The true finches are passerine birds in the family Fringillidae. They are predominantly seed-eating songbirds. Most are native to Southern Hemisphere, but one subfamily is endemic to the Neotropics, one to the Hawaiian Islands, and one subfamily – monotypic at genus level – is found only in the Palaearctic. The scientific name Fringillidae comes from the Latin word fringilla for the Chaffinch – a member of that last subfamily – which is common in Europe.
Many birds in other families are also commonly called "finches", including some species in the very similar-looking waxbills of the Old World tropics and Australia; several groups of the bunting and American sparrow family; and Darwin's finches of the Galapagos islands, which provided evidence of natural selection and are now recognized to be peculiar tanagers.
The "classical" true finches range in size from the Andean Siskin (Carduelis spinescens) at 9.5 cm (3.8 in) and 8.4 g (0.3 oz) to the Collared Grosbeak (Mycerobas affinis) with its nearly 23 cm (9 in) and 80 g (3 oz). They typically have strong, stubby beaks, which in some species can be quite large; however, Hawaiian honeycreepers are famous for the wide range of bill shapes and sizes brought about by adaptive radiation. All true finches have 12 remiges and 9 primary rectrices. The basic plumage colour is brownish, sometimes greenish; many have considerable amounts of black, while white plumage is generally absent except as wing-bars or other signalling marks. Bright yellow and red carotenoid pigments are commonplace in this family, and thus blue structural colours are rather rare, as the yellow pigments turn the blue color into green. Many, but by no means all true finches have strong sexual dichromatism, the females typically lacking the bright carotenoid markings of males.
Finches are typically inhabitants of well-wooded areas, but some can be found on mountains or even in deserts. They are primarily granivorous, but euphoniines include considerable amounts of arthropods and berries in their diet, and Hawaiian honeycreepers evolved to utilize a wide range of food sources, including nectar. The diet of Fringillidae nestlings includes a varying amount of small arthropods. True finches have a bouncing flight like most small passerines, alternating bouts of flapping with gliding on closed wings. Most sing well and several are commonly-seen cagebirds; foremost among these is the domesticated Canary (Serinus canaria domestica). The nests are basket-shaped and usually built in trees, more rarely in bushes, between rocks or on similar substrate.
Systematics and taxonomy
The taxonomic structure of the true finch family, Fringillidae, has been fairly disputed in the past, with some upranking the Hawaiian honeycreepers (Drepanidinae) as family Drepanididae and/or uniting the cardueline and fringilline finches as tribes (Carduelini and Fringillini) in one subfamily; the euphonious finches (Euphoniinae) were thought to be tanagers due to general similarity in appearance and mode of life until their real affinities were realized. In particular North American authors have often have merged the buntings and American sparrow family (Emberizidae) – and sometimes the bulk of the nine-primaried oscines – with the split-up Fringillidae as subfamilies of a single massive family. But the current understanding of Passeroidea phylogeny is better reflected in keeping the fundamental nine-primaried oscine clades as distinct families. However, Przewalski's "Rosefinch" (Urocynchramus pylzowi) is now classified as a distinct family, monotypic as to genus and species, and with no particularly close relatives among the Passeroidea.
Fossil remains of true finches are rare, and those that are known can mostly be assigned to extant genera at least. Like the other Passeroidea families, the true finches seem to be of roughly Middle Miocene origin, around 20-10 million years ago (Ma). An unidentifable finch fossil from the Messinian age, around 12 to 7.3 million years ago (Ma) during the Late Miocene subepoch, has been found at Polgárdi in Hungary.
The Owls are the order Strigiformes, comprising 200 extant birds of prey, species. Most are solitary, and nocturnal, with some exceptions (e.g. the Burrowing Owl). Owls hunt mostly small mammals, insects, and other birds, though a few species specialize in hunting fish. They are found in all regions of the Earth except Antarctica, most of Greenland, and some remote islands. Though owls are typically solitary, the literary collective noun for a group of owls is a parliament.
Living owls are divided into two families: the typical owls, Strigidae; and the barn-owls, Tytonidae.
Owls have large forward-facing eyes and ear-holes, a hawk-like beak, a flat face, and usually a conspicuous circle of feathers -- a facial disc -- around each eye . Although owls have binocular vision, their large eyes are fixed in their sockets, as with other birds, and they must turn their entire head to change views.
Owls are far-sighted, and are unable to see anything clearly within a few inches of their eyes. Caught prey can be felt by owls with the use of filoplumes, which are small hair-like feathers on the beak and feet that act as "feelers". Their far vision, particularly in low light, is exceptionally good. Contrary to popular myth, owls cannot turn their heads completely backwards. They can turn their head 135 degrees in either direction; they can thus look behind their own shoulders, with a total 270 degree field of view.
The smallest owl is the Elf Owl (Micrathene whitneyi), at as little as 31 g (1.1 oz) and 13.5 cm (5.3 inches). Some of the pygmy owls are scarcely larger. The largest owls are two of the eagle owls -- the Eurasian Eagle Owl (Bubo bubo) and Blakiston's Fish Owl (Bubo blakistoni) -- which may reach a size of 60 - 71 cm (28.4 in) long, have a wingspan of almost 2 m (6.6 ft), and an average weight of nearly 4.5 kg (10 lb).
Different species of owls make different sounds; the wide range of calls aids owls in finding mates or announcing their presence to potential competitors, and also aids ornithologists and birders in locating these birds and recognizing species. The facial disc helps to funnel the sound of prey to their ears. In many species, these are placed asymmetrically, for better directional location.[verification needed]
Owl eggs are usually white and almost spherical, and range in number from a few to a dozen, depending on species. The eggs are laid at intervals of 1 to 3 days and do not hatch at the same time. This accounts for the wide variation in the size of sibling nestlings. Owls do not construct nests, but rather look for a sheltered nesting site or an abandoned nest in trees, underground burrows, or in buildings, barns and caves.
Most owls are nocturnal, actively hunting for prey only under the cover of darkness. Several types of owl, however, are crepuscular, active during the twilight hours of dawn and dusk; one example is the pygmy owl (Glaucidium). A few owls are active alsoduring the day; examples are the Burrowing Owl (Speotyto cunicularia) and the Short-eared Owl (Asio flammeus).
Much of the owls' hunting strategy depends on stealth and surprise. Owls have at least two adaptations that aid them in achieving stealth. First, the dull coloration of owls' feathers can render them almost invisible under certain conditions. Secondly, serrated edges on the leading edge owls' remiges muffle an owl's wingbeats, allowing its flight to be practically silent. Some fish-eating owls, for which silence is of no evolutionary advantage, lack this adaptation.
Once prey has been captured, an owl's sharp beak and powerful talons allow it to kill its prey before swallowing it whole (unless it is too big). Scientists studying the diets of owls are helped by their habit of regurgitating the indigestible parts of their prey (such as bones, scales and fur) in the form of pellets. These "owl pellets" -- which are plentiful and easy to interpret -- are often sold by companies to schools for dissection by students as a lesson in biology and ecology.
Hummingbirds are among the smallest of birds, and include the smallest extant bird species, the Bee Hummingbirds. They can hover in mid-air by rapidly flapping their wings 12-90 times per second (depending on the species). They can also fly backwards, and are the only group of birds able to do so. Their English name derives from the characteristic hum made by their rapid wing beats. They can fly at speeds exceeding 15 m/s.
Hummingbirds feed on the nectar of plants and are important pollinators, especially of deep-throated, tubular flowers. Like bees, they are able to assess the amount of sugar in the nectar they eat; they reject flower types that produce nectar which is less than 10% sugar and prefer those whose sugar content is stronger. Nectar is a poor source of nutrients, so hummingbirds meet their needs for protein, amino acids, vitamins, minerals, etc. by preying on insects and spiders, especially when feeding young.
Most hummingbirds have bills that are long and straight or nearly so, but in some species the bill shape is adapted for specialized feeding. Thornbills have short, sharp bills adapted for feeding from flowers with short corollas and piercing the bases of longer ones. The Sicklebills' extremely decurved bills are adapted to extracting nectar from the curved corollas of flowers in the family Gesneriaceae. The bill of the Fiery-tailed Awlbill has an upturned tip, as in the Avocets. The male Tooth-billed Hummingbird has barracuda-like spikes at the tip of its long, straight bill.
The two halves of a hummingbird's bill have a pronounced overlap, with the lower half (mandible) fitting tightly inside the upper half (maxilla). When hummingbirds feed on nectar, the bill is usually only opened slightly, allowing the tongue to dart out and into the interior of flowers.
Like the similar nectar-feeding sunbirds and unlike other birds, hummingbirds drink by using protrusible grooved or trough-like tongues.
Hummingbirds do not spend all day flying, as the energy cost would be prohibitive; the majority of their activity consists simply of sitting or perching. Hummingbirds feed in many small meals, consuming many small invertebrates and up to five times their own body weight in nectar each day. They spend an average of 10-15% of their time feeding and 75-80% sitting and digesting.
Co-evolution with ornithophilous flowers
Hummingbirds are specialized nectarivores and are tied to the ornithophilous flowers they feed upon. Some species, especially those with unusual bill shapes such as the Sword-billed Hummingbird and the sicklebills, are coevolved with a small number of flower species.
Many plants pollinated by hummingbirds produce flowers in shades of red, orange, and bright pink, though the birds will take nectar from flowers of many colors. Hummingbirds can see wavelengths into the near-ultraviolet, but their flowers do not reflect these wavelengths as many insect-pollinated flowers do. This narrow color spectrum may render hummingbird-pollinated flowers relatively inconspicuous to most insects, thereby reducing nectar robbing. Hummingbird-pollinated flowers also produce relatively weak nectar (averaging 25% sugars w/w) containing high concentrations of sucrose, whereas insect-pollinated flowers typically produce more concentrated nectars dominated by fructose and glucose.
The Cardinals or Cardinalidae are a family of passerine birds found in North and South America. The South American cardinals in the genus Paroaria are placed in another family, the Thraupidae.
These are robust, seed-eating birds, with strong bills. The family ranges in size from the 12-cm, 11.5-gram Orange-breasted Bunting to the 25-cm, 85-gram Black-headed Saltator. They are typically associated with open woodland. The sexes usually have distinctive appearances; the family is named for the red plumage (colored cardinal like the color of a Catholic cardinal's vestments) of males of the type species, the Northern Cardinal.
The "buntings" in this family are sometimes generically known as "tropical buntings" (though not all live in the tropics) or "North American buntings" (though there are other buntings in North America) to distinguish them from the true buntings. Likewise the grosbeaks in this family are sometimes called "cardinal-grosbeaks" to distinguish them from other grosbeaks. The name "cardinal-grosbeak" can also apply to this family as a whole.
The Rose-throated Tanager (Piranga roseogularis) is a medium-sized American songbird. Formerly placed in the tanager family (Thraupidae), it and other members of its genus are now classified in the cardinal family (Cardinalidae). The species's plumage and vocalizations are similar to other members of the cardinal family.
The Yellow-Green Grosbeak (Caryothraustes canadensis) is a species of cardinal (bird) in the Cardinalidae family. It is found in Brazil, Colombia, French Guiana, Guyana, Panama, Suriname, and Venezuela. Its natural habitats are subtropical or tropical moist lowland forests and heavily degraded former forest.
The Blue Bunting (Cyanocompsa parellina) is a species of passerine bird found in northern Central America. Measuring 5.5 inches (14 cm) in length with a wingspan of 8.5 inches (22 cm), it is one of the smaller members of its genus. Like most buntings, the Blue Bunting is sexually dimorphic. The male has a dark blue body, with brighter blue highlights on the supercilium, forecrown, malar region, rump and lesser wing coverts. The female is an unstreaked warm brown, slightly paler below.
The bluebirds are a group of medium-sized, mostly insectivorous or omnivorous birds in the genus Sialia of the thrush family. Bluebirds are one of the few thrush genera in the Americas. They have blue, or blue and red, plumage. Female birds are less brightly colored than males, although color patterns are similar and there is no noticeable difference in size between sexes.
Bluebirds are territorial, prefer open grassland with scattered trees and are cavity nesters (similar to many species of woodpecker). Bluebirds can typically produce between two and four broods during the spring and summer (March through August in the Northeastern United States). Males identify potential nest sites and try to attract prospective female mates to those nesting sites with special behaviors that include singing and flapping wings, and then placing some material in a nesting box or cavity. If the female accepts the male and the nesting site, she alone builds the nest and incubates the eggs.
Predators of young bluebirds in the nests can include snakes, cats and raccoons. Non-native bird species competing with bluebirds for nesting locations include the Common Starling and House Sparrow, both of which kill adult bluebirds sitting on their nests along with the young and eggs in order to claim the nesting site.
Bluebirds are attracted to platform bird feeders, filled with grubs of the darkling beetle, sold by many online bird product wholesalers as mealworms. Bluebirds will also eat raisins soaked in water. In addition, in winter bluebirds use backyard heated birdbaths.
By the 1970s, bluebird numbers had declined by estimates ranging to 70% due to unsuccessful competition with house sparrows and starlings, both introduced species, for nesting cavities, coupled with a decline in habitat. However, in late 2005 Cornell University's Laboratory of Ornithology reported bluebird sightings at many locations in the southern U.S. as part of its yearly Backyard Bird Count, a strong indication of the bluebird's return to the region. This upsurge can largely be attributed to a movement of volunteers establishing and maintaining bluebird trails.
In 2009, expert naturalist Bob Coward coined the term "Blog of Bluebirds" to describe an extended grouping of the birds.