INVESTIGADORES
SARASOLA jose Hernan
artículos
Título:
Can a wintering area effect explain population status of Swainsons hawks? A stable isotope approach
Autor/es:
SARASOLA, J.H.; NEGRO, J.J.; HOBSON, K.; BORTOLOTTI, G.R.; BILDSTEIN, K.
Revista:
DIVERSITY AND DISTRIBUTIONS
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2008 vol. 14 p. 686 - 691
ISSN:
1366-9516
Resumen:
It has been suggested that declines in breeding populations of Swainsons hawks
(Buteo swainsoni) in California, Oregon, and Nevada may be due to differential
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.
Buteo swainsoni) in California, Oregon, and Nevada may be due to differential
mortality of hawks on their wintering grounds. Although massive mortality
incidents reported on the wintering grounds partially support this suggestion, there
are no data showing differential use of wintering areas by breeding populations of
Swainsons hawks. We used stable-hydrogen isotope analysis of feathers to determine
whether large flocks of hawks wintering in Argentina consisted of a mixture of individuals
from across the North American breeding range or consisted of individuals
from discrete breeding populations. We found that flocks of wintering Swainsons
hawks consisted of a mixture of individuals. The lack of connectivity between
populations of breeding and wintering hawks suggests that high wintering mortality,
either natural or human-induced, is unlikely to have direct consequences on a single
breeding area in North America. The demographic effects of winter mortality should be
diluted across the entire breeding range of Swainsons hawks.