What are the Bears eating today?

by Derek Ryder, Wildlife Ambassador & IGA Interpretive Guide

By now most bears have emerged from their dens and through the month of May, they’ll leave the higher alpine environments where they den, and move down to the snow free valley bottoms, so bear sightings and encounters will increase through the month. Along the way down from the alpine, if they can find a carcass of something killed over the winter by an avalanche, they’ll be very happy. However, there are no guarantees for that to happen, so most bears will rely on their veggie diets.

Research on bear diets clearly shows that an early season food source are the new, fresh shoots of the Horsetail family of plants. There are nine species here, but the one you’ll most likely see is the Common Horsetail. Other members of the Horsetail family, and reasonably indistinguishable from Common Horsetails, include the Scouring-Rushes. The way to tell the various species apart is to look at the stem joints, which are all different. To a bear, all members of the Horsetail family are just good eats.

Often mistaken for ferns, Horsetails tend to grow in wetter places. Often, they grow in great carpets, and when full grown in mid-June, create a rather magical, elfin-feel to the forest. They get up to 30 cm tall, and are delicate and soft. Bears only eat Horsetails in the spring when they are young and fresh shoots, much as humans eat fiddleheads, which are the immature shoots of ferns.

Part of the reason that bears do not touch Horsetails after early June is the plant has an unusual attribute: it pulls silica out of the soil. As it grows, it becomes more and more made of silica. When it dies in the fall, it turns white because the silica is almost all that is left. That silica can actually cut holes in the digestive tract of anything that eats it. This is how some plants in the family got the name “Scouring-Rush”; in mid- to late-summer, they were used as scouring pads to clean pots, and even as sandpaper. Indigenous people used them to polish arrows, bows and pipes.

We, too, can eat the young ones, but be careful. They contain an enzyme called Thiaminase that destroys vitamin B1. While it has no effect on bears and the many other animals that eat Horsetails, it can kill cattle and sheep that eat it. If eaten raw, it can very severely affect people, especially those with high blood pressure. Horsetails must be cooked to destroy the Thiaminase.

Click here to find out ‘What the bears are eating’ in other months!