Since spring 2017, Anciles Reserve, located in the mountains of Riaño (León-Spain), houses the first specimens of European bison, water buffalo and pottoka horses that share this nature paradise with important populations of Spanish ibex, chamois, roe deer, red deer, boar, wolf and brown bear, as well as with golden eagle, vultures, Egyptian vultures and many other species.

During this first winter, we were able to follow the developments and adaptation of the animals to a changing landscape because of the snow. Conditions in which the bison feel at home thanks to its resistance to cold and ability to feed on all types of plant materials, from pastures under the snow, to shrubs like Genista spp. and even the bark of trees like Salix spp. Sorbus spp. Populus spp. or Prunus spp.

In this area with significant altitude differences, going from 1,100 to 2,000 meters, the bison seem to be comfortable both in the lower and sheltered areas and in the high areas where cold winds blow.

The water buffalos, which in summer spent a good part of the day bathing at the banks of the Riaño reservoir, now prefer to stay together in the warmest areas and gratefully acknowledge with grunts the sporadic contributions of food that the herd managers bring with them to help the animals get through the hardest weeks of winter.

Finally, the pottoka horses, descendants of these Cantabrian mountains, wear their dense winter coat and prefer the sunny but windy slopes covered in large areas of Genista spp. shrubs. In this landscape they remain scattered and divided into two herds led by the two dominant males, grazing this prickly but nutritious plant that can take them even to gain weight during the coldest season.

This winter, the snow has reached more than one meter in some places of Anciles! Due to the strong altitudinal differences and exposure to the sun or wind, the snow does not cover this territory continuously or evenly for a long time on the south-faced slopes. However, the snow remains throughout the winter on the north-faced and higher altitude slopes, which guarantees a permanent supply of water to the springs that feed the two main Anciles streams that flow into the Riaño reservoir.

The hard living conditions that the snow cover implies, is the price to pay for the abundance of grass and water during the spring and summer in the Cantabrian Mountains.