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
Golding Bird classified by the chemistry of the nucleus, but determined that they all fell within two overall groups: organic stones caused by a misfunctioning bodily process, and excessive inorganic salts causing sediment on which the stone could nucleate. In 1842, Bird became the first to describe oxaluria, sometimes called Bird's disease, which is caused by an excess of oxalate of lime in the urine. This is the second most common cause of kidney stones, the first being uric acid and its ammonium salt. There are several others, such as ammonium oxalate. In his great work "Urinary Deposits", Bird devotes much space