These hybrid types are not breeds, but they resemble breeds in that crosses between certain horse breeds and other equine species produce characteristic offspring.

As an illustration of artificial selection, he describes fancy pigeon breeding, noting that " he diversity of the breeds is something astonishing ", yet all were descended from one species of rock pigeon.

However, some " utility " ( general purpose ) breeds, such as the Cochin, Cornish and Silkie, do regularly go broody, and they make excellent mothers, not only for chicken eggs but also for those of other species — even those with much smaller or larger eggs and different incubation periods, such as quail, pheasants, turkeys or geese.

Wild ducks of many species and domesticated breeds are widely consumed around the world.

Some specialise in the liquid in pitchers of particular species of pitcher plants, their larvae feeding on decaying insects that had drowned there or on the associated bacteria ; the harmless genus Wyeomyia provides such examples — Wyeomyia smithii breeds only in the pitchers of Sarracenia purpurea.

# The third type of hybrid consists of crosses between populations, breeds or cultivars within a single species.

The Little Penguin is the only species of penguin that breeds on mainland Australia.

The species usually breeds only once each year.

The Black Swan ( Cygnus atratus ) is a large waterbird, a species of swan, which breeds mainly in the southeast and southwest regions of Australia.

Another population of the same species breeds in South Africa and Namibia ; these birds move northwards after breeding.

In Europe the Wood Pigeon is commonly shot as a game bird, while Rock Pigeons were originally domesticated as a food species, and many breeds were developed for their meat-bearing qualities.

The Eastern Imperial Eagle ( Aquila heliaca ) is a large species of bird of prey that breeds from southeastern Europe to western and central Asia.

Eurasia as a whole domesticated 13 species of large animals ( over 100 lb / 44 kg ); South America just one ( counting the llama and alpaca as breeds within the same species ); the rest of the world none at all.

The orioles are a mainly tropical group, although one species ( Eurasian Golden Oriole, O. oriolus ) breeds in temperate regions.

It is also a place for Green Sea Turtles, the only species of turtle that breeds in Hong Kong, to lay eggs.

This species breeds in woods and gardens, building a neat, mud-lined, cup-shaped nest.

* T. m. mauretanicus, another small dark species with a glossy black male plumage, breeds in central and northern Morocco, coastal Algeria and northern Tunisia.

The differences between subspecies are usually less distinct than the differences between species, but more distinct than the differences between breeds or races ( races can be assigned to different subspecies if taxonomically different ).

The species breeds mainly on cliffs, but is known to use trees to nest in Rajasthan.

This species breeds in western and central Europe, with an allied form or race C. c. orientalis ( 50 – 56 cm or 19 to 22 inches in length ) occurring in eastern Asia.

This species usually breeds in colonies, in trees close to lakes or other wetlands.

This species is found throughout the Old World, apparently breeding where suitable localities are to be found in many European countries, although it no longer breeds in southwestern Europe.

If you really insist on knowing their names, an excellent book on the North American species is Bumblebees And Their Ways by O. E. Plath.

Oliver, in his summary of the habits of the snakes of the United States, could supply data on the maturing period for only three species in addition to the rattlers, which I shall consider separately.

MacLean stressed correctly the importance of the visceral brain for preservation of the individual and the species, as evidenced by the influence of the limbic brain ( including the hypothalamus ) on emotions related to fight and flight and also on sexual functions.

The actual number of species in each group depends on the taxonomic classification followed.

In air, where oxygen is more concentrated, some small species can rely solely on cutaneous gas exchange, most famously the plethodontid salamanders, which have neither lungs nor gills.

In 2006 there were believed to be 4, 035 species of amphibians that depended on water at some stage during their life cycle.

The western terrestrial garter snake ( Thamnophis elegans ) in California is largely aquatic and depends heavily on two species of frog that are diminishing in numbers, the Yosemite toad ( Bufo canorus ) and the mountain yellow-legged frog ( Rana muscosa ), putting the snake's future at risk.

Some unicellular species rely entirely on external energy sources and have limited or no photosynthetic apparatus.

The species that gains the electron pair is the Lewis acid ; for example, the oxygen atom in H < sub > 3 </ sub > O < sup >+</ sup > gains a pair of electrons when one of the H — O bonds is broken and the electrons shared in the bond become localized on oxygen.

The mouth is small and tubular, typical of species that feed on termites.

The family consists of a single genus Xeronema with two species, one found only on the Poor Knights islands in New Zealand and the other in New Caledonia.

** Eunectes murinus, the green anaconda, the largest species, is found east of the Andes in Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia, Brazil and on the island of Trinidad.

However, this name is used to refer to the brown vine snake, Ahaetulla pulverulenta, a slender, arboreal species that grows to five feet ( 152 cm ) at most and feeds only on small vertebrates.

Although originally considered a subspecies of A. ramidus, in 2004 anthropologists Yohannes Haile-Selassie, Gen Suwa, and Tim D. White published an article elevating A. kadabba to species level on the basis of newly-discovered teeth from Ethiopia.

A relation can be both symmetric and antisymmetric ( e. g., the equality relation ), and there are relations which are neither symmetric nor antisymmetric ( e. g., the " preys on " relation on biological species ).

The fully neutral form ( structure ( 1 ) on the right ) is a very minor species in aqueous solution throughout the pH range ( less than 1 part in 10 < sup > 7 </ sup >).

There are four to ten of these holes, depending on the species.

Prohibitions on commercial and recreational harvest of this species have been in place since 1996.

A few species of hummingbirds, notably some hillstars, can be seen at altitudes above, but far higher diversities can be found at lower altitudes, especially in the humid Andean forests (" cloud forests ") growing on slopes in Colombia, Ecuador, Peru, Bolivia and far northwestern Argentina.

Scientists disagree on the content of the genus, with some recognizing Gorgosaurus libratus as a second species.

The largest species are red alder ( A. rubra ) on the west coast of North America, and black alder ( A. glutinosa ), native to most of Europe and widely introduced elsewhere, both reaching over 30 m. By contrast, the widespread Alnus viridis ( green alder ) is rarely more than a 5 m tall shrub.

He was considered the 19th century's leading expert on the geographical distribution of animal species and is sometimes called the " father of biogeography ".