We used tag?recapture data to estimate apparent survival and capture probability for 119,129 hatchery-reared, federally endangered razorback suckers Xyrauchen texanus stocked into upper Colorado River basin streams during 1995?2005. Effects investigated included reach, year, and season of stocking; fish total length (TL) at time of stocking; survival in the first year after stocking versus in subsequent years; and sampling effort. Recapture data were also used to describe poststocking movement. First-year survival rate for stocked razorback suckers of average TL (252.5 mm) was low: 0.05 (95% confidence interval [CI], 0.042?0.071). Total length at stocking and first-year survival were positively correlated; survival approached zero [...]
