Osmoregulatory responses to dietary protein and water intake in the granivorous Zonotrichia capensis (Passerine, Emberizidae)
Author
dc.contributor.author
Aldea, Patricia
Author
dc.contributor.author
Sabat Kirkwood, Alejandro Pablo
Admission date
dc.date.accessioned
2018-12-20T14:11:47Z
Available date
dc.date.available
2018-12-20T14:11:47Z
Publication date
dc.date.issued
2007
Cita de ítem
dc.identifier.citation
Revista Chilena de Historia Natural, Volumen 80, Issue 4, 2018, Pages 447-454
Identifier
dc.identifier.issn
07176317
Identifier
dc.identifier.issn
0716078X
Identifier
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10.4067/S0716-078X2007000400006
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/154641
Abstract
dc.description.abstract
We studied the osmoregulatory responses of the granivore Zonotrichia capensis, acclimated to high- and low-protein diets as well as two levels of water intake. We tested whether Z. capensis has the ability to modify the proportion of nitrogenous waste in the excreta when protein intake and water intake varies. After 21 days of acclimation, plasma osmolality was not significantly affected by dietary treatment; however, excreta osmolality was higher in the high-protein group compared to the low-protein group. Nitrogenous wastes in Z. capensis are excreted mainly in the form of uric acid. The proportion of kidney devoted to medullary tissue was 40% higher in dehydrated birds than in hydrated birds. Excreta osmolality was higher in dehydrated birds, and in all cases higher than plasma concentration by more than 300 mOsm kg″1. Our data do not support the hypothesis that Z. capensis can switch nitrogen excretion pathways. We hypothesize that the low water content of the seed-base diet, the c