Eurasian Duck Diversity: From Teals to Pochards

Eurasia hosts a remarkable range of duck species that fall into two broad ecological groups: dabbling ducks that feed at the water surface or tip up in shallow water, and diving ducks that submerge to forage at depth. This article provides a working overview of that diversity for students, researchers, life-science professionals, and informed general readers, with emphasis on common species such as the Eurasian teal (Anas crecca) and the tufted duck (Aythya fuligula). The practical utility here is a field-oriented checklist of representative Eurasian duck species with habitat and migration notes, plus guidance on how to observe, record, and interpret duck presence in ways that support wetland monitoring and conservation decisions.

Duck diversity matters beyond simple species counts. Waterbirds structure wetland communities through their foraging behavior, and their seasonal movements reveal how habitats function across large geographic scales. A study of migratory waterbirds at Yongan Wetland in Taiwan used 36 months of standardized monthly counts to show that dabbling ducks form positive association networks with each other, consistent with shared habitat use and foraging regimes, while negative links between some species suggest niche partitioning or spatiotemporal segregation 3. That finding has practical implications: when you record which duck species appear together in a wetland, you are observing real ecological structure, not random co-occurrence.

The same monitoring logic applies to disease surveillance. Ducks are important hosts in the ecology of avian influenza viruses, coronaviruses, and parasites, and their movements connect distant regions. Understanding which species use which habitats at which seasons helps researchers and wildlife managers decide where and when to sample. This article gives you the species-level foundation needed to participate in that work, whether you are a student designing a survey, a researcher planning a sampling campaign, or a land manager interpreting observations.

At a Glance: Representative Eurasian Duck Species

The table below summarizes common Eurasian duck species by group, typical habitat, and migration behavior. Use it as a quick field reference when identifying birds or planning surveys.

Dabbling Ducks: Surface Feeders of Shallow Water

Dabbling ducks are the most familiar ducks in Eurasian wetlands. They feed by tipping forward in shallow water, grazing on submerged vegetation, and filtering small invertebrates from the water surface. Their body structure suits this lifestyle: legs positioned near the middle of the body allow efficient walking on land, and broad bills with fine lamellae strain food particles from water.

The Eurasian teal is one of the smallest and most numerous dabbling ducks in Eurasia. It is a species of high research interest because of its role in pathogen surveillance. A long-term study in South Korea examined 2,868 fecal samples from migratory wild birds collected during winter seasons between 2014 and 2022, focusing on four Anas species including the Eurasian teal 6. The study detected coronaviruses in 28 samples, roughly 0.97 percent of the total, and identified both gamma coronaviruses and delta coronaviruses. The Eurasian teal was one of the species sampled, which shows how this small duck contributes to our understanding of virus circulation in wild bird populations.

The mallard is the most widespread dabbling duck in Eurasia and often the most abundant species in wetland surveys. It is a habitat generalist that tolerates urban ponds, agricultural landscapes, and natural wetlands. In a study of small game hunting in the Kirov region of Russia, the mallard was the most harvested species, with a share exceeding 10 percent of total annual small game production 12. That record reflects both the species abundance and its popularity as a game bird.

The northern pintail is a slender, long-necked dabbling duck that favors open wetlands and estuaries. It is a long-distance migrant that moves between breeding grounds in northern Eurasia and wintering areas in southern Europe, Africa, and South Asia. The northern pintail was also included in the South Korean coronavirus surveillance study, confirming its relevance to pathogen monitoring 6.

The Eurasian wigeon differs from other dabblers in its feeding habits. It grazes on land more than most ducks, often visiting grasslands and agricultural fields near wetlands. In the Kirov region study, the Eurasian wigeon ranked among the most harvested small game species, with a share over 10 percent of annual production 12. Its preference for grazing means that wetland management for wigeon must consider adjacent grassland habitats, beyond open water.

The northern shoveler is easily recognized by its large, spatulate bill. It feeds by sweeping its bill through shallow water, filtering out plankton and small invertebrates. The shoveler was another species included in the Kirov region harvest records, ranking among the top harvested species 12.

The garganey, also called teal cracker in some regions, is a small dabbling duck that breeds in Eurasia and migrates long distances to winter in Africa and South Asia. It is one of the earliest migrants to leave breeding grounds. The Kirov region study listed the garganey among the main harvested species, with a share over 10 percent of annual production 12.

Diving Ducks: Foragers of Open Water

Diving ducks feed by submerging completely, often reaching depths of several meters. Their legs are positioned farther back on the body than those of dabbling ducks, which makes them powerful swimmers but awkward walkers on land. Diving ducks typically use larger, deeper water bodies than dabblers.

The tufted duck is one of the most common diving ducks in Eurasia. It breeds across northern Europe and Asia and winters on lakes, reservoirs, and coastal waters throughout Europe and southern Asia. The tufted duck gained research attention after the 2010 to 2011 H5N1 high pathogenicity avian influenza outbreak in Japan, when many tufted ducks succumbed to infection while only one case was reported in migratory dabbling duck species 9. An experimental infection study compared tufted ducks with three dabbling duck species: Eurasian wigeon, mallard, and northern pintail. All ducks shed virus mostly via the oral route and survived the 10 day observation period, but tufted ducks shed higher virus titers than the dabbling ducks, and one tufted duck showed neurological symptoms after 7 days post inoculation. No clinical symptoms were observed in the dabbling ducks, although systemic infection and viremia were detected in some individuals sacrificed at 3 days post inoculation. These results suggest that susceptibility to clade 2.3.2.1 H5N1 virus differs by duck species, with tufted ducks potentially more vulnerable.

The common goldeneye is a diving duck of boreal lakes and rivers. It nests in tree cavities and artificial nest boxes, which makes it a species that responds well to active management. The common goldeneye is also the subject of research on duck fish competition. A review of duck fish interactions in boreal lakes found that diving ducks such as the common goldeneye, which forage in open water, are most affected by competition with fish, while the common teal is intermediate and the mallard, which forages among shore vegetation, is little affected 10. The review concluded that duck fish interactions are important to consider when planning wetland creation and restoration for ducks, and that there is an urgent need to mitigate the effects of fish introductions in wetlands.

Habitat Associations and Guild Structure

Duck species do not distribute themselves randomly across wetlands. Their habitat choices reflect body size, foraging method, and food preferences. Dabbling ducks concentrate in shallow, vegetated areas where they can reach food from the surface. Diving ducks use deeper open water where they can pursue invertebrates and small fish below the surface.

The anomaly-based network analysis from Yongan Wetland in Taiwan provides a quantitative view of this structure 3. The study analyzed 50 regularly recorded species, including a focal subset of 13 shorebirds and ducks, using monthly bird counts collected over 36 survey months. The researchers transformed raw counts to monthly anomalies that remove recurrent seasonal patterns, then quantified pairwise correlations between species. The resulting network showed strong guild structure: positive links were concentrated within dabbling ducks and within shorebirds, consistent with shared habitat use and foraging regimes. Negative links were fewer and suggested potential niche partitioning or spatiotemporal segregation. The authors noted that their framework provides a transparent, time-series-based approach for disentangling phenology from association inference, offering a practical framework for wetland monitoring and hypothesis generation about waterbird community dynamics.

For field observers, this means that recording which species co-occur in a wetland can reveal guild structure. If you consistently see multiple dabbling duck species together in the same shallow marsh, you are observing shared habitat use. If you see dabbling ducks and diving ducks using different zones of the same lake, you are observing spatial segregation driven by different foraging strategies.

Migration Patterns and Seasonal Phenology

Migration is a defining feature of Eurasian duck ecology. Many species breed in northern latitudes and winter in southern Eurasia, Africa, and South Asia. The timing of migration varies by species, age, sex, and weather conditions, and it has direct implications for wetland management and disease surveillance.

Seasonal phenology can complicate the interpretation of co-occurrence data. The Yongan Wetland study specifically addressed this problem by removing recurrent seasonal patterns from raw counts before analyzing species associations 3. Without this step, two species that migrate at the same time might appear associated even if they use different habitats. The study's anomaly-based approach provides a model for how wetland monitoring programs can separate true ecological associations from seasonal artifacts.

Migration also connects distant regions and creates opportunities for pathogen exchange. A virological surveillance study conducted in Yakutia, the largest breeding ground for wild migratory birds in northeastern Siberia, analyzed 1,970 cloacal swab samples collected from 56 bird species between 2018 and 2023 4. The study identified 74 avian influenza viruses of subtypes H3N6, H3N8, H4N6, H5N3, H7N7, H10N3, and H11N9 in Anseriformes. Phylogenetic analysis showed that the isolates belong to the Eurasian lineage and have genetic similarities with strains from East Asia, Europe, and North America. Cluster analysis demonstrated the circulation of stable avian influenza genotypes for several years. The authors concluded that Yakutia is an important territory for viral exchange on the migratory routes of migrating birds.

For wetland managers and researchers, this means that a wetland's duck population is not isolated. The ducks that arrive in autumn may carry viruses or parasites from breeding grounds thousands of kilometers away. Monitoring programs should account for migration timing when interpreting disease surveillance results.

Practical Field Assessment: How to Survey Duck Populations

A structured approach to duck surveys produces data that can support wetland management, disease surveillance, and conservation planning. The following workflow is adapted from standard waterbird monitoring practices and the methods used in the studies cited here.

Step 1: Define Survey Objectives

Decide what question the survey will answer. Common objectives include documenting species presence, estimating abundance, tracking seasonal changes, or supporting disease surveillance. The Yongan Wetland study used standardized monthly counts to build a time series long enough to separate seasonal patterns from ecological associations 3. A survey designed to detect rare species requires different methods than one designed to estimate abundance of common species.

Step 2: Select Survey Sites and Timing

Choose sites that represent the range of habitats in the study area, including shallow vegetated wetlands, open water, and coastal lagoons. Time surveys to match the target species' presence. For migratory species, this means surveying during migration periods and winter. The South Korean coronavirus study collected samples during winter seasons between 2014 and 2022, which matched the period when migratory Anas species were present in large numbers 6.

Step 3: Conduct Standardized Counts

Use consistent methods across surveys so that data are comparable over time. Record the date, time, weather, water level, and habitat conditions for each survey. Count all ducks present, identifying each to species where possible. For large flocks, estimate group size using block counts or other standardized estimation methods.

Step 4: Record Habitat Use

Note which habitat zones each species uses. Dabbling ducks typically concentrate in shallow vegetated areas, while diving ducks use deeper open water. The duck fish competition review found that mallards forage among shore vegetation and are little affected by fish, while common goldeneyes forage in open water and are most affected 10. Recording habitat use helps interpret why species occur where they do.

Step 5: Analyze Data for Patterns

Use the survey data to look for patterns in species occurrence, abundance, and habitat use. The anomaly-based network approach from the Yongan Wetland study offers a transparent method for identifying species associations while controlling for seasonal effects 3. Simpler analyses, such as calculating species richness and relative abundance per site, are also valuable for monitoring trends over time.

Records and Measurements: What to Track

Consistent record keeping is essential for any duck monitoring program. The following measurements and observations provide the foundation for analysis and interpretation.

Species Presence and Abundance

Record every duck species observed during each survey, with an estimate of abundance for each species. Note whether birds are resident, migratory, or in transit. The Kirov region hunting study used questionnaire surveys of 3,220 individuals to assess the species structure and size of small game prey, calculating the average production index by species per hunter 12. While that study measured harvest instead of live counts, it demonstrates how standardized records can quantify species composition across a large area.

Habitat Conditions

Record water level, vegetation cover, weather, and disturbance levels for each survey. These variables influence duck distribution and abundance. The duck fish competition review noted that numbers of invertebrates are higher among vegetation where there are fewer fish preying on them, which means that habitat structure affects food availability for ducks 10.

Behavioral Observations

Note feeding behavior, social interactions, and habitat use. Dabbling ducks tip up or feed at the surface, while diving ducks submerge completely. These observations help confirm species identification and reveal how birds use the wetland.

Health and Mortality Observations

Record any sick or dead birds encountered during surveys. The experimental infection study of H5N1 virus in tufted ducks and dabbling ducks showed that clinical signs can include neurological symptoms and eye lesions, and that species differ in susceptibility 9. Sick or dead ducks should be reported to the appropriate wildlife health authority, and handling should follow biosafety protocols.

Common Failure Patterns in Duck Surveys

Several recurring problems can compromise duck survey data. Recognizing these patterns helps observers correct them before they affect conclusions.

Seasonal Confounding

Raw co-occurrence data can mislead when species share migration timing but not habitat. The Yongan Wetland study addressed this by transforming raw counts to monthly anomalies that remove recurrent seasonal patterns before analyzing species associations 3. Surveys that do not account for seasonality risk overestimating ecological associations between species that simply arrive and depart together.

Incomplete Habitat Coverage

Surveys that cover only open water miss dabbling ducks in vegetated shallows, and surveys that cover only shallow marshes miss diving ducks in deeper zones. The duck fish competition review emphasized that different duck species use different habitat zones, with mallards foraging among shore vegetation and common goldeneyes foraging in open water 10. Comprehensive surveys must cover all habitat types present.

Observer Bias in Species Identification

Small dabbling ducks such as the Eurasian teal and garganey can be difficult to distinguish at a distance, especially in winter plumage. Misidentification leads to inaccurate species records. The South Korean coronavirus study relied on accurate species identification of four Anas species, including the Eurasian teal, Eastern spot-billed duck, mallard, and northern pintail 6. Observer training and field guides are essential quality controls.

Inconsistent Survey Timing

Surveys conducted at different times of day or at irregular intervals produce data that are difficult to compare. The Yongan Wetland study used standardized monthly counts across 36 survey months, which provided a consistent time series for analysis 3. Fixed survey schedules improve data quality.

Disease Surveillance and Duck Health Context

Ducks are important hosts in the ecology of several pathogens that affect wildlife, domestic animals, and humans. Understanding duck diversity supports disease surveillance by identifying which species are present, where they congregate, and how they move.

Avian Influenza Viruses

Ducks are major natural hosts of avian influenza viruses. The Yakutia surveillance study identified 74 avian influenza viruses of multiple subtypes in Anseriformes, with phylogenetic analysis showing that the isolates belong to the Eurasian lineage and have genetic similarities with strains from East Asia, Europe, and North America 4. The study also found amino acid substitutions associated with increased virulence and adaptation to mammalian hosts, highlighting the potential risk of interspecific transmission.

Species differences in susceptibility matter for outbreak prediction. The experimental infection study of clade 2.3.2.1 H5N1 virus found that tufted ducks shed higher virus titers than dabbling ducks and showed neurological symptoms, while dabbling ducks showed no clinical symptoms despite systemic infection 9. This suggests that diving ducks such as the tufted duck may be more vulnerable to certain H5N1 viruses, and that mortality events in diving ducks could signal virus circulation.

Coronaviruses

Ducks also carry coronaviruses. The South Korean study detected coronaviruses in 28 of 2,868 fecal samples from migratory wild birds, including gamma coronaviruses and delta coronaviruses 6. The delta coronaviruses were classified under the Buldecovirus subgenus, and some strains were related to the representative porcine delta coronavirus strain HKU15. The authors noted that delta coronaviruses have been found in a variety of hosts, including humans and mammals, raising concerns about potential interspecies transmission.

Parasites

Wild birds can carry parasites with zoonotic potential. A study in Southern Italy examined 256 carcasses from 39 wild bird species for Toxoplasma gondii and found parasite DNA in 15 birds, roughly 5.9 percent 7. Most infected birds were non-migratory species and omnivore or scavenger species. The authors concluded that monitoring and genotyping Toxoplasma gondii in birds could help understand the environmental spread of oocysts and support public health interventions.

Another study in Cyprus detected Colpodella sp. in domestic and wild animals, including wild birds such as the Eurasian coot and ducks 8. The study analyzed 180 fecal samples and found four positive samples, including one duck. The authors suggested that wildlife could act as zoonotic reservoirs of the parasite.

Antimicrobial Resistance

Wild birds can carry antimicrobial-resistant bacteria. A study in Japan examined fecal samples from wild birds in two prefectures between 2021 and 2024 and isolated Escherichia coli from 70 of 252 samples, roughly 27.8 percent 5. Resistance was found in 4.4 percent of isolates from standard media. Nalidixic acid resistant isolates were found in great cormorants and spot-billed ducks, and an extended-spectrum beta-lactamase or AmpC beta-lactamase producer was isolated from great cormorants. The authors concluded that despite the presence of certain resistant strains, the overall prevalence of antimicrobial-resistant E. coli remains low in wild birds, suggesting limited environmental exposure to antimicrobials.

Wetland Management Implications

Duck diversity has direct implications for wetland management. The duck fish competition review concluded that fish introductions to formerly fishless lakes have profoundly affected competitive and predatory relations in these waters, and that duck fish interactions are important to consider when planning wetland creation and restoration for ducks 10. Diving ducks such as the common goldeneye are most affected by fish competition, while mallards are little affected.

For wetland managers, this means that fish management is duck management. Removing or reducing introduced fish populations can benefit diving ducks by increasing invertebrate food availability. Maintaining vegetated shorelines benefits dabbling ducks by providing foraging habitat and invertebrate refuges.

The Yongan Wetland study offers a practical framework for wetland monitoring that can guide management decisions 3. By using anomaly-based networks to identify species associations, managers can detect changes in guild structure over time and respond to shifts in habitat use.

Limitations and Professional Escalation Criteria

Duck surveys and disease surveillance have inherent limitations that observers should recognize. Single surveys provide snapshots, not trends. Small sample sizes limit statistical power. Species identification errors bias results. Seasonal effects can confound ecological associations.

When observations suggest a serious problem, professional escalation is appropriate. The following situations warrant contacting a wildlife health authority, veterinary diagnostician, or research institution:

• Mass mortality events involving multiple ducks, especially diving ducks. The experimental infection study showed that tufted ducks can succumb to H5N1 infection with neurological symptoms, so unusual deaths in diving ducks merit investigation 9.
• Ducks showing neurological signs such as head tilt, circling, or inability to fly. These signs can indicate highly pathogenic avian influenza.
• Detection of pathogens in routine surveillance samples. The Yakutia study found amino acid substitutions associated with increased virulence and adaptation to mammalian hosts in avian influenza isolates, highlighting the potential risk of interspecific transmission 4.
• Unusual species assemblages or habitat use that suggest ecological change. The Yongan Wetland study demonstrated that species associations can reveal guild structure and niche partitioning, so major shifts in these patterns may signal environmental change 3.

Frequently Asked Questions

What is the difference between dabbling ducks and diving ducks?

Dabbling ducks feed at the water surface or tip forward to reach submerged vegetation and invertebrates in shallow water. Their legs are positioned near the middle of the body, allowing efficient walking on land. Diving ducks submerge completely to forage at depth, and their legs are positioned farther back on the body for powerful swimming. The duck fish competition review noted that diving ducks such as the common goldeneye forage in open water, while dabbling ducks such as the mallard forage among shore vegetation 10.

Where does the Eurasian teal fit in duck diversity?

The Eurasian teal (Anas crecca) is one of the smallest and most numerous dabbling ducks in Eurasia. It uses shallow wetlands, ponds, and flooded fields, and it migrates across much of its range. The Eurasian teal is also a species of research interest because of its role in pathogen surveillance. A long-term study in South Korea included the Eurasian teal among four Anas species sampled for coronaviruses over eight winter seasons 6.

Which diving ducks are common in Eurasia?

The tufted duck (Aythya fuligula) and common goldeneye (Bucephala clangula) are among the most common diving ducks in Eurasia. The tufted duck breeds across northern Europe and Asia and winters on lakes, reservoirs, and coastal waters. The common goldeneye breeds on boreal lakes and rivers and nests in tree cavities and artificial nest boxes. Both species forage in open water and can be affected by competition with fish 10.

Why do duck species differ in susceptibility to avian influenza?

Experimental infection studies show that duck species differ in their response to avian influenza viruses. In a study of clade 2.3.2.1 H5N1 virus, tufted ducks shed higher virus titers than dabbling ducks and one tufted duck showed neurological symptoms, while dabbling ducks showed no clinical symptoms despite systemic infection 9. These differences may explain why some species experience higher mortality during outbreaks.

How do seasonal patterns affect duck survey data?

Seasonal phenology can inflate simple co-occurrence signals in duck survey data. Two species that migrate at the same time might appear associated even if they use different habitats. The Yongan Wetland study addressed this by transforming raw counts to monthly anomalies that remove recurrent seasonal patterns before analyzing species associations 3. Surveys that do not account for seasonality risk overestimating ecological associations.

What role do ducks play in disease surveillance?

Ducks are important hosts in the ecology of avian influenza viruses, coronaviruses, and parasites. The Yakutia surveillance study identified 74 avian influenza viruses of multiple subtypes in Anseriformes and found that the region is an important territory for viral exchange on migratory routes 4. The South Korean study detected coronaviruses in migratory Anas species, including the Eurasian teal 6. Monitoring duck populations supports early detection of pathogens with zoonotic potential.

How does fish presence affect duck populations?

Fish compete with ducks for invertebrate food resources. A review of duck fish interactions in boreal lakes found that diving ducks such as the common goldeneye, which forage in open water, are most affected by fish competition, while mallards, which forage among shore vegetation, are little affected 10. Fish introductions to formerly fishless lakes can profoundly affect duck populations, and fish management should be considered in wetland restoration planning.

What should I do if I find sick or dead ducks?

Report sick or dead ducks to the appropriate wildlife health authority. Mass mortality events, especially involving diving ducks, merit prompt investigation because species differ in susceptibility to highly pathogenic avian influenza 9. Handle dead birds with appropriate biosafety precautions and follow local protocols for specimen submission.

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References and Further Reading

• NCBI Literature Resources. National Center for Biotechnology Information.
• PubMed. National Library of Medicine.
• Disentangling Seasonality from Co-Occurrence: Anomaly-Driven Networks of Migratory Waterbirds.. 2026.
• Exploring Avian Influenza Viruses in Yakutia-The Largest Breeding Habitat of Wild Migratory Birds in Northeastern Siberia.. 2025.
• Prevalence and genetic characteristics of antimicrobial-resistant Escherichia coli in wild birds in Japan.. 2025.
• Long-Term Surveillance of Avian Coronaviruses from Wild Bird in South Korea.. 2025.
• Role of wild birds in the circulation of &lt,i&gt,Toxoplasma gondii&lt,/i&gt, in Southern Italy: molecular and epidemiological insights.. 2025.
• First Detection and Molecular Characterization of Colpodella in Goats, Foxes, and Birds.. 2025.
• Susceptibility of common dabbling and diving duck species to clade 2.3.2.1 H5N1 high pathogenicity avian influenza virus: an experimental infection study. Journal of Veterinary Medical Science, 2023.
• Duck-fish competition in boreal lakes - a review. Ornis Fennica, 2016.
• Evolution of a reassortant North American gull influenza virus lineage: drift, shift and stability. Virology Journal, 2013.
• Species structure of small game hunting in the Kirov region at the beginning of the XXI century. Agricultural science Euro-North-East, 2021.
• Occurrence of anatidae in Sawa lake: A Ramsar wetland site in southern Iraq. Journal of Advanced Zoology, 2017.
• THE 47TH ANNUAL REPORT OF THE CALIFORNIA BIRD RECORDS COMMITTEE: 2021 RECORDS. Western Birds, 2024.
• NEW DATA ON RARE BIRD SPECIES IN THE NORTH OF ZABAIKALSKY KRAI. Geographical Environment and Living Systems, 2020.
• An assessment of threats to Anatidae in Iran. Bird Conservation International, 2015.
• Diversity and IUCN Status of Winter Migratory Avifauna of Mandothi Wetlands, Haryana (India). Biology Bulletin, 2024.
• Seasonal variations and migration phenology of the avifauna of Mandothi wetlands, India. Ornis Hungarica, 2025.

This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.