Predator visitation to acclimatization or soft-release pens containing captive translocated animals has the potential to cause sub-lethal effects or physical injury that could influence post-release survival and establishment. No previous study has examined potential interactions between captive and resident animals during pre-release holding periods. We monitored seven holding pens containing wild-caught northern bobwhite Colinus virginianus or scaled quail Callipepla squamata in the Rolling Plains Ecoregion of Texas, USA, using remote camera systems. Our objectives were to determine if resident predator species and conspecifics visited holding pens, and to characterize visits by species, frequency, duration and behaviour. We recorded visitation to holding pens by four potential predator species. Although most visits by mammalian predators were short in duration, northern raccoons Procyon lotor were observed spending extended periods of time at holding pens. We also recorded resident scaled quail and northern bobwhite quail visiting holding pens containing conspecifics. We recommend that future studies using a soft-release technique in which captive animals are held at the release site consider the potential impacts of predator visitation to holding pens, and methods to mitigate those impacts.

In 2015 10 Iberian lynxes Lynx pardinus were released in south-eastern Portugal, within the framework of a Spanish–Portuguese reintroduction project. We examined each individual's use of space and social interactions during the first year after their release. Lynxes were selected for reintroduction according to behavioural, genetic and health criteria and fitted with collars with VHF and global positioning systems. Both males and females went through an exploratory phase that lasted 65–105 days. The lynxes did not exhibit any movement directionality from the release site during the exploratory period. During August–December 2015 a stable nucleus comprising seven individuals (four males, three females) was established south-west of the release enclosure. Although the males had a slightly larger mean home range (11.18 ± SE 1.36 km2) than females (9.87 ± SE 8.71 km2), the difference was not significant. The knowledge obtained during the first year of the lynx reintroduction project in Portugal is critical to support the future of this reintroduction strategy. Our results suggest that once the soft release technique is no longer possible because of logistical constraints on the construction of more enclosures, new individuals should be released in unoccupied areas surrounded by occupied territories. This will promote strong social ties to the resident population and prevent lynx dispersal.

The term ‘field propagation and release’ refers to the breeding of captive adults in large field enclosures, allowing them to raise their young, and then releasing those young from that location. This technique is currently being implemented in Canada as one of several recovery tools for the endangered eastern loggerhead shrike Lanius ludovicianus migrans. During 2001–2007 a total of 360 shrike fledglings were produced in field propagation enclosures and 301 were released from these enclosures. Annual return rates of birds released since 2004 are 2–6.6%. Seventeen released birds have been re-sighted, including 10 birds that have returned to the breeding grounds the following season to produce young with wild mates. The high annual return rate of release birds and the successful integration of these birds into the wild breeding population represent important milestones for the recovery of this population. The management technique we describe here has the potential to be applicable to other species that require natural habitat for breeding and/or are reliant on a suite of parent-learned behaviours that cannot be accommodated for or adequately replicated within intensive close captive-breeding or hand-rearing conditions.