Search results for "FEEDING ECOLOGY"
showing 9 items of 9 documents
Multispecies tracking reveals a major seabird hotspot in the North Atlantic
2021
The conservation of migratory marine species, including pelagic seabirds, is challenging because their movements span vast distances frequently beyond national jurisdictions. Here, we aim to identify important aggregations of seabirds in the North Atlantic to inform ongoing regional conservation efforts. Using tracking, phenology, and population data, we mapped the abundance and diversity of 21 seabird species. This revealed a major hotspot associated with a discrete area of the subpolar frontal zone, used annually by 2.9–5 million seabirds from ≥56 colonies in the Atlantic: the first time this magnitude of seabird concentrations has been documented in the high seas. The hotspot is temporal…
Forage silica and water content control dental surface texture in guinea pigs and provide implications for dietary reconstruction.
2019
Significance Ingesta leave characteristic wear features on the tooth surface, which enable us to reconstruct the diet of extant and fossil vertebrates. However, whether dental wear is caused by internal (phytoliths) or external (mineral dust) silicate abrasives is controversially debated in paleoanthropology and biology. To assess this, we fed guinea pigs plant forages of increasing silica content (lucerne < grass < bamboo) without any external abrasives, both in fresh and dried state. Abrasiveness and enamel surface wear increased with higher forage phytolith content. Additionally, water loss altered plant material properties. Dental wear of fresh grass feeding was similar to lucerne brows…
Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary impli…
2007
CONCENTRACIÓN DE ISÓTOPOS ESTABLES DE C Y N EN VARIOS TEJIDOS DE LA TORTUGA BOBA CARETTA CARETTA DEL MEDITERRÁNEO OCCIDENTAL E IMPLICACIONES SOBRE LA DIETA. – La concentración isotópica de escudos del caparazón, piel, músculo y sangre de tortuga boba (Caretta caretta) fueron analizados para investigar el patrón de variación entre tejidos y para evaluar la posición de esta especie en las redes tróficas de la cuenca Argelina. La piel presentaba valores más altos de δ13C que el músculo o los escudos del caparazón y éstos presentaban valores más altos que la sangre. En cambio, el músculo presentaba valores más altos de δ15N que la piel, ésta valores más altos que la sangre y ésta valores más al…
Translating taxonomy into the evolution of conodont feeding ecology
2016
Conodont research has long been divided between utilitarian applications to solve geological problems versus analysis of their palaeobiology. However recent advances in conodont functional analysis allow these independent stands of research to be unified, decoding the functional implications of their morphological variation. We demonstrate this using synchrotron tomography and Finite Element Analysis, informed by occlusal and microwear analyses, to analyze functionally the classic evolutionary sequence of the genus Polygnathus. Our study shows that the evolution of the platform in Polygnathus occurred to accommodate and dissipate the stress accumulation derived from the tooth-like function …
Solapamiento del nicho trófico en un área de cría en la costa portuguesa
2002
The diets and the trophic niche overlap between seven flatfish species were studied in a coastal nursery adjoining to the Tagus estuary (Portugal). Fish were sampled monthly, from March to November 1999, using a beach seine. Arnoglossus imperialis (Rafinesque, 1810), Arnoglossus laterna (Walbaum, 1792) and Arnoglossus thori Kyle, 1913, fed mainly on crustaceans. The diets of Buglossidium luteum (Risso, 1810) and Dicologoglossa cuneata (Moreau, 1881) were mainly composed of Bivalvia and Polychaeta, while for Scophthalmus rhombus (Linnaeus, 1758) the main food items were Mysidacea and Teleostei. The diet of Pegusa lascaris (Risso, 1810) was mainly composed by Cumacea, Bivalvia, Decapoda and A…
An invasive species, Carassius gibelio, alters the native fish community through trophic niche competition
2019
Carbon and nitrogen stable isotope analyses were used to determine isotopic niche width of the invasive fish species Carassius gibelio to help assess the niche overlap and potential impact of this species on the native fish fauna in the Karamenderes River, northwest Turkey. C. gibelio had the highest niche area of the coexisting species. The greatest overlap of isotopic niche was between C. gibelio and Mugil cephalus in the river mouth. The freshwater species displayed similar patterns when taking into consideration their relative abundance and isotopic overlap. While C. gibelio is likely to outcompete some species at some localities, the species was found co-occurring with others by maximu…
A multivariate approach to the feeding ecology of the Channel flounder, Syacium micrurum (Pisces, Pleuronectiformes), in Cape Verde, Eastern Atlantic
2009
The feeding ecology of the Channel flounder, Syacium micrurum, from Cape Verde was studied in November 2003 and April 2004, using frequency of occurrence and percentage by number indices, as well as multivariate analyses. Overall, S. micrurum exhibited a generalist feeding strategy with a relatively broad niche width. Analyses indicated Crustacea (especially Brachyura) and Polychaeta as the dominant prey items, although other items, such as Foraminifera, Caridae or Actinopterigii, were preyed on more often or in larger quantities, depending on the sampling date. An ontogenetic shift in diet was also observed with smallsized individuals mostly consuming Crustacea, whereas medium- or large-si…
Arbacia
2020
Arbacia is unique among shallow echinoid genus, not in line with the general rule that sea urchins should be either entirely tropical or entirely temperate, with limited overlap in the subtropics. Six extant Arbacia species have been described by Mortensen. The genus Arbacia has a Neotropical origin and four different fossil species have been described from the Late Miocene. Over the past century, Arbacia has been the subject of intense investigations into the cell biology, toxicology, biochemistry, and embryology. Recently, renewed interest in this genus arose from its phylogeny, ecology, and its resilience to ocean warming and acidification. According to several studies, impacts of ocean …
Diet composition and biomass consumption of harbour seals in Telemark and Aust-Agder, Norwegian Skagerrak
2020
To explore ecosystem dynamics and functions it is vital to obtain knowledge on predator–prey relations. Harbour seals are piscivorous predators that can come into conflict with fisheries. Recently, as the Skagerrak and Kattegat population of harbour seals has increased, claims have emerged that seals are depleting coastal cod populations. The diet of harbour seals in Norwegian Skagerrak was investigated based on otolith identification from scats. The overall seal diet included 20 different fish species/groups. The most important prey (combined index Q i ) were haddock/pollack/saithe (32.7%), genus Trisopterus (Norway pout/poor cod/bib, 12.5%), plaice (12.4%) and herring (10.0%). Plaice also…