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| SABAT,PABLO; NESPOLO,ROBERTO F; BOZINOVIC,FRANCISCO. |
| Birds living in desert environments have been the preferred models for the study of physiological adaptations to water scarcity. Passerine birds living in marine coastal habitats face similar problems, yet physiological adaptations to water conservation in such species have been poorly documented. We measured total evaporative water loss (TEWL) and rates of oxygen consumption (VO2) in three species of passerine birds dwelling in marine and fresh water habitats. Mass specific total evaporative water loss was significantly lower in the marine species, Cinclodes nigrofumosus, than in species inhabiting areas near freshwater sources. We found a positive relationship between TEWL and VO2. The ratio of TEWL to VO2 (relative evaporative water loss, RTEWL) showed... |
| Tipo: Journal article |
Palavras-chave: Evaporative water loss; Cinclodes; Osmoregulation; Passerines; Salt. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000200001 |
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| SABAT,PABLO; FARIÑA,JOSÉ M.; SOTO-GAMBOA,MAURICIO. |
| Feeding on saline marine foods may be especially challenging for passerine birds that lack functional salt glands and have a limited ability to concentrate urine. To reduce the salt load imposed by consumption of marine food these birds may select food with low salt contents and/or increase their intake of freshwater. The genus Cinclodes is particular among passerines because it includes species that inhabit both inland and maritime shores. We analyzed the diet of Cinclodes nigrofumosus and explored the possible relationships between dietary composition and salt load at mesic and arid coastal sites of Chile. From a biogeographical perspective, we hypothesized that freshwater availability is critical to the relationship between diet composition and osmotic... |
| Tipo: Journal article |
Palavras-chave: Cinclodes; Dietary habits; Osmoregulation; Osmotic load. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000200017 |
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| SABAT,PABLO. |
| It has been postulated that both digestive capacity and intestinal biochemical features are correlated to dietary habits in birds. Therefore, it would be expected to find biochemical constraint to hydrolyze sugars in those species, which predate exclusively on marine invertebrates. In vitro intestinal activities of these enzymes were studied in Cinclodes nigrofumosus (d' Orbigny) and Cinclodes patagonicus (Gmelling). Due to differences in dietary habits between species I predicted the lack of sucrase activity in C. nigrofumosus but not in C. patagonicus. Also, low activities of maltase would be expected in both species. On the other hand due to the considerable amount of proteins and trehalose present in preys, high activities of both trehalase and... |
| Tipo: Journal article |
Palavras-chave: Digestion; Dietary adaptation; Disaccharidases; Aminopeptidase-N; Cinclodes. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000200009 |
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| SABAT,PABLO; MARTÍNEZ DEL RÍO,CARLOS. |
| Passerines lack functional salt glands and to a large extent avoid feeding on marine invertebrates. An exception is Cinclodes nigrofumosus. Previous studies reported that the contents of its gastrointestinal tract had a lower osmolality than seawater suggesting that birds were supplementing their marine invertebrate diet with terrestrial invertebrates and fresh water at certain periods of the year. We report seasonal changes in the diet of C. nigrofumosus at two contrasting coastal localities in Central Chile and document the potential correlation between weather and feeding habits with osmoregulatory features in this species. We expected that C. nigrofumosus would increase its use of osmotically challenging marine dietary sources when fresh water is... |
| Tipo: Journal article |
Palavras-chave: Cinclodes; Isotopes; Renal function; Osmoregulation; Seasonal changes. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2005000200009 |
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