Factors affecting waterfowl hunting and harvest at the Evros delta, Greece

The Evros delta is one of the most important wetlands for wintering waterfowl in Greece and the most popular among waterfowl hunters. This study addresses hunting activity and harvest while also investigating the relationship between weather conditions and hunting activity to suggest ways of improving waterfowl management. We counted wintering waterfowl and hunter numbers, and conducted hunter bag surveys during December–February over four hunting seasons. We calculated a 10-day goose and duck Preferential Shooting Index (PSI), which is the ratio of observed number of shot birds to the number of birds expected to have been shot if the birds were shot in proportion to their availability. Common Teal, Mallard and Greater White-fronted Goose were the most abundant species both in the field and in hunter bags. The mean number of hunters/day was 99.9, with each one shooting on average 2.5 birds/day. The overall waterfowl harvested accounted for 1.3% of the total waterfowl population. For geese this proportion was six times higher (8.7%), while for ducks alone and protected species was 1.2% and 1.4% respectively. Geese were shot more often than expected (PSI 6.55), while ducks and protected species were shot according to their availability (PSI 0.86 and 1.02, respectively). Wind speed, precipitation and geese number in the field were the best predictors of overall harvest and number of hunters. To reduce goose overshooting and the probability of protected species being accidentally shot, we suggest habitat management actions for the geese feeding areas and hunters’ awareness raising.

Hydrological Condition Constrains Vegetation Dynamics for Wintering Waterfowl in China’s East Dongting Lake Wetland

As an internationally important wintering region for waterfowls on the East Asian–Australasian Flyway, the national reserve of China’s East Dongting Lake wetland is abundant in animal and plant resources during winter. The hydrological regimes, as well as vegetation dynamics, in the wetland have experienced substantial changes due to global climate change and anthropogenic disturbances, such as the construction of hydroelectric dams. However, few studies have investigated how the wetland vegetation has changed over time, particularly during the wintering season, and how this has directly affected habitat suitability for migratory waterfowl. Thus, it is necessary to monitor the spatio-temporal dynamics of vegetation in the protected wetland and explore the potential factors that alter it. In this study, the data set of time-series Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) from 2000 to 2018 was used to analyze the seasonal dynamics and interannual trends of vegetation over the wintering period from October to January. The results showed that the average NDVI exhibited an overall increasing trend, with the trend rising slowly in recent years. The largest monthly mean NDVI generally occurred in November, which is pertinent to the quantity of wintering waterfowl in the East Dongting Lake wetland. Meanwhile, the mean NDVI in the wintering season is significantly correlated to temperature and water area, with apparent lagging effects. Long-term stability analysis presented a gradually decreasing pattern from the central body of water to the surrounding area. All analyses will help the government to make appropriate management strategies to protect the habitat of wintering waterfowl in the wetland.

Effects of Local Shoreline and Subestuary Watershed Condition on Waterbird Community Integrity: Influences of Geospatial Scale and Season in the Chesapeake Bay

In many coastal regions throughout the world, there is increasing pressure to harden shorelines to protect human infrastructures against sea level rise, storm surge, and erosion. This study examines waterbird community integrity in relation to shoreline hardening and land use characteristics at three geospatial scales: (1) the shoreline scale characterized by seven shoreline types: bulkhead, riprap, developed, natural marsh, Phragmites-dominated marsh, sandy beach, and forest; (2) the local subestuary landscape scale including land up to 500 m inland of the shoreline; and (3) the watershed scale >500 m from the shoreline. From 2010 to 2014, we conducted waterbird surveys along the shoreline and open water within 21 subestuaries throughout the Chesapeake Bay during two seasons to encompass post-breeding shorebirds and colonial waterbirds in late summer and migrating and wintering waterfowl in late fall. We employed an Index of Waterbird Community Integrity (IWCI) derived from mean abundance of individual waterbird species and scores of six key species attributes describing each species’ sensitivity to human disturbance, and then used this index to characterize communities in each subestuary and season. IWCI scores ranged from 14.3 to 19.7. Multivariate regression model selection showed that the local shoreline scale had the strongest influence on IWCI scores. At this scale, percent coverage of bulkhead and Phragmites along shorelines were the strongest predictors of IWCI, both with negative relationships. Recursive partitioning revealed that when subestuary shoreline coverage exceeded thresholds of approximately 5% Phragmites or 8% bulkhead, IWCI scores decreased. Our results indicate that development at the shoreline scale has an important effect on waterbird community integrity, and that shoreline hardening and invasive Phragmites each have a negative effect on waterbirds using subestuarine systems.

How do waterbirds respond to climate change? A study at a key wintering site in Europe

Many species of birds react to climate change, for example, by wintering in areas closer to their breeding areas. We investigated the responses of two different functional groups of waterbirds to factors associated with climate change. The Odra River Estuary (SW Baltic Sea) is of key importance to wintering waterfowl. The most numerous birds here belong to two ecological groups: benthic feeders and fish feeders. We showed that numbers of all benthivorous waterbirds were negatively correlated with the presence of ice, but failed to find such a relationship for piscivores. We anticipated that, with ongoing global warming, the significance of this area would increase for benthic feeders but decrease for fish feeders: our results bore this out. The maximum range of ice cover in the Baltic Sea has a weak and negative effect on both groups of birds. Five of the seven target species are benthivores (Greater Scaup Aythya marila, Tufted Duck A. fuligula, Common Pochard A. ferina, Common Goldeneye Bucephala clangula and Eurasian Coot Fulica atra), while the other two are piscivores (Smew Mergellus albellus and Goosander Mergus merganser). Local changes at the level of particular species vary for different reasons. The local decline of Common Pochard may be a reflection of the species’ global decline. Climate change may be responsible for some of the local changes in the study area, namely, the significance of the area has increased for Greater Scaup and Tufted Duck but declined for Smew.

How do waterbirds respond to climate change? A study at a key wintering site in Europe

Many species of birds react to climate change, for example, by wintering in areas closer to their breeding areas. We investigated the responses of two different functional groups of waterbirds to factors associated with climate change. The Odra River Estuary (SW Baltic Sea) is of key importance to wintering waterfowl. The most numerous birds here belong to two ecological groups: benthic feeders and fish feeders. We showed that numbers of all benthivorous waterbirds were negatively correlated with the presence of ice, but failed to find such a relationship for piscivores. We anticipated that, with ongoing global warming, the significance of this area would increase for benthic feeders but decrease for fish feeders: our results bore this out. The maximum range of ice cover in the Baltic Sea has a weak and negative effect on both groups of birds. Five of the seven target species are benthivores (Greater Scaup Aythya marila, Tufted Duck A. fuligula, Common Pochard A. ferina, Common Goldeneye Bucephala clangula and Eurasian Coot Fulica atra), while the other two are piscivores (Smew Mergellus albellus and Goosander Mergus merganser). Local changes at the level of particular species vary for different reasons. The local decline of Common Pochard may be a reflection of the species’ global decline. Climate change may be responsible for some of the local changes in the study area, namely, the significance of the area has increased for Greater Scaup and Tufted Duck but declined for Smew.

How do waterbirds respond to climate change? A study at a key wintering site in Europe

Many species of birds react to climate change, for example, by wintering in areas closer to their breeding areas. We investigated the responses of two different functional groups of waterbirds to factors associated with climate change. The Odra River Estuary (SW Baltic Sea) is of key importance to wintering waterfowl. The most numerous birds here belong to two ecological groups: benthic feeders and fish feeders. We showed that numbers of all benthivorous waterbirds were negatively correlated with the presence of ice, but failed to find such a relationship for piscivores. We anticipated that, with ongoing global warming, the significance of this area would increase for benthic feeders but decrease for fish feeders: our results bore this out. The maximum range of ice cover in the Baltic Sea has a weak and negative effect on both groups of birds. Five of the seven target species are benthivores (Greater Scaup Aythya marila, Tufted Duck A. fuligula, Common Pochard A. ferina, Common Goldeneye Bucephala clangula and Eurasian Coot Fulica atra), while the other two are piscivores (Smew Mergellus albellus and Goosander Mergus merganser). Local changes at the level of particular species vary for different reasons. The local decline of Common Pochard may be a reflection of the species’ global decline. Climate change may be responsible for some of the local changes in the study area, namely, the significance of the area has increased for Greater Scaup and Tufted Duck but declined for Smew.

Density of Lead and Nontoxic Shotshell Pellets in Gulf Coast Prairie Ricelands

Waterfowl ingest residual lead or nontoxic shotshell pellets while foraging for food in agricultural and other habitats. The Chenier Plain of Louisiana and Texas and the Texas Mid-Coast provide important habitats for wintering waterfowl, yet these regions are characterized by long traditions of waterfowl and other game-bird hunting, which potentially exposes waterfowl to historical lead pellets remaining in the environment. Recent evidence suggests that migrant and resident waterfowl within the Chenier Plain and Texas Mid-Coast regions continue to ingest lead pellets despite strict shotshell regulations. Thus, we randomly collected and radiographed soil cores (10-cm diameter and depth) from production and idled ricelands (n = 500 from each type) in the Chenier Plain (n = 760) and Texas Mid-Coast (n = 240) during November 2013 to estimate density of lead and nontoxic pellets in important waterfowl habitats of these regions. Across all regions and field types, we detected only one lead pellet and zero nontoxic pellets, despite 100% detection of known numbers of pellets in test samples. The single lead pellet was recovered from a production rice field in the Chenier Plain, yielding an estimated density of 1,019 lead pellets/ha (95% CI: 0–3,034) in this sampling region. Failure to detect lead pellets in other regions and nontoxic pellets across all regions precluded estimation but suggested pellet densities < 3,000 pellets/ha. We speculate that regular soil tillage of ricelands helps incorporate pellets into the soil, rendering all or most unavailable to our sampling and foraging by waterfowl. We recommend that future research estimate densities of lead pellets in areas where they may be concentrated (e.g., near permanent hunting blinds), where dove hunting is prevalent, and in other heavily hunted waterfowl habitats along the Gulf Coast (e.g., coastal marsh).