The subspecies is named after I. R. P. Heslop, who claimed in 1945 to have shot a pygmy hippo in the Niger Delta region and collected several skulls.

The subspecies R. t. platyrhynchus from Svalbard island is very small compared to other subspecies ( a phenomenon known as insular dwarfism ), with females having a length of approximately, and a weight around in the spring and in the autumn.

Other populations ( e. g., in Europe ) have a shorter migration, and some, for example the subspecies R. t. pearsoni and R. t. platyrhynchus ( both restricted to islands ), are residents that only make local movements.

* † Arctic reindeer ( R. tarandus eogroenlandicus ), an extinct subspecies found until 1900 in eastern Greenland.

* Svalbard reindeer ( R. tarandus platyrhynchus ), found on the Svalbard islands of Norway, is the smallest subspecies of reindeer.

Very similar to R. tarandus groenlandicus, and probably better regarded as a junior synonym of that subspecies.

* † Queen Charlotte Islands caribou ( R. tarandus dawsoni ) from the Queen Charlotte Islands was believed to represent a distinct subspecies.

* R. leucophrys leucophrys, the nominate subspecies, is the most widely distributed form found in Australia.

The Madeira Firecrest was formerly considered to be a subspecies, R. i. madeirensis, of the Common Firecrest R. ignicapillus.

A phylogenetic analysis based on the cytochrome b gene showed that the Madeiran form is distinct at the species level from the Firecrest nominate subspecies R. i. ignicapillus.

They were sometimes called the Tenerife Goldcrest, no matter which of the islands they lived on ; however, a 2006 study of the vocalisations of these birds indicate that they actually comprise two subspecies of the Goldcrest that are separable on voice ; R. r. teneriffae occurring on Tenerife and the newly described subspecies, R. r. ellenthalerae, occurring on the smaller islands of La Palma and El Hierro.

One researcher has suggested the Javan rhino on Sumatra belonged to a distinct subspecies, R. s.

The southern subspecies R. l. aequatorialis is sometimes split as the Ecuadorean Rail Rallus aequatorialis.

The eastern subspecies, R. a. indicus, has distinctive markings and a call that is very different from the pig-like squeal of the western races, and is sometimes split as a separate species.

At the genetic level, the two Central Asian forms, R. r. sikkimensis and R. r. himalayensis, are very close to each other, and have differentiated only in the recent past, but they diverged from the western subspecies around 2. 8 mya.

A difference between subspecies might explain the great range in size.

It is possible that especially large anacondas will prove to belong to subspecies limited to a small area.

In snakes difference in size is a common characteristic of subspecies.

There are two subspecies: Proteles cristatus cristatus of Southern Africa and Proteles cristatus septentrionalis of East Africa.

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.

The most comprehensive treatment of the family considers 56 species valid, with 18 additional subspecies.

During the Neolithic Revolution, which occurred during the early Holocene, there were at least two aurochs domestication events: one related to the Indian subspecies, leading to Zebu cattle ; the other one related to the Eurasian subspecies, leading to taurine cattle.

The Mexican tetra has been treated as a subspecies of A. fasciatus, the banded tetra, but this is not widely accepted.

It is usually resident all year, except in the coldest parts of its range, and in the case of one subspecies.

Buzzard subspecies fall into two groups.

Adult bears generally weigh between and its largest subspecies, the Kodiak bear, rivals the polar bear as the largest member of the bear family and as the largest land-based predator.

There are several recognized subspecies within the brown bear species.

In North America, two types are generally recognized, the coastal brown bear and the inland grizzly bear, and the two types could broadly define all brown bear subspecies.

The exact number of overall brown subspecies remains in debate.

However, the Californian, North African ( Atlas bear ), and Mexican subspecies were hunted to extinction in the 1870s, 1922, and more recently, respectively, and the not officially recognized Marsican brown bear in central Italy is believed to have a population of just 30 to 40 bears.

Some systems have proposed as many as 90 subspecies, while recent DNA analysis has identified as few as five clades.

DNA analysis recently revealed that the identified subspecies of brown bears, both Eurasian and North American, are genetically quite homogeneous, and that their genetic phylogeography does not correspond to their traditional taxonomy.

As of 2005, 16 subspecies have been recognized.

Bongos are further classified into two subspecies: Tragelaphus eurycerus eurycerus, the lowland or " western bongo ", and the far rarer Tragelaphus eurycerus isaaci, the mountain or " eastern bongo " restricted to north-eastern Central Africa.

Two other subspecies are described from West and Central Africa, but taxonomic clarification is required.

***** Domestic zebu, Bos indicus ( increasingly considered a subspecies of Bos primigenius )

There is some variation in the twelve subspecies of House Sparrow, which are divided into two groups, the Oriental indicus group, and the Palaearctic domesticus group.

Of the less widespread indicus group subspecies, P. d. hyrcanus is larger than P. d. indicus, P. d. hufufae is paler, P. d. bactrianus is larger and paler, and P. d. parkini is larger and darker with more black on the breast than any other subspecies.

The subspecies groups are: P. p. porphyrio in the Mediterranean, P. p. madagascariensis in Africa, P. p. poliocephalus in tropical Asia, P. p. melanotus in much of Australasia, P. p. indicus in Indonesia and P. p. pulverulentis in the Philippines.

Three subspecies are recognized — Elephas maximus maximus from Sri Lanka, the Indian elephant or E. m. indicus from mainland Asia, and E. m. sumatranus from the island of Sumatra.

The subspecies indicus is found in peninsular India and Sri Lanka.

In 1924, an all-black tapir was sent to Rotterdam Zoo and was classified as a subspecies called Tapirus indicus brevetianus after its discoverer, Captain K. Brevet.