This photo of a hybrid between a red kangaroo (Macropus rufus)and a great grey kangaroo (Macropus giganteus) was taken at the Rothschild Zoological Museum in Tring. It was probably bred at the end of the 19th Century.

Over a 10 year period, Eastern and Western grey kangaroos were bred in enclosures. All western subspecies interbred freely. Western grey kangaroo males bred with Eastern grey kangaroo females and produced hybrid young. Eastern grey kangaroo males did not breed with Western grey kangaroo females. The male hybrids were sterile. The female were fertile and readily backcrossed with male western grey kangaroos. (Poole, WE "Reproduction in the Two Species of Grey Kangaroos, Macropus Giganteus Shaw and M. Fuliginosus (Desmarest). Ii. Gestation, Parturition and Pouch Life." Australian Journal of Zoology 23(3) 333 - 353 (1975))

Several wallaby or wallby/kangaroo hybrids have been experimentally bred. The male parent is given first:

- Hill wallaroo (Macropus robustus) X red kangaroo (M rufus) produced an infertile female hybrid with only one ovary
- Swamp/Black wallaby (Wallabia bicolor) X Red-necked wallaby (M rufogriseus) produced a sterile male hybrid
- Agile wallaby (M agilis) X Red-necked wallaby (M rufogriseus) produced a sterile male hybrid
- Tammar Wallaby (M eugenii) X Black striped wallaby (M dorsalis) produced a sterile male hybrid

All of the above hybrids showed a mix of traits from both parents and all were found to be sterile (the female may have been so poorly fertile as to be considered sterile). Although the males had testes, they did not produce sperm and some were found to have Y-chromosome abnormalities. (MJ Smith, DL Hayman and RM Hope, "Observations on the chromosomes and reproductive systems of four macropodine interspecific hybrids" Australian Journal of Zoology 27(6) 959 - 972 (1979))

Hybrids have also been bred from male red kangaroo X female wallaroo and, based on the research of Smith, Hayman and Hope, are assumed to be sterile.

Hybrids of Garden Island Tammars (Scrub Wallabies, Macropus eugenii) and Kangaroo Island Tammars have been bred. These wallabies have been physically separated for at least 10,000 years and, though classified as the same species and interfertile, have genetic differences. Hybrids of Tammar Wallaby and Pademelon (Thylogale sp. a small Wallaby-like marsupial) have also been attempted. (ARC Centre for Kangaroo Genomics: "Breeding marsupial hybrids to provide markers for mapping" by Marilyn Renfree, Des Cooper, Geoff Shaw, Cathy Herbert). To create hybrids, the young from one species must be transferred into the pouch of a mother from the other species (called cross-fostering). This imprints the young on the foster-species. In addition to cross-fostering, hybrids of Tammar Wallabies and and Parma (Macropus parma) were created using in-vitro fertilization. The hybrid embryos can be implanted into a female of either species.

Note: A wallaroo is a macropod, intermediate in size between kangaroos and wallabies. The name "wallaroo" is a portmanteau of wallaby and kangaroo, but the walleroo is not a hybrid.

Textual content is licensed under the GFDL.