Please cite this article as: Horton, M., Keys, A., Kirkwood, L., Mitchell, F., Kyle, R., Roberts, D.,Sustainable catchment restoration for reintroduction of captive bred freshwater pearl mussels Margaritifera margaritifera., Limnologica (2014), http://dx. AbstractThe Ballinderry River, Co. Tyrone (SAC), is one of only six rivers in Northern Ireland that still supports a population of the globally endangered freshwater pearl mussel, Margaritifera margaritifera. Fewer than 1000 individuals still exist in the river; without intervention it is predicted the Ballinderry pearl mussel will be extinct by 2098. This paper aims to identify key catchment pressures on remaining mussel stocks and prioritise tributaries within the catchment for remediation work to ensure effective targeting of limited resources. A combination of redox assessment, river surveys and SCIMAP modelling was used to rank tributaries, taking into consideration their size and proximity to the main mussel population at the "sanctuary site". Diffuse and point sources of sediment were identified within the prioritised catchment. The Tulnacross tributary was selected as the highest priority tributary and has been used in a pilot remediation study. A number of different hard and soft engineering techniques have been used for remediation as well as replacing cattle drinkers with pasture pumps and fencing alongside the river. Initial observations suggest river substrate is cleaner. This study is an example of how to tackle problems within a large-scale catchment with limited resources with participation of local stakeholders and riparian landowners.

American black bears (Ursus americanus) have recolonized western Texas following extirpation in the mid‐1900s. Knowledge of winter ecology of black bears is important for conservation and management because denning, parturition, and early cub development occur during this period. We monitored 13 radiocollared black bears for 22 den‐years in Big Bend National Park (BBNP) during 1998–2003. All pregnant females (n = 6), 2 females with yearlings, 7 subadults, and 1 adult male denned. Three females with yearlings remained active during winter 1998–1999. We located 4 cave dens, 5 ground dens, and 6 rock‐pile dens. Volume and elevation of den sites averaged 2.00 m3 (SD = 1.51) and 1,800 m (SD = 346), respectively. Mean (±SD) dates of den entrance and emergence for 5 pregnant females were 30 December±17 days and 27 April±21 days, respectively, producing a mean denning period of 118±29 days. Pregnant females exited dens later (P= 0.003) and denned longer (P=0.02) than solitary females and males. Black bears in western Texas used den sites located in higher elevations that were remote and highly defensible. A den‐habitat model described less than 56 km2 of suitable denning habitat within and bordering BBNP. Resource managers should reduce visitor and management activities in and around potential denning areas during winter.