Dunnock relatively lower success for females. In times of scarcity, female territories expand to accommodate the lack of resources, causing males to have a more difficult time monopolizing females. Hence, females gain a reproductive advantage over males in this case. The dunnock possesses variable mating systems. Females are often polyandrous, breeding with two or more males at once, which is quite rare among birds. This multiple mating system leads to the development of sperm competition amongst the male suitors. DNA fingerprinting has shown that chicks within a brood often have different fathers, depending on the success of the males at monopolising
Common redpoll Common redpoll The common redpoll ("Acanthis flammea") is a species of bird in the finch family. It breeds somewhat further south than the Arctic redpoll, also in habitats with thickets or shrubs. The common redpoll was listed in 1758 by Linnaeus in the 10th edition of his "Systema Naturae" under the binomial name "Fringilla flammea". The current genus name "Acanthis" is from the Ancient Greek "akanthis", a name for a small now-unidentifiable bird, and "flammea" is the Latin for "flame-coloured". The common redpoll was previously placed in the genus "Carduelis". Molecular phylogenetic studies showed that the Arctic and common redpolls