INVESTIGADORES
TRAVAINI Alejandro
artículos
Título:
Analysis of trophic structure of two carnivore assemblages by means of guild identification
Autor/es:
SONIA CRISTINA ZAPATA; ALEJANDRO TRAVAINI; PABLO FERRERAS; MIGUEL DELIBES
Revista:
EUROPEAN JOURNAL OF WILDLIFE RESEARCH
Editorial:
SPRINGER
Referencias:
Año: 2007 p. 276 - 286
ISSN:
1612-4642
Resumen:
Abstract We evaluated the existence of trophic guild struc-ture,
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.
We evaluated the existence of trophic guild struc-ture,
considering seasonal and annual variation, in two
terrestrial carnivore assemblages: one from Santa Cruz
province (Argentinean Patagonia, composed by six carni-vore
species), and the other from Doñana National Park (SW
Spain, composed by five carnivore species). To identify
trophic guilds, we first studied seasonal and annual diets of
predators, calculated trophic overlap among species pairs,
and then constructed overlap matrices (similarity matrices).
We determined guild membership objectively by entering
the similarity matrices into the clustering technique un-weighted
pair-group method with arithmetic averaging.
Carnivores from both assemblages were grouped, respec-tively,
into four feeding guilds. Lagomorphs and rodents
promoted the formation of two feeding guilds in both study
sites, although the taxonomic composition of predator
species that composed them was different. The ungulates-edentates
feeding guild was only present at Santa Cruz,
whereas the birds and reptiles feeding guild was only present
at Doñana. Invertebrates and fruits were the base for the
formation of a guild composed by species of the same
taxonomic origin both in Santa Cruz and Doñana. Guild
structure of Santa Cruz and Doñana assemblages did not
exhibit seasonal or annual variation, although the specific
guild composition changed over the two studied periods for
both assemblages. This structure probably responded to
discontinuities in resource spectra in Santa Cruz and
fluctuations in rabbit abundance in Doñana. Our results
support the hypothesis that establishes that guilds are
originated by opportunistic convergence of species on
abundant and energetically rewarding resources.