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- Bensch, Staffan, et al.
(author)
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Linkage between nuclear and mitochondrial DNA sequences in avian malaria parasites: Multiple cases of cryptic speciation?
- 2004
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In: Evolution. - : Wiley. - 1558-5646 .- 0014-3820. ; 58:7, s. 1617-1621
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Journal article (peer-reviewed)abstract
- Analyses of mitochondrial cytochrome b diversity among avian blood parasites of the genera Haemoproteus and Plasmodium suggest that there might be as many lineages of parasites as there are species of birds. This is in sharp contrast to the approximately 175 parasite species described by traditional methods based on morphology using light microscopy. Until now it has not been clear to what extent parasite mitochondrial DNA lineage diversity reflects intra- or interspecific variation. We have sequenced part of a fast-evolving nuclear gene, dihydrofolate reductase-thymidylate synthase (DHFR-TS), and demonstrate that most of the parasite mitochondrial DNA lineages are associated with unique gene copies at this locus. Although these parasite lineages sometimes coexist in the same host individual, they apparently do not recombine and could therefore be considered as functionally distinct evolutionary entities, with independent evolutionary potential. Studies examining parasite virulence and host immune systems must consider this remarkable diversity of avian malaria parasites.
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- Pérez-Rodrigo, Carmen, et al.
(author)
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The school setting : an opportunity for the implementation of dietary guidelines
- 2001
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In: Public Health Nutrition. - : Cambridge University Press (CUP). - 1368-9800 .- 1475-2727. ; 4:2B, s. 717-724
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Journal article (peer-reviewed)abstract
- Nutrition, physical activity and health related promotion programmes in schools have developed into a mature field of research over the past decades. A number of success factors have been identified and evidence-based interventions have been performed. However, the school setting as an arena for evidence-based health promotion programmes, is still not used to its full potential. Schools provide an excellent arena for reaching large segments of the population, such as young people, school staff, families and the surrounding community.There is a need for an overview regarding the current status of nutrition, physical activity, related health as well as support structures in the EU member states. Based upon such an analysis, a consensus report should be written, pointing out the major problems at hand. Self-assessment tools for national as well as for school level should be produced, in order to guide changes, but also to include an element of continuous assessment of change, for evaluation purposes.
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- Perez-Tris, Javier, et al.
(author)
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Are Iberian Chiffchaffs Phylloscopus (collybita) brehmii long-distance migrants? An analysis of flight-related morphology
- 2003
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In: Bird Study. - 0006-3657. ; 50:2, s. 146-152
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Journal article (peer-reviewed)abstract
- Capsule Iberian Chiffchaffs Phylloscopus (collybita) brehmii are genetically, morphologically and bioacoustically different from European Chiffchaffs (P [c.] collybita). Aim To examine the difference in migratory pattern between brehmii and collybita. Methods We inferred variation in distance of migration between brehmii and collybita by analysing differences in flight-related morphology (wing-length, wing shape and tail-length) between individuals breeding or wintering in the Iberian Peninsula. Results Controlling for body size and allometry of feather dimensions, birds captured in spring had more pointed wings (more concave wing shapes and pointed wing tips) and a shorter tail than birds caught in winter, although no spring-to-winter difference was found for wing-length. Conclusion Iberian breeders appear better suited to long-distance migration (their traits are likely to give a higher speed and a lower energy consumption during long non-stop flights) than wintering individuals, which strongly supports the hypothesis that brehmii move south of the Sahara in autumn and are substituted by central European collybita populations in winter. This different migration pattern of brehmii and collybita has important implications for the maintenance of differentiation in their contact zone, because selection against hybrids with maladaptive, intermediate migratory behaviours might contribute to reproductive isolation.
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| 5. |
- Perez-Tris, Javier, et al.
(author)
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Historical diversification of migration patterns in a passerine bird
- 2004
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In: Evolution. - 1558-5646. ; 58:8, s. 1819-1832
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Journal article (peer-reviewed)abstract
- Migratory strategies of birds require complex orientation mechanisms, morphological adaptations, and life-history adjustments. From an evolutionary perspective, it is important to know how fast this complex combination of traits can evolve. We analyzed mitochondrial control-region DNA sequences in 241 blackcaps (Sylvia atricapilla) from 12 populations with different migratory behaviors. The sample included sedentary populations in Europe and Atlantic archipelagos and migratory populations with different distances of migration, from regional to intercontinental migrations, and different heading directions (due to a migratory divide in central Europe). There was no genetic structure between migratory and sedentary populations, or among populations from different biogeographic areas (Atlantic islands, the Iberian Peninsula, or the continent), however we found evidence of a genetic structure when comparing populations located on either side of the migratory divide. These findings support an independent evolution of highly divergent migratory strategies in blackcaps, occurring after a postglacial colonization of the continent along western and eastern routes. Accordingly, mismatch-distribution analyses suggested an expansion of blackcaps from a very small population size, and time estimates dated such an expansion during the last postglacial period. However, the populations in Gibraltar, located in a putative Mediterranean refuge, appeared to be independent of these processes, showing evidence of restricted gene flow with other populations and demonstrating insignificant historical changes in effective population size. Our results show that the interruption of gene flow between migratory and sedentary populations is not necessary for the maintenance of such a polymorphism, and that even the most divergent migratory strategies of a bird species are susceptible to evolution in response to historical environmental changes.
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- Perez-Tris, Javier, et al.
(author)
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Loss of body mass under predation risk: cost of antipredatory behaviour or adaptive fit-for-escape?
- 2004
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In: Animal Behaviour. - : Elsevier BV. - 1095-8282 .- 0003-3472. ; 67:3, s. 511-521
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Journal article (peer-reviewed)abstract
- Predation risk may compromise the ability of animals to acquire and maintain body reserves by hindering 14 foraging efficiency and increasing physiological stress. Locomotor performance may depend on body mass, so losing mass under predation risk could be an adaptive response of prey to improve escape ability. We studied individual variation in antipredatory behaviour, feeding rate, body mass and escape performance in the lacertid lizard Psammodromus algirus. Individuals were experimentally exposed to different levels of food availability (limited or abundant) and predation risk, represented by reduced refuge availability and simulated predator attacks. Predation risk induced lizards to reduce conspicuousness behaviourally and to avoid feeding in the presence of predators. If food was abundant, alarmed lizards reduced feeding rate, losing mass. Lizards supplied with limited food fed at near-maximum rates independently of predation risk but lost more mass when alarmed; thus, mass losses experienced under predation risk were higher than those expected from feeding interruption alone. Although body mass of lizards varied between treatments, no component of escape performance measured during predator attacks (endurance, speed, escape strategy) was affected by treatments or by variations in body mass. Thus, the body mass changes were consistent with a trade-off between gaining resources and avoiding predators, mediated by hampered foraging efficiency and physiological stress. However, improved escape efficiency is not required to explain mass reduction upon predator encounters beyond that expected from feeding interruption or predation-related stress. Therefore, the idea that animals may regulate body reserves in relation to performance demands should be reconsidered.
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| 7. |
- Perez-Tris, Javier, et al.
(author)
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Spanish research on avian migration: historical trajectory and future perspectives.
- 2004
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In: Ardeola. - 0570-7358. ; 51:1, s. 71-89
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Research review (peer-reviewed)abstract
- Aim: To value the importance of research on avian migration for the development and current status of Spanish ornithology. Results and Conclusions: Avian migration has always been an outstanding field in ornithology. This assertion is particularly true in Spain, as we illustrate here by discussing the contribution of migration research to both the scientific and historical development of Spanish ornithology. After all, the Iberian Peninsula is one of the best scenarios for the study of migration in Europe (Fig. 1), as it forms natural bridges for birds migrating between Europe and Africa and between the Atlantic Ocean and the Mediterranean Sea. As well, it is one of the main wintering grounds for European birds in the Mediterranean area. Migration ecology experienced a relatively early development in Spain, compared to other fields in ornithology. Short after the foundation of the Spanish Ornithological Society (SEO) in 1954, migration surveys often triggered pioneering attempts to build up long-term research programs (Table 1). Thus, massive ringing campaigns were among the very first scientific activities organised by SEO, and became formally regularised with the creation of the Bird Migration Centre (CMA) in 1957, one of the first successful attempts to institutionalize ornithological research in Spain. Later on, these activities acquired international relevance with the publication of their results in international meetings, and the participation of the CMA in the foundation of EURING. These facts, together with the creation of the Spanish Group of Raptor Migration (GEMRA) for monitoring the passage of soaring birds across the Strait of Gibraltar, were fundamental pieces in the training of a whole generation of Spanish ornithologists. Perhaps migration gained a prominent position relative to other fields in Spain owing to the personal interests of Francisco Bernis, who was responsible, directly or indirectly, of most of the achievements of a newly born Spanish ornithology (from the 1940's to the late 1970's). Leading the foundation of SEO, he published a profuse collection of seminal reports, monographs and handbooks, which pushed forward several fields of ornithology in Spain, but paid special attention to migration. Such interests could be motivated by a late advent of Spanish ornithological research in the international framework: the advantages of the Iberian Peninsula for the study of migration, and the still poor knowledge of the ecological processes occurring south of the scientifically leading countries (central and northern Europe), offered a good opportunity for Bernis' school to make a contribution of general relevance to the scientific community. Thus, the analysis of ringing recoveries in Spain of birds ringed in Europe, the ecological and evolutionary interpretation of wintering in the Mediterranean (Table 1), or the study of visible migration in Gibraltar (Fig. 2) were all major contributions of F. Bernis to the growth and international diffusion of Spanish ornithology. This contribution of migration studies to the maturation of Spanish ornithology is also reflected by nearly as many publications on migration in Ardeola, the Spanish ornithological journal, as there were derived from faunistic research (which traditionally dominated the contents of the journal; Fig. 3). Today, Spanish ornithology has reached a high average standard, being recognised as internationally influential. As a consequence, the research published in Ardeola seeks to broaden its potential readership (using more frequently the English language) and has become increasingly professionalized (Fig. 4). This healthiness of Spanish ornithology in general is also perceived in migration research (Fig. 4). Spanish researchers and amateurs (particularly ringers) are keen to enrol in international co-operative projects, being institutionally supported by the Spanish ringing scheme (Migratory Species Office, Ministry of Environment). As an immediate benefit, this should help us to put our knowledge on migration through and to the Iberian Peninsula in a broader ecological and geographic context. Besides, Spanish researchers are taking advantage of excellent chances to study the ecological and evolutionary implications of migration and wintering in the Mediterranean. Future research should contribute to fulfil the social demand for studies that may help us to foresee the consequences of processes such as climate change or habitat destruction, a research front that both Spanish authorities and scientists have a decisive obligation to push forward.
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