14-8-2017 AMSTERDAM ZOO, NETHERLANDS - BURROWING OWL (Athene cunicularia)

The Burrowing owl (Athene cunicularia) is a small, long-legged owl found throughout open landscapes of North and South America. Unlike most owls, these owls are often active during the day, but like many other kinds of owls, though, they do most of their hunting during dusk and dawn, when they can use their night vision and hearing to their advantage. Living in open grasslands as opposed to forests, the burrowing owl has developed longer legs that enable it to sprint, as well as fly, when hunting.

Burrowing owls have bright eyes and their beaks can be dark yellow or gray depending on the subspecies. They have prominent white eyebrows and a white "chin" patch which they expand and display during certain behaviors, such as a bobbing of the head when agitated. Adults have brown heads and wings with white spotting. The chest and abdomen are white with variable brown spotting or barring, also depending on the subspecies. Juvenile owls are similar in appearance, but they lack most of the white spotting above and brown barring below; their breast may be buff-colored rather than white.

Burrowing owls range from the southern portions of the western Canadian provinces through southern Mexico and western Central America. They are also found in Florida and many Caribbean islands. In South America, they are patchy in the northwest and through the Andes but widely distributed from southern Brazil to Patagonia and Tierra del Fuego. Burrowing owls are year-round residents in most of their range. Birds that breed in Canada and the northern U.S. usually migrate south to Mexico and the southern U.S. during winter months. These owls inhabit grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation.

Burrowing owls spend most of their time on the ground, and may breed in loose colonies. They nest and roost in burrows, such as those excavated by prairie dogs. Unlike most owls, Burrowing owls are often active during the day, although they tend to avoid the midday heat. However, most of their hunting is done from dusk until dawn, when they can use their night vision and hearing to their advantage. When hunting, Burrowing owls wait on a perch patiently until they spot prey. Then, they swoop down on prey or fly up to catch insects in flight. Sometimes, they walk, hop, or chase prey on foot across the ground. When not hunting Burrowing owls sleep at their burrow entrances or on depressions in the ground. The rest of the time is spent stretching, preening, and bathing in a puddle and the birds will also take a dust bath in a shallow depression in the dirt. Disturbed Burrowing owls bob jerkily up and down and can scream, cluck, and chatter when defending the nest. Their main call is a mellow 'coo-coooo' and a song 'co-hoo' that can usually be heard at night.

14-8-2017 AMSTERDAM, NETHERLANDS - 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.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - BLACK SWAN (Cygnus atratus)

The black swan (Cygnus atratus) is a striking large waterbird, native to the southeastern and southwestern regions of Australia. It is characterized by its predominantly black plumage and a distinctive red bill, with a pale bar and tip. The legs and feet are a greyish-black hue. Males, known as cobs, are marginally larger than females, or pens, and possess a longer, straighter bill. Juveniles, referred to as cygnets, display a greyish-brown coloration with pale-edged feathers.

Adult black swans range from 110 to 142 centimeters in length and weigh between 3.7 and 9 kilograms. Their wingspan stretches from 1.6 to 2 meters. Notably, they have the longest neck relative to body size among swans, which is typically curved into an elegant "S" shape.

Black swans inhabit a variety of wetland environments, including fresh, brackish, and saltwater lakes, as well as swamps and rivers with abundant underwater and emergent vegetation. They are also found in permanent wetlands and ornamental lakes, and may occasionally venture into flooded pastures, tidal mudflats, or the open sea near islands or the coast.

Within Australia, black swans are common in the wetlands of the southwest and east, and their range extends to adjacent coastal islands. They are nomadic birds, with migration patterns influenced by climatic conditions, such as rainfall or drought.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - GREAT WHITE PELICAN (Pelecanus onocrotalus)

The great white pelican, known scientifically as Pelecanus onocrotalus, is a gargantuan bird, surpassed in size only by its cousin, the Dalmatian pelican. With a body length ranging from 140 to 180 cm and a wingspan stretching from 226 to 360 cm, it is one of the largest flying birds. The pelican's bill is an impressive 28.9 to 47.1 cm long, colored in hues of pink and yellow, and is accompanied by a pale-yellow gular pouch. Males are generally larger than females and exhibit a pronounced sexual dimorphism, with males averaging more than 30% heavier than females.

Adult great white pelicans are predominantly white with black flight feathers and a faint pink tinge on the neck. The bill is bluish-grey with a red tip and a yellowish gular pouch. During the breeding season, males display pinkish facial skin, while females exhibit a more orangey hue. Juveniles are distinguishable by their darker, brownish underparts and patterned underwings.

These pelicans favor shallow, warm freshwater environments, such as lakes, swamps, and lagoons, often with dense reed beds nearby for nesting. They are also found in coastal estuarine areas and occasionally at elevations up to 1,372 m in East Africa and Nepal.

The great white pelican breeds from southeastern Europe through Asia to Africa. It is a migratory species with populations found from Eastern Europe to Kazakhstan during the breeding season. In Africa, it is resident south of the Sahara Desert.

The great white pelican is a highly sociable bird, often forming large flocks. It is an adept swimmer and an elegant flier, known for its soaring flight with occasional slow wingbeats followed by glides. These birds are cooperative feeders, often foraging in groups.

This species is mostly silent but can emit a variety of low-pitched calls, including a deep, quiet croak in flight and deep "moooo" calls at breeding colonies.

Breeding occurs in large colonies with nests varying from stick nests in trees to ground scrapes lined with grass and other materials. The female lays 1 to 4 eggs, with incubation lasting 29 to 36 days. Chicks fledge at 65 to 75 days of age, with sexual maturity reached at 3 to 4 years.

The great white pelican can be confused with the Dalmatian pelican, which has greyish-white plumage and a fully feathered face. The spot-billed and pink-backed pelicans are smaller and have different plumage and bill colors.

Their diet consists mainly of fish, with daily requirements ranging from 0.9 to 1.4 kg. They feed cooperatively, using their pouches to scoop up water and fish, then contracting the pouch to drain the water and retain the fish. They may also opportunistically consume other birds' chicks and, in some cases, have been observed eating pigeons.

The great white pelican is listed as Least Concern on the IUCN Red List. It is protected under various international agreements and occurs within numerous Important Bird Areas and Special Protection Areas. However, it faces threats from overfishing, habitat loss, and human disturbance.

14-8-2017 AMSTERDAM, NETHERLANDS - GREY HERON (Ardea cinerea)

The Grey Heron (Ardea cinerea) is a statuesque wading bird belonging to the family Ardeidae. It is a familiar sight in both rural and urban settings, often seen standing stoically along the water's edge. An adult Grey Heron is a large bird, reaching up to 100 cm in height, with a wingspan between 155 to 195 cm. It weighs between 1 to 2 kg. The plumage is predominantly ashy-grey above, with a greyish-white underbelly and some black on the flanks. A striking feature is the white head and neck adorned with a broad black stripe that extends from the eye to the black crest. The beak is pinkish-yellow, long, and sharply pointed, while the legs are a brown hue.

When identifying the Grey Heron, look for the white head with the black supercilium and crest, the long grey neck, and the ashy-grey wings and back. The underparts are lighter, and the legs are long and brown. Juveniles can be distinguished by their duller grey neck and smaller crest. The beak is a useful indicator of age, being brighter in breeding adults.

Grey Herons are highly adaptable and can be found in a variety of watery habitats including lakes, rivers, ponds, marshes, and coastal environments. They require shallow waters for foraging or areas with shelving margins where they can wade.

Native to temperate Europe and Asia, as well as parts of Africa, the Grey Heron has a broad range. Northern populations may migrate southwards in autumn, while others remain resident year-round. Vagrant sightings have occurred in the Caribbean, Bermuda, and parts of North America.

The Grey Heron exhibits a slow, deliberate flight with its neck retracted in an S-shape. It is known for its solitary foraging habits, often standing motionless or stalking prey through shallow waters. It is also a communal rooster, often found in trees or cliffs at night.

The primary call of the Grey Heron is a loud croaking "fraaank." At breeding colonies, a variety of guttural and raucous noises can be heard, including greeting calls between mates and alarm calls when predators are nearby.

Breeding takes place in colonies, or heronries, typically in high trees near water. Nests are reused and added to each year. The breeding season sees a clutch of three to five bluish-green eggs laid, which both parents incubate. Chicks fledge at 7-8 weeks old.

The Grey Heron can be confused with the larger North American Great Blue Heron or the South American Cocoi Heron. However, it can be distinguished by its size and the coloration of its flanks and thighs.

Grey Herons are apex predators within their ecosystem, feeding on a variety of aquatic creatures such as fish, amphibians, crustaceans, and insects. They have also been known to consume small mammals and juvenile birds.

The Grey Heron is classified as Least Concern by the IUCN, indicating a stable and widespread population.

14-8-2017 AMSTERDAM, NETHERLANDS - 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.

14-8-2017 AMSTERDAM, NETHERLANDS - MALLARD HYBRID (MALE) (Anas platyrhynchos)

14-8-2017 AMSTERDAM, NETHERLANDS - NORTHERN LAPWING (JUVENILE) (Vanellus vanellus)

The Northern Lapwing, known scientifically as Vanellus vanellus, is a distinctive bird with a notable crest on its head. It measures 28–33 cm in length, with a wingspan of 67–87 cm and a body mass ranging from 128–330 g. The species exhibits sexual dimorphism; males have a pronounced crest and a stark black crown, throat, and breast, which contrasts sharply with their white face. Females and juveniles have shorter crests and less defined head markings, but their overall plumage is similar to that of the males, with a black and white coloration and a greenish tint on the back.

When identifying the Northern Lapwing, look for its rounded wings, short legs, and the characteristic crest that adorns its head. The male's long crest and contrasting black and white facial patterns are particularly striking during the breeding season. In flight, the species can be recognized by its slow wingbeats and the rounded shape of its wings.

The Northern Lapwing is a ground-nesting bird that favors open landscapes such as cultivated fields, grasslands, and wetlands. It is adaptable and can be found in a variety of temperate environments across Eurosiberia.

This bird is a widespread resident throughout temperate regions of Eurosiberia. It is highly migratory, wintering in regions as far south as North Africa and parts of Asia. Western European populations are more sedentary, while vagrants have been known to appear in North America following storms.

The Northern Lapwing is known for its acrobatic display flights, accompanied by a cacophony of calls during the breeding season. It migrates predominantly during the day, often in large flocks. The species is fiercely protective of its nest and young, boldly confronting any potential threats. In winter, it gathers in massive flocks on open land, and it is known to feed nocturnally when the moon is bright.

The Northern Lapwing is quite vocal, especially in the breeding season. Its contact call is a loud "pee-wit," which is also the origin of one of its common names. Males perform a display flight while emitting a wheezy "pee-wit, wit wit, eeze wit," and they may also produce squeaking or mewing sounds.

Breeding takes place on the ground in a simple scrape. The species typically lays 3–4 eggs, which are zealously defended against all intruders. The Northern Lapwing's breeding strategy includes feigning injury to distract predators from its nest.

Its diet consists primarily of insects and other small invertebrates. The Northern Lapwing often feeds in mixed flocks with Golden Plovers and Black-headed Gulls, the latter of which may steal food but also offer some protection against predators.

The Northern Lapwing is currently classified as Near Threatened on the IUCN Red List. Its populations have declined due to intensive agricultural practices, habitat loss, and predation. Conservation efforts include habitat restoration and management to support this species' recovery.

14-8-2017 AMSTERDAM, NETHERLANDS - 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.

14-8-2017 AMSTERDAM, NETHERLANDS - MUTE SWAN (JUVENILE) (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.

14-8-2017 AMSTERDAM, NETHERLANDS - GREAT TIT (Parus major)

The Great tit (Parus major) is a widespread and common songbird throughout Europe, the Middle East, Central Asia, and east across the Palearctic to the Amur River, south to parts of North Africa. It has adapted well to human changes in the environment and is a common and familiar bird in urban parks and gardens. It is also an important study species in ornithology.

The Great tit has a distinctive appearance that makes it easy to recognize. The nominate race has a bluish-black crown, black neck, throat, bib, and head, and white cheeks and ear coverts. The breast is bright lemon-yellow and there is a broad black mid-line stripe running from the bib to the vent. There is a dull white spot on the neck turning to greenish yellow on the upper nape. The rest of the nape and back are green-tinged with olive. The wing-coverts are green, and the rest of the wing is bluish-grey with a white wing bar. The tail is bluish-grey with white outer tips. The plumage of the female is similar to that of the male except that the colors are overall duller.

14-8-2017 AMSTERDAM, NETHERLANDS - BLACK CROWNED NIGHT HERON (Nycticorax nycticorax)

The Black-crowned Night Heron, scientifically known as Nycticorax nycticorax, is a medium-sized heron with a global presence, spanning parts of Europe, Asia, and the Americas. It is distinguished by its black crown and back, contrasting with a white or grey body, red eyes, and short yellow legs. Notably, it deviates from the typical heron silhouette, appearing more robust with shorter bills, legs, and necks compared to its egret and day heron relatives.

Adults boast a striking black crown and back, with the rest of their plumage primarily white or grey. Their eyes are a vivid red, and they stand on short yellow legs. During social interactions, such as greeting or courtship, they display two or three elongated white plumes that extend from the back of their heads. Males and females are similar in appearance, though males may be marginally larger. Juveniles, on the other hand, are cloaked in a dull grey-brown with pale spots and streaks, and their eyes are a more subdued orange with less vibrant legs.

These herons favor fresh and salt-water wetlands as their breeding grounds, which are found across their vast range.

The Black-crowned Night Heron breeds across various regions: from Eurasia to Africa, the Indonesian Archipelago, North and South America, and even the remote Falkland Islands. While migratory in the northern extremes, it is generally a resident species, with North American populations wintering in warmer climes from Mexico to the West Indies.

Known for their ambush hunting tactics, these herons stand motionless at the water's edge, striking at prey primarily during the night or early morning. They exhibit a diverse diet, consuming fish, amphibians, insects, and more. They are also one of the few heron species to use tools, such as bait, to fish. By day, they rest in trees or shrubbery, and outside of breeding season, some subspecies display more sociable tendencies.

 

The Black-crowned Night Heron is a vocal species within its colonies, often heard making a "quok" or "woc" sound.

Colonial nesters, they construct platforms of sticks in trees or on the ground in protected areas. Clutch sizes range from three to eight eggs.

 

Their diet is varied, including small fish, crustaceans, insects, small mammals, and even refuse. They have been observed using bait to attract fish, a rare behavior for birds.

The IUCN lists the Black-crowned Night Heron as Least Concern, indicating a stable population across its extensive range.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - BURROWING OWL (Athene cunicularia)

Burrowing owls are monogamous; pairs may stay together for one breeding season or mate for life. Occasionally males may be polygynous and have two mates. The breeding season begins in late March or April in North America. Burrowing owls sometimes nest in loose colonies in open grassland or prairie, but may occasionally adapt to other open areas like airports, golf courses, and agricultural fields. They also often nest near roads, farms, homes, and regularly maintained irrigation canals. The nest is located in a burrow; if burrows are unavailable and the soil is not hard or rocky, the owls may excavate their own. The female will lay a clutch, which can consist of 4 to 12 eggs (usually 9). She will then incubate the eggs for 3 to 4 weeks while the male brings her food. After the eggs hatch, both parents will feed the young. Four weeks after hatching, the owlets can make short flights and begin leaving the nest burrow. The parents will still help feed their young for 1 to 3 months until they are ready to hunt their own meals.

Burrowing owls are common and widespread in open regions of many countries in Central and South America. However, these birds are endangered in Canada and threatened in Mexico. They are a state-threatened species in Colorado and Florida. The major reasons for declining populations in North America are control programs for prairie dogs and loss of habitat. Other important threats include collisions with vehicles when crossing roads, the use of pesticides, shooting, and predation by feral and domestic cats, dogs, coyotes, and snakes.

According to the All About Birds resource the total breeding population size of the Burrowing owl is around 2 million individuals. According to the Defenders of Wildlife resource, the total population size of the species is less than 10,000 breeding pairs. Overall, currently Burrowing owls are classified as Least Concern (LC) on the IUCN Red List but their numbers today are decreasing.

Burrowing owls control populations of small mammals and insects that they consume in their diet. In turn, these little owls also serve as food items for some local predators.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - INCA TERN (MALE) (Larosterna inca)

The Inca tern is one of the world’s most beautiful and interesting birds. It occurs along the Pacific Coast from northern Peru to central Chile. This bird is easily recognizable with its dark gray body, and red-orange beak and claws, and its lovely white moustache. It is an adept flier that swoops and hovers before it dives after its prey. It sometimes plucks pieces of fish out from between sea lions’ teeth. Unfortunately, their populations are declining quickly because of the loss of nesting sites. They have been included in the “close to vanishing species” category. Inca terns in the wild live up to 14 years and in captivity up to 20 years.

The Inca tern is a large tern, approximately 40 cm (16 in) long. Sexes are similar; the adult is mostly slate-grey with white restricted to the facial plumes and the trailing edges of the wings. The large bill and legs are dark red. Immature birds are purple-brown, and gradually develop the facial plumes.

The Inca tern is a diurnal, gregarious species, living and nesting in large colonies numbering several thousand birds, often close to gull colonies. Inca terns follow fishing boats and often associate with whales and sea lions when feeding, stealing food from these fellow marine mammals. Inca terns feed by plunge-diving from a height, after a brief flight above their prey, or by surface-dipping, whereby they swim or sit on the water and pick up prey from the surface. They are not strong swimmers, as their webbed feet are not big enough. Inca terns remain resident within their range, though non-breeding birds sometimes move, depending on food resources.

Inca terns are monogamous, pairs often returning to the same nesting site year on year. Courtship consists of an elaborate ritual, particularly for birds seeking their mate for the very first time. Males perform an agile flight display to impress their chosen female. They also perform courtship feeding while following the female while flying, with a fish in their bill. This species breeds twice a year, firstly between April and July, secondly between October and December. Nests are on guano islands or sandy beaches and they choose deep rock crevices where there are many cavities and cliffs that offer good protection. Chicks hatching in deep holes are given protection for longer from predators, whereas nests that are further from cliffs are more accessible to raptors and large seabirds. 1-3 eggs are laid and incubation lasts for about 3-4 weeks. The parents both incubate and feed the chicks. The young are grayish in color and fledge at about 4 weeks old. They reach their independence one month later and will be ready to breed at age 2 or 3.

Inca tern numbers are affected by food resources, as well as El Niño and other strong storms. Populations decline during such severe storms, though they fairly quickly become stable again. The biggest threat currently is over-fishing, as this reduces the fish available for the terns to eat. Production of guano can also reduce the number of nesting sites available, and cats and rats may eat eggs and chicks.

According to the IUCN Red List, the total Inca tern population size is more than 150,000 individuals. Currently this species is classified as Near Threatened (NT) and their numbers today are decreasing.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - INCA TERN (JUVENILE) (Larosterna inca)

The Inca tern, Larosterna inca, is a bird of striking appearance, cloaked in a dark slate gray plumage with a paler throat and underwing coverts. A distinctive white mustache-like stripe extends from the base of its bill, fanning out into elegant, satiny feathers along the neck. The trailing edge of their wings and the edges of the outer primaries are touched with white. Their tails are black and moderately forked, adding to their graceful silhouette. Adults boast a brown iris, dark red legs and feet, and a dark red bill with a patch of bare yellow skin at its base. Juveniles initially display a purplish brown hue, transitioning through brownish gray as they mature, with their bill and legs evolving from a dark horn color to the red of adulthood.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - INCA TERN (FEMALE) (Larosterna inca)

The Inca tern, Larosterna inca, is a bird of striking appearance, cloaked in a dark slate gray plumage with a paler throat and underwing coverts. A distinctive white mustache-like stripe extends from the base of its bill, fanning out into elegant, satiny feathers along the neck. The trailing edge of their wings and the edges of the outer primaries are touched with white. Their tails are black and moderately forked, adding to their graceful silhouette. Adults boast a brown iris, dark red legs and feet, and a dark red bill with a patch of bare yellow skin at its base. Juveniles initially display a purplish brown hue, transitioning through brownish gray as they mature, with their bill and legs evolving from a dark horn color to the red of adulthood.

To identify the Inca tern, look for the unique white mustache and the overall dark gray body. The contrast of the white trailing edge on the wing and the red bill with yellow at the base are also key features. The moderately forked tail and the dark red legs and feet are additional characteristics to observe.

The Inca tern is a coastal bird, favoring the rich marine environment of the Humboldt Current. It breeds on sea cliffs and guano islands, as well as utilizing man-made structures such as under piers and abandoned barges for nesting. It is also known to congregate with other seabirds on sandy beaches.

This tern breeds from Lobos de Tierra in northern Peru to the Aconcagua River near Valparaíso, Chile. Post-breeding dispersal can lead some individuals north into Ecuador. It is a casual visitor to Panama and Costa Rica and has been recorded as a vagrant in Guatemala and Hawaii.

The Inca tern is largely sedentary, with some dispersion to the north after the breeding season. It has been known to wander great distances, as evidenced by sightings in Central America and Hawaii.

At nesting colonies, the Inca tern is quite vocal, producing a variety of sounds including "raucous cackling notes" and "mewing" calls, the latter of which is reminiscent of a kitten's cry.

Breeding for the Inca tern is not confined to a specific season, with evidence of breeding activities and eggs found at various times throughout the year. Nesting sites are diverse, ranging from rock fissures to abandoned burrows of other seabirds, and even on human structures. Clutches typically contain two eggs, with both parents sharing incubation duties and care for the young. Fledging occurs around four weeks post-hatching, with juveniles remaining dependent on their parents for an additional month.

The Inca tern's diet consists mainly of small fish like anchoveta, supplemented by planktonic crustaceans and offal. They often form large flocks, sometimes numbering in the thousands, to attend fishing boats or to follow feeding marine mammals. They primarily catch prey through plunge-diving but will also pick food items from the surface while in flight or on the water.

The IUCN has classified the Inca tern as Near Threatened. The species faces threats from human fishing activities, climate change, and reduced reproductive success during El Niño events. Although the exact population size is unknown, it is believed to be in decline, with an estimate of around 150,000 individuals in 2011.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - SMEW (Mergellus albellus)

Generally uncommon and fairly local small diving duck. Frequents lakes, reservoirs, and rivers. Shy, often found alone or in small groups; frequently kept in European waterfowl collections. Both sexes have bushy crest. Striking male mostly white with black face mask and fine black lines on sides of breast and flanks. Female has dark rusty brown head with big white throat and cheek patch. In flight appears strikingly black-and-white.

The Smew is a compact diving duck with a delicate bill. The male is white with a black mask and a black back, the female is grey with a reddish-brown head and white cheek. In flight, it shows black and white wings. It's a winter visitor in small numbers from Scandinavia and Russia. Sometimes birds move here from Holland and Denmark to escape freezing weather. Little is known about this bird on its breeding grounds. 

30-7-2017 CENTRAL PARK, BUDAPEST - MEXICAN BLUEWING BUTTERFLY (Myscelia ethusa)

Myscelia ethusa, the Mexican bluewing or blue wing, is a butterfly of the family Nymphalidae. The species was first described by Louis Michel François Doyère in 1840. It is found from Colombia north through Central America to Mexico. Strays can be found up to the lower Rio Grande Valley of Texas in the United States.

The wingspan is 64–76 mm (2.5–3.0 in). Many generations occur per year.

The larvae feed on the Dalechampia species. Adults feed on rotting fruit.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - EUROPEAN COMMA BUTTERFLY (Polygonia c-album)

Polygonia c-album, or the “comma”, is a food generalist (polyphagous) butterfly species belonging to the family Nymphalidae. The angular notches on the edges of the forewings are characteristic of the genus Polygonia, which is why species in the genus are commonly referred to as anglewing butterflies. Comma butterflies can be identified by their prominent orange and dark brown/black dorsal wings.

Both the larval and adult stages exhibit protective camouflage, mimicking bird droppings and fallen leaves respectively, which reduces predation. The pupae are also cryptic, resembling shriveled leaves. During the later stage of development, the larvae also develop strong spines along their backs. The species is commonly found in Europe, North Africa, and Asia, and contains several subspecies. Although the species is not migratory, the butterflies are strong fliers, resulting in an open population structure with high gene flow and increased genetic variation.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - MOON SATYR BUTTERFLY (PIERELLA LUNA)

Pierella luna, the moon satyr, is a species of butterfly of the family Nymphalidae. It is found in Mexico, Costa Rica, Colombia, Panama, Nicaragua, Ecuador, Belize, Brazil, Guatemala and Honduras.

Subspecies

Pierella luna luna (nominate)

Pierella luna lesbia Staudinger, 1887

Pierella luna pallida (Salvin & Godman, 1868)

Pierella luna rubecula Salvin & Godman, 1868

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - BAR HEADED GOOSE (Anser indicus)

The bar-headed goose, Anser indicus, is a remarkable species known for its striking appearance and incredible high-altitude flights. This pale grey goose is distinguished by two distinctive black bars on its head, setting it apart from other members of the Anser genus. It is a mid-sized bird, measuring between 71 to 76 cm in length and weighing between 1.87 to 3.2 kg.

When identifying the bar-headed goose, look for the unique black bars on the head, which are the key distinguishing feature. The bird's overall pale grey plumage contrasts with these markings. In flight, its honking call is characteristic of geese, aiding in identification from a distance.

During the summer, the bar-headed goose can be found around high-altitude lakes where it grazes on short grass. These areas provide the ideal setting for breeding and feeding.

The bar-headed goose breeds in Central Asia, including regions such as Tibet, Kazakhstan, Mongolia, and Russia. It is known for its winter migration to South Asia, reaching as far south as peninsular India.

This species is renowned for its migratory patterns, particularly for the extreme altitudes it reaches when crossing the Himalayas. The bar-headed goose has been recorded at elevations over 7,000 meters, showcasing remarkable physiological adaptations to hypoxic conditions.

The bar-headed goose emits a typical goose honking sound, especially noticeable during flight, which can be used as an auditory clue for identification.

Breeding occurs in colonies of thousands near mountain lakes, where the bar-headed goose lays three to eight eggs in a ground nest. The Tibetan Plateau serves as the primary breeding ground for this species.

In its winter habitat, the bar-headed goose feeds on cultivated fields, consuming crops such as barley, rice, and wheat. This can sometimes lead to crop damage.

The IUCN lists the bar-headed goose as Least Concern. While the total population may be increasing, assessing trends is complex due to the species' extensive range.

The bar-headed goose is a testament to the wonders of avian adaptation, thriving in environments that would be inhospitable to many other species. Its presence in the skies above the Himalayas is a marvel to behold, a true high-flyer in every sense.

30-7-2017 CENTRAL PARK, BUDAPEST - HELICONIUS LONGWING BUTTERFLY (Heliconius hewitsoni)

Hewitson’s Longwing occurs on the Pacific Slope of western Panama and Costa Rica. The wings are black with two white forewing stripes and one white hindwing stripe. The underside is similar, but with small red patches close to the body. Adults have a fast flight, and can be found in forests, usually within the canopy. Females gather in groups to lay eggs together.

The caterpillars are yellow and green, and feed on passion vine (Passifloraceae). They pupate in groups in pale yellow to pale brown chrysalids covered in black veins and spines.