in DOY (n = 0.67, P < 0.001) and year (n² = 0.62, P = 0.001). Overall, birds exhibited depleted body condition and triglycerides throughout the season at the control site: a pattern likely biased by the capture date. Contrary to the disturbed site, most samples at the control site were collected from mid-to-late breeding season each year, and most birds were likely renesting. Sex differences observed for body condition suggest greater energy-costly reproduction activities for males, including territory defense and courtship behaviors. No significant differences were found in stress responses, and based on observations in the field, birds may tolerate human disturbance. Habituation was a previously suggested coping mechanism for reducing the costs of repeated exposure to non-lethal stimuli, such as human activity. Given that no treatment effects on physiological traits were observed, beyond triglycerides, our results may still help to improve the decisions of wildlife managers toward protecting beachnesting areas by preventing impacts to nests, chicks, and pairs during their breeding season.

El Hornero

En esta investigación, se evaluó el potencial efecto de las actividades humanas sobre la tasa de ... more En esta investigación, se evaluó el potencial efecto de las actividades humanas sobre la tasa de supervivencia de nidos del Chorlo Doble Collar (Charadrius falklandicus), el éxito reproductivo, la condición física de los individuos reproductores y la fidelidad

J. Cetacean Res. Manage.

Science of The Total Environment

Journal of Field Ornithology, 2019

Life-history stages such as reproduction and molt are energetically costly. Reproductive costs in... more Life-history stages such as reproduction and molt are energetically costly. Reproductive costs include those associated not only with offspring production, but also protecting and provisioning young. Costs typically associated with molting include decreased thermoregulatory and locomotive performance and/or increased metabolic and nutritional costs. Energetic demands may disrupt homeostasis, particularly in terms of its maintenance (e.g., oxidative stress and immunity). Few investigators have explored the relationship between effort (increased metabolic rate) and oxidative status and stress by comparing life-history stages that have different energetic demands. However, comparative studies are crucial for understanding the processes of energy allocation and their consequences for different physiological functions. Our objective was to determine how two highly demanding life-history stages, breeding and molting, affected oxidative balance in Chinstrap Penguins (Pygoscelis antarcticus), a species where these two activities do not overlap. We found that the heterophil/lymphocyte (H/L) ratio was significantly higher during breeding than molting; oxidative damage was also higher during breeding, but the difference was only marginally significant. In contrast, we found no significant differences between these stages in total antioxidant capacity. We also found sex differences, with males showing higher oxidative damage (ROM) than females. Our results suggest that breeding is more stressful and more demanding for Chinstrap Penguins than molting, and provide further support for the relationship between effort, in terms of increased metabolic rate, and oxidative balance.

El Hornero, Dec 1, 2002

RESUMEN.-La Gaviota Cocinera (Larus dominicanus) es una especie abundante y de amplia distribució... more RESUMEN.-La Gaviota Cocinera (Larus dominicanus) es una especie abundante y de amplia distribución en Argentina. Aunque se han analizado los patrones espaciales y temporales de la dieta durante la temporada reproductiva en el litoral de Chubut, el listado de las especies consumidas en cada localidad no ha sido aún reportado. Se presenta el espectro trófico de la Gaviota Cocinera en tres áreas protegidas durante los ciclos reproductivos de 1994 y 1995. El análisis se efectuó sobre la base de 1331 y 1515 egagrópilas durante 1994 y 1995, respectivamente. La dieta de la Gaviota Cocinera presentó un total de presas de al menos 38 especies diferentes. Estas incluyeron al menos 8 especies de peces, 11 de crustáceos, 6 de pelecípodos, 10 de gasterópodos y 3 de poliquetos. A estas se agregaron un número de especies no identificadas de octópodos, decápodos, equinoideos, asteroideos, aves e insectos. Aunque algunas presas mostraron una frecuencia de ocurrencia relativamente importante, la mayoría presentaron frecuencias inferiores al 5%. La diversidad observada en la dieta de la Gaviota Cocinera en las tres localidades confirma que es una especie generalista y oportunista.

Marine Biology, 2022

Ecological segregation has been documented between males and females in different populations of ... more Ecological segregation has been documented between males and females in different populations of seabirds. Moreover, foraging behaviour and diet have been associated with markers of oxidative status, and have been suggested to be a driver of sex-biased oxidative costs of reproduction in wild marine vertebrates. Nevertheless, the ecological role of sex driving such associations has been little studied. We, therefore, examined whether foraging habitat ( δ 13 C), trophic level ( δ 15 N), dietary antioxidants (retinol and α-tocopherol) and oxidative status (antioxidant capacity and oxidative damage, ROM) were ecologically segregated by sex in Magellanic penguins ( Spheniscus magellanicus ) breeding in Peninsula Valdés (Argentina) visualizing the isotopic, dietary antioxidant, and oxidative status Bayesian spaces as proxies for ecological niches. Our results suggest that specific sexual segregation by ecological niche partially drives the relation between foraging, dietary antioxidants, and oxidative status. The dietary antioxidant niche showed females with extremely low α-tocopherol levels relative to males, although retinol values seemed to be similar between sexes. Higher trophic levels preys (high δ 15 N) were positively associated with α-tocopherol in males suggesting that their greater dependence on the Argentinian hake (a benthopelagic fish rich in α-tocopherol) led to a higher absorption of specific dietary antioxidants than females. In addition, a positive relation between α-tocopherol and ROMs in males suggested that their benthic foraging was associated with greater oxidative damage, and that higher levels of alpha-tocopherol in benthopelagic fish were not sufficient to prevent higher levels of oxidative damage associated with the consumption of such fish. Overall, sex-biased dietary antioxidant niche linked with sex-specific ecological segregation.