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Understanding how different ecological and evolutionary processes influence the distribution of pathogens within the environment is important from many perspectives including wildlife epidemiology, evolutionary ecology and conservation. The simultaneous use of ecological and evolutionary frameworks can enhance our conceptual understanding of host-parasite interactions, however such studies are rare in the wild. Using samples from 12 bird species caught across all habitats existing on an oceanic island, we evaluated how environmental variables, parasite host specificity and parasite phylogenetic relationships determine the distribution and prevalence of haemosporidians (Haemoproteus, Plasmodium and Leucocytozoon) in the wild living avifauna. Differences were found in the prevalence of Plasmodium, but not Leucocytozoon, strains between habitats. The warmest temperature best predicted Plasmodium prevalence in the low altitude habitats, which had the highest incidence of Plasmodium. The prevalence of Leucocytozoon lineages was associated with natural factors, i.e. rainfall, temperature and habitat, but the two most important predictors (from model averaging) for models of Leucocytozoon were anthropogenic: poultry farms and distance to a water reservoir. We found no relationship between local (Tenerife, Canary Islands) versus global host range indices (which assess the diversity of hosts that a parasite is observed to infect), thus global generalist lineages do not behave in the same way on Tenerife (i.e. they infected less avian hosts than was expected). Phylogenetic analysis revealed that the most abundant haemosporidians on Tenerife grouped with lineages found in African host species. Our data indicate that climatic and anthropogenic factors, plus proximity to the African mainland, are the main factors influencing the presence and distribution of avian haemosporidians on Tenerife. Future climate projections for the archipelago foresee significant temperature increases which would, given our results, increase rates of Plasmodium infection in bird species in all habitats. Such patterns could be of concern if those increase mortality rates in the unique avifauna of these islands., DPP was supported by a postdoctoral fellowship (based at the University of East Anglia (UEA), UK) from the Spanish Ministry of Economy and Competitiveness. CGQ was funded by a PhD grant from Colciencias, Colombia and by the School of Biological Sciences at UEA. JCI was supported by the Spanish Administration of National Parks, Spanish Minister of Agriculture, Food and Environment (grant ref.: 375/2011).

Secondary seed dispersal is a multistep process with two or more phases, which involve different dispersers that usually extend the distance from the seed's parent plant. This ecological process has been recorded in some subtropical oceanic islands, where predatory birds commonly consume frugivorous lizards and disperse seeds already consumed by the lizards. We evaluated the overall importance of this type of secondary dispersal in the Canary Islands, the only place worldwide where it has been studied in depth. From an examination of all the islands and their suitable habitats, we found seeds from 78 plant species inside 2098 shrike pellets and 5304 kestrel pellets. A greater number of species were secondarily dispersed by kestrels (76; 97%) than by shrikes (26; 34%). Forty-four (56%) of the total species detected in pellets were identified at the species level, comprising 73% native and 27% introduced species. Seventy per cent of these identified species were fleshy fruit-bearing plants and 84% of the interactions took place in open habitats, close to coastal areas. Germination experiments showed that seeds of at least 32 plant species were viable after being removed from the bird pellets. A similar pattern of seed germination was detected for seeds from the droppings of lizards and pellets of shrikes, showing both to be effective dispersers. However, the seeds dispersed by kestrels had different levels of success depending on the number of gut passages experienced. Seeds that had undergone double gut treatment (lizard and secondary ingestion by kestrel) had reduced germination rates of many small- and medium-sized seeds compared with seeds ingested by lizards and discarded inside the lizard guts by kestrels. We also studied the relationship between body length and gape width of lizards in order to assess limitations on the sizes and quantities of seeds available for secondary dispersal. Kestrels can disperse a greater number and variety of seeds because they predate larger lizards that potentially carry greater seed loads. Synthesis. The current results show how these non-standard long-distance dispersal events produced by predatory birds can be considered as a regular and generalized process on all islands of the Canary archipelago. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society.

Pathogens can exert strong selective forces upon host populations. However, before we can make any predictions about the consequences of pathogen-mediated selection, we first need to determine whether patterns of pathogen distribution are consistent over spatiotemporal scales. We used molecular techniques to screen for a variety of blood pathogens (avian malaria, pox and trypanosomes) over a three-year time period across 13 island populations of the Berthelot's pipit (Anthus berthelotii). This species has only recently dispersed across its range in the North Atlantic, with little subsequent migration, providing an ideal opportunity to examine the causes and effects of pathogenic infection in populations in the early stages of differentiation. We screened 832 individuals, and identified two strains of Plasmodium, four strains of Leucocytozoon, and one pox strain. We found strong differences in pathogen prevalence across populations, ranging from 0 to 65%, and while some fluctuations in prevalence occurred, these differences were largely stable over the time period studied. Smaller, more isolated islands harboured fewer pathogen strains than larger, less isolated islands, indicating that at the population level, colonization and extinction play an important role in determining pathogen distribution. Individual-level analyses confirmed the island effect, and also revealed a positive association between Plasmodium and pox infection, which could have arisen due to dual transmission of the pathogens by the same vectors, or because one pathogen lowers resistance to the other. Our findings, combined with an effect of infection on host body condition, suggest that Berthelot's pipits are subject to different levels of pathogen-mediated selection both across and within populations, and that these selective pressures are consistent over time., Grant from the Natural Environment Research Council to DSR and LGS, and a Spanish fellowship (Ramón y Cajal program) to JCI.

Although the Ring Ouzel has been considered accidental in the Canary Islands, it has been observed for the last five years in the high mountain zone of Tenerife (Canary Islands), showing it to be a regular winter visitor. Its interaction with female Juniperus cedrus cones and seeds was studied by analysing its wintering diet during January–April 2008. This juniper is endemic to the Canaries and Madeira and is classified as endangered by the IUCN. Previously, its sole long-distance disperser was known to be the Raven Corvus corax, which is unfortunately now extinct in the distribution range of J. cedrus. The results show that the diet of T. torquatus in Tenerife consists mostly of female J. cedrus cones (95% of the biomass consumed). Due to the large amount of seeds dispersed by Ring Ouzels and the effectiveness in seed germination, this winter visitor constitutes an important vector in the dispersal of J. cedrus that appears to have gone undetected in the past. This passerine plays a key role in...

Capsule Faecal DNA gives accurate results of habitat use.

Phenology and female cone characteristics of the two endemic cedars (Juniperus cedrus and J. brevifo- lia) from the Macaronesian islands were studied. Despite their closely taxonomic affinity and their evolution under insular conditions, different trends were recorded. Mature J. cedrus female cones were present throughout the year, while those from J. brevifolia were only present in summer and autumn. J. cedrus female cone size was significantly larger than that of J. brevifolia, a trend consistent with the presence of larger vertebrates (lizards and birds) in the Canary Islands. However, water content was four times higher in J. brevifolia female cones, which can be related with the higher rainfall existing in the Azores. J. cedrus has two or three seeds per cone, whereas J. brevifolia frequently had three. Seeds from J. cedrus were clearly larger and heavier, coinciding with the female cone size trend. However, tetrazolium tests revealed higher viability values in J. brevifolia. The relatively low percentage of filled seeds in J. cedrus could be a consequence of the climatic stress and limits to pollination due to fragmented populations as described for other Juniperus species. In summary, our results reveal that some environmental fac- tors such as the harsh conditions, high population frag- mentation and the dependence on large dispersers have compromised the fitness of J. cedrus in the Canary Islands.

The seasonal diet and prey selection of the Southern Grey Shrike (Lanius meridionalis) was studied in two different insular habitats: shrub environments of the Canary Islands in coastal and high mountain zones. We measured, in each season, food availability and prey size in order to determine prey size selection of shrikes along an altitudinal gradient. Moreover, we compared the diet patterns observed with those documented on the continent, to determine if Southern Grey Shrikes in the islands' high mountain zone (which has a continental climate) showed seasonal diet variation similar to those in northern continental areas. We analysed a total of 1,139 shrike pellets collected in 1 year and identified 10,179 prey items. Numerically arthropods (91%), and in terms of biomass lizards (70%) were the main prey consumed by the shrikes. The proportions of the main prey items differed significantly between seasons and habitats. Diet in the coastal areas was less variable than in the high mountain zone. The greater seasonal climatic variation in the high mountain zone was associated with diet patterns similar to those found in some northern continental areas, such as the Iberian Peninsula and southern France. Finally, shrikes selected the largest prey in the high mountain habitat. This suggests that foraging behaviour in this species is related to climatic conditions, as the biggest and most profitable prey were consumed in the most harsh habitats., David P. Padilla is currently financed by a PhD grant awarded by the Canarian Government. This contribution was part of two projects, one financed by the Spanish Ministry of Science and Technology (BOS2003-00044) and the other by the Canarian Government (PIO42004/037), both partially supported by the FEDER funds from the European Union. Our study complied with all the current laws of Spain.

Secondary seed dispersal is a multistep system that includes 2 or more dispersal processes that can increase the distance from which seeds arrive. This phenomenon is relatively common in some habitats of subtropical oceanic islands due to the frequent frugivore-predator interactions found in them. In this study, we describe how the Eurasian Kestrel is an effective disperser of plants in the secondary seed dispersal process, through interaction with frugivorous lizards. Experiments using captive wild kestrels, along with field data, showed that predation of kestrels on lizards leads to a secondary seed dispersal with 2 possible outcomes: 1) most seeds (89%) are not consumed by kestrels because they reject the lizards' digestive tracts and so receive only the gut treatment of lizards and 2) a small fraction of seeds (11%) appeared inside the kestrel pellets as a result of indirect ingestion by this raptor, thus undergoing double gut treatment. So, 2 different seed dispersal distances may result from this interaction: 1) when the kestrels capture the lizard and transport it to a perch where the seed-containing guts are discarded and 2) when they indirectly ingest a few seeds from lizards, consequently increasing the dispersal distance. Seeds from the Macaronesian plant species Rubia fruticosa were tested, finding that those passed through kestrels had a lower germinability than those that remained inside the rejected lizards' digestive tracts, which had similar germination rates to those from control plants (uningested seeds). The kestrel can be considered an important and effective long-distance seed disperser due to the high abundance of frugivorous lizards in their diet, their stereotyped consumption behavior, and the effectiveness of their seed dispersal., PhD Thesis grant, Canarian Government (to D.P.P).

Faecal DNA isolation identifies two Columba species P. M rrero et al. Short communic Molecular identification of two threatened pigeon species (Columbidae) using faecal samples PATRICIA MARRERO, 1 * VICENTE M. CABRERA, 2 DAVID P. PADILLA 1 & MANUEL NOGALES 1 1 Island Ecology and Evolution Research Group, IPNA-CSIC, La Laguna E-38206, Tenerife, Canary Islands, Spain 2 Department of Genetics, University of La Laguna, La Laguna E-38271, Tenerife, Canary Islands, Spain

6 pages, 1 figure, 1 table., Size-related selection of insular lizards by two sympatric predatory bird species (Southern Grey Shrike and Eurasian Kestrel) was studied in an arid insular environment. The endemic lizard genus Gallotia was a key resource in the diet of both predators, constituting more than 50% of the total biomass. Shrikes captured smaller lizards than kestrels during all seasons (mean snout-vent length (SVL): 7.4 ± 1.9 vs. 9.4 ± 2.1 cm respectively), presenting a sequential use of lizard sizes and avoiding potential competition. On the other hand, shrikes and kestrels showed the same seasonal variation pattern, capturing the largest lizards during their breeding periods (spring). Considering lizard availability, shrikes displayed less selective predation than kestrels in all seasons. Shrikes positively selected the medium lizard size (SVL: 5-10 cm) during the nestling period, but negatively selected the small lizard size (SVL: < 5 cm) in autumn and winter, probably due to an explosion of juvenile lizards. Lastly, kestrels appeared to be more selective, negatively choosing the small lizard size but positively selecting the largest ones all the year round (SVL: > 10 cm)., This research was supported by grants to David P. Padilla and Patricia Marrero from the Canarian Government and Proyectos Intramurales Especiales (2004 3 0E 169) of the Spanish National Scientific Research Council, respectively. It was also partially financed by the project PI042004/037 (Consejería de Educación, Cultura y Deportes, Gobierno de Canarias), which are partially supported by Feder funds from the European Union.

Summary 1 Secondary seed dispersal occurs whenever a seed is dispersed in two or more different dispersal events, so that different dispersal agents (e.g. animal frugivores or invertebrates) contribute to different events. Three secondary seed dispersal systems, in which lizards and predatory birds participate, are studied in Lanzarote (Canary Islands). 2 Seeds from all three plant species studied (Lycium intricatum, Rubia fruticosa and Asparagus nesiotes) were found with the remains of lizards (Gallotia atlantica) when they appeared inside shrike (Lanius meridionalis) and kestrel (Falco tinnunculus) pellets. This suggests that these two avian predators might secondarily disperse these plants by incidentally ingesting seeds when they prey upon the frugivorous lizards. 3 Lycium and Rubia seeds dispersed by Falco had significantly thinner seed coats compared to the other treatments (Gallotia and Lanius) and to uningested seeds. Correlated with this result, seed hardness increased from Lycium (the softest coat), to Rubia (intermediate values), to Asparagus. 4 Seed viability was high in all three species, although both viability and germination were significantly reduced in seeds of Lycium and Rubia dispersed by Falco. 5 The seed distribution was markedly different, Gallotia being an important disperser in the open ground microhabitats, Lanius in hillocks and Falco in hills. Because all three plant species were present in all these microhabitats, our observations suggest that the dispersal of these plants might be associated with the differential use of the habitat by the different dispersers. 6 Synthesis: Contrary to some long-distance seed dispersal (LDD) paradigms, the complex seed dispersal systems we describe are common and affect an important number of seeds that are moved each year to particular microhabitats. Finally, the simultaneous ecological factors analysed in this study support the hypotheses that diplochory by double endozoochory could have played a more important role in LDD events than is currently recognized, both in recent volcanic areas (lowlands) and also probably in the colonization of other subtropical islands.

Three chemical viability tests were evaluated in the seed dispersal system of Rubia fruticosa, in which three main groups of dispersers participate: reptiles, birds and mammals. Tetrazolium chloride (TTC) and indigo carmine (IC) indicated a lower viability of seeds from droppings of introduced rabbits (Oryctolagus cuniculus) than of those from control plants and the native dispersers, lizards and gulls. In the rabbit seed treatment, significant differences were observed between results obtained with TTC and IC tests. Interpretation of these data, due to the presence of doubtful embryo staining, was more difficult using the IC test. Furthermore, some seeds that were clearly dead had been underestimated. In contrast with results obtained from the two staining methods, the EC test did not confirm that viability of control seeds and those seeds consumed by native dispersers were clearly higher than in seeds ingested by O. cuniculus. Further, compared to the other two tests, the EC method requires more careful handling of the embryo during the extraction process to avoid errors in viability estimation, since this method measures concentration of electrolytes that are released through cellular membranes. Thus, TTC was the most reliable test to assess seed viability in the seed dispersal system of R. fruticosa, and these results agree with those obtained in previous germination experiments made on the same set of seeds given the same treatments.

A comparison of the germination rate of a Macaronesian endemic plant (Rubia fruticosa) between two xeric badland areas of the easternmost islands of the Canaries (Lanzarote and Fuerteventura) is presented. A similar germination rate was observed between both seed control plants from the populations of Lanzarote and Fuerteventura in the two years. However, some germination asynchronies were observed when the native frugivores participated in this seed dispersal system; seeds from Lanzarote germinated earlier than in Fuerteventura when they were consumed by lizards and birds. Although this pattern did not present a between-year consistency, seeds germinated earlier in the more stressed badland even when climatic differences are not so great. This asynchrony, caused by frugivorous dispersers (lizards and birds), is important in geographical zones where rain is unpredictable and where it increases the probability that seedlings can recruit successfully and for a longer period.

Summary 1. This study shows the first results obtained concerning the relative importance and effect on the seeds of a particular plant species, Rubia fruticosa Ait. (Rubiaceae), of passage through the digestive tube of the three main groups of vertebrate seed dispersers: native reptiles and birds, and alien mammals. 2. Native birds and reptiles dispersed a high proportion of undamaged seeds of R. fruticosa . 3. In contrast, seeds defecated by the two alien mammals showed significantly greater proportions of damaged seeds. Seed viability was much higher for reptiles and birds than for mammals, which was consistent with germination results. 4. Ingested seeds had a significantly thinner coat than uningested control seeds. Seeds that had passed through native dispersers had a significantly thicker coat than those passed through one of the alien mammals (the squirrel). 5. Considering both quantitative and qualitative components of seed dispersal, we conclude that native reptiles and birds are the most important seed dispersers in this multidisperser system.

Studying the population history and demography of organisms with important ecological roles can aid understanding of evolutionary processes at the community level and inform conservation. We screened genetic variation (mtDNA and microsatellite) across the populations of the southern grey shrike (Lanius meridionalis koenigi) in the Canary Islands, where it is an endemic subspecies and an important secondary seed disperser. We show that the Canarian subspecies is polyphyletic with L. meridionalis elegans from North Africa and that shrikes have colonized the Canary Islands from North Africa multiple times. Substantial differences in genetic diversity exist across islands, which are most likely the product of a combination of historical colonization events and recent bottlenecks. The Eastern Canary Islands had the highest overall levels of genetic diversity and have probably been most recently and/or frequently colonized from Africa. Recent or ongoing bottlenecks were detected in three of the islands and are consistent with anecdotal evidence of population declines due to human disturbance. These findings are troubling given the shrike's key ecological role in the Canary Islands, and further research is needed to understand the community‐level consequences of declines in shrike populations. Finally, we found moderate genetic differentiation among populations, which largely reflected the shrike's bottleneck history; however, a significant pattern of isolation‐by‐distance indicated that some gene flow occurs between islands. This study is a useful first step toward understanding how secondary seed dispersal operates over broad spatial scales., DPP was financed by Ph.D. grants awarded by the UK Natural Environment Research Council and the Canarian Government, and by a postdoctoral fellowship (Ramón y Cajal).

This article evaluates the seed dispersal systems of two congeneric and endemic fleshy-fruited plants in the context of two relatively close oceanic archipelagos. For this purpose, representative populations of the endangered junipers Juniperus cedrus in the Canary Islands and Madeira, and Juniperus brevifolia in the Azores were studied. Despite both species sharing the same biogeographic region, we set out to test whether different conditions of the islands and biological characteristics of each juniper species determine the distinctive guilds of seed dispersers involved. We assessed the quantitative and qualitative role of the potential frugivores, showing that the wintering Turdus torquatus and the native Turdus merula were the main seed dispersers for J. cedrus and J. brevifolia, respectively (Frequency of occurrence: 74.9%, 80.2%; germination increase with respect to controls: 11.6%, 15.5%; for J. cedrus and J. brevifolia, respectively). The endemic lizard Gallotia galloti was quantitatively outstanding as seed disperser of J. cedrus, although its qualitative effect does not appear to be beneficial. The introduced rabbit Oryctolagus cuniculus acts as a disruptor in both natural seed dispersal systems, as inferred from the high percentage of damaged seeds found in their droppings. Our results indicate that J. cedrus and J. brevifolia are primarily adapted to ornithochory processes, T. torquatus and T. merula being their respective legitimate long-distance dispersers. Although these birds should be playing a key role in the connectivity of fragmented populations, the dependence of J. cedrus on a migrant bird involves a notable fragility of the system., B. Rumeu was funded by a Spanish National Research Council grant (CSIC: JAE-PRE), and D. P. Padilla was funded by a PhD grant awarded by the Canary Islands Government. This study is framed within the projects: CGL2010-18759 and PI2007/053 and financed by the Spanish Ministry of Science and Innovation, and the Canary Islands Government, respectively; both of which were partially funded by the European Union. The Organismo Autónomo de Parques Nacionales also financed this project (051/2010).

The success of many alien plant species depends on mutualistic relationships with other species. We describe the assemblage of seed dispersers on three species of alien Opuntia invading Mediterranean and Macaronesian habitats, and examine the quality of such plant-animal interactions. We identified vertebrates consuming O. maxima, O. dillenii and O. stricta fruits by direct observation and collecting droppings and pellets. Phenology of the alien species, as well as that of coexisting native species, was monitored for an entire year. Germination tests of ingested and non-ingested seeds were performed both in the greenhouse and in the field. Seed coat thickness and viability were also measured for all treatments. A great variety of taxa, including reptiles, birds and mammals actively participate in the seed dispersal of Opuntia. Phenology of Opuntia fruits in Menorca and Tenerife overlaps with only a few native fleshy-fruited plants present in the study areas, which suggests an advantage for the invader. Most seeds germinated during the second year of the experiment, independently of the effect produced by the dispersers’ guts. We found great variation in the germination percentage of Opuntia after gut passage and in the effects of ingestion on seed coat thickness. Seed viability was somewhat reduced after gut passage compared to manually depulped seeds. Our results show how different Opuntia species are integrated into native communities by means of mutualistic interactions, with both native and alien dispersers. Although with heterogeneous effects, either type of disperser potentially contributes to the spread of these alien cacti in the recipient areas., Research was funded by the Spanish Ministry of Science and Education and FEDER funds of the European Union (CGL2004-0161BOS and CGL2007-61165BOS projects). Some authors have been funded by several Spanish grants (BP: Spanish Ministry of Science and Education, AMA: JAE-doc CSIC, DPP: Canarian Government and PM: Proyectos Intramurales CSIC).

6 pages, 2 figures, 1 table.-- Article in press., Seed germination percentage and rate of Rubia fruticosa, an endemic Macaronesian shrub was assessed with seed lots collected at three levels of an altitudinal gradient (200–800 m asl) located in El Hierro Island (Canarian Archipelago). Both seeds collected from control plants and those found in lizard droppings were studied. A significant decrease in the germination percentage was observed with control seeds and those seeds which are previously eaten by lizards if collected at 800 m asl. This indicates that R. fruticosa is a plant whose optimal germination environment is located between 200 and 500 m asl, occurring in higher altitudes only under sub-optimal conditions. The effect of lizard gut on R. fruticosa seeds was variable in the two study years: while germination percentage of seeds having passed through the lizards was not significantly different to that of control seeds in the first year, an increased germination was found for the animal-treated seeds in all three altitudinal zones in the second year. In general, germination rate of control seeds was rather variable between years. However, improvement of R. fruticosa seed germination caused by lizards may be important for its fitness; and a co-evolution may have occurred, since lizards and seeds of this endemic plant have been intensively interacting for millions of years in the lower zones of the Canary Islands., Benigno Padrón, David P. Padilla and Patricia Marrero received grants financed by the Ministerio de Educación y Ciencia of Spain, Gobierno de Canarias and Consejo Superior de Investigaciones Científicas (Proyectos Intramurales Especiales, 2004 3 0E 169), respectively. This contribution was financed by the projects CGL2004-04884-C02-01/BOS (Ministerio de Educación y Ciencia) and PI042004/037 (Consejería de Educación, Cultura y Deportes, Gobierno de Canarias). The two projects have been partially supported by Feder funds from the European Union.