The persecution of wolves in order to remove them from human settlements has culminated in their near-disappearance in numerous European countries, like Spain and Sweden. Following a recovery of the species, a team of scientists has determined what geographic areas in the Scandinavian country would be most suitable for a redistribution of the specie’s range, in the interests of increasing the social acceptance of wolves.

The passage of ions through the cell membrane is controlled by ion channels, which are protein complexes that regulate vital processes, such as the heartbeat, as well as being the target towards which many drugs are directed. Now a study by the University of Wisconsin, led by a Spanish researcher, presents a novel model to explain how the pores of these channels open and close.

The pangasius, originally from Vietnam, is one of the most consumed fish in the world for its low cost, mild flavor and fillet presentation without skin or thorns. It is especially requested in school canteens and senior centers. But the toxicological evaluation carried out by a team of Spanish scientists now shows that the mercury content in some samples exceeds all limits, so the consumption of other fish in the child population is recommended.

Foxes are one of the main predators of rabbits in Spain, but instead of going to hunt them where they abound, these carnivores prefer roads to find run-over animals or trash. The result is that the foxes themselves are overrun. A team of scientists analyzes the cascading effects that occur on Spanish roads with carnivorous mammals.

In Barcelona, the image of wild boar herds in the streets is increasingly common, which is a problem for the species and its coexistence with humans. Researchers from the Autonomous Universities of Barcelona and Aveiro (Portugal) have identified the main factors that lead these animals to the cities: they look for green corridors and dry foods like those of cats.

In recent years, egg production has been in the spotlight for animal welfare issues. While in most European countries the number of farms with free-range hens increases, in Spain 93% of laying hens are still caged. Added to this are the effects that the industry generates on the environment. A team of Spanish scientists reveals the environmental cost of egg production in a typical farm in Spain.

The Andes mountain range hides many biological treasures between its altitudes. One of them is the great diversity of frogs that is coming to light little by little thanks to the work of a Spanish researcher, among others. The biologist has discovered many new amphibian species in the last decade, including a new genus. Its latest finding is that of a small brown frog in the Cordillera Real de los Andes of Bolivia, which due to its limited distribution area should be considered 'vulnerable'.

If a high-speed train runs at 185 m/h through little urbanized areas, it is possible that some animals will be surprised in their path. This is the case of birds such as magpies, pigeons, crows or buzzards, whose death due to run over has not been scientifically analyzed or quantified so far. A study has now allowed obtaining the first estimates in Spain.

According to the glacier refuges theory, after the last glaciations the bears of northern Europe sought shelter in the South. Researchers from A Coruña University reject this idea: they have reconstructed the colonization of brown bears in the Iberian Peninsula and have shown that the lineage of the Pleistocene bears was lost.

A sugar called Neu5Gc, present in red meat, some fish and dairy products, is related to the appearance of spontaneous tumors in humans. Researchers at the University of Nevada, Reno, led by Spaniard David Álvarez Ponce, have analyzed the evolutionary history of the CMAH gene - which allows the synthesis of this sugar - and shown which groups of animals have lost the gene and therefore are more suitable for human consumption and for organ transplants.