Summary1. Dispersal contributes to spatio-temporal variation in population size and is a key process in studies of life history evolution and studies with conservation implications. However, dispersal is still one of the major gaps in our knowledge of ecological dynamics. The very large literature on metapopulation dynamics lacks empirical bases on dispersal and relevant behavioural parameters. We used multistate capturerecapture models (data from 1988 to 2001) to address hypotheses about movement probability and habitat selection within a system of two breeding colonies in Audouin's gulls ( Larus audouinii ), an endemic species breeding in the Mediterranean and considered as threatened. 2. Movement probability varied over time, and differed greatly between the colonies. 3. We did not find evidence of an influence of colony size or density of predators on movement probability. 4. In dispersers, our results did not support the hypotheses that movement probability between year t and t + 1 was influenced by mean breeding success in the colony of origin (i.e. an indicator of habitat quality) or the destination colony in year t or t + 1, or by the ratio of breeding success in these colonies in year t or t + 1 (i.e. quality gradient). 5. Overall, movement probability was higher from the smaller colony to the larger, and from the colony with lower breeding success in year t to the more productive one. This provides slight support for two nonexclusive hypotheses about habitat selection (conspecific attraction and conspecific success attraction). 6. Movement probability from the smaller, less productive colony was very high in some years, suggesting that the dynamics of both colonies were strongly influenced by adult dispersal. However, in absolute numbers, more individuals moved from the larger, more productive colony to the smaller one. This suggests that the system may function as a source-sink system. 7. Use of multistate models to re-assess local survival showed that survival was lower in the less productive colony with higher emigration probability. This may reflect genuine differences in mortality between colonies, or more probably differences in permanent emigration from the study area.

Summary 1.Wind farms are emerging as a major cause of mortality of large scavenging bird species, which may be catastrophic when they operate in concert with other threats. As a study model, we examine the impact of wind turbines on the population dynamics of a soaring bird species, when acting in conjunction with a sudden decrease in food availability following the European bovine spongiform encephalopathy (BSE) epidemic. 2. In Spain, vultures have been provided with supplementary food at traditional vulture restaurants for centuries. In 2006 ⁄ 2007, these feeding stations were closed as part of disease control measures. At the same time, wind farms were deployed within the vulture foraging range. We used capturerecapture data and direct observation to monitor the impacts of these changes on the vulture population. 3. The number of breeding pairs decreased by c. 24%, adult survival by 30% and fecundity by 35%. However, the population recovered as soon as the perturbations ceased, the vulture restaurants were reopened, and the most problematic wind turbines were closed. Population recovery was faster than predicted by a retrospective stochastic population model. 4. Our analyses indicate that fecundity and survival were influenced predominantly by wind turbines. Food scarcity promoted a shift in foraging behaviour that drove vultures to fly into the path of wind turbines as they sought out new food sources in a landfill site. Elasticity and sensitivity analyses of the population model showed that mortality of adult birds had a much greater effect on population declines than mortality of immature birds, whereas reduction in fecundity had negligible effects. 5. The most likely explanation for the rapid recovery of the vulture population is that the observed decline in breeding pairs was not solely because of increased mortality. The decline probably included dispersal away from the area and a greater incidence of skipped breeding during the perturbation years. Subsequent immigration from large nearby populations was probably a factor in population recovery. 6. Synthesis and applications. Where specific wind turbines are causing substantial mortality, their closure is an effective management response. For vulture populations dependent on supplemental feeding stations, the feeding sites should be relocated away from the most problematic wind turbines, or other anthropogenic sources of mortality, to prevent negative impacts. We recommend the establishment of scattered, low-value food sources to replicate historical conditions and to avoid the problems associated with high concentrations of individuals in one place.

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Schizophrenic patients are known to exhibit inhibitory impairments in response suppression and selective attention. However, the impairment of inhibitory control in memory retrieval has not clearly been documented. In two experiments, we investigate inhibition in memory retrieval by using the retrieval practice procedure. In Expt 1, a cued recall final test was used. Consistent with previous research, we found similar retrieval-induced forgetting (RIF) effects in schizophrenic patients and in controls. However, these effects could be the result of interference/blocking or the results of inhibition. In order to reduce the influence of blocking in Expt 2, we used a recognition test. We found that RIF was reduced in patients, compared to healthy controls. The elimination of RIF effect in patients, when the influence of blocking is reduced, indicates that inhibitory processes in memory are altered in schizophrenia. Result suggest that schizophrenic patients suffer from critical impairments in inhibitory processes involved in memory retrieval, similar to the inhibitory deficits found in other cognitive domains.