Waterbird census was carried out on 52 survey plots around Lake Balaton and its surrounding wetlands on 29th January 2022, like in previous years (KOVÁCS, 2008a, 2008b, 2008c, 2013a, 2013b, 2013c, 2013d, 2015, 2023a, 2023b, 2023c, 2023d, 2023e; KOVÁCS & HAJDU, 2015a, 2015b; KOVÁCS & BRUCKNER 2022a, 2022b, 2022c, 2025a) by BirdLife Hungary South- Balaton Local Group. A total of 40 waterbird species from 8 orders and 8 families were observed (Table 1). More than half of the observed individuals were ducks and geese, and more than one-sixth were coots. The Eurasian Coot was the most numerous species (>10,200 individuals), followed by the Greater White-fronted Goose (>9,100), the Mallard (>6,600), the Great Cormorant (~6,400), the Common Pochard (~5,500), the Tufted Duck (~5,100), the Black-headed Gull (~4,600) and the Goldeneye (~4,400), all of which were also significant throughout the survey area. A notable count was also recorded for the Common Merganser, with a total of 267 individuals observed. In fishponds and marshes, the dominant species (those with a dominance value D > 5%) were the Black-headed Gull, Greater White-fronted Goose, Mallard, Greylag Goose, Yellowlegged/ Caspian Gull, and Mew Gull. On Lake Balaton itself, the dominant species were the Eurasian Coot, Greater White-fronted Goose, Great Cormorant, Mallard, Common Pochard, Tufted Duck and Goldeneye. The highest number of individual birds was counted at Balatonaliga (>15,000 individuals). Significant numbers were also recorded at Fonyód (~7,500 ind.), Balatonföldvár (>5,300 ind.) and Tihany Gödrös (~5,000 ind.). Additionally, more than 1,000 waterbirds were recorded at 17 other survey locations (Table 2 and Map 1). The highest species richness was recorded at Fonyód, with 19 waterbird species observed. Furthermore, at 28 additional locations, more than 10 species were recorded (Map 2). Several locally outstanding records were also made: 1,702 Great Cormorants at Balatonfenyves; 2,600 Greater White-fronted Geese and 1,857 Common Pochards at Fonyód; 2,000 Common Pochards and 1,500 Goldeneyes at Balatonföldvár; 1,000 Mallards at Szabadi- Sóstó; 2,600 Greater White-fronted Geese at Balatonkenese (Füzfő Bay); 4,700 Eurasian Coots at Tihany Gödrös and 1,104 Great Cormorants at Vonyarcvashegy. At Királyszentistván, 2,000 Black-headed Gulls were counted, while a flock of 15,000 wild geese was observed near Balatonaliga; due to the large distance, species-level identification was not reliably possible. Species occurring at more than half of the observation sites (constancy C > 50%) included the Mallard, Mute Swan, Goldeneye, Black-headed Gull, Yellow-legged/Caspian Gull, Great Crested Grebe, Mew Gull, Eurasian Coot and Tufted Duck, indicating their widespread presence in the study area. An interesting faunistic result was the occurrence of the following species: Greater Scaup (5-3-7-3-4-1-6 ind. at Bélatelep, Fonyód, Fonyódliget, Ordacsehi elágazó, Zamárdi, Tihany rév, Balatonudvari Fövenyes, and Badacsony); Velvet Scoter (5 ind. at Vonyarcvashegy); Common Scoter (2 ind. at Balatonboglár); Long-tailed Duck (1 ind. at Fonyódliget Ordacsehi elágazó); Common Merganser (at 17 plots, with a maximum count of 82 individuals at Balatonföldvár); Red-breasted Merganser (3 ind. at Tihany rév); Pallas’s Gull (1 ind. at Balatonboglár); European Herring Gull (1-2 ind. at Fonyódliget and Ordacsehi elágazó, Badacsony) and Black-throated Diver (1 ind. at Balatonakarattya).

Fine‐scale spatial and temporal genetic structuring of nests is possible in colonial birds that return to breed at their natal sites, and notably in waterfowl for which females are more philopatric than males. We genotyped female Red‐breasted Mergansers Mergus serrator breeding colonially on a coastal archipelago in eastern New Brunswick, Canada, during 2015 and calculated pairwise kinship coefficients using 4270 single nucleotide polymorphisms to assess whether related hens nest near each other and initiate their nests around the same time. We found no spatial or temporal genetic structure across islands; however, nesting was relatively synchronous between hens nesting close together. Red‐breasted Mergansers initiating their nests at the same time may select nearby nest‐sites based on the availability of dense vegetation that conceals nests, limiting opportunities for kin to nest near one another in this population.

Brood parasitism can be costly to host fitness, which in turn may favour host strategies that decrease these costs. Duck (Anatinae) nests are often parasitized by eggs of other ducks, and one way that hosts can respond to potentially costly brood parasitism is to move parasitic eggs to the clutch periphery, where egg incubation temperatures can be suboptimal relative to the clutch centre. We explored whether red‐breasted mergansers Mergus serrator use discriminatory egg incubation against parasitic eggs laid by conspecifics in a population where conspecific brood parasitism (CBP) is common. We used isoelectric focusing electrophoresis of egg albumen from entire clutches of 12 parasitized nests to identify parasitic eggs. A randomization test pooling identified parasitic eggs (n = 50) across nests revealed that hosts did not position parasitic eggs along the periphery of clutches or out of the central region more than was expected by chance, and this was the case for parasitic eggs laid both before and after the onset of incubation. Similarly, nest‐level analyses showed that parasitic eggs were random in all but the smallest clutch, which contained one identified parasitic egg. Thus, parasitic eggs were not moved to the periphery of heavily parasitized clutches, where egg temperature gradients between central and peripheral regions of nests are expected to be greatest. Only four eggs (< 0.5% of 1276 eggs) were found buried within nest bowls. Eggs that were removed from nests consisted of parasite and host eggs and were more likely along the periphery of clutches prior to their removal than was expected by chance. Our results indicate that discriminatory egg incubation of parasitic eggs is not a well‐developed tactic for defending against CBP in red‐breasted mergansers, though hosts may rely on certain cues to decide which eggs are to be removed from nests (e.g. addled eggs).

This article presents an analysis of 180 ornithological specimens representing 72 bird species collected within the boundaries of the modern Trakhtemyriv Regional Landscape Park and Nyzhniosulskyi National Nature Park. The materials are housed in the scientific collection of the National Museum of Natural History of the National Academy of Sciences of Ukraine and cover the period from 1908 to 1991. The most numerous species represented include Emberiza schoeniclus (24 specimens), Emberiza calandra (22), Oriolus oriolus (14), Motacilla flava (4), Calidris alpina (2), among others. The collection also contains six specimens of species listed in the Red Data Book of Ukraine, including Gallinago media, Phalaropus lobatus, Sternula albifrons, Coracias garrulus, Charadrius hiaticula, and Mergus serrator. Of particular scientific value are specimens collected prior to the creation of the Kaniv and Kremenchuk reservoirs, which allow for the reconstruction of historical faunal assemblages before anthropogenic landscape alteration. Noteworthy findings include Emberiza leucocephalos, a rare species for the region, as well as the oldest specimens dated to 1908. The analysis of the collection highlights the contributions of individual researchers – M. L. Klyestov, M. I. Holovushkin, S. D. Lubkin, Yu. M. Markovskyi, O. B. Kistiakivskyi, M. O. Osypova, P. O. Yezerkyi, H. H. Havrys, and others – to the formation of the museum’s holdings. Their long-term efforts ensured the representativeness of the material and laid the foundation for contemporary research in zoogeography, conservation biology, biodiversity monitoring, and nature protection. This collection serves as a valuable resource for the retrospective analysis of changes in the avifauna of the Middle Dnipro region, enabling studies of bird responses to landscape transformation and supporting further research in biodiversity conservation.

Status of the Red-Breasted Merganser in India Based on Two Historical Occurrences and Recent Sightings

Results of the November 2019 waterbird census at Lake Balaton. Waterbird census was carried out on 54 survey plots around Lake Balaton and its surrounding wetlands on 17th November 2019, like in previous years (KOVÁCS, 2008a, 2008b, 2008c, 2013a, 2013b, 2013c, 2013d, 2015; KOVÁCS & HAJDU, 2015a, 2015b; KOVÁCS & BRUCKNER 2022a, 2022b, 2022c) by BirdLife Hungary South-Balaton Local Group. A total of 44 waterbird species from 9 orders and 11 families were observed (Table 1.). The highest number (>2500 ind.) was counted at Balatonboglár, the highest species richness was found at Fonyód and at Balatonszemes. We counted more than 1000 individuals in further 4 plots (Table 2., Map 1.), while species richness was exceeded 10 in 15 survey plots (Map 2.). On the fishponds and marshes, the dominant (D>5%) species were the Greater White-fronted Goose, the Black-headed Gull, the Greater White-fronted Goose, the Mallard, and the Northern Lapwing. On Lake Balaton the Eurasian Coot, the Mallard, the Greylag Goose, the Common Pochard, and the Black-headed Gull. Interesting faunistic result was the occurrence of the the Black-throated Loon (2-3-2-1-1 ind. at Szántód, Balatonföldvár, Balatonszabadi, Balatonaliga, Alsóörs), the Common Scoter (3-1 ind. at Balatonszabadi, Balatonakarattya), the Red-necked Grebe (2-1 ind. at Balatonfűzfő kikötő-Tobruk, Balatonakali), the Red-breasted Merganser (1-1 ind. at Bélatelep, Balatonaliga), the Horned Grebe (1-1 ind. at Szántód, Balatonszabadi), the Red-throated Loon (1 ind. at Fonyód), the Red Phalarope (1 ind. at Balatonszabadi) and the European Herring Gull (1 ind. at Alsóörs).

Results of the January 2021 waterbird census at Lake Balaton and its surrounding wetlands. Waterbird census was carried out on 59 survey plots around Lake Balaton and its surrounding wetlands on 17th January 2021, like in previous years (KOVÁCS, 2008a, 2008b, 2008c, 2013a, 2013b, 2013c, 2013d, 2015; KOVÁCS & HAJDU, 2015a, 2015b; KOVÁCS & BRUCKNER 2022a, 2022b, 2022c) by BirdLife Hungary South-Balaton Local Group. A total of 37 waterbird species from 8 orders and 8 families were observed (Table 1.). The highest number (>5700 ind.) was counted at Királyszentistván, the highest species richness was found at Balatonfűzfő. We counted more than 1000 individuals in further 9 plots (Table 2, Map 1.), while species richness was exceeded 10 in 21 survey plots (Map 2.). On the fishponds and marshes, the dominant (D>5%) species were the Black-headed Gull, the Yellow-legged/Caspian Gull and the Mallard; on Lake Balaton the Eurasian Coot, the Mallard, the Tufted Duck, the Common Pochard, the Black-headed Gull and the Common Goldeneye. The highest abundance of Eurasian Coots (>8500 ind.) was observed, but also Mallards (~6400 ind.), Black-headed Gulls (~5900 ind.), Tufted Ducks (>3600 ind.), Common Pochards (>3000 pd), Yellow-legged/Caspian Gulls (~2700 ind.), Common Goldeneyes (>2200 ind.), Great Cormorants (>1400 ind.) and Pygmy Cormorants (>1000 ind.) were also significant throughout the survey area. Another remarkable record was the total number of Common Merganser 164. Interesting faunistic result was the occurrence of the Greater Scaup (1-1-1-2 ind. at Fonyódliget, Balatonszemes, Balatonszárszó, Szántód), Common Scoter (1 ind. at Balatonfenyves); Red-breasted Merganser (1-4-2-4-4 ind. at Fonyód, Balatonlelle, Balatonkenese, Balatonfűzfő Tobruk, Alsóörs); Red-necked Grebe (3-3-2 ind. at Balatonfűzfő Tobruk, Alsóörs, Balatonfüred MVM port); Black-necked Grebe (14-1-1-1 ind. at Fonyód, between Balatonkenese-Balatonfűzfő, Örvényes, Keszthely). However, not a single loon could be observed on the given day, although the observation conditions were not optimal.

Report on the waterbird censuses of Danube River between Gönyű and Szob (River kms 1791 – 1708) during the period August 2022 and April 2023. Based on the results of the waterfowl counts (shown in Tables 2 and 3) completed during the 2022/2023 season in the section between Gönyű and Szob of the Danube river, we recorded the largest number of waterbirds (n=13 496) in December, while the smallest total number of birds occurred in September (n=478). The daily water level of the Danube River on the observation days shows Table 1. We observed the highest number of species (24 species) in December, while in September we saw only 8 species. During the 9-month study, we observed 30 species. Species that only appeared occasionally or in small numbers (˂100 per observation) included Cygnus olor (max. 64), Melanitta fusca (max. 1), Mergellus albellus (max. 26), Mergus serrator (max. 2), Aythya ferina (max. 24), Spatula clypeata (max. 4), Mareca penelope (max. 18), Gavia arctica (max. 1), Tachybaptus ruficollis (max. 9), Podiceps cristatus (max. 19), Fulica atra (max. 7), Egretta garzetta (max. 14), Ardea alba (max. 80), Aquila heliaca (max. 4), Haliaeetus albicilla (max. 6), Larus cachinnans (max. 8), Sterna hirundo (max. 2) and Alcedo atthis (max. 2). Species that appeared in larger numbers and quantities (˃100 per observation) were as follows: Anser anser: 0–580, Anser albifrons: 0–1780, Anas platyrhynchos: 14–5282, Anas crecca: 0–130, Phalacrocorax carbo: 131–1463, Bucephala clangula: 0–980, Chroicocephalus ridibundus: 0–2665, Larus canus: 0–2425, Aythya fuligula: 0–386 and Larus michahellis: 3–872. Figures 1 present the dynamics of common species. There are 3 known Great Cormorant nesting colonies in the studied section of the Danube; in 2023, 335–390 pairs nested there. There were 118–145 pairs of Grey Heron (Ardea cinerea) which, like the Great Cormorant, also nests in 3 colonies. There are also four known White-tailed Eagles (Haliaeetus albicilla) nests in the section of the Danube (Nagy-Erebe Island, Komárom Szt. Pál Island, Szőnyi Island and Mocsi Island); booth nests were inhabited in 2023 and breeding were as well. One pair of Imperial Eagle (Aquila heliaca) breeding at Neszmély on Radvány Island were still present during the nesting, but in the spring the stormy wind severely damaged the nest.

Several sea duck species in Europe face dwindling population numbers with following increased conservation focus. Shot gun practices may put extra pressure on populations not only by direct hunting mortality but also crippling and lead poisoning from ingestion of pellets. In this study, we examined three sea duck species breeding in the Swedish Archipelago of the Baltic Sea by x-raying trapped incubating females to detect prevalence of imbedded and ingested shot gun pellets. The study was carried out during the 2021 and 2022 breeding seasons and designed to aid our understanding of the role of physical restraints of putative pellets to breeding performance at our study site. A total of 205 individual females of common eider (n = 113), velvet scoter (n = 57), and red-breasted merganser (n = 35) were x-rayed without finding any imbedded or ingested pellets. For this study, a combination of decreasing hunting pressure, remoteness of study site, improved hunters’ shooting performance along the flyway and depletion of crippling rates due to life-long negative effects of carrying imbedded pellets may explain our finding on non-detection. For common eider, specific interventions to reduce the negative impacts of shotgun practices have been reported successful, and our data suggest a continuing positive trend. Based on our findings, we advise future conservation efforts for the three species, breeding in this part of the flyway, to focus on other factors that may have negative impact on incubating female survival and reproduction.

Report on the waterbird censuses of Danube River between Gönyű and Szob (River kms 1791 – 1708) during the period August 2021 and April 2022. Based on the results of the waterfowl counts (shown in Tables 2 and 3) completed during the 2021/2022 season in the section between Gönyű and Szob of the Danube river, we recorded the largest number of waterbirds (n=16 2014) in January, while the smallest total number of birds occurred in September (n=324). The daily water level of the Danube River on the observation days shows Table 1. We observed the highest number of species (18 species) in November, while in August we saw only 6 species. During the 9-month study, we observed 29 species. Species that only appeared occasionally or in small numbers (˂100 per observation) included Cygnus olor (max. 80), Anser anser (max. 1), Anser albifrons (max. 65), Clangula hyemalis (max. 2), Mergellus albellus (max. 9), Mergus serrator (max. 2), Aythya fuligula (max. 95), Spatula clypeata (max. 1), Mareca penelope (max. 34), Anas crecca (max. 40), Tachybaptus ruficollis (max. 3), Podiceps cristatus (max. 2), Gavia stellata (max. 3), Egretta garzetta (max. 1), Ardea alba (max. 39), Microcarbo pygmeus (max. 1), Pandion haliaetus (max. 1), Haliaeetus albicilla (max. 5), Larus cachinnans (max. 8), Larus marinus (max. 1) and Sterna hirundo (max. 1). Species that appeared in larger numbers and quantities (˃100 per observation) were as follows: Bucephala clangula: 0–1176, Aythya fuligula: 0–95, Mergus merganser: 0–186, Anas platyrhynchos: 23–11 068, Ardea cinerea: 0–124, Phalacrocorax carbo: 7–745, Larus michahellis: 12–943, Larus canus: 0–1198 and Croicocephalus ridibundus: 9–3020, Figures 1 present the dynamics of common species. There are 3 known Great Cormorant nesting colonies in the studied section of the Danube; in 2022, 290–330 pairs nested there. There were 115–125 pairs of Grey Heron (Ardea cinerea) which, like the Great Cormorant, also nests in 3 colonies. On the Süttői Island are nesting 5 pairs of Black-crowned Night Heron (Nycticorax nycticorax) and 5 pairs of Little Egret (Egretta garzetta) as well. There are also three known White-tailed Eagles (Haliaeetus albicilla) nests in the section of the Danube (Gönyű, Nagy-Erebe Island, Komárom, Szent Pál Island and Komárom, Szőnyi Islands. In the Radvány Island at Neszmély nested 1 pair of Eastern Imperial Eagles (Aquila heliaca).

As a key group in the Anatidae, the Mergini tribe (sea ducks) is strongly structured, with clear genetic assignments and phylogenetic relationships. The tribes also differ in terms of breeding strategy, longevity, and bionomic strategy. The mitochondrial genome (mitogenome) of Mergus serrator was 16,627 bp in length, and its structure was circular. The structure and gene arrangement of the genome were basically the same as those of Anseriformes species. The mean base composition of the mitogenome of Anseriformes was T (22.31 0.51%), C (32.63 0.64%), A (29.36 0.64%), and G (15.71 0.52%), indicating a slight specific bias towards A and C. AT content ranged of the mitogenome was from 50.27% to 55.31%, with an average value of 51.67 1.10%, higher than the GC content and similar to that of birds in general (50.5% to 57.7%). In addition, the start and stop codons, the mitogenome consists of 3662 codons. The most commonly used amino acid was leucine (13.63%) in the use of M. serrator. The analyses indicated that the Anseriformes include the families Anseranatidae, Anhimidae, and Anatidae. Furthermore, Anatinae is composed of Aythyini, Anatini, Somaterini, and Mergini. M serrator was sister to M. merganser and M. squamatus, and this group belongs to Mergini. The value of the ND3 gene in the Mergini tribe is lower than those for other tribes. The phylogenetic relationships were analyzed and M. serrator was sister to M. merganser and M. squamatus, and formed a closely evolved Mergini clade. Different evolutionary rates between the Mergini tribe and other tribes were found.

Breeding bird populations were monitored at a wind farm in the Båtskär area of the southern Åland archipelago in 2006–2017. The area is situated in the outer archipelago and comprises four islands with six wind turbines in total. The wind turbines began operating in autumn 2007. An environmental impact assessment for the area was conducted in 2002. A control area called Stenarna, located 22 km NW of Båtskär, was used for comparison. The Båtskär area annually recorded 850–1,050 pairs of breeding birds. Four species showed significantly decreasing trends in Båtskär, namely the Common Eider Somateria mollissima, Lesser Black-backed Gull Larus fuscus, Herring Gull L. argentatus , and Black Guillemot Cepphus grylle. In Stenarna, only the Common Eider significantly decreased over the same period. The Arctic Tern Sterna paradisaea increased in both areas, while the Velvet Scoter Melanitta fusca, Red-breasted Merganser Mergus serrator, Common Gull Larus canus, Rock Pipit Anthus petrosus, and White Wagtail Motacilla alba increased in Stenarna, the control area. The Herring Gull population decline is unlikely to be related to the wind farm. However, the proximity of a wind turbine to a breeding colony of the Lesser Black-backed Gull has most likely contributed to its decline. The reason for the Black Guillemot decline in Båtskär is unknown. The decline of Common Eider in both areas may be connected to increasing predation from White-tailed Eagles Haliaeetus albicilla. Some species, such as the House Martin Delichon urbicum and auks, have benefitted from the wind farm construction. They can utilize new microhabitats created by the construction, while other species, such as the Common Eider, gain protection against predation because of human activities.

ABSTRACT Capsule Recording of behavioural responses to ferry traffic for 11 target species showed that Red-throated Diver Gavia stellata, Slavonian Grebe Podiceps auratus, and Black-throated Diver Gavia arctica were most likely to react to passing vessels. Aim To provide information on how responses to marine traffic vary between waterbird species to inform marine spatial planning and environmental impact assessments in the near-shore environment. Methods We recorded behavioural responses to ferry traffic for 11 target species in near-shore waters: Common Eider Somateria mollissima, Goldeneye Bucephala clangula, Long-tailed Duck Clangula hyemalis, Velvet Scoter Melanitta fusca, Red-breasted Merganser Mergus serrator, Black-throated Diver, Great Northern Diver Gavia immer, Red-throated Diver, European Shag Gulosus aristotelis, Slavonian Grebe and Black Guillemot Cepphus grylle. Responses were analysed using generalized linear models and mixed models. Results Red-throated Diver, Black-throated Diver and Slavonian Grebe were the most likely species to exhibit a response to passing vessels. While Red-throated Divers and Slavonian Grebes were highly likely to flush, Black-throated Divers and Great Northern Divers rarely took flight, instead favouring swim or dive responses. In rougher sea conditions birds were more likely to take flight, and the propensity to respond declined across the wintering period. Conclusions This research provides comparative evidence on the behavioural responses of waterbirds to marine traffic. The results support previous studies which highlighted the high sensitivity of diver species to disturbance and provide new evidence that Slavonian Grebe may also be a high sensitivity species.

The classifications of the grouping of the birds reflect the faunistic or the ecological position of the species in certain habitats and landscapes. Most of them consider the species diversity of the birds of the studied regions in general, including synanthropic, invasive and widespread species. This approach prevents singling out the habitats which are important for supporting the existence of native (or autochtonous) species and their groupings. Native groupings of the birds in the dry steppe zone of Ukraine are almost not studied despite the rapid contraction in the range and population of most component species, especially Anthropoides virgo, Otis tarda, Tetrax tetrax and Burhinus oedicnemus. The definition of the taxonomic and the ecological composition of these grouping will help in understanding the strategy of the reproduction and the protection of native avifauna. In connection with this, the faunistic-topomorphic classification of native birds in the dry steppes zone of Ukraine according to the following scheme is proposed: ornithofaunistic complex (by priority landscapes and habitats) – the place of the feeding (by priority substrate on/in which a species’ diet is extracted) – the nesting place (by the priority substrate of the location of the nest for nesting individuals) – the place of rest (the priority substrate where non-nesting individuals rest). The classification is aimed at the definition of the general requirements of native birds and their groupings in terms of the landscapes and the habitats which provide the conditions for their preservation and the protection in the researched region. It has been determined that in the south of Ukraine 33 nesting species are dry-steppe autochthons (18.3% of nesting species of the region), of which 18 species form the ornithofaunistic complex of dry steppes (Buteo rufinus, Perdix perdix, Anthropoides virgo, Otis tarda, Tetrax tetrax, Burhinus oedicnemus, Glareola nordmanni, Galerida cristata, Calandrella cinerea, C. rufescens, Melanocorypha calandra, Anthus campestris, Motacilla feldegg, Saxicola rubetra, S. torquata, Oenanthe oenanthe, Oe. isabellina, Emberiza melanocephala), and 15 species form the complex of the sea coast (Phalacrocoraх aristotelis, Phoenicopterus roseus, Tadorna ferruginea, T. tadorna, Mergus serrator, Charadrius alexandrinus, Recurvirostra avosetta, Larus ichthyaetus, L. melanocephalus, L. genei, L. cachinnans, L. michahellis, Gelochelidon nilotica, Hydroprogne caspia, Thalasseus sandvicensis). The above-mentioned species are mainly xerophiles (54.6% of species) and hygrophils (24.2% of species), and they are in the most threatened position because they feed, nest and rest mainly or exclusively on the soil surface. According to the proposed classification, native birds of dry steppes require: for xerophiles – areas of soil without vegetation or with rarefied low grass, which does not prevent birds from moving freely, searching and obtaining food, leading their chicks, looking over their territories; for hygrophiles – shallow water bodies with islands, surface vegetation, shallows, adjacent meadows and salt-marshes; for dendrophiles – single shrubs and trees or small groves; for most xerophiles and dendrophiles – fresh or slightly saline water bodies for drinking. Unfortunately, in the protected natural territories of the researched region, most native birds do not have this combination of the above-mentioned habitats, which are simultaneously suitable for feeding, nesting and resting.

We present the first records of the Red-breasted Merganser (Mergus serrator) in the Colombian Caribbean, with photo-graphic evidence. The presence of this species in the islands of Old Providence and Saint Andrew (i.e., Providencia and San Andrés) probably relates to erratic movements outside its regular fall migration range, perhaps as a result of a severe winter in North America and the occurrence of cold fronts in the Caribbean when the birds were recorded.

In the present study number(187) birds were collected, examined and dissected and the results revealed the presence of the following parasites: Parasitic protozoa: The Pterocles olchata and Columba Livia were found infected with Haemoproteus and this protozoa was recorded for the first time in Ptercle olchata.Plasmodium was found in blood of Cotunix coturnix and the Eimeria was found in Cotunix coturnix and pterocles olchata whereas Cryptosporidium and Giardia were found in Ptercles olchata and Mergus serrator. Cestoda: The genus Metadilepis and genus Cotugina were found in Columba livia and Mergus serrator, respectively. Nematode: The genus Ascarida hermaphrodite was found in Columba livia and Mergus serrator whereas genus Acuaria laticepiا was found in Sturnus vulgaris. Lice: Columbicola columbae and Companulotez compare were found in Columba livia whereas (Laemobothrion maximum, Craspedorrhynchus platystomus and Degeeriella leucopleura were found in Aquila chrysaetos. These louse species were new recods in lraq.

Plastic debris ingestion by seabirds on the Korean Peninsula

Conspecific brood parasitism (CBP) has been observed in approximately half of all species of waterfowl, a philopatric group in which breeding females are frequently locally related. It has been suggested that kin selection can facilitate the evolution of CBP in waterfowl via fitness benefits for the host and parasite. One model demonstrates that discrimination of related and unrelated parasites by the host must be sufficient for kinship to promote CBP, provided that costs of brood parasitism to host fitness are sufficiently low. We parameterized the model using demographic data and behavioural observations from a population of colonial Red-breasted Mergansers (Mergus serrator Linnaeus, 1758) in which 47% of nests were parasitized by conspecifics. The costs of 1–3 foreign eggs to host hatching success were generally small (decline of 1.8% per additional egg). Nevertheless, model outputs revealed that brood parasites maximize their inclusive fitness by avoiding nests of relatives, primarily because of constraints on a host’s ability to detect parasites at the nest. Indeed, hosts spent <8% of the diurnal period at the nest during egg laying, a period when parasite activity is greatest. It is thus highly unlikely that relatedness and kin selection promote brood parasitism in this population.

The addition of eggs to a nest by a conspecific is known for approximately 250 bird species. Understanding the evolution of conspecific brood parasitism (CBP) requires assessment of fitness consequences to the egg recipient (host). We addressed host traits and the effects of CBP on future reproduction (i.e., annual survival) and hatching success of hosts by following the nesting of 206 red-breasted mergansers ( Mergus serrator) for a colony in which an average of 41% of nests was parasitized annually. Each host was tracked for ≥2 seasons and up to seven seasons. The proportion of a host’s nesting attempts that was parasitized averaged 43% and varied considerably across individuals (range 0%–100%). Probability of parasitism, however, was not repeatable across a host’s nests. Rather, rates of CBP throughout a host’s lifetime increased with earlier dates of nest initiation. CBP had no effect on annual survival of a host. Hatching success throughout a host’s lifetime declined with a greater number of foreign eggs added to the individual’s nests. This study revealed that there may be measurable costs of CBP to lifetime reproductive success in red-breasted mergansers, although our observations suggest that costs to hosts are limited to the most heavily parasitized clutches.

Among birds exhibiting conspecific brood parasitism (CBP), parasites demonstrate a variety of intriguing tactics for selecting a host nest, including preference for safe nests (i.e., avoiding nests depredated during the previous season). Brood parasites of birds that do not reuse nest sites, however, are limited to nest-site information available to them during the current breeding season. This study explores cues used by brood parasites in a population of red-breasted mergansers nesting in upland vegetation and sandy substrate that prohibits reuse of nest sites in consecutive years. Nest-site and host traits were measured for 33 parasitized and 23 non-parasitized nests. There was no association between CBP and nest-site traits potentially providing cues about nest safety from avian predators (concealment and density of nesting larids), likely due to very low rates of egg predation. Distance to shore for parasitized nests was slightly greater than for unparasitized nests. Parasites did not select nests in relation to host age, mass, date of nest initiation, or stage of nesting (laying or incubation). Artificial nests were used to simulate natural nests without a host and to assess whether host presence serves as a cue for parasites. The proportion of natural nests receiving ≥ 1 foreign egg (60% of 15 nests) was thrice that for artificial nests (21% of 14 nests). Some aspect of host presence may therefore be an important, but not necessary, cue for brood parasites targeting nests that are heavily concealed in uplands. Whenever brood parasitism is a well-developed component of reproduction, selection is expected to favor brood parasites that make use of environmental or social information allowing them to discriminate among host nests and maximize reproductive success. We assessed cues used by brood parasites in ground-nesting red-breasted mergansers for which conspecific brood parasitism (CBP) is common, and nests are well concealed in upland vegetation. Observations at parasitized and unparasitized nests revealed that nest-site safety and visibility from habitat edges are not central to laying decisions by parasites in this population. Brood parasites, however, were considerably more likely to lay their eggs in natural nests with a host than in artificial nests without a host, suggesting that some aspect of host presence is important in the nest-site selection process for parasites. The ability of brood parasites to discriminate among nests based on host presence is expected to affect parasite success because individuals can avoid nests in which their eggs are doomed to fail (e.g., abandoned nests).