Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species.

Temporal variation in natural selection is predicted to strongly impact the evolution and demography of natural populations, with consequences for the rate of adaptation, evolution of plasticity, and extinction risk. Most of the theory underlying these predictions assumes a moving optimum phenotype, with predictions expressed in terms of the temporal variance and autocorrelation of this optimum. However, empirical studies seldom estimate patterns of fluctuations of an optimum phenotype, precluding further progress in connecting theory with observations. To bridge this gap, we assess the evidence for temporal variation in selection on breeding date by modeling a fitness function with a fluctuating optimum, across 39 populations of 21 wild animals, one of the largest compilations of long-term datasets with individual measurements of trait and fitness components. We find compelling evidence for fluctuations in the fitness function, causing temporal variation in the magnitude, but not the direction of selection. However, fluctuations of the optimum phenotype need not directly translate into variation in selection gradients, because their impact can be buffered by partial tracking of the optimum by the mean phenotype. Analyzing individuals that reproduce in consecutive years, we find that plastic changes track movements of the optimum phenotype across years, especially in bird species, reducing temporal variation in directional selection. This suggests that phenological plasticity has evolved to cope with fluctuations in the optimum, despite their currently modest contribution to variation in selection.

The increase of urban areas has led to a fragmentation of habitats for many forest-living species. Man-made parks might be a solution, but they can also act as sinks that are unable to maintain themselves without immigration from natural areas. Alternatively, parks might act as true metapopulations with extinctions and colonizations. In both cases, we can expect genetic variation to be reduced in the parks compared to the natural habitat. A third alternative is that the parks have sufficient reproduction to maintain themselves. To test these hypotheses, we analysed the pattern of genetic variation in the great tit (Parus major) in 12 parks in central Barcelona, and in an adjacent forest population using microsatellites. Genetic variation was not lower in the parks compared to the forest population, but larger, and gene flow was higher from the town to the forest compared to vice versa. We found a significant genetic differentiation among the parks, with a structure that only partly reflected the geographic position of the parks. Relatedness among individuals within parks was higher than expected by chance, although we found no evidence of kin groups. Assignment tests suggest that some parks are acting as net donors of individuals to other parks.

An evaluation of monk parakeet damage to crops in the metropolitan area of Barcelona.-We evaluated damage to commercial crops caused by the monk parakeet, Myiopsitta monachus, in the Baix Llobregat agricultural area (1,024 ha) bordering the city of Barcelona, Spain. Average crop loss was 0.4% for tomatoes, 28% for corn, 9% for red plums, 36% for round plums, 37% for pears, 17% for persimmons, and 7% for quinces. Our data show that the potential damage to crops by monk parakeets in this invaded area is now a reality. As a wait-and-see approach is likely to be a more costly strategy in the long-term, policy makers should assess issues such as the extent of damage, feasibility/cost benefit analysis, and public opinion so as to avoid greater damage and loss in the future.

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BACKGROUND The monk parakeet Myiopsitta monachus (Boddaert), native to South America, is an invasive species in several European countries, causing crop damage and potential negative impacts on wildlife. Only Spain and Great Britain have regulations to control monk parakeets, thus fast growth and spread of populations are likely to occur on a wide scale. The aims of this research are to update information on the distribution and population size of monk parakeets in Europe, assess whether differences in population growth or spread rate exist between populations, and provide recommendations to decision‐makers. RESULTS Our study estimates that there are 23 758 monk parakeets in the wild, across 179 municipalities in eight European Union (EU) countries; 84% of these municipalities hold between 1 and 100 monk parakeets. All countries with a representative historical record are experiencing exponential growth of monk parakeets. Mediterranean countries are experiencing higher exponential growth, spread rate and faster colonization of new municipalities than Atlantic countries. CONCLUSIONS We recommend that EU Mediterranean countries consider declaration of the monk parakeet as invasive alien species of regional concern, and develop coordinated efforts to monitor and manage the species, taking advantage of the low population sizes in most municipalities. © 2019 Society of Chemical Industry

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