14-8-2017 AMSTERDAM ZOO, NETHERLANDS - MENELAUS BLUE MORPHO BUTTERFLY (Morpho menelaus)

The Menelaus blue morpho (Morpho menelaus) is one of thirty species of butterfly in the subfamily Morphinae. Its wingspan is approximately 12 cm (4.7"), and its dorsal forewings and hindwings are a bright, iridescent blue edged with black, while the ventral surfaces are brown. Its iridescent wings are an area of interest in research because of their unique microstructure. Due to its characteristic blue color, Morpho menelaus is considered valuable among collectors and was widely hunted in the 20th century.

This neotropical butterfly is found in Central and South America, including the Cerrado which is a vast tropical savanna in Brazil. Other locations include Mexico and Venezuela. Ancestors of the Morpho menelaus butterfly may have been distributed in the Andean regions. Morpho menelaus is one of the six species of Morpho in Costa Rica. The genus of Morpho is present in regions beginning in Mexico and throughout South America, except Chile. Moreover, the Morpho menelaus struggle to survive in the northern Pacific area of Costa Rica since they can’t tolerate such dry conditions. They also need habitats in old growth forests with proper differentiation between the understories and canopies (Murillo-Hiller & Canet, 2018).

There is great variation among the various species of Morpho. Two groups of Morpho butterflies, achilles and hecuba, are distinct in flight behavior and vertical forest distribution. This habitat stratification between the two forest levels may have led to the diversification of the Morpho butterflies. Flight pattern behavior may also have led to changes in the wing shape to make it more suitable for gliding or flapping. Phylogenetic studies suggest these are indicative of ancestral qualities.

Females inhabit the forest understory and perch on tree stumps, but are found near the tree tops when it is time to lay eggs. Both sexes have a slow and floppy flight pattern and feed on rotting fruit that has dropped to the ground. Males tend to fly in open clearings or high in the canopy. These butterflies collectively emerge in the beginning and the end of the wet season in Cerrado. They do not appear in the middle of the wet season because the heavy rain can cause physical harm to their wings. Their emergence depends on the availability of food which is dependent on climate. For protection from the rain, Morpho menelaus prefers small and enclosed spaces.

The egg of the Morpho menelaus butterfly is typically small, round, and somewhat flattened. They are usually pale green or whitish in color, sometimes with a slightly metallic sheen, but not as vibrant as the adult butterfly's iridescent blue wings, and shaped like dew drops. The female laid around 12 eggs in cluster of 5 or 6 eggs on the undersides of the leaves. The eggs are laid so that the caterpillars may feed as soon as they hatch.

These social caterpillars feed on Erythroxylum, Dalbergia, and Fabaceae, and may prefer to feed on new leaves of host plants since these new leaves are easier and more nutritious to eat. The caterpillars are red-brown in color with bright green spots. They are covered with bristles that release an irritant upon contact. Conversely, the peak of the caterpillar is in the dry season, a climate that is unsuitable for most animal communities. These caterpillars will enter diapause or suspend development and can delay pupation in order to survive this harsh period and the lack of water. As the dry season continues, the caterpillar population declines due to predation.

One of the best seasonal predictors of adult butterfly occurrence is the ripening of zoochorous fruit. Adult emergence occurs primarily in the beginning of the wet season, when the climate and air humidity makes food resources plentiful and oviposition advantageous. The butterfly spends 3 to 4 weeks as an adult, and the entire life cycle is about 115 days. Adults fly along rivers, or anywhere that open land has been revealed.

Eyespots on wings are visual anti-predatory adaptations that have evolved in many species within Lepidoptera. The eyespots are usually dark circles surrounded by a brighter outer layer. The 'pupil' of the eye has a sparkle that mimics the natural reflection of the cornea. These eyes are thought to deflect a predator's attack away from more vital organs and toward that spot on the wings. Bigger eyespots have also been shown to deter predators from attacking completely. Menelaus specifically has an eyespot that is 6.8 mm in diameter on its ventral wings that it uses to help avoid predation.

The wings of Morpho menelaus are a prime example of iridescent blue coloration in the insect world. The bright and iridescent colors of other butterflies are typically caused by optical interference, but the iridescent blue color of butterflies in the family Morphidae results from the microstructures of the wings. Scientists use SEM, scanning electronic microscope, and spectroscopy, to understand the wings in greater detail.

Each wing is covered in multi-layered scales, which are responsible for the coloration of the wings. The wing colors vary with viewing angle, a phenomenon referred to as structural color. In the female, the dorsal side is more camouflaged while the male presents with a vibrant blue. In the male, the outer layer of the cover scales are long and narrow (250 μm × 50 μm), 2 μm apart, and parallel to the wing plane. The dimensions of the cover scales in other species of the subfamily Morphinae vary greatly, but all are pigment-less and lowly iridescent. The inner layer, called ground scales, are pigmented, iridescent, do not overlap, and are responsible for the blue coloration. They consist of alternating layers of chitin and air, each having its own refractive indexes. The wings of the genus Morpho are noteworthy for their diversity of function, including being hydrophobic, lightweight, sturdy, thermally regulated, and bright blue iridescent. These unique characteristics originate from the photonic nanostructures in the ridges of the scales. There has been increasing interest in the bioengineering community into understanding the structural components of the wing which can have potential applications in creating structural-color devices and selective gas-sensors.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - DOT DASH SERGEANT BUTTERFLY (Athyma kanwa)

Athyma kanwa, the dot-dash sergeant, is a species of brush-footed butterfly found in tropical and subtropical Asia and Cambodia.

The Dot-Dash Sergeant is dark brown to black with an interrupted, white, macular and curved fascia running from mid-costa on the forewing to near the base of the dorsum on the hindwing. On the forewing, the white post-discal spot in space 2 is roughly oval and well separated from the spot in space 1b. Usually there is no post-discal spot in space 3. The forewing cell-streak is entire and separated from the triangular spot beyond. There are submarginal lines of white markings irrorated with dark scales on both wings, that on the hindwing taking the form of a broad band running from the apex to dorsum. The underside is greyish brown with markings as on the upperside.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - 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.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - INDIAN BLUE PEAFOWL (JUVENILE) (Pavo cristatus)

The Indian peafowl, also known as the common peafowl or blue peafowl, is a species native to the Indian subcontinent. It is a bird of resplendent beauty, with the male, or peacock, showcasing a spectacular array of iridescent colors. The peacock's most striking feature is its fan-like crest of spatula-tipped wire-like feathers and the long train made up of elongated upper-tail covert feathers adorned with colorful eyespots. These feathers can be raised into a fan and quivered during courtship displays. Despite their size, peacocks are capable of flight. The female, or peahen, is more subdued in coloration, with a white face, iridescent green lower neck, and overall dull brown plumage.

The Indian peafowl is unmistakable within its range. The male has a metallic blue crown, a fan-shaped crest, and a spectacular train with eye-spot markings. The peahen is smaller, with a rufous-brown head, mottled upper body, and dark brown lower parts. The loud "pia-ow" or "may-awe" calls are distinctive and often indicate the presence of predators.

Indian peafowl are ground-dwelling birds that prefer open forest or land under cultivation. They are adaptable and can be found near water sources in both moist and dry-deciduous forests.

Native to the Indian subcontinent, the Indian peafowl has been introduced to many other countries. It thrives mainly below elevations of 1,800 meters, occasionally being spotted up to 2,000 meters.

Peafowl are known for their social behavior, foraging on the ground in small groups. They are adept at escaping predators by running and prefer to roost in tall trees at night. The peacock's elaborate train is used in courtship displays, although the exact mechanisms of sexual selection are still debated.

The Indian peafowl is vocal, with a variety of calls. The most common are loud "pia-ow" or "may-awe," which increase in frequency before the monsoon season. They also emit rapid "ka-aan" or "kok-kok" calls and a low-pitched "honk" when agitated.

Peafowl are polygamous, with the breeding season varying by region but often linked to the rains. The peahen incubates a clutch of 4-8 eggs, with chicks that are nidifugous, following the mother shortly after hatching.

The Indian peafowl is similar to the green peafowl but can be distinguished by its size, color, and the shape of the crest.

Omnivorous, Indian peafowl consume a variety of foods including berries, grains, and small prey like snakes, lizards, and rodents. They forage on the ground and can adapt to a wide range of crops and food scraps around human habitations.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - INDIAN BLUE PEAFOWL (FEMALE) (Pavo cristatus)

The Indian peafowl (Pavo cristatus) is a brightly-colored bird that lives mainly on the ground. Its loud calls make it easy to detect, and in forest areas often indicates the presence of a predator such as a tiger. The bird is celebrated in Hindu and Greek mythology and is the national bird of India.

The male Indian peafowl (peacock) is brightly colored, with a predominantly blue fan-like crest of spatula-tipped wire-like feathers, and is best known for the long train (tail) made up of elongated upper-tail covert feathers which bear colorful eyespots. These stiff feathers are raised into a fan and quivered in a display during courtship. Despite the length and size of these covert feathers, peacocks are still capable of flight. Females (peahens) lack the train and have a greenish lower neck and duller brown plumage. Downy chicks are pale buff with a dark brown mark on the nape that connects with the eyes. Young males look like the females but their wings are chestnut colored.

Indian peafowl are resident breeders across the Indian subcontinent and inhabit the drier lowland areas of Sri Lanka. They are found in moist and dry-deciduous forests near water, in montane forests, and can also adapt to live in cultivated regions and around human habitations.

Indian peafowl live mainly on the ground where they forage in small groups that usually have a cock and 3 to 5 hens. After the breeding season, the groups tend to be made up only of females and young. They are found in the open early in the morning and tend to stay in cover during the heat of the day. Indian peafowl often dust-bathe and at dusk and groups walk in single file to a favorite waterhole to drink. When disturbed, they usually escape by running and rarely take to flight. During the night, peafowl roost in groups on tall trees but may sometimes make use of rocks, buildings, or pylons. Birds arrive at dusk and call frequently before taking their position on the roost trees. Indian peafowl produces loud calls, especially in the breeding season. They may call at night when alarmed and neighboring birds may call in a relay-like series. The most common calls are a loud 'pia-ow' or 'may-awe'. They also make many other calls such as a rapid series of 'ka-aan..ka-aan' or a rapid 'kok-kok'. They often emit an explosive low-pitched honk! when agitated.

Indian peafowl are polygynous (one male to several females), and their breeding season usually depends on the rain. The peak season in southern India is April to May, January to March in Sri Lanka, and June in northern India. During this time several males may congregate at a lek site and these males are often closely related. Males at lek appear to maintain small territories next to each other and they allow females to visit them and make no attempt to guard harems. Females do not appear to favor specific males. The males display in courtship by raising the upper-tail coverts into an arched fan. The wings are held half open and drooped and it periodically vibrates the long feathers producing a ruffling sound. The cock faces the hen initially and struts and prances around and sometimes turns around to display the tail. Males may also freeze over food to invite a female in a form of courtship feeding. Males may display even in the absence of females. When a male is displaying, females do not appear to show any interest and usually continue their foraging. Indian peafowl nest on the ground; it is a shallow scrape lined with leaves, sticks, and other debris. The clutch consists of 4-8 fawn-to-buff white eggs which are incubated only by the female for about 28 days. The chicks are precocial (fully developed) and follow the mother around soon after hatching. Downy young may sometimes climb on their mother's back and she may carry them in flight to a safe tree branch. The chicks can fly about one week after hatching and become self-sufficient in 8 weeks. They usually reach reproductive maturity at the age of 2 to 3 years old.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - AFRICAN PENGUIN (Spheniscus demersus)

The African penguin, known scientifically as Spheniscus demersus and colloquially as the Cape penguin or South African penguin, is a flightless bird distinguished by its streamlined body and flippers adapted for life in the water. Adults typically weigh between 2.2 and 3.5 kilograms and stand 60 to 70 centimeters tall. Notable for the pink patches of skin above their eyes and a stark black facial mask, their upper parts are a contrasting black against the white underparts, which are adorned with spots and a distinctive black band.

To identify the African penguin, look for the unique pink gland above their eyes, which becomes more vibrant as they regulate their temperature. Their black and white plumage is a classic example of countershading, providing camouflage from predators. Each penguin has a unique pattern of black spots on the chest, akin to human fingerprints. Males are generally larger with longer beaks than females.

These penguins are found along the coastlines of southern Africa, with colonies established on various islands and some mainland sites. They prefer nesting in burrows or under vegetation to protect against predators and the hot sun.

The African penguin is endemic to the southwestern coast of Africa, breeding on 24 islands between Namibia and Algoa Bay, South Africa. Notably, they have also established colonies on the mainland near Cape Town.

African penguins are monogamous and known for their loud, donkey-like calls. They are pursuit divers, hunting for fish and squid, and can travel up to 20 kilometers from shore. They are social birds, breeding in colonies and often forming crèches for their young.

The African penguin's vocalizations are varied and serve multiple functions, from mate recognition to territorial defense. Their most famous call is a loud braying, which has earned them the nickname "jackass penguin."

Breeding occurs throughout the year, with peaks varying by location. Nests are made in burrows or under cover to protect from the heat. Two eggs are laid, and both parents share incubation duties. Chicks join crèches after about a month, and parents continue to forage at sea to feed them.

The African penguin is similar in appearance to the Humboldt, Magellanic, and Galápagos penguins, with which it shares the genus Spheniscus. However, it can be distinguished by its unique chest markings and the single black band across the chest.

Their diet consists mainly of pelagic fish like sardines and anchovies, as well as squid and small crustaceans. They are known to consume up to 540 grams of prey daily, which can increase when feeding older chicks.

The African penguin is classified as Endangered, with a rapid decline in population due to several threats, including oil spills, historical exploitation for their eggs, competition with fisheries, and habitat degradation. Conservation efforts are underway, including habitat protection, pollution mitigation, and captive breeding programs.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - NICOBAR PIGEON (Caloenas nicobarica)

The Nicobar pigeon, a large and resplendent bird, measures 40 cm in length. Its plumage is a tapestry of metallic green, with a head of soft grey transitioning to vibrant green and copper hackles. The tail, in stark contrast, is a pure white and notably short.

Males are distinguished by their slightly larger size and more pronounced bill knob. Females, on the other hand, exhibit a smaller knob, shorter hackles, and a tendency towards browner underparts. Juveniles can be identified by their black tails and a near absence of iridescence. Across its range, the species shows little variation, with the exception of the Palau subspecies, which sports marginally shorter neck hackles.

This species thrives in dense forests on secluded offshore islets, often forming large colonies.

The Nicobar pigeon's range spans from the Andaman and Nicobar Islands of India, through the Malay Archipelago, to New Guinea, the Philippines, Solomon Islands, and Palau.

These pigeons are gregarious, moving in flocks from island to island, favoring predator-free offshore islets for roosting and foraging in human-inhabited areas during the day. They exhibit a swift and rhythmic flight pattern, often flying in single file or columns.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - ANTHONY'S POISON ARROW FROG (Epipedobates anthonyi)

Anthony's poison arrow frog (Epipedobates anthonyi) is a species of poison dart frog in the family Dendrobatidae. The species is endemic to Ecuador and Peru.

The specific name, anthonyi, is in honor of American mammalogist Harold Elmer Anthony (1890–1970), who was Curator of Mammals at the American Museum of Natural History.

Anthony's poison arrow frog has a snout-to-vent length of about 19 to 26 mm (0.7 to 1.0 in). The hind legs are short and robust. The dorsal surface is usually dark red or brown and there are several yellowish-white oblique stripes and a central longitudinal stripe. Young froglets that have just completed metamorphosis are 11 mm long in snout-vent length.

Anthony's poison arrow frog is known only from a number of locations in southwestern Ecuador and northwestern Peru at heights of between 153 and 1,769 m (502 and 5,804 ft) above sea level.

The natural habitat of E. anthonyi is the leaf litter on the floor of tropical dry forests, especially near streams. It has also been found in some modified habitats, such as near roads, on banana and cacao farms.

Anthony's poison arrow frog is diurnal and terrestrial. Males are territorial. A clutch of 15 to 40 eggs is laid on the ground among leaf litter, and the male guards them till they hatch in about two weeks. He then carries the tadpoles on his back to a suitable water body where they develop (through metamorphosis) into frogs in about sixty days. Epibatidine, an extremely toxic nicotine-like substance, was first derived from and named for Epipedobates anthonyi. Once investigated for possible use as an analgesic agent, the alkaloid proved far too toxic for any application in human medicine and is presently used exclusively for research purposes. Scientists infer that the frog acquires the alkaloids through its diet because frogs collected from different types of habitats showed different levels of toxin, and frogs raised in captivity had none.

Anthony's poison arrow frog is listed as "Near Threatened" by the IUCN and the government of Peru. Institutions in Ecuador classify it as "Least Concern." Its population seems stable but it has a limited range, estimated to be less than 20,000 square kilometres (7,700 sq mi), and its habitat is being degraded by pollution from agrochemicals. It is also collected for medicinal use. There is some collection for the international pet trade, but scientists do not know if this poses a threat to the species' survival.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - COMMON EURASIAN EIDER (MALE) (Somateria mollissima ssp. mollissima)

The common eider, known scientifically as Somateria mollissima, is a large sea-duck that captivates with its considerable size, ranging from 50 to 71 cm in body length. It is the largest of the four eider species and, in Europe, it is the largest duck present. In North America, it is only surpassed in size by the Muscovy duck in certain locales. The common eider is a robust bird, with males displaying a striking black and white plumage and a distinctive green nape, while females are cloaked in brown, yet both sexes are recognizable by their large, wedge-shaped bills.

The male common eider is unmistakable with its contrasting black and white feathers and verdant nape. The female, though predominantly brown, can be distinguished from other ducks by her size and head shape. The drake's unique display call resembles a human-like "ah-ooo," and the hen's voice is characterized by hoarse quacks. The species is often approachable and can be identified by its bulky shape and size.

Common eiders are found nesting close to the sea, often on coastal islands where they form colonies. They prefer Arctic and northern temperate regions for breeding but migrate slightly south to temperate zones during winter.

This species graces the northern coasts of Europe, North America, and eastern Siberia. It breeds in the Arctic and some northern temperate regions, wintering farther south in temperate zones where it may gather in large flocks on coastal waters.

Eiders are colonial breeders, with colonies varying from less than a hundred to over 15,000 individuals. They exhibit natal philopatry, with females often returning to their birthplace to breed. This has led to the development of kin-based social structures and cooperative breeding behaviors, such as shared rearing of ducklings.

The male common eider's display call is a distinctive "ah-ooo," while the female emits hoarse quacks. These vocalizations contribute to the bird's unique auditory presence in its natural habitat.

The eider's nest is built near the sea and is lined with the female's own eiderdown, a soft and warm material once harvested for human use. The species demonstrates cooperative breeding behaviors, including shared rearing of ducklings in crèches.

While the male common eider is unique in appearance, the female may be confused with other eider species. However, size and head shape are key distinguishing features.

The common eider dives for crustaceans and molluscs, with mussels being a preferred food. It consumes mussels whole, crushing the shells in its gizzard. Crabs are also on the menu, with the eider skillfully removing claws and legs before consumption.

The common eider is currently classified as Near Threatened on the IUCN Red List. Populations are estimated at 1.5–2 million birds in both North America and Europe, with additional, albeit unknown, numbers in eastern Siberia. Conservation efforts and studies, particularly in Canada's Hudson Bay, are ongoing to monitor and support the species' recovery.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - COMMON EURASIAN EIDER (FEMALE) (Somateria mollissima ssp. mollissima)

The common eider, known scientifically as Somateria mollissima, is a large sea-duck that captivates with its considerable size, ranging from 50 to 71 cm in body length. It is the largest of the four eider species and, in Europe, it is the largest duck present. In North America, it is only surpassed in size by the Muscovy duck in certain locales. The common eider is a robust bird, with males displaying a striking black and white plumage and a distinctive green nape, while females are cloaked in brown, yet both sexes are recognizable by their large, wedge-shaped bills.

The male common eider is unmistakable with its contrasting black and white feathers and verdant nape. The female, though predominantly brown, can be distinguished from other ducks by her size and head shape. The drake's unique display call resembles a human-like "ah-ooo," and the hen's voice is characterized by hoarse quacks. The species is often approachable and can be identified by its bulky shape and size.

Common eiders are found nesting close to the sea, often on coastal islands where they form colonies. They prefer Arctic and northern temperate regions for breeding but migrate slightly south to temperate zones during winter.

This species graces the northern coasts of Europe, North America, and eastern Siberia. It breeds in the Arctic and some northern temperate regions, wintering farther south in temperate zones where it may gather in large flocks on coastal waters.

Eiders are colonial breeders, with colonies varying from less than a hundred to over 15,000 individuals. They exhibit natal philopatry, with females often returning to their birthplace to breed. This has led to the development of kin-based social structures and cooperative breeding behaviors, such as shared rearing of ducklings.

The male common eider's display call is a distinctive "ah-ooo," while the female emits hoarse quacks. These vocalizations contribute to the bird's unique auditory presence in its natural habitat.

The eider's nest is built near the sea and is lined with the female's own eiderdown, a soft and warm material once harvested for human use. The species demonstrates cooperative breeding behaviors, including shared rearing of ducklings in crèches.

While the male common eider is unique in appearance, the female may be confused with other eider species. However, size and head shape are key distinguishing features.

The common eider dives for crustaceans and molluscs, with mussels being a preferred food. It consumes mussels whole, crushing the shells in its gizzard. Crabs are also on the menu, with the eider skillfully removing claws and legs before consumption.

The common eider is currently classified as Near Threatened on the IUCN Red List. Populations are estimated at 1.5–2 million birds in both North America and Europe, with additional, albeit unknown, numbers in eastern Siberia. Conservation efforts and studies, particularly in Canada's Hudson Bay, are ongoing to monitor and support the species' recovery.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - SUN PARAKEET (Aratinga solstitialis)

The Sun parakeet (Aratinga solstitialis) is a medium-sized, brightly colored parrot native to northeastern South America. Sun parakeets are very social birds, typically living in flocks. They form monogamous pairs for reproduction and nest in palm cavities in the tropics. They are commonly bred and kept in aviculture and may live up to 30 years.

Adult Sun parakeets have a rich yellow crown, nape, mantle, lesser wing coverts, tips of the greater wing coverts, chest, and underwing coverts. The face and belly are orange with red around the ears. The base of the greater wing coverts, tertials, and base of the primaries are green, while the secondaries, tips of the primaries, and most of the primary coverts are dark blue. The tail is olive green with a blue tip. From below, all the flight feathers are dark greyish. The bill is black. The legs and the bare eye-ring are grey, but the latter often fade to white in captivity (so using the amount of grey or white in the eye ring for determining the "purity" of an individual can be misleading). The sexes are similar in plumage, although females may be lighter and slenderer in body, having a shorter tail, with a smaller, rounder head and a smaller beak. Juvenile Sun parakeets have predominantly green plumage. The distinctive yellow, orange, and reddish coloration on the back, abdomen, and head is attained with maturity.

Sun parakeets live in a relatively small region of northeastern South America: the north Brazilian state of Roraima, southern Guyana, extreme southern Suriname, and southern French Guiana. They also occur as vagrants to coastal French Guiana. These birds are mostly found in tropical habitats, but their exact ecological requirements remain relatively poorly known. They occur within dry savanna woodlands and coastal forests, but, at the edge of humid forests growing in foothills in the Guiana Shield, and cross more open savannah habitats only when traveling between patches of forest. Sun parakeets have been seen in shrublands along the Amazon riverbank, as well as forested valleys and coastal, seasonally flooded forests. They usually inhabit fruiting trees and palm groves.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - EURASIAN EAGLE OWL (Bubo bubo)

The Eurasian eagle-owl (Bubo bubo) is a formidable avian predator and one of the largest owl species. The females, which are larger than the males, can reach a total length of 75 cm (30 in) and boast a wingspan of up to 188 cm (6 ft 2 in). This species is characterized by prominent ear tufts, mottled upper parts with darker blackish and tawny coloring, barred wings and tail, and a buff underpart streaked with darker shades. The facial disc is not sharply defined, and the orange eyes are a striking feature.

To identify the Eurasian eagle-owl, look for its large size, barrel-shaped body, and erect ear tufts. The orange eyes are distinctive, and the plumage is a mix of brown-black to tawny-buff with dense freckling on the forehead and crown, and dark splotches on a pale background on the back and mantle. The underparts are creamy to tawny with fine dark barring.

Eurasian eagle-owls favor a variety of habitats but are predominantly found in mountainous or other rocky regions near woodland edges, shrubby areas, and wetlands. They also inhabit coniferous forests, steppes, and other areas at varied elevations that are typically remote.

The Eurasian eagle-owl has an extensive range across Europe and Asia, from the Iberian Peninsula to Japan. It is also present in the UK, where it is considered non-native.

This species is mostly nocturnal, hunting a variety of prey from small mammals to larger birds, reptiles, amphibians, and insects. They are sedentary and territorial, with a deep, resonant territorial call.

The male's territorial call is a deep "ooh-hu," while the female's is higher-pitched. They may also produce a faint laughter-like sound and a harsh "kveck-kveck."

Eurasian eagle-owls typically breed on cliff ledges, in gullies, or among rocks. The female incubates the eggs and broods the young, while the male provides food. Both parents care for the young for about five months.

The Eurasian eagle-owl can be distinguished from other large owls like the great grey owl and Ural owl by its ear tufts and orange eyes. It is also larger than the snowy owl.

The diet is mainly small mammals, such as rodents and rabbits, but also includes larger mammals, birds, reptiles, amphibians, fish, and large insects.

The IUCN lists the Eurasian eagle-owl as Least Concern, with a decreasing population trend. However, it remains widespread with a large total population.

14-8-2017 AMSTERDAM ZOO, NETHERLANDS - RED RUFFED LEMUR (Varecia rubra)

The red ruffed lemur (Varecia rubra ) is one of two species in the genus Varecia, the ruffed lemurs; the other is the black-and-white ruffed lemur (Varecia variegata ). Like all lemurs, it is native to Madagascar. It occurs only in the rainforests of Masoala, in the northeast of the island. It is one of the largest primates of Madagascar with a body length of 53 cm, a tail length of 60 cm and a weight of 3.3–3.6 kg. Its soft, thick fur is red and black in color and sports a buff or cream colored spot at the nape, but a few are known to have a white or pink patch on the back of the limbs or digits and a ring on the base of the tail in a similar color.

The Red ruffed lemurs are unique, medium-sized lemurs with a primate-like appearance. These animals differ greatly from all other types of lemur. They exhibit thick, soft, reddish coat with a long, black and heavily furred tail. The tail base is ringed with pink colored fur. On the top of their head, the Red ruffed lemurs display a conspicuous white colored tuff. They have black faces and long snouts.

The social structure of Red ruffed lemurs is largely associated with their habitat. Some populations may form groups of 18 - 32 individuals, whereas other can live in smaller units of 2 - 5 animals. When looking for food, a group usually divides into smaller sub-groups. Various groups may have the same core home range, where they rear their offspring. With the coming of the wet season, the food becomes abundant and these animals gather into larger aggregations.

As the food sources gradually exhaust by the end of the wet season, these large units break up into smaller groups that disperse. As diurnal animals, red ruffed lemurs are active during the daytime hours, particularly in the morning and evening. They are known to display territorial behavior and border scuffles may sometimes take place. The communication system of this vocal species includes at least 12 different calls. They most frequently give out low grunts, gurgles and cackle-like roars, which are thought to act as alarm calls.

Red ruffed lemurs have a polygynous mating system, where males generally mate with females in their group. Occasionally, males from the outside come to the home range of a group to mate with receptive females. Breeding occurs during the dry season, in May-July. Up to 6 young are born after a very short gestation period (90 - 103 days) for a primate of this body size. Young are raised in nests or secluded places in special areas known as parkings. These parkings are located in the core of the group's home range. Group members practice communal care, while mothers are far in the forest. Between 3 and 7 weeks old, the infants begin venturing from the nest. Weaning occurs by 4 months old. The age of reproductive maturity is 1 - 2 years old in males and 2 - 3 years old in females.

Currently, the Red ruffed lemurs are among the most endangered lemur species in Madagascar due to tiny range and small population. Most Red ruffed lemurs live outside the protected area called the Masoala Nature Reserve, which poses additional threat to the survival of these animals. The Red ruffed lemurs are often captured for pet or animal trade. Other notable threats to this species are hunting and habitat destruction.

According to the Woodland Park Zoo, the total population of the Red ruffed lemurs in the wild is 1,000 to 10,000 individuals. However, this species’ numbers are decreasing today, and the animal is classified as Critically Endangered (CR) on the IUCN Red List.

The primary role of these animals in the local ecosystem is pollination for various hardwood trees. The Red ruffed lemurs have long snouts, resembling these of foxes. When eating nectar of deep tubular flowers, their snouts are covered with pollen, which they carry to other flowers that they consume.

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

Grey Herons are unmistakeable – tall, with long legs, a long beak and grey, black and white feathering. They can stand with their neck stretched out, looking for food, or hunched down with their neck bent over their chest.

The Grey Heron is a distinctive species with grey, black, and white plumage. It is often seen along rivers or lake margins, or standing in flooded fields.

In flight their large size, impressive wingspan, long legs, and folded neck give them an unmistakable silhouette. Largely silent away from colonies, flight is sometimes accompanied by a harsh ‘kraank’ call.

Grey Herons gather to nest in treetop sites called heronries, some of which have been occupied for many decades. These have been monitored in the UK since 1928 through the Heronries Census. Overall the UK's breeding population has increased, with numbers peaking in the early 2000, but with some more recent declines.

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 - GREY HERON (Ardea cinerea)

Raising a nest full of baby herons is hard work! During the breeding season, some Gray Herons spend up to 23 hours per day foraging and some travel up to 38 km (24 miles) from their nest in search of food.

Gray Herons usually feed on smaller fish, 10–25 cm (4–10 inches) long, but some ambitious individuals take fish weighing up to 500 grams (1.1 pounds) and eels that are up to 60 cm (24 inches) long.

Gray Herons live in Eurasia and Africa, but rare individuals stray from their normal range to places like the Lesser Antilles in the Caribbean Sea. Despite the Gray Heron's similarity to Great Blue Heron, some observers have also documented this species from the Atlantic Coast of mainland North America, from Newfoundland to Virginia, and also from Alaska’s Aleutian Islands.

14-8-2017 AMSTERDAM, NETHERLANDS - EGYPTIAN GOOSE (Alopochen aegyptiaca)

The Egyptian goose, Alopochen aegyptiaca, is a striking bird, native to Sub-Saharan Africa and the Nile Valley. It is a member of the Anatidae family, which includes ducks, geese, and swans. This species is unique in its appearance, resembling a goose more than a duck when in flight, with a heavy and robust stature. Adults typically measure between 63 to 73 centimeters in height.

Both sexes of the Egyptian goose display identical plumage, though males are generally larger. Plumage tones can vary from grey to brown, not necessarily indicative of age or sex. Mature birds boast a significant white patch on their wings, concealed by wing coverts when at rest but prominently displayed when the bird is agitated or in flight.

The Egyptian goose favors open or semi-open environments, often found near freshwater sources. Its habitat ranges from lowlands to high altitudes, such as the Ethiopian Highlands, up to 4,000 meters above sea level. It avoids dense forests and deserts.

This species is widespread and common in its native range, though numbers have dwindled in the northern Nile Valley. Historically found in southeastern Europe and parts of the Middle East, its presence in these areas has diminished.

The Egyptian goose is largely terrestrial, capable of perching on trees and buildings. It is known for its aggressive territorial behavior, especially during breeding season, and is not hesitant to engage in aerial combat with intruders. The species is monogamous, with both parents caring for their offspring.

The male's call is a subdued, hoarse quack, becoming louder and more rapid when agitated, resembling a steam engine. The female's quack is raucous and frequently heard, particularly when defending her young.

Nesting occurs in a variety of locations, with a preference for holes in mature trees. Both parents incubate the eggs, and the young are capable of foraging for themselves shortly after hatching.

Egyptian geese primarily consume seeds, leaves, grasses, and plant stems. They may also eat small animals such as locusts and worms. Goslings initially feed on small aquatic invertebrates before transitioning to grazing.

The Egyptian goose is classified as Least Concern by the IUCN, indicating a stable population. However, in regions where it has been introduced, it is considered invasive and may pose a threat to native species.