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F. Campos – 1st expert on this subject based on the ideXlab platform
recent changes in the food of the grey heron Ardea cinerea in central west spainIbis, 2008Co-Authors: S J Peris, F J Briz, F. CamposAbstract:
As far as we know, there are no data on how changes in the freshwater fauna within the same area affect the feeding preference of the Grey Heron Ardea cinerea. We present data on the diet of the bird during the breeding seasons of 1990 and 1991 in central-west Spain and compare these data with those obtained from the same colonies in 1986–1987.
Temporal variations in the feeding habits of the Purple Heron Ardea purpurea during the breeding seasonIbis, 1997Co-Authors: F. Campos, J. M. LekuonaAbstract:
The foraging strategies of adult Purple Herons Ardea purpurea from an increasing colony in northern Spain were studied in the feeding areas (nonagricultural habitats) during the breeding season (May-July). In this area, herons were mainly piscivorous, and there was no seasonal variation in prey type. Small fish (
Antoon F De Bont – 2nd expert on this subject based on the ideXlab platform
movements of radio tagged grey herons Ardea cinerea during the breeding season in a large pond areaIbis, 2008Co-Authors: Janike Van Vessem, Dirk Draulaks, Antoon F De BontAbstract:
This paper describes the strategies of resource utilization in the course of the breeding season by five radio-tagged Grey Herons Ardea cinerea. The seasonal changes in exploitation of the environment by two breeding adults, one non-breeding adult and two non-breeding first-year birds were studied from March to August 1982, near Zonhoven in Belgium.
Two adult breeding birds could be followed continuously from the end of March until the middle of June. During the first month they explored an extended area all around the colony, but each concentrated its search in a specific direction. From the end of April until the beginning of June, most probably from egg-hatching until the end of breeding activities, each bird spent a very large proportion of its time at a particular feeding site, from which other herons were actively excluded. In the first part of June they again visited different sites, each maintaining its preferred direction. From the middle of June onwards they seemed to have left the fish-pond area.
The pattern of movements of the first-year birds differed markedly from that of the breeding adults. In April, although both non-breeding and breeding birds explored large areas, only the areas used by non-breeders were centred on the colony. From the end of April onwards, probably after general egg-hatching in the colony, the non-breeders very rarely revisited the colony, and from May till August their ranges became more and more restricted to very small areas at an increasing distance from the colony. They were never observed defending particular sites.
The results are discussed with regard to recent speculations about the evolution of colonies as an adaptation for the exploitation of food resources. Breeding herons seem to explore a large part of the environment during incubation and defend a particular site while feeding their young. Choice of feeding site by non-breeding birds may be influenced by the site defence of the breeding birds. Non-breeding birds exploit a large area when breeding birds occupy feeding territories. Perhaps they are forced to forage in less suitable places at this time. Colonies might have evolved as a strategy to minimize effort in resource esploitation as, especially at the beginning of the breeding season, the colony could act as an assembly point in the exploration of the environment. However, its importance as an assembly point diminishes in the course of the season, as non-breeding birds no longer visit the colony and adults defend territories.
Ricardo M. Takemoto – 3rd expert on this subject based on the ideXlab platform
Phylogenetic position of Diplostomum spp. from New World herons based on complete mitogenomes, rDNA operons, and DNA barcodes, including a new species with partially elucidated life cycleParasitology Research, 2020Co-Authors: Sean A. Locke, Fabiana B. Drago, Verónica Núñez, Geza Thais Rangel E Souza, Ricardo M. TakemotoAbstract:
Diplostomum Ardeae Dubois, 1969 has seldom been reported since its description from the great blue heron ( Ardea herodias L., 1758) in the USA. Sequences obtained in this study from the barcode region of cytochrome c oxidase 1 (CO1) in diplostomids from black-crowned night heron ( Nycticorax nycticorax (L., 1758)) in Puerto Rico matched data from D. Ardeae from A. herodias in the type region. We also obtained DNA barcodes from morphologically similar diplostomids from a rufescent tiger heron ( Tigrisoma lineatum (Boddaert, 1783)) and from metacercariae from eye lenses of Trachelyopterus galeatus (Linnaeus, 1766) from the Paraná River basin in Argentina and Brazil, respectively. Barcodes matched (97–100% identity) in these South American adult and larval specimens as well as in recently published sequences from metacercariae from 11 other siluriform fishes from the same region. Barcodes from the South American species, which we describe as Diplostomum lunaschiae n. sp., differed from those of D. Ardeae by 7.2–9.8%, and the new species differs from D. Ardeae in its size, pharynx:oral sucker length ratio, egg:body length ratio, and distribution of vitellaria. As in prior phylogenetic analysis of CO1 sequences, both D. Ardeae and D. lunaschiae n. sp. were not associated with Diplostomum . In more character-rich analyses of nuclear rDNA and of mitochondrial genomes, D. Ardeae was an early divergent member of clades of species of Diplostomum . Consequently, we continue to consider D. Ardeae and D. lunaschiae n. sp. members of Diplostomum , in contrast to recent suggestions that these species may belong to a different genus.