Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 16

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  feeding ecology
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Feeding ecology and reproductive biology of some economically important fish species in the Tono Reservoir, Ghana

100%
Akongyuure D. N.
International Letters of Natural Sciences
|
2020
|
tom 78
The study of feeding ecology and reproductive biology ensures that the right management measures are applied for best output of fish stocks. Selection of good fish species for culture is also made possible through feeding and reproductive studies. Ghana over-relies on the culture of Nile tilapia and African catfish because there is no reliable scientific information on potential fish species that can be included for fish farming. The current study sought to investigate food habits and reproductive characteristics of economically important fish species in the Tono Reservoir of Northern Ghana. Monthly sampling was carried out from January, 2015 to December, 2016 (24 months). Specimens were obtained using cast net and gillnets of varying mesh sizes. Specimens were immediately transported to the laboratory in a chilled iced chest of temperature 4 ◦ C for morphometric measurements and microscopic analysis of gut content and gonads. Thirty-three (33) individual food items were identified from all the fish species. Phytoplankton was the most important diet (Index of Relative Importance, IRI = 1923) whereas zooplankton was the least important diet (IRI = 35) out of the five major categories of food items identified from all the fish species. The major peaks of gonadosomatic index (GSI) of females were noted in February – March and June – July. Over 80 % variation of fecundity was explained by the predictors (standard length, fish weight and gonad weight) for Clarias gariepinus and Auchenoglanis occidentalis. All the fish species were classified as omnivores and they spawned more than once in a year making all of them good candidates for aquaculture. Management measures should focus on regulating agricultural activities close to the reservoir and fishing activities in the reservoir for sustainable fish production and exploitation.
2

Feeding ecology of Cobitis paludica and Cobitis calderoni in Central Spain

100%
Valladolid M., Przybylski M.
Folia Biologica
|
2003
|
tom 51
|
nr Suppl.
3

Feeding ecology of the European wildcat Felis silvestris in Portugal

100%
Sarmento P.
Acta Theriologica
|
1996
|
tom 41
|
nr 4
The feeding ecology of the European wildcat Felis silvestris Schreber, 1777 was studied by analysing 220 scats collected between January and December 1994 at Serra da Malcata Nature Reserve (Portugal). Feeding trials, carried out with a captive male and female, allowed the author to relate the dry excreted weight of prey items in the scats with the fresh biomass ingested. Rodents, particularly Apodemus silvaticus and Microtus lusitanicus, were the dominant component of the diet. Lagomorphs, mostly rabbit Oryctolagus cuniculus, were the second most heavily consumed item in terms of consumed biomass, being more preyed upon, in spring and summer. Although insectivores were regularly consumed throughout the year, this group only represented a small fraction of the total consumed biomass. Reptiles, especially species of Lacer- tidae, were the third most favoured quarry, with higher predator pressure in spring and summer. Bird remains were found at low levels throughout the year. Insects and plants were unimportant items in the diet. The wildcats feeding spectrum showed little variation throughout the year.
4

Temporal and spatial differences in the feeding ecology of the Spanish Imperial Eagle Aquila adalberti during the non-breeding season: effects of the rabbit population crash

84%
Sanchez R., Margalida A., Gonzalez L. M., Oria J.
Acta Ornithologica
|
2009
|
tom 44
|
nr 1
The paper describes the diet of territorial Spanish Imperial Eagles during the non-breeding season, comparing prey identified across different regions (Central, Western and Southern), breeding season vs non-breeding season, and periods (1983-1985 or pre-viral haemorrhagic disease [RHD] vs 1991-2000 or post-RHD). Comparison of the nonbreeding with the breeding season revealed a slight variation in the diet. The Rabbit Oryctolagus cuniculus continues to be the most important prey species in the eagle's diet during the non-breeding season, followed by pigeons and the Red Partridge Aledoris rufa, although this varies from one region to another. In general, the decrease in the rabbit population after the epizooty (RHD) does not appear to have had an impact on the occurrence of this prey species in the Spanish Imperial Eagle's diet. Although this species is generally considered to be specialised in the capture of rabbits, the variability found between regions suggests that when the main prey (wild Rabbit) is scarce, the Spanish Imperial Eagle's diet is based on alternative prey such as pigeons or carrion.
5
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Feeding ecology of the American crab Rhithropanopeus harrisii (Crustacea, Decapoda) in the coastal waters of the Baltic Sea

84%
Hegele-Drywa J., Normant M.
Oceanologia
|
2009
|
tom 51
|
nr 3
361-375
The feeding ecology of the American crab Rhithropanopeus harrisii Gould, 1841 from brackish waters of the Baltic Sea was studied by analyses of the stomach repletion index (SRI) and stomach content with regard to sex, size and habitat (Dead Vistula River and the Gulf of Gdańsk). Neither the sex nor the size of an individual crab had a significant (P>0.05) influence on the SRI or on the diversity of food items found in the stomachs of R. harrisii. But the type of food consumed was significantly (P<0.05) dependent on the locality inhabited: the greater the biodiversity of the habitat, the richer the dietary composition. In Baltic coastal waters this species feeds on detritus, and also on animal and plant matter. Remains of Chlorophyta, Amphipoda, Ostracoda, Polychaeta, Gastropoda and Bivalvia were found in the stomachs of the specimens analysed.
6
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Macroevolutionary and morphofunctional patterns in theropod skulls: A morphometric approach

84%
Foth C., Rauhut O. W. M.
Acta Palaeontologica Polonica
|
2013
|
tom 58
|
nr 1
Theropod dinosaurs are one of the most remarkable lineages of terrestrial vertebrates in the Mesozoic, showing high taxo− nomic and ecological diversity. We investigate the cranial diversity of non−avian theropods and some basal birds, using geometric morphometrics to obtain insights into the evolutionary modifications of the skull. Theropod skulls mostly vary in the shape of the snout and length of the postorbital region (principal component [PC] 1), with further variation in orbit shape, depth of the postorbital region, and position of the jaw joint (PC 2 and PC 3). These results indicate that the cranial shape of theropods is closely correlated with phylogeny and dietary preference. Skull shapes of non−carnivorous taxa dif− fer significantly from carnivorous taxa, suggesting that dietary preference affects skull shape. Furthermore, we found a significant correlation between the first three PC axes and functional proxies (average maximum stress and an indicator of skull strength). Interestingly, basal birds occupy a large area within the morphospace, indicating a high cranial, and thus also ecological, diversity. However, we could include only a small number of basal avialan species, because their skulls are fragile and there are few good skull reconstructions. Taking the known diversity of basal birds from the Jehol biota into account, the present result might even underestimate the morphological diversity of basal avialans.
7

Feeding ecology of sterlet Acipenser ruthenus L. in the Hungarian section of the Danube River

84%
Fieszl J., Bogacka-Kapusta E., Kapusta A., Szymanska U., Martyniak A.
Archives of Polish Fisheries
|
2011
|
tom 19
|
nr 2
8

Barn Owl Tyto alba predation on small mammals in relation to the Mediterranean environment [Pisa Province, Italy]

84%
Varuzza P., Capizzi D., Santini L., Apollonio M.
Acta Ornithologica
|
2001
|
tom 36
|
nr 2
The diet of the Barn Owl was investigated in 13 localities in the Pisa province, Central Italy. In each locality the percentage of forest and cultivated land, and the linear development of roads and rivers were recorded. To estimate the prey availability, the small mammal communities in seven different localities within the same province were sampled during live trapping sessions. Barn Owls preyed mainly upon rodents (79.4%) and insectivores (18.8%), while birds were eaten to a small degree (1.9%). The main prey taxon was Apodemus sp. (39.7%), followed by Microtus savii (26.1%). The relative frequencies of these two prey items were negatively correlated. Statistically significant differences in the mean prey weight in the thirteen localities were detected. The mean prey weight was positively associated with the wood surface and negatively with the area of cultivated fields. A positive relationship between prey diversity and cultivation was recorded. This indicates that Barn Owls which forage in cultivated habitats tend to prey on smaller species, mainly shrews and voles, and to have a more diversified prey spectrum. On the contrary, owls foraging in wooded areas were more specialized and preyed on larger Animals.
9

Feeding relations among cyprinids in the Lozoya River [Madrid, Central Spain]

84%
Valladolid M., Przybylski M.
Polskie Archiwum Hydrobiologii
|
1996
|
tom 43
|
nr 2
10

Prey size selection of insular lizards by two sympatric predatory bird species

67%
Padilla D. P., Nogales M., Marrero P.
Acta Ornithologica
|
2007
|
tom 42
|
nr 2
167-172
11

Intestine morphometrics of fishes: a compilation and analysis of bibliographic data

67%
Karachle P. K., Stergiou K. I.
Acta Ichthyologica et Piscatoria
|
2010
|
tom 40
|
nr 1
Background. The examination of morphological features related to feeding in fish, as well as their relation with body length, are of increasing scientific interest. In the present study, information on intestine (gut) morphometrics that appear in the relevant literature has been compiled, analysed, and discussed. Materials and Methods. Search of gut-related bibliography was conducted, using online literature databases on fish feeding and ecomorphology. The resulted data was tabulated. Relationships between mean, minimum, and maximum relative gut length (RGL) and intestine length weight index (ILW, Zihler’s index), as provided by the original author, with species’ fractional trophic levels (TROPHs; extracted from FishBase) were explored. Finally, using the relations between gut length (GL) and body length (L) provided by the original authors, regressions were reconstructed and compared based on species’ feeding habits and taxonomy. Results. The amount of information related to gut morphometrics referred to 498 species. The relations between GL and L referred to 71 species, but four species were omitted from the analyses. Mean, minimum, and maximum RLG and ILW values were negatively related (for all cases: P < 0.01) with TROPH. The GL–L regressions performed for 67 species revealed the presence of two major groups as herbivorous fishes and carnivorous fishes. Grouping according to species’ taxonomic order did not form any significant groupings. Conclusion. Existing information on intestine morphometrics is generally accumulated in a few scientific papers. All the analyses performed on the compiled data reinforced the pattern generally accepted that herbivores have longer intestines than carnivores. In addition, the influence of species’ evolutionary history on comparisons of gut length between species with different feeding habits was not verified. Finally, equations relating RGL and ILW to TROPH can be used for TROPH value estimates from morphological data that are easy to obtain, especially in the lack of species’ feeding habits data.
12

Seasonal diet of the Grey Heron Ardea cinerea on an oceanic island [Tenerife, Canary Islands]: indirect interaction with wild seed plants

67%
Rodriguez A., Rodriguez B., Rumeu B., Nogales M.
Acta Ornithologica
|
2007
|
tom 42
|
nr 1
77-87
13

Badger Meles meles feeding ecology in dry Mediterranean environments of the southwest edge of its distribution range

67%
Barea-Azcon J. M., Ballesteros-Duperon E., Gil-Sanchez J. M., Virgos E.
Acta Theriologica
|
2010
|
tom 55
|
nr 1
45-52
The dietary preference of badgers Meles meles (Linnaeus, 1758) for earthworms and other food resources has been widely discussed. In the Mediterranean area, rabbits Oryctolagus cuniculus, fruits (mainly olives Olea europaea) and arthropods are the most important foods. We describe badger dietary habits in a xeric Mediterranean area, comparing use and availability of olives and rabbits. Our results indicated that olives and rabbits are the predominant resources consumed, however we did not detect any evidence of specialisation when we compared consumption versus field availability. In the case of olives we found that their consumption is reduced when juvenile rabbits or figs Ficus carica are widely available, which is evidence against any specialisation in this resource. Figs appear to be a key food item for badgers; they were consumed in large amounts when available. Badgers in this xeric area can be viewed as generalist or facultative specialists, using the most profitable resource when available but shifting its preferences to other less profitable food resources when availability of other primary food resource are reduced. Our results also indicated the high suitability of some human agricultural uses (eg fruit orchards) for this species, especially in the otherwise harsh Mediterranean environments.
14
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Feeding ecology of sprat (Sprattus sprattus L.) and sardine (Sardina pilchardus W.) larvae in the German Bight, North Sea

67%
Voss R., Dickmann M., Schmidt J. O.
Oceanologia
|
2009
|
tom 51
|
nr 1
117-138
The abundance of the sardine in the North Sea suddenly increased after 1995. Since 2002, the sardine has been spawning regularly in the German Bight, and all its life stages can be found in the area. The larval feeding ecology of two small pelagic clupeiform species with very similar life histories was investigated, the particular aim being to determine signs of food overlap. The distribution and feeding of sprat and sardine larvae were investigated during late spring 2003 on two transects covering a wide range of environmental conditions in the German Bight. Larvae co-occurred at all the stations investigated. Sprat and sardine larvae shared a wide range of prey types. Gut fullness and feeding success were similar in both species; however, potential food competition is avoided to some extent by different habitat preferences.
15

First results on the feeding ecology of sympatric shrews (Insectivora: Soricidae) in the Tai National Park, Ivory Coast

67%
Churchfield S., Barriere P., Hutterer R., Colyn M.
Acta Theriologica
|
2004
|
tom 49
|
nr 1
The feeding ecology of a multi-species community of shrews inhabiting secondary forest and cacao-coffee plantations in the Tai National Park (Ivory Coast) was investigated. A total of 553 shrews were captured and 194 alimentary tracts were examined. Ten species were found, including Sylvisorex megalura and nine species of Crocidura, forming a series with respect to body size. New ecological data on these little known African species are presented. All species of shrews ate a wide diversity of arthropods, with Coleoptera, Araneae, Formicidae and Diplopoda making the largest dietary contributions. Lumbricidae were eaten by two species. C. obscurior had an exceptionally long intestine for its size but there was no evidence of dietary specialisation in this or other shrew species. All species investigated ate predominantly small prey and there was no correlation between size of prey items consumed and body mass of shrew species. There was little evidence of resource partitioning amongst the shrews, despite differences in body size.
16

Diverse feeding ecology and habitat use in coral reef fishes in the Malaysian South China Sea, as revealed by liver fatty acid composition

59%
Arai T., Amalina R., Bachok Z.
Oceanological and Hydrobiological Studies
|
2015
|
tom 44
|
nr 1
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.