Abstract1. Effective prevention and control of invasive species generally relies on a comprehensive, coherent and representative list of species that enables resources to be used optimally. European Union (EU) Regulation 1143/2014 on invasive alien species (IAS) aims to control or eradicate priority species, and to manage pathways to prevent the introduction and establishment of new IAS; it applies to species considered of Union concern and subject to formal risk assessment. So far, 49 species have been listed but the criteria for selecting species for risk assessment have not been disclosed and were probably unsystematic.2. We developed a simple method to systematically rank IAS according to their maximum potential threat to biodiversity in the EU. We identified 1,323 species as potential candidates for listing, and evaluated them against their invasion stages and reported impacts, using information from databases and scientific literature. 4. Policy implications. We propose a systematic, proactive approach to selecting and prioritising IAS for risk assessment to assist European Union policy implementation.We assess an unprecedented number of species with potential to harm EU This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Introduced predators are one of the main threats to island avifaunas. However, the magnitude of their impact in the Mediterranean has not often been studied. This is the case for the introduced alien black rats Rattus rattus, the most destructive predator of seabirds in the Mediterranean. Here, we analyse the impact of black rats on the breeding performance of Cory's shearwater Calonectris diomedea breeding at the Chafarinas Islands, an archipelago with a very high density of rats. An intensive rat control campaign (through anticoagulant poison) was carried out during 1999–2004 at two shearwater sub‐colonies with contrasting habitat features (vegetated vs. rocky). Breeding success of Cory's shearwaters increased in proportion to the effort of rat control. Such increase was mainly due to a decline in black rat predation on chicks, while eggs losses remained constant throughout the period. We found a differential effectiveness of rat control in each sub‐colony. The increase in breeding success after rat control was higher in the sub‐colony with lower breeding success (the vegetated habitat), but this parameter never reached the values shown by the other sub‐colony (the rocky habitat). Our results suggest that habitat characteristics of each case of study must be taken into account when designing and evaluating specific rat control programs.

The northern bald ibis Geronticus eremita was once widespread throughout the Middle East, northern Africa, and southern and central Europe. Habitat destruction, persecution and the impacts of pesticides have led to its disappearance from most of its former range. It disappeared from central Europe > 400 years ago, but has persisted as a relict and slowly growing breeding population in Morocco, where c. 700 wild birds of all ages remain. In Algeria, the last confirmed breeding was in 1984; in Turkey the fully wild population disappeared in 1989, but a population remains in semi-wild conditions. In Syria a small population was rediscovered in 2002, only to subsequently decline to functional extinction. Restoration programmes have been initiated independently in several locations, with over 300 free-flying birds resulting from reintroduction projects in Austria, Germany, Spain and Turkey, to restore both sedentary and fully migratory populations. Maintaining current efforts in Morocco remains a high conservation priority.

. 1993. Tooth wear and its relation to kind of food: The repercussion on age criteria in Capra pyrenaica. Acta theriol. 38: 93 -102.Tooth wear was studied in two Iberian populations of Capra pyrenaica Schinz, 1838. Age-specific variation in type of wear and molar height was compared between sites. Age-specific wear of Mi and M3 was different between the two populations. The relationship of molar height and age (assumed to be wear rate) was also different in each population. The largest differences were found if we consider tooth wear rate as the sum of Mi height + height of mandible. The population of ibex from Gredos appeared to have a much faster tooth wear rate than of Cazorla. The relationship between the results and food types in the different mountain ranges are discussed. A positive relationship was found between tooth wear and the presence of abrasive elements in the diet. Tooth wear appears to be highly population-specific and this implies important consequences for their life history. Our results question the validity of age-determination techniques based on tooth wear for inter-populational comparisons.Museo Nacional de Ciencias Naturales, José Gutiérrez Abascal, 2. 28006 Madrid, Spain

We show the results of an eradication campaign against Rattus rattus developed in Rey Francisco Island (12 ha), Chafarinas islands, southwestern Mediterranean. Rat population size was estimated by snap trapping in up to 93.47 ind./ha and a trapping index of 9.58 captures/100 traps-night. We think that population was underestimated because of the number of traps found strung but without capture. Several products were tested in order to define the method of eradication. In 1992, we selected a second generation anticoagulant, pelleted brodifacoum 50 ppm into 5 l plastic containers as baiting stations. Bait consumption reached zero after three pulses, and intensive searching of tracks and signals were unsuccessful. After more than two years of absence of signals and sightings, in 1995, rat scats were observed in Rey Francisco, and the population rose dizzily. After several snap-trapping sessions in 1996, 1997 and 1999, when trapping success reached 37 captures/100 trap-nights, a new campaign started in autumnÀwinter 1999À2000 using flocoumafen 50 ppm inside 180 baiting stations. Eradication occurred with a very low risk for non-target fauna, setting less than 1 kg/ha of bait each time. Monitoring, both with snap traps and baiting at a lower intensity assures the absence of reinvasion.