Nature on our doorsteps: Natural processes in autumn
THE autumn equinox occurred on September 22, when there was an equal share of daytime brightness and night-time darkness.
After that day, as the northern half of the planet continues to tilt away from the sun, we receive less sunshine.
As a result, the number of darker hours in the day increases.
While this change in day length commenced after the year’s longest day on June 22, the effects of this natural process become more noticeable as the autumn equinox is reached.
By the time late summer has arrived, the shorter days have already triggered the natural world to prepare for winter.
Trees begin to withdraw their valuable nutrients from their leaves and store them instead deep inside the tree for winter.
Signs of woodmice feeding on hazelnuts outside a mouse hole in the woods
As leaves wither and fall to the ground, their remaining organic matter is recycled for use next year by an army of soil inhabitants that include worms, slugs, fungi, and other microbes.
In autumn, birds that arrived in Ireland in springtime to breed in Ireland’s cooler summer climate begin their long migration back home.
Mammals also need to prepare for the coming winter, and their priority is to gain as much weight before their food sources disappear.
Bats feed on flying insects like moths and midges.
Many adult insects, however, die away in autumn, leaving their larvae to develop further in the soil or in cocoons.
Bats survive winter by hibernating.
They prepare for this by building up layers of fat to keep them alive before colder weather conditions and the lack of food become a problem.
Small mammals like hedgehogs also hibernate.
As autumn proceeds into frosty winter, the hedgehog’s food sources that include worms and slugs are harder to find as they hide away from frosty weather.
Other small mammals like mice and squirrels do not fully hibernate.
These will sleep during periods of harsh weather, after which they will head out again to feed on their store of nutritious nuts and seeds
