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Temporal trends (2006-2019) of metals (Cd, Co, Cs, Cu, Fe, Hg, K, Mg, Mn, Na, Rb and Zn) and nonmetals (Br, Cl and Se) were assessed in livers of great egrets (Ardea alba) from São Paulo Metropolitan Region, Brazil. Male and female concentrations were compared and the relation between body mass and contaminant levels was evaluated as well as the risks of contaminant levels for the birds. Large variations were observed for toxic elements (Cd and Hg) over time. Some specimens presented toxic levels of Hg, Cu, Fe and Zn. Females presented lower concentrations of Br, Co, Cs, Rb, Se and Zn, while body mass and Zn were negatively correlated.

Waterbird species face numerous threats and many are declining globally, but knowledge of distribution, abundance, and trend remains poor for many species. Five species of marsh-nesting colonial waterbirds are poorly monitored in Canada, and especially so in the core of their range in the Canadian Prairie Provinces (Alberta, Saskatchewan, and Manitoba). We summarized published and unpublished data on abundance and distribution of breeding colonies of Western Grebe (Aechmophorus occidentalis), Franklin's Gull (Leucophaeus pipixcan). Black Tern (Chlidonias niger), Forster's Tern (Sterna forsteri), and Black-crowned Night-Heron (Nycticorax nycticorax) in Alberta. Saskatchewan, and Manitoba. We also examined the degree of overlap in nesting phenology (egg dates) and summarized survey methods that have been used to monitor the species during the breeding season–information that may be useful for the development of a multispecies monitoring program. For all species, the largest number of records of breeding colonies occurred in Alberta, with records declining eastward through Saskatchewan and Manitoba. We identified a number of breeding colonies occurring outside of currently defined species ranges, especially for the poorly studied Forster's Tern. Of 137 waterbodies hosting a colony of at least one species over the past 10 yr, 57 (41.6%) hosted colonies of at least 2 species, and 3 (2.2%) hosted colonies of all 5 species. Species tended to be reasonably synchronous in their breeding phenology, but Franklin's Gulls and Black-crowned Night-Herons tended to initiate nesting slightly earlier than the other species. We conclude that a multispecies survey timed in late May or early June to count nests and/or incubating adults, using either ground-based or aerial surveys, would likely be the most appropriate for monitoring all species jointly in the Prairie Provinces. The approach we take to compiling data from multiple sources on species occurrence and breeding phenology may be applicable to others wishing to examine the feasibility of a multispecies monitoring plan. Received 19 December 2018. Accepted 2 April 2019.

In northwestern Italy, traditional rice cultivation using permanent flooding has been replaced by cultivation that uses a reduced water depth and a shortened submersion period. Prey availability for the numerous herons and egrets using this intensive rice cultivation region changed as well, with a diminution of amphibians and an increase of crayfish (Procambarus clarkii) and oriental weatherfish (Misgurnus anguillicaudatus). The prey intake in 2014 was compared with data available for 1987 for the three most common species of waterbirds that forage in the paddies. Total biomass intake by Grey Herons (Ardea cinerea) feeding in the paddies decreased from 28 g dry mass/min in 1987 to 7 g in 2014, and by Black-crowned Night-Herons (Nycticorax nycticorax) from 8 g to 5 g, while the intake by Little Egrets (Egretta garzetta) remained similar (12 and 13 g in 1987 and 2014, respectively). The observed levels of prey intake allowed breeding Grey Herons to meet their energy needs by feeding exclusively in the rice paddies in 1987, but not in 2014. The other two study species could not meet their daily requirements for successful breeding by feeding in the paddies only, either in 1987 or 2014. Yet the three species bred successfully in the study area, and their reproductive output remained stable both in 1987 and 2014. Successful breeding was probable by the three species foraging in other habitats, such as rivers, small natural wetlands and irrigation canals, in the region. Received 15 February 2017, accepted 30 May 2017.

In October 2021, a wild bird-origin H3N8 influenza virus-A/Chinese pond heron/Jiangxi 5-1/2021 (H3N8)-was isolated from Chinese pond heron in China. Phylogenetic and molecular analyses were performed to characterize the genetic origin of the H3N8 strain. Phylogenetic analysis revealed that eight gene segments of this avian influenza virus H3N8 belong to Eurasian lineages. HA gene clustered with avian influenza viruses is circulating in poultry in southern China. The NA gene possibly originated from wild ducks in South Korea and has the highest homology (99.3%) with A/Wild duck/South Korea/KNU2020-104/2020 (H3N8), while other internal genes have a complex and wide range of origins. The HA cleavage site is PEKQTR↓GLF with one basic amino acid, Q226 and T228 at HA preferentially bind to the alpha-2,3-linked sialic acid receptor, non-deletion of the stalk region in the NA gene and no mutations at E627K and D701N of the PB2 protein, indicating that isolate A/Chinese pond heron/Jiangxi 5-1/2021 (H3N8) was a typical avian influenza with low pathogenicity. However, there are some mutations that may increase pathogenicity and transmission in mammals, such as N30D, T215A of M1 protein, and P42S of NS1 protein. In animal studies, A/Chinese pond heron/Jiangxi 5-1/2021 (H3N8) replicates inefficiently in the mouse lung and does not adapt well to the mammalian host. Overall, A/Chinese pond heron/Jiangxi 5-1/2021 (H3N8) is a novel wild bird-origin H3N8 influenza virus reassortant from influenza viruses of poultry and wild birds. This wild bird-origin avian influenza virus is associated with wild birds along the East Asian-Australasian flyway. Therefore, surveillance of avian influenza viruses in wild birds should be strengthened to assess their mutation and pandemic risk in advance.

Abstract The composition of assemblages, diet and behavior of waterbird species with similar ecological features are important aspects in the functioning of aquatic ecosystems. Closely related animal species often share resources such as space and food in ways that reduce competition, but if the diets of different species strongly overlap, interspecific competition may intensify. This analysis examined behavioral data relating to Great Egret, Little Egret, and Squacco Heron to explore their foraging efficiencies in rich aquatic habitats in an arid zone during post-breeding movements. The fieldwork was carried out in small estuaries of a Wadi on the southern coast of Oman. The frequency of interactions was the highest in Squacco Heron and the lowest in Great Egret. However, the differences in the numbers of inter- and intra-specific interactions between the 3 species were significant. Activity indices calculated for a 5-min period, i.e., the number of interactions (interaction index) and times of flying and walking (movement index) differed among the 3 species. The number of successful attacks was the highest in Squacco Heron, while the foraging effectiveness of Great Egret and Little Egret was similar. GLM analysis showed that only the movement index was significant, as it had a positive impact on individual foraging success. Great Egret caught more fish than the other 2 heron species which, in turn, caught a greater number of smaller prey items, mostly invertebrates. This study shows that heron species in the same rich habitat employ different foraging tactics. In comparison to the other two heron species, the foraging tactics of Squacco Heron seem to be the most susceptible to competition. However, its greater mobility and using different foraging tactics, enhance its foraging success.

Climate and land use/land cover (LULC) changes have far-reaching effects on various biological processes in wildlife, particularly interspecific interactions. Unfortunately, interspecific interactions are often overlooked when assessing the impacts of environmental changes on endangered species. In this study, we examined niche similarities and habitat overlaps between wild Crested Ibis and sympatric Egret and Heron species (EHs) in Shaanxi, China, using Ecological niche models (ENMs). We aimed to forecast potential alterations in habitat overlaps due to climate and LULC changes. The results showed that although EHs possess a broader niche breadth compared to the Crested Ibis, they still share certain niche similarities, as indicated by Schoener’s D and Hellinger’s I values exceeding 0.5, respectively. Notably, despite varying degrees of habitat reduction, the shared habitat area of all six species expands with the changes in climate and LULC. We suggest that with the climate and LULC changes, the habitats of sympatric EHs are likely to suffer varying degrees of destruction, forcing them to seek refuge and migrate to the remaining wild Ibis habitat. This is primarily due to the effective conservation efforts in the Crested Ibis habitat in Yangxian County and neighboring areas. Consequently, due to the niche similarity, they will share and compete for limited habitat resources, including food and space. Therefore, we recommend that conservation efforts extend beyond protecting the Crested Ibis habitat. It is crucial to control human activities that contribute to LULC changes to safeguard the habitats of both Crested Ibis and other sympatric birds.

The purpose of this study was to explore whether domestication could lead to evolutionary changes towards flightlessness in the domestic duck (Anas platyrhynchos domesticus) compared to the cattle egret (Bubulcus ibis) as a nonflying and flying biological model, respectively. Bones of the pectoral girdle (scapula, clavicle, and coracoid) and the foramen triosseum were comparatively assessed using anatomical, radiographic, and 3D computed tomographic (CT) studies. Additionally, the muscles pectoralis and the supracoracoideus were histologically and immunohistochemically assessed. Among the differences observed, radiographically, the distance between the paired clavicles was significantly wider (p < 0.05) in the domestic duck (mean [+ or -] SD 1.43 [+ or -] 0.23 cm) compared with the cattle egret (0.96 [+ or -] 0.13 cm). Unlike cattle egrets, there was no connection between the sternum and the hypocladium of furcula in domestic ducks. The scapula, clavicle, coracoid, sternum, and humerus were considerably longer in domestic ducks than in cattle egrets. The foramen triosseum appeared significantly (p < 0.01) wider in domestic ducks (0.7 [+ or -] 1.17 cm) compared to cattle egrets (0.49 [+ or -] 0.03 cm). Histologically, compared to cattle egrets, the muscle fibers in domestic ducks were loosely connected and contained fewer nuclei and perimysial/endomysial spaces. A higher myoglobin expression was evident in cattle egrets compared with domestic ducks.

As heron and egret colonies are sometimes abandoned due to human activity and subsequently newly established at nearby locations, colony locations per se cannot represent colony fates. Here, “colony lineages” were traced by connecting short-distance location shifts between colony sites in consecutive years to quantify the site fidelity of heron colonies themselves rather than the breeding-site fidelity of individuals. Site fidelity of 61 colony lineages recorded from 1963 to 2013 in and around Ibaraki Prefecture, Japan, was evaluated by persistence periods with survival analysis and shapes of historical trajectories by applying the correlated random walk analysis. While 36% (n = 22) of colony lineages did not show site fidelity and lasted only 1 year or indicated untangled shapes of historical trajectories, 64% (n = 39) of colony lineages exhibited site fidelity by reusing the same locations for multiple years or by staying within a small area with entangled shapes of historical trajectories. Even though suitable breeding sites were abundant in the study area and site fidelity of colony members was low, a high rate of site fidelity in colony lineages may be achieved when a few faithful pioneer herons and egrets are followed by many others.

The Madagascar Pond-heron (Ardeola idae) is a migratory species that breeds exclusively in Madagascar and nearby islands (Europa, Aldabra and Mayotte). Changes in the population of this species were investigated over the last 23 years through literature reviews, field monitoring, and surveys undertaken from 1993 to 2016. Data from 111 sites were collected and analyzed for population assessment, including 11 known breeding sites in Madagascar (n = 6), Mayotte (n = 4), and Europa (n = 1). Trend analyses were done with surveys from 1993-2016 (omitting 1996) and population estimates from the last 5 years of surveys, 2012-2016. The species occurred in all types of wetlands including lakes, ponds, marshes, rivers, mangroves, pasture wet meadow, and rice fields. During the non-breeding season (May-September), many pond-herons migrate to eastern and central Africa; however, some birds (911 records) remained in Madagascar and Mayotte during austral winter. Data show the current population estimated at ∼1100 breeding birds in the total breeding area. The population has declined significantly, with 41.6% and 52.9% declines, respectively, at the two colony sites in Tsimbazaza and Tsarasaotra parks with the longest history of breeding. Main threats to the species are habitat destruction, collection of eggs and fledglings, predation, and human disturbance at all breeding sites.