| There were also large differences between populations in diversity, some of the populations being monomorphic and some polymorphic. |
| The house wren is a small, sexually monomorphic and monochromatic migratory songbird that breeds throughout much of North America. |
| Siberian jays are sexually monomorphic with a substantial overlap in size between sexes. |
| The black guillemot is a sexually monomorphic seabird that exhibits marked interpair variation in a number of breeding parameters. |
| Molecular sexing can provide an added benefit, especially for sexually monomorphic species. |
| In each case, interbreeding between the uniformly coloured monomorphic and sexually distinct dimorphic populations is limited. |
