Netherlands Antilles 100 guldens, 2006 (P#31d) Thanks to Ante Jerončić from Antigua!

The Bananaquit (Coereba flaveola) is a species of passerine bird of uncertain relation. It is tentatively placed in the tanager family, but classified as incertae sedis by other authorities such as the American Ornithologists' Union. Its classification is debated, and it is often placed in its own family: Coerebidae. It has recently been suggested the Bananaquit should be split into three species, but this has yet to receive widespread recognition. This small, active nectarivore is found in warmer parts of the Americas, and is generally common. 

The Bananaquit was first described by Linnaeus in his Systema Naturae in 1758 as Certhia flaveola. It was reclassified as the only member of the genus Coereba by Louis Jean Pierre Vieillot in 1809. Prior to 2005 the Bananaquit was assigned to the monotypic family Coerebidae; there is currently no agreement to which family it belongs; some authors place it into the Emberizidae. Since recent studies have shed some light on the Bananaquit's affinities, many authorities consider Coerebidae an obsolete taxon. The Coerebidae used to contain other nectar-eating birds from the tropical Americas, but these have since been moved. The Bananaquit is part of a group that includes Darwin's finches, Tiaris (grassquits), Loxigilla, etc.—most of which were previously placed in Emberizidae, but are now known to actually be part of the Thraupidae. As such this species is tentatively placed in the Thraupidae family unless a study suggests more accurate placement. Nevertheless, its precise relations remain unresolved, so the American Ornithologists' Union classes it as a species incertae sedis. 

It is still unclear if any of the island subspecies should be elevated to species, but phylogenetic studies by Seutin et al. and Bellemain et al. have revealed three clades: the nominate group from Jamaica, Hispaniola and the Cayman Islands, the bahamensis group from the Bahamas and Quintana Roo, and the bartholemica group from South and Central America, Mexico (except Quintana Roo), the Lesser Antilles and Puerto Rico. Several taxa were not sampled, but most of these are easily placed in the above groups based on zoogeography alone. Exceptions are oblita (San Andrés Island) and tricolor (Providencia Island), and their placement is therefore uncertain. Bellemain et al. suggested that the two taxa bahamensis and bartholemica be split, and in February 2010, the International Ornithological Congress listed as proposed splits from C. flaveola.

Netherland Antilles 50 guldens, 2006 (P#30d) Thanks to Ante Jerončić from Antigua!

The Rufous-collared Sparrow (Zonotrichia capensis) is an American sparrow found in a wide range of habitats, often near humans, from the extreme southeast of Mexico to Tierra del Fuego, and on the island of Hispaniola. It is famous for its diverse vocalizations, which have been intensely studied since the 1970s, particularly by Paul Handford and Stephen C. Lougheed (UWO), Fernando Nottebohm (Rockefeller University) and Pablo Luis Tubaro (UBA). Local names for this bird include the Portuguese tico-tico and the Spanish chingolo and copetón (tufted) in Colombia. 

The Rufous-collared Sparrow is 13.5–15 cm long and weighs 20–25 g. The adult has a stubby grey bill and a grey head with broad black stripes on the crown sides and thinner stripes through the eye and below the cheeks. The nape and breast sides are rufous and the upperpart are black-streaked buff-brown. There are two white wing bars. The throat is white, and the underparts are off-white, becoming brown on the flanks and with a black breast patch. Young birds have a duller, indistinct head pattern, with brown stripes and a buff ground colour. They lack the rufous collar, and have streaked underparts. There are between 25 and 29 subspecies. In general, the smaller forms occur in coastal mountains, intermediate birds in the Andes, and large, darker, forms breed on the tepuis. The largest of the tepui subspecies, Z. c. perezchincillae, has grey underparts, and the rufous collar extends as a black band of freckles across the breast. This form might be separable as a distinct species, or it might just be a particularly distinct population due to genetic bottleneck effects.

 

Netherland Antilles 10 gulden, 2006 (P#28d)

Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings 12–80 times per second (depending on the species). To conserve energy while they sleep or when food is scarce, they have the ability to go into a hibernation-like state (torpor) where their metabolic rate is slowed to 1/15th of its normal rate. They are also the only group of birds with the ability to fly backwards. Their English name derives from the humming sound made by the very fast beating of their wings. They can fly at speeds exceeding 15 m/s. 

Aztecs wore hummingbird talismans, the talismans being representations as well as actual hummingbird fetishes formed from parts of real hummingbirds: emblematic for their vigor, energy, and propensity to do work along with their sharp beaks that mimic instruments of weaponry, bloodletting, penetration, and intimacy. Hummingbird talismans were prized as drawing sexual potency, energy, vigor, and skill at arms and warfare to the wearer. 

*Aerial photograph of hummingbird image as part of Nazca Lines in Peru The Aztec god Huitzilopochtli is often depicted as a hummingbird. The Nahuatl word huitzil (hummingbird) is an onomatopoeic word derived from the sounds of the hummingbird's wing-beats and zooming flight. 

* One of the Nazca Lines depicts a hummingbird. 

* The Ohlone tells the story of how Hummingbird brought fire to the world. 

* Trinidad and Tobago is known as "The land of the hummingbird," and a hummingbird can be seen on that nation's coat of arms and 1-cent coin as well as its national airline, Caribbean Airlines. 

* Chrysler's gear-reduction starter motor used from the early 1960s to the late 1980s was nicknamed the "Highland Park Hummingbird" after Chrysler's hometown and the starter's distinctive cranking sound.

 

Netherlands Antilles 25 gulden, 2006 (P#29d) Thanks to Ante Jerončić from Antigua!

Flamingos or flamingoes are a type of wading bird in the genus Phoenicopterus, the only genus in the family Phoenicopteridae. 

There are four flamingo species in the Americas and two species in the Old World. A wide variety of birds have been proposed as their closest relatives, on a wide variety of evidence. As a result, flamingos are generally placed in their own order. Traditionally, the long-legged Ciconiiformes, probably a paraphyletic assemblage, have been considered the flamingos' closest relatives and the family was included in the order. Usually the ibises and spoonbills of the Threskiornithidae were considered their closest relatives within this order. Earlier genetic studies, such as those of Charles Sibley and colleagues, also supported this relationship. Relationships to the waterfowl were considered as well, especially as flamingos are parasitized by feather lice of the genus Anaticola, which are otherwise exclusively found on ducks and geese. Other scientists proposed flamingos as waders most closely related to the stilts and avocets, Recurvirostridae. The peculiar presbyornithids were used to argue for a close relationship between flamingos, waterfowl, and waders but they are now known to be unequivocal waterfowl with a peculiarly derived morphology paralleling waders and flamingos. 

Flamingos often stand on one leg, the other tucked beneath the body. The reason for this behavior is not fully understood. Some species of Flamingos have the ability to have half of its body to go into a state of sleep, and when one side is rested, the flamingo will swap legs and then let the other half sleep, but this has not been proven. Recent research has indicated that standing on one leg may allow the birds to conserve more body heat, given that they spend a significant amount of time wading in cold water. As well as standing in the water, flamingos may stamp their webbed feet in the mud to stir up food from the bottom. Young flamingos hatch with greyish reddish plumage, but adults range from light pink to bright red due to aqueous bacteria and beta carotene obtained from their food supply. A well-fed, healthy flamingo is more vibrantly coloured and thus a more desirable mate; a white or pale flamingo, however, is usually unhealthy or malnourished. Captive flamingos are a notable exception; many turn a pale pink as they are not fed carotene at levels comparable to the wild. This is changing as more zoos begin to add prawns and other supplements to the diets of their flamingos.