Red-crested Pochard Research Articles

Diversity and Population of Ducks and Geese in Keibul Lamjao National Park (KLNP) in Manipur, India

As a part of the Asian Waterbird Census (AWC), surveys on ducks and geese were made at five (5) major waterbird congregation sites of Keibul Lamjao National Park (KLNP) during 2020-2024. A total of 18 species of ducks and two species of geese belonging to the family of Anatidae were recorded during the period. The duck species includes 14 migratory and 4 resident species and the two migratory geese species. Lesser Whistling Duck Dendrocygna javanica was the most abundant and dominant species in terms of population followed by Gadwall Anas strepera and Red - crested Pochard Netta rufina and minimum value was observed in Greylag Goose Anser anser. The Critically Endangered Baer’s Pochard Aythya fuligula was recorded in the year 2023 at Pabot Chingmang site (2 individuals). Another two globally Near threatened (NT) Ferruginous Pochard Aythya nyroca and Falcated Duck Anas falcata have been recorded here.

The genome sequence of the red-crested pochard, Netta rufina (Pallas, 1773).

We present a genome assembly from a female specimen of Netta rufina (the red-crested pochard; Chordata; Aves; Anseriformes; Anatidae). The genome sequence has a total length of 1,167.00 megabases. Most of the assembly (98.76%) is scaffolded into 42 chromosomal pseudomolecules, including the Z and W sex chromosomes. The mitochondrial genome has also been assembled and is 16.62 kilobases in length.

A PRELIMINARY SURVEY ON DIVERSITY OF AVIFAUNA IN KATWA, PURBA BURDWAN, WEST BENGAL, INDIA

Birds are used as bio-indicator due to their sensitivity to minor environmental changes. A survey was done from July 2022 to February 2023 to study the avifaunal diversity of Katwa. A total of 67 bird species were recorded during the study period. The species were categorized in three namely common resident (CR), not common resident (NCR) and migratory (M) of which 40 are common resident, 24 are not common resident and 3 are migratory. The found common birds species were house crow, common myna, red vented bulbul, house sparrow, spotted dove, asian koel, little ringed plover etc. Among the not common resident avifauna were Long-legged Buzzard, Cotton teal, Pied-cuckoo, Grey Wagtail, yellow Wagtail, White Wagtail etc. and the three migratory birds were Common Pochard, Red-crested Pochard and Northern Pintail. Katwa and adjoining Ajay Baadh has wide variety of trees, wetland, grassland and agricultural land which is the major contributing factor for the rich avifaunal diversity found during the short study period. This is a preliminary effort for documentation of the avifauna, but more studies and suitable conservation strategies are required in the study area.

Changes in the adult sex ratio of six duck species breeding populations over two decades

Despite all efforts, long-term changes in the adult sex ratios of breeding duck populations are still unclear; this uncertainty is especially true for male-bias populations, which are often under the scrutiny of researchers lacking convenient results for the active protection of endangered species. Species with male-bias populations are usually strongly affected by a decline in population size that leads to a higher extinction risk. In this study, we examined our long-term data of the abundance of breeding populations in six duck species (Mallard Anas platyrhynchos, Gadwall Mareca strepera, Red-crested Pochard Netta rufina, Common Pochard Aythya ferina, Tufted Duck Aythya fuligula, and Common Goldeneye Bucephala clangula) from fishponds in South Bohemia, Czechia, between 2004 and 2022. This evidence was used to assess long-term changes in the adult sex ratio in these breeding populations and investigate the possible effects of the NAO index (North Atlantic Oscillation index) on them, indicating climate conditions in winter. We determined a long-term decrease of the proportion of females in the breeding season in two of the six examined species: Common Pochard and Red-crested Pochard, which is driven by the long-term increase in the number of males in contrast to the decreasing or stable number of females likely caused by different migration behaviours between females and males. In the case of Common Pochard, in breeding populations, we estimated 60–65% of males in the early 2000s rising to 75–80% in the early 2020s. However, we establish no significant effects linked to climate conditions of the previous winter in these species as a crucial cause of the changes of the proportion of females in the breeding population.

New Data on the Staging and Winter Behavior of the Red-Crested Pochard Netta rufina in Lake of Birds (North-Eastern Algeria)

New Data on the Staging and Winter Behavior of the Red-Crested Pochard Netta rufina in Lake of Birds (North-Eastern Algeria)

Interactions between stoneworts (Charales) and waterbirds.

Stoneworts (Charales) are green algae that represent an important food resource for many waterbird species in Europe and elsewhere. Browsing avian herbivores (e.g. swan, goose, duck and coot species) consume Charales plant vegetative parts, by head-dipping, up-ending or diving. A lower fibre content and longer growing season may make Charales as attractive to such herbivores as sympatric submerged higher plant species in some circumstances. Charales respond to environmental stress (e.g. drought) by producing abundant diaspores, in the form of oospores (sexual) and bulbils (asexual), both rich in starch, generating abundant food for waterbirds at critical stages in their annual migratory cycles. Waterbirds feed on these by diving (e.g. common pochard Aythya ferina and red-crested pochard Netta rufina) or by filtering from the water column (e.g. dabbling duck species), ensuring dispersal of sexually produced and vegetative diaspores locally (because of predator swamping) and remotely (through endo- and ectozoochorous dispersal by long-distance migratory waterbirds). Greater invertebrate density and diversity associated with Charales canopies enhances their attractiveness over other submerged macrophyte beds to diving predators [e.g. tufted duck Aythya fuligula, common pochard and Eurasian coot Fulica atra (hereafter coot)]. Fish fry preying on these invertebrates use such vegetation as predator cover, in turn providing prey for avian piscivores such as grebes and cormorants. Abundant Charales contribute to maintaining a transparent water column due to canopy density, nutrient effects, dampening of sedimentation/remobilisation of suspended matter and nutrients and allelopathic effects on other plants (especially phytoplankton). Shallow, relatively eutrophic waters can flip between clear-water high-biodiversity (where Charales thrive) and turbid species-poor depauperate stable states (lacking Charales). Shifts between turbid conditions and rich submerged Charales beds have profound elevating effects on aquatic diversity, to which waterbirds show rapid aggregative responses, making them ideal indicator species of ecological change; in the case of Charales specialists (such as red-crested and common pochard), indicators of the presence and abundance of these plants. Large-bodied colonial nesting birds (e.g. cormorants, gulls, heron and egrets) aggregating along lake shores contribute high N and P loadings to water bodies sensitive to such external and internal inputs and can cause local eutrophication and potential loss of Charales. Despite variation from complete seasonal removal of Charales biomass to undetectable grazing effects by herbivorous birds, evidence suggests little effect of avian grazing on biomass accumulation or the stability of community composition (under otherwise stable conditions), but we urge more research on this under-researched topic. We also lack investigations of the relative foraging profitability of different Charales organs to waterbirds and the degree of viability of gyrogonites (fertilised and calcified oospores), vegetative bulbils and plant fragments after passage through the guts of waterbirds. We especially need to understand better how much the carbonate armour of these organs affects their viability/dispersal via waterbirds and urge more research on these neglected plants and their relationships and interactions with other organisms in the aquatic biota.

New Data on the Staging and Winter Behavior of the Red-Crested Pochard Netta rufina in the Lac des Oiseaux (North-Eastern Algeria)

New Data on the Staging and Winter Behavior of the Red-Crested Pochard Netta rufina in the Lac des Oiseaux (North-Eastern Algeria)

Interspecific differences in brood desertion by female diving ducks in relation to duckling age and environmental conditions

Studies on brood desertion in birds have been mainly conducted on species with biparental care, and less often on uniparental species. Females of many duck species remain with their ducklings, unassisted by males, during variable periods of time before the chicks can fledge. In this paper, we examined factors that influence brood desertion by female red-crested pochards ( Netta rufina), common pochards ( Aythya ferina) and white-headed ducks ( Oxyura leucocephala) during a 10-year period in lakes in southern Spain that experienced interannual variations in water levels. At an interspecific level, we found that brood desertion was less frequent in the species that nested earlier (red-crested pochard), while it was more frequent in the species that nested later (white-headed duck). Larger (older) ducklings were deserted more frequently than smaller ones in the three species. However, an interaction between flooding conditions in wetlands and species identity on brood desertion, after accounting for chick age, suggests that there were variations between the ducklings of the three species in their requirements for maternal care, conditioned by environmental conditions. Therefore, our study indicates that environmental conditions may affect parental care. A longer duration of brood attendance by female ducks may buffer against adverse effects of environmental conditions.

Red-crested pochard, <em>Netta rufina</em>, breeding population in Piedmont (North Western Italy)

[The breeding of the Red-crested pochard in Piedmont is known since 2006, when it was first described in a pond near the town of Asti. Data were collected from specific databases and from field observations performed in 3 sites located in the Asti province and 2 sites in the Cuneo province, all of them placed along the Tanaro riversides. A further site is located in the province of Alessandria near the Po river along the border of Lombardy. On the whole, in the time span 2006-2019 the number of breeding pairs increased from 2 to a maximum of 7 per year. A total of 64 females with 326 chicks were recorded (average 5.1/female), June being the most favorable month for reproduction. Results point to the occurrence of a seemingly stable small breeding population. The lack of any kind of legal site protection, the anthropogenic disturbance (hunting, fishing, abandoning wastes), and the loss of the ideal habitat for reproduction are among the critical threats for the maintenance of a vital breeding population. There was a probable case of nest parasitism by Mallard duck, which is seldom observed since the opposite situation seems to be more common.]
 
 [Article in Italian]

A Record of Red-crested Pochard in Ufa

A Record of Red-crested Pochard in Ufa

MIGRATORY WETLAND BIRDS DIVERSITY IN LOWER CHOTA NAGPUR PLATEAU WITH SPECIAL REFERENCE TO PURULIA DISTRICT, WEST BENGAL, INDIA

Lower Chota Nagpur Plateau has several large and small water bodies having diverse aquatic flora and fauna. These wetlands not only provide suitable habitat for resident and as well as migratory avian species but also contribute much to the biodiversity. The present study deals with the diversity, abundance and variations of avian migratory species at wetlands of Purulia district. The study reflects that there are 43 migratory bird species in number in these wetland regions belonging to 8 orders and 12 families. Red-crested Pochard, Tufted Duck, Lesser Whistling Duck, Northern Pintail, Gadwall, Eurasian Wigeon, Common Coot etc. are found in large number in winter season in these wetlands.

Diurnal time-activity budget and foraging techniques of red-crested pochards (Netta rufina) wintering at the wetlands of West Bengal, India

The present study aimed at recording the time-activity budget and feeding techniques of red-crested pochards (RCPs) to test the hypotheses that feeding techniques were influenced by the sexes and contrasting physical conditions of the habitat. The timeactivity budget was quantified using the scanned sample approach. In this study, the mean sex ratio of the RCPs was recorded as 0.655. Dominant behavior was sleeping or resting (42.8% in February to 47.0% in January), followed by swimming (27.1% in February to 29.8% in December), feeding (10.9% in December to 16.6% in February), and preening (9.0% in January to 12.1% in February). During the diurnal hours, resting was highest in the morning, while swimming and feeding were both highest midday. Climatic factors, such as the maximum and minimum air temperatures, maximum and minimum air temperature differences, and day length, were considered to be influential on the diurnal time activities of the RCPs. Male birds were more frequent divers than the females and the duration of diving was greater in males than in females. However, in shallow water, beak dipping and upending were major foraging techniques in both sexes. The depth of the water played a significant role in the selection of the feeding techniques.

Spatial prioritization of selected mining pitlakes from Eastern Coalfields region, India: A species distribution modelling approach

AbstractPitlake conservation is still a naive idea in a developing country. Species distribution modelling approaches can prove to be a useful tool in protecting biodiversity. The current study considers the ecological health of pitlakes through models of three winter migratory waterfowl species, namely Anser indicus (bar‐headed goose), Nettapus coromandelianus (cotton pygmy goose) and Netta rufina (red‐crested pochard), providing practical information for conservation setups in and around selected pitlakes in Eastern India. The AUC ± SD (Standard deviation) values of MaxEnt models of target species, viz. A. indicus, N. coromandelianus, and N. rufina are 0.729 ± 0.026, 0.772 ± 0.012, and 0.732 ± 0.024, respectively. Thus through the evaluation of the respective models and ground truth verification criteria, three pitlakes have proven to hold excellent conditions for the survival of these winter migratory birds as compared to the 20 studied ones. Three zones were created in these three lakes based on their characteristics to support these species and their associates. A large chunk of the region falls under the proposed zone of conservation priority sites from each of the three pitlakes. The need of the hour is to fulfill the voids between researchers, policymakers, and Eastern Coalfield's administration and work towards implementing the proposed idea.

Hazards of wind turbines on avifauna - a preliminary appraisal within the Indian context

Wind farms are substantial sources of renewable energy in India; however, their spread across the country potentially present new hazards to local and migratory birds. This study explored the risk of electrocution and collision of birds with wind turbines close to eco-sensitive zones in India, including Bakkhali, a UNESCO World Heritage site. Geographic information system and remote sensing technology were used. The results indicate vulnerability of local bird species such as barn owl, Indian Scops Owl, Blue Rock Pigeon, Asian Koel, House Crow, Common Sandpiper, Common Snipe, Ruddy Shelduck, Lesser Whistling Duck, Cattle Egret, Great Egret, and Pond Herons, as well as migratory species such as Bar-headed Goose, Red-crested Pochard, and American Black Duck. Modification of wind turbine design and location were considered determinant factors to reduce risk of bird collisions.

Seasonal diversity of water birds of Tapti River in Burhanpur District (M.P.)

Birds have been always fascinated for their ability to fly in air and for their exquisite coloration. They have their functional role in the ecosystem as potential pollinators and scavengers, and are rightly called as bio-indicators. The avifaunal diversity in Tapti River from Dedtalai to Burhanpur M.P. was studied for a period of one and half years (July 2017 –January 2019) The River inhabits several local and migratory bird species. Reduction in water retention in this river in summer has affected the avifaunal diversity in the study area. This habitat attracted 29 bird species belongs to 10 families, which are local and migratory. Highest population of migratory Red crested pochard, Spot billed Ducks and Great whistling Ducks were recorded in January while residents were herons and little cormorants.

Status of water birds in Haripura-Baur Reservoir, western Terai-Arc landscape, Uttarakhand, India

We surveyed water birds in Haripura-Baur Reservoir using total count method between 2013 and 2015. A total of 65 species were recorded representing eight orders and 14 families. Numerically Anatidae was the dominant family followed by Ardeidae and Scolopacidae. Common Coot Fulica atra, Red-crested Pochard Netta rufina, Common Pochard Aythya ferina, Gadwall Anas strepera, and Tufted Pochard Aythya fuligula were dominant species in the reservoir. The Shannon diversity of water birds was more or less consistent over the years and ranged between 2.56 (2013–14) and 2.23 (2015–16). The reservoir supports water birds having declining population trends globally (41% of species), including three Vulnerable (Asian Woollyneck Ciconia episcopus, Lesser Adjutant Leptoptilos javanicus, and Sarus Crane Grus antigone and four Near Threatened species (Oriental Darter Anhinga melanogaster, Painted Stork Mycteria leucocephala, Black-necked Stork Ephippiorhynchus asiaticus, and River Lapwing Vanellus duvaucelii). Bird species belong to four feeding guilds with the domination of the carnivore group. The current information is expected to serve as preliminary database of water birds for further research and monitoring.

Diving duck census efficiency based on monitoring of individually marked females: the influence of breeding stage and timing of census

ABSTRACTCapsule: Observations of individually marked females of three diving duck species showed that the stage of breeding season and census month most affected their resighting probability in the breeding season.Aims: To evaluate the efficiency of a diving duck census in the breeding season based on an analysis of the resighting probability of individually marked female ducks.Methods: We used monitoring data from 2004 to 2015 of individually marked females of Common Pochard Aythya ferina, Tufted Duck Aythya fuligula and Red-crested Pochard Netta rufina in South Bohemia, Czech Republic. Using a model selection approach, the resighting probabilities of females were modelled incorporating covariate parameters, such as stage of breeding, census month, year, numbers of counted individuals, individual species, water surface area and proportion of emergent vegetation.Results: We demonstrated the significant effect of the stage of breeding, year and census month on the resighting probability of females, while the number of individuals, water surface area and proportion of emergent vegetation did not contribute to the best models. Moreover, the three investigated species with different local population sizes did not differ in resighting probabilities. The incubation period of the females (i.e. June) corresponded to the lowest detection probability in the study area.Conclusions: Our approach of using individually marked females contributed to modelling to show census accuracy for diving ducks was substantially enhanced by avoiding counting females during the incubation period. Ultimately, these findings are crucial to increase the accuracy of their breeding population size estimation.

Current condition of the ornithofauna of the Alexandria Dendrological Park

The species composition of birds of the Alexandria Dendrological Park has been analyzed. The studies were conducted in 2008–2018. In total 148 bird species were registered (35% of the ornithofauna of Ukraine). Birds were analyzed by biotopic groups, nature of stay and type of nesting. It was found that in the conditions of the Alexandria Dendrological Park, the dominant ecological groups were dendrophiles (80 species). According to the nature of their stay, nesting birds accounted for 90 species, migratory – 48 species, wintering – 31 species. Depending on the type of nesting, canopy-nesting and hole-nesting birds prevailed – 27.8 and 24.4% respectively. Representatives of Piciformes and Passeriformes make up a significant part of the nesting species, which is 10 and 57.8% respectively. Falconiformes are represented by 4 species, which is 4.4% of the total number of nesting species. The value of the park also consists in the presence of favorable wetlands for wintering and forage migration of a number of taxon birds in its territory. As a result, the bird population is growing. The emergence of new bird species in recent years can provide a unique indication of the importance of ornithocenosis in these areas. This concerns in particular Green Woodpecker, Black kite, Honey Buzzard, Night Heron, Stock Dove, Spotted Crake. It has been established that new species appear in the park, settling from nearby or remote areas. During the years of observation, 9 species from the Red Data Book of Ukraine (Ciconia nigra, Netta rufina, Haliaeetus albicilla, Milvus migrans, Buteo rufinus, Pandion haliaetus, Bucephala clangula, Picus viridis, Columba oenas) have been recorded. The factors influencing the species composition of birds have been analyzed. They include felling of trees, thinning of shrubs, uncontrolled recreation and direct predation from dogs. One of the main problems limiting the number of birds in the park is trespassing of logging processes, in particular during the nesting period. In the future, more comprehensive studies are planned on the quantitative composition of birds, as well as features of the topical distribution according to the biocenosis.

Density-dependent regulation of breeding success in the Red-crested Pochard Netta rufina

ABSTRACTCapsule: Numbers of breeding Red-crested Pochard Netta rufina in the Czech Republic were positively correlated with reproductive success in the previous year, yet annual productivity, declined with increasing numbers of females at the beginning of the breeding season, suggesting local limiting factors on this population.Aims: To test the hypothesis that long-term increases in numbers of a breeding population of Red-crested Pochard Netta rufina can be explained by the productivity (numbers of ducklings fledged) in the previous year. We also test for the potential adverse effect of population size on population productivity in the current year.Methods: Data from 2004 to 2016 from South Bohemia, Czech Republic, were analysed using TRends and Indices for Monitoring Data software to investigate changes in numbers of adults, numbers of females at the start of the breeding season and number of broods produced.Results: There was a significant increase in the numbers of adults and females at the beginning of each breeding season. Numbers of adults in May positively correlated with productivity (numbers of ducklings fledged) in the previous breeding season, but relative productivity (broods per adult female) in the current year was negatively correlated with females abundance at the beginning of the breeding season.Conclusions: The study identifies density-dependent regulation as a factor in the population productivity of Red-crested Pochards using intensively managed fishponds as a breeding ground.

Dramatic impact of alien carp Cyprinus carpio on globally threatened diving ducks and other waterbirds in Mediterranean shallow lakes

Mediterranean shallow lakes support high biodiversity but suffer many anthropogenic threats, including introductions of alien fish. We studied the impact of introduction of common carp (Cyprinus carpio) to Medina and Zoñar lakes in SW Spain. Both lakes were protected as Ramsar sites because of their importance for waterbirds, particularly the globally threatened white-headed duck (Oxyura leucocephala IUCN Endangered) and common pochard (Aythya ferina IUCN Vulnerable). Two carp introduction events in Medina lake, with total eradication of carp in between, provided a unique opportunity to study the impacts of carp on the waterbird community (counted monthly from 2001 to 2013, with up to 69 species) and submerged macrophyte cover (quantified with satellite images). A comparison of waterbird abundance before and after carp eradication in the smaller Zoñar lake supported the results from Medina lake. Carp consistently led to the destruction of macrophyte beds and a radical change in the waterbird community. After controlling for the influence of depth fluctuations, the numbers and species richness of diving ducks were significantly reduced by carp, whilst the opposite effect was observed for piscivores such as herons. Negative impacts on O. leucocephala, A. ferina, red-crested pochard (Netta rufina) and herbivorous coots (Fulica spp.) were particularly pronounced. A significant negative impact of carp was also recorded on greater flamingos (Phoenicopterus ruber), black-necked grebes (Podiceps nigricollis), little grebes (Tachybaptus ruficollis) and gadwall (Anas strepera). In contrast, carp presence had a positive impact on grey herons (Ardea cinerea). The ongoing expansion of alien cyprinids in the Mediterranean region constitutes a major threat for waterbirds and particularly for sedentary, threatened taxa such as the white-headed duck and red-knobbed coot (F. cristata). Of 22 key sites for the isolated Iberian population of white-headed duck identified in a European action plan in 1996, at least 14 have since suffered carp invasions. Further development of successful control methods for carp populations is urgently required to support the conservation of waterbirds in the Mediterranean region.