Biomedical subjects

Franz Bairlein

Publications and source records attributed to Franz Bairlein.

5 recordsLinked to original sources

PubMed2005

Is there a "migratory syndrome" common to all migrant birds?

Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a "migratory syndrome," a tightly integrated, old group of adaptive traits that enables birds to commit themselves to highly organized seasonal migrations, is assessed. A list of problems faced by migratory birds is listed first and the traits that migratory birds have evolved to deal with these problems are discussed. The usefulness of comparative approaches to investigate which traits are unique to migrants is then discussed. A provisional conclusion that, perhaps apart from a capacity for night-time compass orientation, there is little evidence for deeply rooted coadapted trait complexes that could make up such a migratory syndrome, is suggested. Detailed analyses of the genetic and physiological architecture of potential adaptations to migration, combined with a comparative approach to further identify the phylogenetic levels at which different adaptive traits for migration have evolved, are recommended.

Adaptation, Physiological↗

PubMed2005

Vertebrate host specificity of two avian malaria parasites of the subgenus Novyella: Plasmodium nucleophilum and Plasmodium vaughani.

The susceptibility of wild-caught European passeriform birds to naturally isolated malaria parasites, Plasmodium (Novyella) nucleophilum and Plasmodium (Novyella) vaughani, was studied by means of intramuscular subinoculation of infected citrated blood. Plasmodium nucleophilum of the great tit, Parus major, was transmitted to 3 great tits, but 3 blackcaps (Sylvia atricapilla) were not susceptible. Plasmodium vaughani of the robin, Erithacus rubecula, was transmitted to 1 robin and 1 blackcap, but 1 dunnock, Prunella modularis, was not susceptible. The prepatent period was between 8 and 10 days in all experimental infections. Maximum experimental parasitemia (3.4% of red cells) was detected in great tits infected with P. nucleophilum 23 days postexposure. A light (<0.01%) transient parasitemia of P. vaughani developed in the robin and blackcap. This study is in accord with former experimental observations on host specificity of P. nucleophilum and P. vaughani, which are characterized by a wide, but selective, range of avian hosts. Two new host-parasite associations were recorded.

Animals↗

PubMed2004

Factors affecting the relapse of Haemoproteus belopolskyi infections and the parasitaemia of Trypanosoma spp. in a naturally infected European songbird, the blackcap, Sylvia atricapilla.

The effects of photoperiod and stress on the relapse of Haemoproteus belopolskyi infections and the parasitaemia of Trypanosoma spp. were studied in naturally infected blackcaps, Sylvia atricapilla. Twenty-one birds (12 infected with H. belopolskyi, 5 with Trypanosoma spp.) were kept indoors and investigated by microscopic examination of stained blood films. All infections were latent before the experiments started on 7 February 2002. The relapse of H. belopolskyi and the parasitaemia of Trypanosoma spp. after the latent stage of infection were induced by increased day length and stress due to a change of room. At 44 days after the beginning of the experiment, all latent infections were patent in the experimental birds, while no parasites were recorded in the control birds. The relapse of avian Haemoproteus spp. infection and of the parasitaemia of avian Trypanosoma spp. may be related to gonadal hormones, corticosterone and melatonin.

Animals↗

PubMed2002

Ecological responses to recent climate change.

There is now ample evidence of the ecological impacts of recent climate change, from polar terrestrial to tropical marine environments. The responses of both flora and fauna span an array of ecosystems and organizational hierarchies, from the species to the community levels. Despite continued uncertainty as to community and ecosystem trajectories under global change, our review exposes a coherent pattern of ecological change across systems. Although we are only at an early stage in the projected trends of global warming, ecological responses to recent climate change are already clearly visible.

Animals↗

PubMed2002

How to get fat: nutritional mechanisms of seasonal fat accumulation in migratory songbirds.

Many migratory birds accumulate large amounts of lipids as the prime energy source for their long-distance flights. This fat accumulation is mostly under endogenous control, reflecting genetically programmed temporal shifts of the body mass set point. It is accompanied by an increase in daily food intake and food utilisation efficiency and by a seasonal shift in food selection. In particular, seasonal frugivory appears to play a key role in many migrants. Fruits have a high content of fatty acids indispensable for building up the specific depot lipids. In addition, plant secondary compounds seem to play some kind of supportive role, but the mechanisms are not yet known. The effect of being fat on the metabolic situation in migrant birds appears to be similar to the metabolic syndrome in obese humans. The fat migratory bird provides a model through which to study nutritional factors as well as the biochemical and endocrine regulation of food intake, body mass and obesity.

Animals↗