BIRDWALKERMONDAY

Wednesday, 9 August 2017

9-8-2017 BAMBERG, GERMANY - CANADA GOOSE (Branta canadensis)

The Canada goose (Branta canadensis) is a large wild goose species with a distinctive black head and neck, white cheeks, white under its chin, and a brown body. It is well-known for its black head and neck with a white 'chinstrap' that distinguishes it from all other goose species, except for the cackling goose and barnacle goose.

Adult Canada geese feature a black head, neck, and bill with a contrasting white cheek and throat patch. Their bodies are largely brown with paler underparts. They have a long neck and a large body relative to other geese. The sexes are similar in appearance, but males are generally larger. Juveniles are duller and lack the white chinstrap.

Canada geese are highly adaptable and can be found in a variety of habitats, including lakes, rivers, ponds, marshes, and estuaries. They thrive in both wild and human-altered environments, often seen in urban parks, golf courses, and agricultural fields.

Native to arctic and temperate regions of North America, Canada geese have a wide distribution that includes much of Canada and the United States. They have also been introduced to parts of Europe, New Zealand, and other regions.

Canada geese are known for their migratory habits, although some populations have become non-migratory. They are social birds, often found in flocks, and exhibit strong territorial behavior. They are also known for their aggressive defense of nesting sites.

The male's call is a loud honk, while the female emits a shorter, higher-pitched hrink. Canada geese have a variety of vocalizations used for communication, including honks, hisses, and grunts.

Canada geese are monogamous and typically mate for life. They build their nests on the ground near water and the female lays 2-9 eggs. Both parents protect the nest, but the female spends more time incubating the eggs. Goslings are precocial and able to walk, swim, and feed shortly after hatching.

The cackling goose is very similar in appearance but is smaller with a shorter neck and smaller bill. The barnacle goose can be confused with the Canada goose but has a black breast and gray body plumage.

Primarily herbivorous, Canada geese feed on grasses, grains, and aquatic plants. They are known to graze on lawns and agricultural fields, and in water, they may upend to reach submerged vegetation.

The Canada goose is listed as Least Concern by the IUCN. While some local populations may be declining, overall numbers are stable or increasing, and in some areas, they are considered pests due to their adaptability to human environments.

9-8-2017 BAMBERG, GERMANY - MUTE SWAN (Cygnus olor)

The mute swan, Cygnus olor, is a majestic bird, easily recognized by its all-white plumage and the distinctive orange beak bordered with black. The male, known as a cob, is noted for a prominent knob atop the beak, which is more pronounced than that of the female, or pen.

Adult mute swans measure between 125 to 160 cm in length, with a wingspan of 200 to 240 cm. The males are generally larger than females and possess a larger knob on their bill. The species is one of the heaviest flying birds, with males reaching weights up to 14.3 kg and females up to 10.6 kg. Juveniles, or cygnets, are not as bright white as adults and have a dull greyish-black bill for their first year.

Mute swans are found in a variety of wetland habitats, including lakes, ponds, rivers, and coastal areas, where they build large mounds of vegetation for nesting.

Native to Eurosiberia, the mute swan has been introduced to North America, Australasia, and southern Africa. It is partially migratory in northern latitudes, with some populations moving as far south as North Africa and the Mediterranean.

Mute swans are territorial and monogamous, often reusing the same nest each year. They are less vocal than other swan species but are known for their aggressive defense of their nests and offspring. They can be seen performing a threat display known as busking, with wings half raised and neck curved back.

While not as vocal, mute swans produce a range of sounds including grunting, hoarse whistling, and snorting. They also have a rhythmic song during courtship displays and a unique throbbing sound from their wings in flight.

Mute swans lay 4 to 10 eggs, with the female brooding for around 36 days. Cygnets typically fledge at around 120 to 150 days old.

The mute swan can be distinguished from other swan species by its orange beak with a black border and the pronounced knob on the male's beak.

Their diet consists mainly of submerged aquatic vegetation, which they reach with their long necks, and they also graze on land. They may consume small amounts of aquatic insects, fish, and frogs.

The mute swan is listed as Least Concern by the IUCN, with a native population of about 500,000 birds. However, in some introduced regions, it is considered invasive and subject to population control measures.

8-8-2017 NUREMBERG, GERMANY - MALLARD HYBRID (FEMALE) (Anas platyrhynchos)

The mallard (/ˈmælɑːrd, ˈmælərd/) or wild duck (Anas platyrhynchos) is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. Belonging to the subfamily Anatinae of the waterfowl family Anatidae, mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes.

Males (drakes) have green heads, while the females (hens) have mainly brown-speckled plumage. Both sexes have an area of white-bordered black or iridescent purple or blue feathers called a speculum on their wings; males especially tend to have blue speculum feathers. The mallard is 50–65 cm (20–26 in) long, of which the body makes up around two-thirds the length. The wingspan is 81–98 cm (32–39 in) and the bill is 4.4 to 6.1 cm (1.7 to 2.4 in) long. It is often slightly heavier than most other dabbling ducks, weighing 0.7–1.6 kg (1.5–3.5 lb).

The female lays 8 to 13 creamy white to greenish-buff spotless eggs, on alternate days. Incubation takes 27 to 28 days and fledging takes 50 to 60 days. The ducklings are precocial and fully capable of swimming as soon as they hatch.

The non-migratory mallard interbreeds with indigenous wild ducks of closely related species through genetic pollution by producing fertile offspring. Complete hybridisation of various species of wild duck gene pools could result in the extinction of many indigenous waterfowl. This species is the main ancestor of most breeds of domestic duck, and its naturally evolved wild gene pool has been genetically polluted by the domestic and feral mallard populations.

The mallard is considered to be a species of least concern by the International Union for Conservation of Nature (IUCN), and, unlike many waterfowl, are considered an invasive species in some regions. It is a very adaptable species, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development.

8-8-2017 NUREMBERG, GERMANY - MALLARD (FEMALE) (Anas platyrhynchos)

The Mallard, or wild duck (Anas platyrhynchos), is a familiar and widespread dabbling duck with a presence across temperate and subtropical regions of the Americas, Eurasia, and North Africa. It has also been introduced to parts of the Southern Hemisphere. The male is renowned for its iridescent green head and white collar, while the female sports a brown-speckled plumage. Both sexes boast a speculum—a patch of feathers with iridescent purple or blue hues bordered by white. The Mallard's length ranges from 50 to 65 cm, with a wingspan of 81 to 98 cm, and it typically weighs between 0.7 and 1.6 kg.

Males during the breeding season are unmistakable with their glossy green heads, white collars, and purple-tinged brown breasts. Females are mottled brown with buff cheeks and an eye-stripe. Both sexes have the distinctive speculum on their wings. The male's bill is yellowish-orange tipped with black, while the female's is darker, ranging from black to mottled orange and brown.

Mallards are found in a variety of wetlands, including parks, small ponds, rivers, lakes, and estuaries. They prefer water depths less than 0.9 meters and are drawn to areas with aquatic vegetation.

This species is distributed across the Northern and Southern Hemispheres, from Alaska to Mexico, the Hawaiian Islands, across the Palearctic, and down to southeastern and southwestern Australia and New Zealand.

8-8-2017 NUREMBERG, GERMANY - EURASIAN GREAT CORMORANT (Phalacrocorax carbo)

The great cormorant (Phalacrocorax carbo), a robust seabird, is cloaked in predominantly black plumage. It is a member of the cormorant family, with a widespread distribution. The species exhibits considerable size variation across its range, with males generally larger than females. Notable features include a longish tail and a distinctive yellow throat-patch. During the breeding season, adults boast white patches on their thighs and throat.

To identify the great cormorant, look for its large size, heavy build, and thick bill. It lacks a crest and its plumage does not have a green tinge, distinguishing it from the common shag. In North America, it is bulkier than the double-crested cormorant and has less yellow on the throat and bill. The white thigh patches are a key identifier.

Great cormorants are found in a variety of aquatic environments including seas, estuaries, freshwater lakes, and rivers. They often nest in colonies close to these water bodies.

This species has a broad distribution, breeding across the Old World, Australia, and the Atlantic coast of North America. Northern populations tend to migrate southward in winter, seeking coasts rich in fish.

Great cormorants are generally silent but may emit guttural noises at breeding colonies. They are known for their wing-drying posture, often seen with wings outstretched to dry after diving.

Mostly silent, the great cormorant vocalizes with guttural sounds in the vicinity of its breeding colonies.

Great cormorants typically nest in colonies near wetlands, rivers, or sheltered inshore waters, often returning to the same site annually. Their nests are constructed from sticks and can be located in trees, on cliff ledges, or on predator-free ground. They lay clutches of three to five pale blue or green eggs, which are incubated for about 28 to 31 days.

These birds are piscivorous, diving to catch fish such as wrasses, sand smelt, flathead, and common soles. They exhibit seasonal dietary shifts, preferring larger fish in colder temperatures. Their foraging efficiency is influenced by the size of the prey rather than the quantity.

The great cormorant is currently listed as Least Concern by the IUCN. Conservation efforts have led to a population rebound, with approximately 1.2 million birds in Europe alone. However, their increasing numbers have led to conflicts with fisheries due to predation on fish stocks.

8-8-2017 NUREMBERG, GERMANY - HOUSE SPARROW (FEMALE) (Passer domesticus)

The house sparrow (Passer domesticus) is a member of the sparrow family Passeridae. This small bird typically measures around 16 cm (6.3 in) in length and weighs between 24–39.5 g (0.85–1.39 oz). The species exhibits sexual dimorphism, with females and young birds displaying pale brown and grey plumage, while males are characterized by more vibrant black, white, and brown markings.

Males can be identified by their bright black, white, and brown markings, with a distinctive black bib, white cheeks, and a grey crown. Females lack the striking head patterns of males and are predominantly buffish with softer coloration. Juveniles resemble adult females but are generally paler with less defined markings.

The house sparrow is highly adaptable and can thrive in both urban and rural environments. It is commonly found in close association with human habitation and avoids dense forests, grasslands, polar regions, and deserts far from human development.

Native to Europe, the Mediterranean Basin, and much of Asia, the house sparrow has been introduced to various regions worldwide, including parts of Australasia, Africa, and the Americas, making it one of the most widely distributed wild birds.

Tuesday, 8 August 2017

30-7-2017 CENTRAL PARK, BUDAPEST - CRESTED OROPENDOLA (Psarocolius decumanus)

The crested oropendola, also known as the Suriname crested oropendola or the cornbird, is a striking member of the icterid family. Males are predominantly black with a chestnut rump and a vivid yellow tail, save for two central dark feathers. A distinctive feature is their long, narrow crest, which can be elusive to the observer's eye. The iris of this bird is a captivating blue, and the bill is a pale whitish hue. Females share a similar coloration but are smaller, less vibrant, and lack the male's crest.

To identify the crested oropendola, look for the male's long crest and the bright yellow of the tail, which contrasts with the black body and chestnut rump. The female is similar but smaller and without the crest. The blue iris and whitish bill are also key identification features.

This species is found in the forest edges and clearings, where it can be seen foraging among the trees.

The crested oropendola is a resident breeder in lowland South America east of the Andes, ranging from Panama and Colombia south to northern Argentina. It is also present on the islands of Trinidad and Tobago.

A colonial breeder, the crested oropendola constructs an impressive hanging woven nest, often exceeding 125 cm in length, high in the trees. The species exhibits some seasonal movements and is known to be quite mobile outside the breeding season. Dominant males perform an elaborate bowing display to attract females, with a single male mating with most females in a colony.

The male's song is a distinctive descending call, reminiscent of a hand sliding down a piano's keys. Both sexes emit a loud clack call, which is a notable part of their vocal repertoire.

The crested oropendola lays two blotched blue-grey eggs in its pendulous nest. The eggs hatch in 15-19 days, and the young fledge after an additional 24-36 days. Breeding colonies typically consist of 15-30 females and only 3-4 males.

While there are no specific similar species mentioned, it is important to note the differences in subspecies, which vary slightly in plumage details and distribution.

The diet of the crested oropendola includes large insects, fruit, seeds, and some nectar, which they forage for in trees.

The crested oropendola is classified as Least Concern by the IUCN, indicating that it currently faces no significant threats to its survival.

2-8-2017 CENTRAL PARK, BUDAPEST - RED POSTMAN BUTTERFLY (Heliconius erato)

Heliconius erato, or the red postman, is one of about 40 neotropical species of butterfly belonging to the genus Heliconius. It is also commonly known as the small postman, the red passion flower butterfly, or the crimson-patched longwing. It was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

H. erato exhibits Müllerian mimicry with other Heliconius butterflies such as Heliconius melpomene in order to warn common predators against attacking, which contributes to its surprising longevity. It also has a unique mating ritual involving the transfer of anti-aphrodisiacs from males to females.

Recent field work has confirmed the relative abundance of this butterfly.

H. erato is a neotropical species, found from southern Texas to northern Argentina and Paraguay, and resides on the edges of tropical rainforests. It is philopatric, having a particularly restricted home range. In areas of dense population in Trinidad, some home ranges are only separated by 30 yards, but H. erato rarely travels to neighboring home ranges.

Larvae feed on the host plant, first consuming the terminal bud. After they have exhausted the resources of the plant they have hatched on, later instars may move to another plant.

H. erato is a pollen-feeding species, collecting from the Lantana camara flower. They do not spend much time or energy collecting nectar (only remaining for a few seconds). Instead, they collect pollen in a mass on the ventral side of their proboscis. They then agitate the pollen by coiling and uncoiling their proboscis in order to release its nutrients. H. erato is then able to extract nitrogenous compounds in a clear liquid, including amino acids like arginine, leucine, lysine, valine, proline, histidine, isoleucine, methionine, phenylalanine, threonine, and tryptophan. Females typically carry larger loads of pollen than males as females require more amino acids for egg production.

Previous studies have shown that host plants, such as Passiflora, have coevolved with Heliconius butterflies. Passiflora plants are usually found in low densities with even less plants in fruiting or flower conditions due to caterpillar feeding.[10] To increase chances of survival and cross-pollination, Passiflora plants synthesize toxins in leaves to deter Heliconius. Passiflora species produce different toxins, leading to different preferences for oviposition among Heliconius species. This leads to a lower chance of herbivore damage for individual Passiflora species and thus helps protect Passiflora plants. Chemical composition of toxins in such plants have not been studied widely. Studies have identified cyanogenic glycosides and alkaloids as potential chemicals that drive distasteful reactions among Heliconius. Toxin variation among Passiflora is one of the reasons for host specificity among Heliconius butterflies.

Studies have shown that H. erato species that feed on specific Passiflora species tend to spend more time on the host plant and are thus exposed to the toxins for a longer period. Accumulation of toxins such as cyanogenic glycosides leads to a low survival rate among H. erato larvae. Increasing exposure to parasitoids due to longer time spent on the host plant also contributes to the high mortality rate. One recent study showed that mortality increased among H. erato larvae which fed on cyanide-releasing Passiflora. Survived butterflies were capable of excreting higher levels of cyanides, suggesting a defense mechanism in H. erato.[14] H. erato species with more mechanisms to detoxify and secrete ingested toxins are the result of genetic differences among H. erato subspecies. Toxin excretion, from previous studies, results in changes in wing pattern and body size. Consequences include decreased fecundity, egg size, and survival rate.

Nectar excretion from Passiflora has also been studied as one factor which contributes to coevolution. Passiflora nectar is known to produce aggressive behaviors among ants, wasps, and egg parasitoids. Ehrlich and Gilbert have estimated that parasitoids are capable of destroying most Heliconius eggs under nectar influence. Therefore, host plants such as Passiflora are believed to have self-defense mechanisms that utilize predators against Heliconius butterflies.

2-8-2017 CENTRAL PARK, BUDAPEST - CHOCOLATE PANSY BUTTERFLY (Junonia iphita)

Junonia iphita, the chocolate pansy or chocolate soldier, is a butterfly found in Asia.

The wingspan is about 5–6 cm (2.0–2.4 in) and the female can be told apart from the male by white markings on the oblique line on the underside of the hindwing. The wavy lines on the underside of the wings vary from wet- to dry-season forms.

Individuals maintain a territory and are usually found close to the ground level and often bask in the sun.

Upperside of both sexes brown of varying depths of colour. Forewing: cell with one pair of subbasal and one pair of apical transverse sinuous fasciae, the outermost defining the discocellulars; a short, broad, dark, oblique fascia beyond to vein 4, its inner margin diffuse, its outer sinuous but sharply defined; below vein 4 a sinuous, transverse, more faint fascia, followed by a discal blackish fascia, very broad and diffuse, below costa, bordered by a row of faint ocelli, and a postdiscal and a subterminal similar fascia following the outline of the termen. Hindwing with a slender blackish loop near apex of cellular area; a broad inwardly diffuse, outwardly well-defined short discal fascia in continuation of the one on the forewing; a series of postdiscal somewhat ochraceous ocelli with black pupils minutely centred with white; postdiscal and subterminal broad lines as on the forewing.

Underside brown, with very broad darker brown transverse fasciae, the interspaces between the markings irrorated (sprinkled) with purplish silvery scales. Forewing with two sinuous fasciae on basal half succeeded by a discal fascia, very broad at the costal margin and decreasing in width to the dorsum, bearing on its outer border a row of obscure ocelli. This is succeeded by a zigzag dark line, and sinuous subterminal and terminal lines; apex and tornal area suffused with purplish silvery. Hindwing: two irregular, very broad, dark brown, curved short fasciae near base; a straight, transverse, prominent, narrow ochreous-brown discal band defined outwardly by a black line; a transverse postdiscal dark brown fascia, widest in the middle and bearing outwardly a curved row of ochreous-brown white-centred ocelli, followed by a zigzag dark line in continuation of the one on the forewing; a subterminal somewhat diffuse dark fascia and a terminal dark line. Antennae, head, thorax and abdomen dark brown..

The eggs are often laid on the ground or on dry twigs near the host plants rather than on them. On hatching the larvae find their way to the host plants.

Larva are "Cylindrical, slightly pubescent and armed with nine longitudinal rows of many-branched spines, except on the head which is clothed with short bristles. ... Colour dark dull brown." (Davidson and Aitken)

The pupa "is regular, with three or five dorsal rows of small tubercular points, hung perpendicularly. ... Colour smoky brown."(Davidson & Aitken)

8-8-2017 NUREMBERG, GERMANY - COMMON CUCKOO (Cuculus canorus)

The common cuckoo (Cuculus canorus) is a member of the cuckoo order of birds, Cuculiformes, which includes the roadrunners, the anis and the coucals.

This species is a widespread summer migrant to Europe and Asia, and winters in Africa. It is a brood parasite, which means it lays eggs in the nests of other bird species, particularly of dunnocks, meadow pipits, and reed warblers. Although its eggs are larger than those of its hosts, the eggs in each type of host nest resemble the host's eggs. The adult too is a mimic, in its case of the sparrowhawk; since that species is a predator, the mimicry gives the female time to lay her eggs without being attacked.

2-8-2017 CENTRAL PARK, BUDAPEST - GULF FRITILLARY BUTTERFLY (Agraulis vanillae)

The Gulf fritillary or passion butterfly (Dione vanillae) is a bright orange butterfly in the subfamily Heliconiinae of the family Nymphalidae. That subfamily was formerly set apart as a separate family, the Heliconiidae. The Heliconiinae are "longwing butterflies", which have long, narrow wings compared to other butterflies.

Dione vanillae is most commonly found in the southern areas of the United States, specifically in many regions of Florida and Texas.

Gulf fritillaries have a chemical defense mechanism in which they release odorous chemicals in response to predator sightings. As a result, common predators learn to avoid this species. Pheromones play a critical role in male-female courtship behaviors, with male gulf fritillaries emitting sex pheromones that contribute to mate choice in females.

In its adult form, the gulf fritillary is a medium-sized butterfly that has extended forewings and a wingspan range of 6.5 to 9.5 cm. This butterfly exhibits sexual dimorphism as females are typically distinctively larger in size than males. The underside of the wings is brown and speckled with silvery white dots. In contrast, the top surface layer of the wings is deep orange in color with black streaks running across. In addition to the size difference between the two sexes, females are usually darker in color and are more marked with black streaks as compared to the males.

Gulf fritillaries are found primarily in the southern parts of the contiguous United States, from Florida and Georgia to Texas and California. However, this butterfly’s range can extend from the Southern United States into parts of Mexico and Central America and sometimes as far as parts of South America. They are also found in Hawaii.

Gulf fritillaries are found in open habitats, like in moderately sunny areas near open grasslands, parks, and woodlands. Gulf fritillaries are also commonly seen in local butterfly gardens across the U.S.

With Florida constituting a major component of the geographic range of this butterfly, the migration pattern of gulf fritillaries in Florida is well-documented. In Florida, gulf fritillaries have two major flights during the year. The first major migration involves huge populations of butterflies flying northward while the second migration involves the butterflies moving southward throughout the state, especially throughout the peninsular parts of Florida. The first and second migrations occur in the spring and the fall, respectively.

The general process for a typical courtship interaction begins when a male flies and lands near a perching female, who is most likely perched on a host plant, such as several species of the Passiflora genus. Once the male has landed, the male assumes a position next to the female with their heads together and with their bodies aligned at a 45-degree angle. At this time, the male engages in a specific action called the wing clap display in which the male continuously claps its wings open and closed. During this time, the antennae of the female are placed between the opening and closing wings. After the male ceases wing movement, the male butterfly will move into a position that facilitates genital contact with the female. The average duration of the copulation process including the wing clap display is approximately 11 seconds.

Monday, 7 August 2017

8-8-2017 NUREMBERG, GERMANY - BLACK GROUSE (Tetrao tetrix)

The black grouse, or Lyrurus tetrix, is a sedentary game bird of notable size within the grouse family. Males are distinguished by their striking black plumage with iridescent blue hues on the neck and back, white wing bars, and red wattle over the eyes. Females are more subdued in color, with mottled greyish-brown feathers, providing excellent camouflage in their natural habitat.

Male black grouse, or blackcocks, are approximately 60 centimeters in length and can weigh up to 2.1 kilograms. They boast a lyre-shaped tail and a unique white under-tail. The females, or greyhens, are smaller at about 45 centimeters and weigh up to 1.1 kilograms. Their plumage is cryptic, aiding in concealment during the nesting period.

The black grouse thrives in a variety of habitats across Eurasia, favoring the transitional zones between forests and open spaces. They are commonly found in moorlands, heathlands, grasslands, and pastures, particularly when these areas are adjacent to wooded regions.

This species spans the Palearctic, from the British Isles across Scandinavia and the European continent into Russia and parts of Asia, including Siberia, northern Mongolia, and northwestern China. Notably absent from Ireland, the black grouse has also seen local extinctions in other parts of its range.

Black grouse are known for their elaborate courtship displays at leks, where males fan their tails and emit a distinctive bubbling song to attract mates. They form large flocks in winter, roosting in dense forests and feeding predominantly on conifer needles.

The male's courtship song is a series of low, bubbling coos, while the female emits a cackling or warbling call. These vocalizations are particularly prominent during the breeding season.

The breeding season is marked by the males' lekking behavior, where they compete for the attention of females. After mating, the female takes sole responsibility for nesting and rearing the chicks, often in dense undergrowth for protection.

The black grouse can be confused with other grouse species, but its distinctive male plumage and lekking behavior are usually sufficient for identification.

Their diet shifts seasonally; in winter, they feed on conifer needles, while in spring and summer, they consume a variety of berries, shoots, and stems from shrubs like Vaccinium.

Globally, the black grouse is classified as Least Concern, with an estimated population of 15-40 million. However, it has experienced declines in western Europe due to habitat loss, predation, and other factors. Conservation efforts are underway in various regions to address these challenges.

2-8-2017 CENTRAL PARK, BUDAPEST - COMMON POCHARD (Aythya ferina)

The Common Pochard (Aythya ferina) is a medium-sized diving duck, belonging to the family Anatidae. It is a bird of robust build, with a sloping forehead and a relatively long bill. The male is distinguished by its chestnut head and neck, black breast and tail, and pale grey body with fine vermiculations. The female is more subdued in coloration, with a brownish body and a less vibrant head and neck.

Males can be identified by their striking chestnut head and neck, black breast, and pale grey body. They have a dark grey bill with a blue-grey band and yellow-orange to red irises, which intensify during the breeding season. Females and juveniles are less colorful, with brownish tones and grey legs and feet. The female's iris is brown, sometimes with a yellowish tinge, while juveniles have a yellow-olive iris that darkens with age.

The Common Pochard favors marshes and lakes with at least a meter of water depth for breeding. These habitats provide the necessary cover and food resources for the species.

This species has a widespread distribution across the Palearctic. It breeds mainly in the steppe regions of Scandinavia and Siberia and winters in the south and west of Europe. In the British Isles, it breeds in eastern England and lowland Scotland, with increasing numbers in Northern Ireland and sporadically in the Republic of Ireland.

Common Pochards are gregarious, forming large flocks in winter, often alongside other diving duck species. They are strong fliers, capable of reaching speeds of 49-54 mph in direct flight.

The male is generally silent but may emit a soft whistle during courtship. The female produces a soft growl when disturbed, and ducklings have a short contact call, which becomes higher and faster when they are distressed.

The female constructs a platform nest of plant material, lined with down, either on the ground near water or over water on a platform. Clutches typically consist of 8-10 greenish-grey eggs, with incubation beginning only after the entire clutch is laid. The species is known for high rates of conspecific brood parasitism.

The male Common Pochard can be confused with the male Canvasback, which has an all-dark bill, or the Redhead, which has a yellow iris and a greyer back.

Common Pochards feed on plant material, seeds, small fish, molluscs, and aquatic invertebrates, obtained by diving or dabbling. They often forage in association with Bewick's and Whooper Swans, benefiting from the swans' sediment-disturbing activities.

The Common Pochard is classified as Vulnerable by the IUCN. Despite its large range and population, there have been significant declines in several regions, attributed to habitat transformation, urbanization, overhunting, and introduced predators like the American mink. Conservation efforts are complicated by the diversity of languages spoken across its range.

2-8-2017 CENTRAL PARK, BUDAPEST - ATLAS MOTH (Attacus atlas)

Attacus atlas, the Atlas moth, is a large saturniid moth endemic to the forests of Asia. The species was described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

The Atlas moth is one of the largest lepidopterans, with a wingspan measuring up to 24 cm (9.4 in) and a wing surface area of about 160 cm2 (≈25 in2). It is only surpassed in wingspan by the white witch (Thysania agrippina) and Attacus caesar, and in wing surface area by the Hercules moth (Coscinocera hercules). As in most silk moths, females are noticeably larger and heavier than males, while males have broader antennae.

Atlas moths are named after Atlas, the Titan of Greek mythology (due to their size). In Hong Kong, the Cantonese means "snake's head moth", referring to the prominent extension of the forewing that resembles the head of a snake.

Their habitat is primarily dry tropical forests, secondary forests, and shrublands across South Asia, East Asia, and Southeast Asia, including Borneo.

In India, Atlas moths are cultivated for their silk in a non-commercial capacity. Unlike silk produced by the related domestic silkmoth (Bombyx mori), Atlas moth silk is secreted as broken strands and is therefore less desirable. This brown, wool-like silk, known as fagara, is thought to have greater durability. Atlas moth cocoons are sometimes used as small pocket change purses in Taiwan. There is ongoing research as to whether the silk of the Atlas moth can be used as a substitute for common silks. The quality of the heavier cocoons, less restrictive rearing conditions and competent properties of the fibers, makes the silk produced by the Atlas moth a potential alternative for common silks. A study concluded that the silk fibers of the atlas moth had about an 80% higher density of cells and growth compared to the silk fibers of the silk moth.

The Japanese subspecies A. a. ryukyuensis, native to Yonaguni in the Yaeyama Islands.

6-8-2017 RIVER DANUBE, PASSAU - COMMON RAVEN (Corvus corax)

The common raven (Corvus corax) is a large, all-black passerine bird, a member of the corvid family. It is one of the two largest corvids, alongside the thick-billed raven, and is possibly the heaviest passerine bird. The common raven is distinguished by its size, averaging 63 centimeters in length and 1.47 kilograms in mass at maturity. Its plumage is iridescent, displaying a blue or purple sheen in sunlight. The bird's bill is large and slightly curved, and its throat feathers are elongated and pointed. The common raven's lifespan in the wild can exceed 23 years, with a typical range of 10 to 15 years.

The common raven can be identified by its large size, heavy black beak, and shaggy throat feathers. Its tail is wedge-shaped, and in flight, it exhibits a more stable soaring style with less wing flapping compared to crows. The bird's call is a deep, resonant croak, distinct from other corvids.

Common ravens inhabit a variety of environments, from Arctic and temperate habitats to deserts and islands. They prefer contoured landscapes and are often found in mountainous or coastal regions, as well as in wooded areas with open land nearby.

The common raven has the most extensive range of any corvid, found across the Northern Hemisphere. It is resident throughout its range, which includes North America, Europe, Asia, and parts of North Africa.

Common ravens are known for their intelligence and problem-solving abilities. They travel in mated pairs or in flocks when young. These birds are territorial and demonstrate devotion to their families. They are also playful, engaging in aerial acrobatics and games with other species.

The common raven's vocalizations are varied and complex, including alarm calls, chase calls, and flight calls. Its distinctive call is a deep "prruk-prruk-prruk." Ravens can mimic sounds, including human speech, and produce non-vocal sounds such as wing whistles and bill snapping.

Common ravens mate for life and defend a territory where they build a large stick nest, usually in a tree or on a cliff ledge. Females lay 3 to 7 pale bluish-green eggs, and incubation lasts about 18 to 21 days. Both parents feed the young, which fledge at 35 to 42 days.

Ravens are omnivorous and opportunistic feeders. Their diet includes carrion, insects, grains, berries, fruit, small animals, and food waste. They are known to store surplus food and have been observed raiding the food caches of other species.

The common raven is listed as Least Concern by the IUCN. It has coexisted with humans for thousands of years and is revered in many cultures as a spiritual figure or godlike creature. However, in some regions, their numbers have increased to the point where they are considered pests.

6-8-2017 RIVER DANUBE, PASSAU - MUTE SWAN (Cygnus olor)

The mute swan (Cygnus olor) is a species of swan and a member of the waterfowl family Anatidae. It is native to much of Eurasia, and (as a rare winter visitor) the far north of Africa. It is an introduced species in North America, home to the largest populations outside of its native range, with additional smaller introductions in Australasia and southern Africa. The name "mute" derives from it being less vocal than other swan species.

Measuring 125 to 160 cm (49 to 63 in) in length, this large swan is wholly white in plumage with an orange beak bordered with black. It is recognisable by its pronounced knob atop the beak, which is larger in males.

The mute swan is found naturally mainly in temperate areas of Europe, then across the Palearctic as far east as Primorsky Krai, near Sidemi.