INVESTIGADORES
MAHLER Bettina
artículos
Título:
Hooded Grebe (Podiceps gallardoi) population diminished eighty per cent in the last twenty-five years
Autor/es:
ROESLER, I.; IMBERTI, S.; CASAÑAS, H.; MAHLER, B.; REBOREDA, J.C.
Revista:
BIRD CONSERVATION INTERNATIONAL
Editorial:
CAMBRIDGE UNIV PRESS
Referencias:
Lugar: Cambridge; Año: 2012 vol. 4 p. 371 - 382
ISSN:
0959-2709
Resumen:
We estimated the present population size of the Hooded Grebe Podiceps gallardoi and compared it
with the population in 1985. During the breeding seasons 2009/2010 and 2010/2011 we monitored
Podiceps gallardoi and compared it
with the population in 1985. During the breeding seasons 2009/2010 and 2010/2011 we monitored1985. During the breeding seasons 2009/2010 and 2010/2011 we monitored
251 lakes on the main plateaus of Santa Cruz province, southern Patagonia, Argentina, where the
entire population of Hooded Grebes spends the breeding season. During 2009/2010 we monitored
lakes on the main plateaus of Santa Cruz province, southern Patagonia, Argentina, where the
entire population of Hooded Grebes spends the breeding season. During 2009/2010 we monitored2009/2010 we monitored
131 lakes and observed 521 Hooded Grebes in 16 lakes, while during 2010/2011 we monitored 186lakes and observed 521 Hooded Grebes in 16 lakes, while during 2010/2011 we monitored 186
lakes and observed 535 individuals in 14 lakes. At both breeding seasons five lakes contained near535 individuals in 14 lakes. At both breeding seasons five lakes contained near
85% of the population.We only observed 6 breeding colonies, two in 2009/2010 and four in 2010/% of the population.We only observed 6 breeding colonies, two in 2009/2010 and four in 2010/
2011, totalling 242 nesting attempts. Nearly 90%of the nests failed during egg stage, mainly due to
strong winds and depredation by American mink Neovison vison. Only 28 nests hatched chicks, but
none of the young survived to independence due to low temperatures. We compared the results of
our 2010/2011 survey with one conducted during 1984/1985 and detected that the population
diminished by approximately 80%. This decline was observed on all but one plateau (?Buenos
Aires?) where most breeding attempts occurred. Our results show that at present Hooded Grebes
are highly dependent on a few suitable lakes where they congregate to breed. We analyse possible
causes for the decline of the population and propose conservation actions to protect this species.
, totalling 242 nesting attempts. Nearly 90%of the nests failed during egg stage, mainly due to
strong winds and depredation by American mink Neovison vison. Only 28 nests hatched chicks, but
none of the young survived to independence due to low temperatures. We compared the results of
our 2010/2011 survey with one conducted during 1984/1985 and detected that the population
diminished by approximately 80%. This decline was observed on all but one plateau (?Buenos
Aires?) where most breeding attempts occurred. Our results show that at present Hooded Grebes
are highly dependent on a few suitable lakes where they congregate to breed. We analyse possible
causes for the decline of the population and propose conservation actions to protect this species.
Neovison vison. Only 28 nests hatched chicks, but
none of the young survived to independence due to low temperatures. We compared the results of
our 2010/2011 survey with one conducted during 1984/1985 and detected that the population
diminished by approximately 80%. This decline was observed on all but one plateau (?Buenos
Aires?) where most breeding attempts occurred. Our results show that at present Hooded Grebes
are highly dependent on a few suitable lakes where they congregate to breed. We analyse possible
causes for the decline of the population and propose conservation actions to protect this species.
2010/2011 survey with one conducted during 1984/1985 and detected that the population
diminished by approximately 80%. This decline was observed on all but one plateau (?Buenos
Aires?) where most breeding attempts occurred. Our results show that at present Hooded Grebes
are highly dependent on a few suitable lakes where they congregate to breed. We analyse possible
causes for the decline of the population and propose conservation actions to protect this species.
80%. This decline was observed on all but one plateau (?Buenos
Aires?) where most breeding attempts occurred. Our results show that at present Hooded Grebes
are highly dependent on a few suitable lakes where they congregate to breed. We analyse possible
causes for the decline of the population and propose conservation actions to protect this species.
?) where most breeding attempts occurred. Our results show that at present Hooded Grebes
are highly dependent on a few suitable lakes where they congregate to breed. We analyse possible
causes for the decline of the population and propose conservation actions to protect this species.