Waterbird counts on large water bodies: comparing ground and aerial methods during different ice conditions

The aerial and ground methods of counting birds in a coastal area during different ice conditions were compared. Ice coverage of water was an important factor affecting the results of the two methods. When the water was ice-free, more birds were counted from the ground, whereas during ice conditions, higher numbers were obtained from the air. The first group of waterbirds with the smallest difference between the two methods (average 6%) contained seven species: Mute Swan Cygnus olor, Whooper Swan Cygnus cygnus, Greater Scaup Aythya marila, Tufted Duck Aythya fuligula, Common Goldeneye Bucephala clangula, Smew Mergellus albellus and Goosander Mergus merganser; these were treated as the core group. The second group with a moderate difference (average 20%) included another six species: Mallard Anas platyrhynchos, Eurasian Wigeon Mareca penelope, Common Pochard Aythya ferina, Great Crested Grebe Podiceps cristatus and Eurasian Coot Fulica atra. The third group with a large difference (average 85%) included five species, all of the Anatini tribe: Gadwall Mareca strepera, Northern Pintail Anas acuta, Northern Shoveler Spatula clypeata, Eurasian Teal Anas crecca and Garganey Spatula querquedula. During ice conditions, smaller numbers of most species were counted from the ground. The exception here was Mallard, more of which were counted from the ground, but the difference between two methods was relatively small in this species (7.5%). Under ice-free conditions, both methods can be used interchangeably for the most numerous birds occupying open water (core group) without any significant impact on the results. When water areas are frozen over, air counts are preferable as the results are more reliable. The cost analysis shows that a survey carried out by volunteer observers (reimbursement of travel expenses only) from the land is 58% cheaper, but if the observers are paid, then an aerial survey is 40% more economical

Quantification of mass mortality event in freshwater mollusks within the Lower Odra, a large European river, data

• In the summer of 2022, an ecological disaster occurred on the River Odra in Europe, caused by Golden Algae toxins, resulting in an unprecedented mass mortality of fish, bivalves, and water snails. • The disaster led to an estimated 66 million dead individuals, with the Unionidae population declining by 87%, and the native Anodonta anatina species particularly affected with a 95% decrease. • The invasive Sinanodonta woodiana species suffered the least damage, highlighting the potential for an invasive species to take over the ecological niche left by the native mussels. • The disaster resulted in a minimum of 144 million dead water snails washed ashore. • Further research is needed to determine the adaptive capacity of the river's ecosystem and its potential for recovery

Advances in Scale Assessment of Seabird Bycatch: A New Methodological Framework

This paper presents a methodology for indirectly estimating the scale of seabird bycatch using existing data. The study focuses on five key species of ducks that winter in the Polish waters of the Baltic Sea and are highly susceptible to bycatch: Long-tailed Duck, Velvet Scoter, Common Scoter, Greater Scaup, and Tufted Duck. The evaluation units used are divided into the Bornholm (BS) and Gotland Subdivisions (GS) within the Polish Exclusive Economic Zone (PEEZ). The analysis acknowledges the lack of bycatch data for certain areas known to have high concentrations of diving birds and fishing activity. The population sizes of waterbirds were assessed using ship-based surveys and a distance sampling approach. Fishing effort data from the five winter seasons between 2015/2016 and 2019/2020 were analyzed. Bycatch rates were estimated based on surveys conducted in previous seasons, and threshold values for bycatch were established using the concept of “small numbers” defined in EU directives. The results show that within the GS of the PEEZ, the estimated average abundance of all diving waterbirds was 174,800 individuals, with an average annual bycatch of 7921 birds (4.5% of the total). The Velvet Scoter was the most abundant species, followed by the Long-tailed Duck. In the BS, the estimated average abundance of diving waterbirds was 624,600 individuals, with an average annual bycatch of 5056 birds (0.8% of the total). The Long-tailed Duck was the most numerous species, followed by the Velvet Scoter. Acceptable bycatch thresholds were exceeded for all species in both subdivisions despite a much smaller scale of bycatch in the BS. The findings highlight the need for effective management and conservation measures to address the high mortality of seabirds due to bycatch. The methodology presented in this study offers a valuable approach for estimating bycatch scale and can support efforts to minimize the impact on seabird populations

R codes for quantifying a mass mortality event in freshwater wildlife within the Lower Odra River

<p>In the summer of 2022, the Odra River in Europe was struck by an ecological calamity. Toxins from Golden Algae led to an unprecedented mass die-off of fish, bivalves, and aquatic snails. It is estimated that around 65 million bivalves perished, translating to an 88% reduction in the population of Unionidae mussels. The native species <i>Anodonta anatina</i> was particularly affected, witnessing a 95% decline. The invasive mussel <i>Sinanodonta woodiana</i> suffered the least damage, underscoring the potential of invasive species to fill the ecological void left by native mussels. The disaster also resulted in at least 147 million dead aquatic snails being washed ashore, marking an 85% decrease in their population. Around 3.3 million dead fish (1,025 tons) were found in the river's lower section, indicating a significant 64% drop in the biomass of the fish population across the impacted stretch.</p><p>• The text presents codes for analysis and modeling of the disaster using the R programming language.</p><p>• Only open-source software was utilized for the analysis.</p><p>• The analysis includes detailed data on the disaster's impact on various species.</p&gt

Imagined Discovery: Reconstructing the Aquiladon marinus, an Early Marine Bird from the Late Cretaceous

<p>This is a fictional story created to demonstrate the capabilities of the Generative Pre-trained Transformer (ChatGPT-4) in crafting narratives. It is made for scientific and educational purposes to showcase the potential of AI in creative writing.</p&gt

Drones, automatic counting tools and artificial neural networks in wildlife population censusing

1. The use of a drone to count the flock sizes of 33 species of waterbirds during the breeding and non-breeding periods was investigated. 2. In 96% of 343 cases, drone counting was successful. 18.8% of non-breeding birds and 3.6% of breeding birds exhibited adverse reactions: in the former, the birds were flushed, whereas the latter attempted to attack the drone. 3. The automatic counting birds was best done with the microbiology software - ImageJ / Fiji: the average bird counting rate was 100 birds in 82 seconds. 4. Machine learning using neural network algorithms proved to be an effective and fast way of counting birds – 100 birds in 23 seconds. However, as the preparation of images and machine learning time are time-consuming, this method is recommended only for large data sets and large bird assemblages. 5. The responsible study of wildlife using a drone should only be carried out by persons experienced in the biology and behaviour of the animals concerned.</jats:p