Not only does it undertake the greatest migratory journey of any creature on the planet, it also looks more graceful than any bird has a right to.
There may be two other drivers of decline: being hunted on their migratory journeys to and from Africa, especially in France and Spain; and the effects of a parasite, trichomonas, which is known to infect many of the birds.
Cortisol spikes induce fat consumption, and European eels need a layer of healthy fat for their migratory journey to the Sargasso Sea to breed, so if our eels are too tweaked out on government run-off coke it might delay their migration patterns and in turn impact on reproduction.
It is also the beginning and ending point for species that make one of the planet's most amazing migratory journeys: the salmon.
Using stable isotopes of carbon and nitrogen as dietary tracers, we provide here strong support to the controversial hypothesis that the giant noctule bat Nyctalus lasiopterus feeds on the wing upon the multitude of flying passerines during their nocturnal migratory journeys, a resource which, while showing a predictable distribution in space and time, is only seasonally available.
They may be vanishing because of problems here, problems on their African wintering grounds, or problems on their 3,000-mile 3,000-milejourneys.
Migratory journeys are widespread throughout the animal kingdom [1] and even beyond (e.g. vertical migration of phytoplankton [2]).
Avian species of a wide size range, from the 25 g little swift (Apus affinis) to the 11 kg Andean condor (Vultur gryphus), soar over land on convective thermals, gaining altitude that allows horizontal progress by gliding, when seeking food, mates, and breeding sites and during long distance migratory journeys [1], [2].
