females, or will actively search for them. Their vocalization is a high-pitched, sonorous trill lasting an average of 2.6 seconds and repeated frequently. Males intermittently call from pool margins, under logs, or inside willows to attract females. When females arrive, they are immediately grasped in amplexus by one or multiple males as the males fight for a limited number of mating opportunities. Breeding sex ratios can be very skewed toward males since females breed less frequently than males, although both sexes typically do not breed in consecutive years. While in amplexus, females will lay one clutch of 1,000–2,000 eggs. Eggs hatch after 1–2 weeks, and the length of time depends heavily on ambient temperature and fluctuations in temperature. Females generally breed once and leave after 2–3 days, while males remain for 1–2 weeks. Habitat use The species primarily uses montane and subalpine wet meadows for breeding, but will occasionally breed in ephemeral ponds, lake margins, or other riparian areas. Flatter, southwesterly meadows, with more precipitation, containing warmer waters seem to be favored by the species. More specifically, breeding takes place in shallow snowmelt ponds or flooded areas, and eggs are usually deposited in water less than 5 cm deep. Shallow water makes eggs vulnerable to freezing, because nighttime temperatures are particularly low during springtime snow melt off. Females will sometimes split their clutch into multiple areas, or deposit their clutch communally with other pairs in a single area. The relatively large amount of pigmentation in eggs and tadpoles is thought to help expedite development, and tadpoles will congregate in the shallowest, warmest margins of ponds during the day. At nighttime tadpoles settle down into the silty detritus where they are more insulated from the cold nighttime temperatures. This often gives their pools the appearance of "golf ball" texture, because tadpoles leave divots in the silt (see picture of breeding pool). It is not uncommon for a large number of breeding ponds to desiccate each season before tadpoles successfully metamorphose, hence there is apparently a selective tradeoff between shallow ponds (which accelerate tadpole development) and ponds with long hydroperiods (which ensure survival). Time from hatching to tadpole metamorphosis is 4–6 weeks, and this is highly dependent upon environmental factors (elevation, weather, food, competition) and possibly genetic background. Tadpoles are apparently unable to overwinter. Subadult and adult habitat use patterns are poorly understood. Metamorphs appear to move away from breeding ponds soon