Search results for "Waterfowl"
showing 10 items of 16 documents
Assessing the effect of emergent vegetation in a surface-flow constructed wetland on eutrophication reversion and biodiversity enhancement
2018
Abstract A free water-surface constructed wetland (F4-unit) was created in a Mediterranean protected site to treat eutrophic inflows to the Albufera de Valencia lagoon, and enhance biodiversity. In 2013, the F4-unit was divided into three subunits and planted with different compositions of emergent macrophytes (Phragmites australis, Iris pseudacorus, and a mixture of several macrophytes: F4-Reed, F4-Iris and F4-Mixed subunits). Two nine-month periods were monitored after planting, and water quality variables were measured in the inflows and outflows. Waterfowl occupation and plankton biomass were analyzed to evaluate their role in eutrophication reversion. The low removal efficiencies relat…
Differential endozoochory of aquatic invertebrates by two duck species in shallow lakes
2017
Abstract Animal vectors are essential for the movement of invertebrate resting eggs between water bodies. However, differences in habitat preferences and feeding behaviour between bird species may result in variations in the dispersal of invertebrates via these birds, even if the different bird species live in the same lake. To test such effects, faecal samples from Anas platyrhynchos (collected in autumn and spring) and Tadorna tadorna (collected in spring) were cultured in water at 20° C and 12 L: 12 D conditions in order to quantify the resting eggs which could be internally transported by these birds. One half of each faecal sample was initially cultured at a conductivity of 0.6 mS cm −…
Interannual variation and long-term trends in proportions of resident individuals in partially migratory birds
2016
Partial migration - a part of a population migrates and another part stays resident year-round on the breeding site - is probably the most common type of migration in the animal kingdom, yet it has only lately garnered more attention. Theoretical studies indicate that in partially migratory populations, the proportion of resident individuals (PoR) should increase in high latitudes in response to the warming climate, but empirical evidence exists for few species. We provide the first comprehensive overview of the environmental factors affecting PoR and the long-term trends in PoR by studying 27 common partially migratory bird species in Finland. The annual PoR values were calculated by divid…
Bycatch in gillnet fisheries - An overlooked threat to waterbird populations
2009
Bird mortality in fishing gear is a global conservation issue and it is recognised that bycatch in industrial longline and trawl fisheries threatens several seabird species. Little is known however about the effects of bycatch in small-scale gillnet fisheries on bird populations. Here we review 30 studies reporting bird bycatch in coastal gillnet fisheries in the Baltic Sea and the North Sea region in order to assess the magnitude of this problem and potential effects on bird populations. All species of diving birds that occur in the study region, including divers (loons), grebes, sea ducks, diving ducks, auks and cormorants, have been reported as dying in fishing nets. The cumulative bycat…
Goose, Duck and Garganey
2019
Duck, goose and garganey are waterfowls consumed in a lower proportion than chicken. These species are of great economic importance in Asia, Europe and USA. Among the three species, duck is the main bird produced for the meat system while goose is commercially produced by at lower proportion than duck. Differently, garganey is considered as game meat, which has been poorly studied in last decades. The productive system of duck and goose share similarities with which other such as physical structure, animal management, feeding strategies, management of environmental conditions, transport, and slaughter. However, these variables and related aspects of farming and meat processing can be manage…
Presence of plastic particles in waterbirds faeces collected in Spanish lakes
2017
Plastic intake by marine vertebrates has been widely reported, but information about its presence in continental waterfowl is scarce. Here we analyzed faeces of waterbirds species (European coot, Fulica atra, mallard, Anas platyrhynchos and shelduck, Tadorna tadorna) for plastic debris in five wetlands in Central Spain. We collected 89 faeces of shelduck distributed in four lakes, 43.8% of them presented plastic remnants. Sixty percent of 10 faeces of European coot and 45% of 40 faeces of mallard contained plastic debris. Plastic debris found was of two types, threads and fragments, and were identified as remnants of plastic objects used in agricultural fields surrounding the lakes. Differe…
The occurrence of runt eggs in waterfowl clutches
2004
Abstract Eggs that are abnormally small are called runt eggs, and they occur in clutches across a wide variety of bird species. We surveyed waterfowl researchers to determine the natural frequency of occurrence of runt eggs in wild nesting ducks, geese, and swans. Of 551,632 eggs examined, 215 were runts, yielding a frequency of 0.039%. They occurred at about four times this frequency (0.156% in 21,832 eggs) in a museum oological collection. Runt eggs were not significantly more common within any taxonomic group among wild waterfowl, and their occurrence was not related to the mean clutch size of a species or to whether waterfowl exhibited regular conspecific nest parasitism. Cavity-nesting…
Effect of Incubation Body Mass on Reproductive Success and Survival of Two European Diving Ducks: A Test of the Nutrient Limitation Hypothesis
1997
The nutrient limitation hypothesis postulates that variation in nutrient reserves during egg laying and incubation are important predictors of future reproductive success of female waterfowl. We tested one component of this hypothesis in two European diving ducks, Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula), relating body masses of incubating females to subsequent nest success, and to duckling and adult survival. We based our analyses on 3,224 Common Pochards and 1,812 Tufted Ducks captured and weighed during the last two weeks before ducklings hatched at Engure Marsh, Latvia, in 1978-1993. Adult (ASY) females from successful nests weighed significantly more than those …
Benefits of the European Agri-Environment Schemes for Wintering Lapwings : A Case Study from Rice Fields in the Mediterranean Region
2020
Mediterranean European rice fields provide important habitats for migrating waterbirds. In winter. one waterbird species that particularly benefits from rice fields is the Northern Lapwing (VaneIlus vanellas), a species threatened in Europe. To assess the effect of agii-environmental measures on rice field selection and use by wintering lapwings, bird counts were conducted in northeastern Spain during two consecutive winters (2005-2006 and 2006-2007). Information on two mandatory post-harvest management prescriptions of the agri-environment schemes was collected, namely winter flooding (percent ground surface covered by water) and whether fields were rolled or not. The number of lapwings in…
Status of Corynosoma (Acanthocephala: Polymorphidae) based on anatomical, ecological, and phylogenetic evidence, with the erection of Pseudocorynosom…
2006
The possession of genital spines has been considered as a key taxonomic trait to differentiate Corynosoma from other genera of the Polymorphidae. However, Corynosoma currently consists of 2 groups of species with clear ecological and morphological divergences: the "marine" group (with ca. 30 species) infects mammals and piscivorous birds in the marine realm, whereas the "freshwater" group (with ca. 7 species) infects waterfowl in continental waters. Species from these groups differ in shape of body and neck, trunk spination, lemnisci length and shape, testes arrangement, and number and shape of cement glands. We tested whether species from these 2 groups formed a monophyletic assemblage bas…