2012

Autumn acorn fuss in forests

The middle of autumn has arrived after a distinctly warm September. Not only astronomical and calendar, but also the phenological autumn has arrived in Latvia’s forests. Trees lose their leaf adornments, turning yellow, brown, giving up their splendor due to the relatively high temperature. Some species of trees, however, remain summer-like. Alder leaves are still green, but, just like every autumn, beetle-gnawed.

Late autumn edible mushrooms – russulas, ugly milk-caps and woolly milk-caps - can still be easily found. Nevertheless, to be successful in picking penny buns, excellent skills or luck are required - there are not that many of them. Chanterelle enthusiasts also find it tough – yellow and brown fallen leaves make it more difficult to pick mushrooms in deciduous and mixed forests.

With raindrops falling and winds swinging tree branches, dead leaves are accompanied by tree seeds on their way to the ground. Hazel-trees are out of nuts, some were collected by people, others taken away by birds, rodents or eaten by weevil larvae. These insect children have already left their nurseries and morphed into cocoons, leaving empty shells behind them.

Oak seeds – acorns – are the most noticeable ones. They rarely fall down when there are no winds, but make a lot of noise when they do so. The feet of some mighty oaks are littered with acorns.  However, they do not stay there for too long – wild boars nuzzle and snack on them. Their basic foods are elsewhere though. Last winter favored the boars, which can be seen this year - there are many boars and their digs. Everywhere around, they dig up forest soils, fields, meadows and lawns, searching for roots, insects and their cocoons, larvae or small animals.

Not all acorns have fallen. Some still linger on tree branches, and jays have a particular interest in them. These birds can be seen every day, flying back and forth between forests and oaks, collecting and storing acorns. At first, they pick only those acorns that can still be found on branches. Later on, they will have to swoop down and pick up the fallen seeds. Jays exclusively collect non-damaged acorns, untouched by acorn moth and acorn weevil larvae. They are rather skillful when it comes to determining the condition of acorns. First of all, they assess the size and weight of acorns, since damaged acorns are often smaller and lighter. Afterwards, they squeeze the seeds in their beaks – damaged acorns have more flexible and coarse shells. It is interesting that, during the acorn period, jays eat only acorn cotyledons. Those acorns that cannot be consumed immediately are hidden in similar places. Usually, the birds fail to find their own stashes. The majority of these places, however, are found by their brethren, who are familiar with their hiding methods and know where to look for. Some stashes are found by other acorn-eaters, others by no one, and oak seedlings sprout from these seeds in spring. This is how jays spread oak seeds. The majority of jays currently seen in Latvia’s forests are wanderers from other lands, pillaging, eating acorns and seeding oaks.