Les Écureuils Volants et Leurs Arbres

Appréciez, touchez, aimez la forêt ! Voilà le message que M. Brownlie nous livre.

Dans les forêts âgées, il existe une interrelation intime entre la santé des arbres et celle de ses habitants…

Dans le cas des écureuils volants, une espèce clef, les forêts leur procurent un habitat idéal et, en échange, ils répandent une espèce de champignon qui favorise la croissance des arbres. Malheureusement, les forêts âgées sont maintenant extrêmement rares au N.-B., ce qui veut dire que l’habitat des écureuils volants (et beaucoup d’autres espèces !) est de plus en plus restreint. C’est un cercle vicieux : moins il y a de forêts, moins il y a d’espèces et moins la croissance des arbres est favorisée par les animaux.

L’auteur vous invite donc à être complice de la nature afin de mieux apprécier l’inestimable valeur de nos magnifiques forêts.

Little Squirrels - Big Trees

John Brownlie
Naturalist and member of the
Fundy Environmental Action Group

June 1998

hen I see a big, old tree in the forest I say, "Wow! What a beautiful tree!" Then I put my arms around it to measure its girth. Of course, it's also so I can rub my cheek against its old, craggy bark without looking silly. Sometimes I lie down with my head next to the trunk and gnarly roots, gazing way up into the branches. Obviously, I like big, old trees.

"And the widely spaced trees give them lots of room to move and escape predators."
gforbes1.jpg (25598 bytes)
(photo: G. Forbes)

Flying squirrels also like big, old trees, even though they can't get their arms around them. For them, maybe it's not so much a feeling as a need.

Everyone knows that flyers glide and this is important in escaping predators such as marten (a large weasel) and owls. Well, in younger forests the trees are short and grow close together. So gliding is more restricted and the chances of getting eaten are greater. In older-growth forests, starting their glide from higher up, flying squirrels can go further. And the widely spaced trees give them lots of room to move and escape predators.

Older-growth forests also supply large enough trees for nest cavities where these animals raise their young. In younger forests, flying squirrels are forced to nest in ground cavities amongst tree roots where they have little protection from weasels.

So, older growth forests are critical, not only for flying squirrels, but also for marten, pileated woodpeckers, owls, and plants.

Research in Fundy National Park has found that not only do flying squirrels need big, old trees - the trees need flying squirrels!

How could a tree need a squirrel? Flying squirrels eat truffles. Truffles are the underground fruits of some types of fungi. These fungi attach themselves to the tips of tree roots and help the roots to absorb nutrients from the soil. So without truffles, trees may grow more slowly and may become more susceptible to disease.

When a flying squirrel eats a truffle, the truffle's spores (seeds) are deposited on the forest floor in the squirrel's droppings and grow into more truffles. So every time a squirrel eats a truffle, it helps plant more truffles and keep trees healthy and growing well.

Today, our natural older-growth forests are being cut and replaced by tree plantations made of single types of trees. Thus we risk losing about 25 species of birds and mammals which depend upon older-growth forests for their survival. But the loss of flying squirrels is particularly devastating. Flying squirrels are called a keystone species. They help keep the forest healthy by spreading truffle spores. When flying squirrels disappear from the forest, the trees may grow more slowly and may die, thus jeopardizing the whole ecosystem and all the plants and animals in it.

"What can we do? Go out into natural forests and hug big trees!"
gforbes1.jpg (25598 bytes)
(photo: B. Townsend)

So we need to change the way we harvest our forests. Instead of just maximizing the production of timber, we must think about how to conserve enough habitat in New Brunswick for flying squirrels.

For example, the provincial government's forest policies now require forestry companies cutting on Crown lands to keep 10% of the softwood forests in an older condition. Also, in 1992, New Brunswick agreed to establish a network of protected areas. Although government staff had identified 54 potential sites, only part of one has been officially set aside.

What can we do? Go out into natural forests and hug big trees! The more time we spend observing nature, hugging big trees, the more we will appreciate what we have left. You can join a local naturalist group and participate in projects to monitor birds, frogs, and beetles. Enjoying nature leads to appreciation and support for those groups fighting to conserve habitats and wildlife that live there.

You may even decide to write your MLA or the Premier to let him/her know you want action to conserve older growth forests in New Brunswick.

You can click here to send mail to Premier Thériault.