Breeding ecology of snowy plovers at Great Salt Lake, Utah

I studied the breeding ecology of snowy plovers (Charadrius alexandrinus) at Great Salt Lake, Utah, from 1990 to 1993. Plovers began arriving in late March, nests were initiated from mid April to mid July, and most adults departed by late August. Both sexes shared incubation duties, but only males cared for broods. Most plovers in Utah were monogamous, at least one was sequentially polyandrous, and the majority were potentially double-brooded. Annual nest success was poor (range = 5.4%-49.2%). Most nest failures (92.8%) were due to predators, primarily red foxes (Vulpes vulpes).;I uniquely color-banded and subsequently resighted 44.7% of the females (n = 199) and 52.5% of the males (n = 162). Adult annual survival estimates did not differ between the sexes and ranged from.578 to.880 (;The movement of banded birds around Great Salt Lake implied that snowy plovers breeding there represent a metapopulation. Ecological nest density (i.e., number of nests ;Plovers typically nested on salt flats; approximately 75% of the area within a 15-m radius of nests was bare ground. Microhabitat characteristics appeared to affect nest-site selection; 68% were associated with an object (e.g., dead shrub, woody debris). When nest success was relatively high, nests under objects were more successful than those in other microhabitats. Nests situated in habitat patches with high densities of potential nest sites tended to be more successful than those in other patches. Plovers readily used experimental nest substrates and drawdown areas, both of which could be effective management tools.;The primary threat facing plovers today at Great Salt Lake is nest predation by red foxes (Vulpes vulpes). A management plan may have to be developed to help alleviate this problem.