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
Bird Creek Creek and had threatened to close some of the oil wells nearest the site. Bird Creek Bird Creek is a stream in northeast Oklahoma. The main creek is formed from the waters of North Bird Creek, Middle Bird Creek, and South Bird Creek, all of which rise in Osage County. The South and Middle branches of the creek converge at Bluestem Lake. Outflow from the lake is called Middle Bird Creek. North Bird Creek joins Middle Bird Creek northwest of Pawhuska, and from that point on is simply Bird Creek. From Pawhuska, the creek flows southeastward and eastward through the