Skip to main content

The Reproductive Advantages of Large Male Fish

In mosquitofish, of the genus Gambusia, male fish are smaller than females – sometimes only half the size. Biologists had previously assumed that smaller male mosquitofish had at least some reproductive advantages. Researchers from the transregional collaborative research centre NC3 at Bielefeld University, among them Bora Kim who is now doing research work at the Konrad Lorenz Institute of Ethology, have shown in a systematic review and meta-analysis that larger mosquitofish are actually more successful at reproduction: they can, for instance, better challenge their rivals; they produce more sperm; and they are preferred by female fish.

The article "Male size and reproductive performance in three species of livebearing fishes (Gambusia spp.): a systematic review and meta-analy-sis" by Bora Kim, Nicholas Patrick Moran, Klaus Reinhold, Alfredo Sánchez-Tójar was published in July in the Journal of Animal Ecology.



Tracking white-tailed eagle population - on the rise in Austria

20 years ago Austria's heraldic animal, the white-tailed eagle, was still considered extinct in this country. The white-tailed eagle population has now grown to around 45 breeding pairs. A great success for nature conservation, which goes back to the strict Europe-wide protection. The research and protection programme of the nature conservation organization WWF is an essential part of this. Six young eagles in Lower Austria and Burgenland have now been equipped with GPS-GSM transmitters. The Donau-Auen National Park and Esterhazy Betriebe GmbH are important cooperation partners for this year's young birds. Together with the WWF, transmitters were attached to them at three locations - in the Danube floodplains, west of Lake Neusiedl along the Leithagebirge, and in the WWF reserve in the March-Thaya floodplains.

The feather-light telemetry tags do not impact the eagles´ movements and fall off by themselves after three to four years. Rings of the Austrian Ornithological Centre, which were also attached to the legs, ensure that the animals can be identified throughout their lifetime.

Press release of the WWF (in German)


Avian fitness: birds go easy on their pectoral muscles

A European research team led by Vetmeduni Vienna has discovered a protective mechanism in migratory birds. According to the study, common quails are able to specifically safeguard their pectoral muscles from oxidative stress during migration. The researchers believe this mechanism is an essential factor in the ability of migratory birds to successfully complete their long flights.

The article „Controlled expression of the migratory phenotype affects oxidative status in birds“ by Valeria Marasco, Manrico Sebastiano, David Costantini, Gianni Pola and Leonida Fusani was published in the Journal of Experimental Biology.



The migration of Austrian blackcaps decoded

The blackcap (Sylvia atricapilla) is one of the most common songbird species in Europe - and also in Austria. In their area of ​​distribution, the small birds show a variety of different migration strategies. Ivan Maggini and Wolfgang Vogl, experts from the Austrian Ornithological Centre (Konrad Lorenz Institute of Ethology, Vetmeduni Vienna), examined these migration strategies in cooperation with colleagues from Germany (Max Planck Institute for Evolutionary Biology, Plön) using geolocators, which were attached to the backs of birds. During the study, the researchers found that some blackcap populations over-winter in the UK. It seems that blackcaps discovered the more favorable climatic conditions in Great Britain very quickly and adapted their migration behavior accordingly within a short period of time.

According to Maggini and Vogl, this study shows how the common blackcap helps to understand the flexibility and adaptability of migrating bird species to rapidly changing environmental conditions.

The article “Individual variability and versatility in an eco-evolutionary model of avian migration” by Delmore K. et al. was published in Proceedings of the Royal Society B.