Insects & Other Invertebrates
By far and away the most abundant wildlife in our woods are the insects and other invertebrates. Most are inconspicuous or, because they are nocturnal, are rarely seen. They have good reason to hide away; they are a key food source for the many small birds as well as mammals such as the Shrew; and of course the bats that hunt among the trees and along the woodland edges.
Most people enjoy seeing the more conspicuous butterflies and bumblebees which are active during the daytime, and the latter are especially important in carrying pollen from flower to flower thus ensuring that seeds are set and we can enjoy future generations of flowers in the years to come. [For more information on Bumblebees please see the guide to Dalgety Bay Bumblebees on the Blog page or the link to Bumblebee Conservation Trust] Far more important, both numerically and ecologically, are the moths. Most of the adults are beautifully patterned for camouflage as they rest up during the day. Most then fly at night, taking energy from night opening flowers or just seeking a mate and a place to lay their eggs. Most insect eating birds will take adult moths if they can find them, but it is the bats that are the specialist moth hunters using echolocation to find them in the dark.
Of greater importance for most of the birds however are the moth caterpillars that feed on the leaves of the trees. Almost all the small birds that we like to see coming to our bird feeders rely on moth caterpillars to feed their young, and Blue Tits and Great Tits are known to time their nesting to coincide with the emergence of the small caterpillars that they need to feed their nestlings. But not all tree species will have a similar range of catterpillars available. As a general guide, Gilbert and Anderson's Guide to Habitat Creation and Repair (Publ 1998 Oxford University Press) lists the numbers of Lepidoptera species, (mainly moths) associated with different woodland trees, and for the trees found in our woods, a selection of the figures they give is shown below. While this will not be a count of all that will be seen in our woods, it is nevertheless a very good guide to the diversity of moths on these different trees. A perusal of this list indicates why there is a need to improve the diversity of trees and shrubs in these woodlands as this is the best way to support the widest diversity of the birdlife that can so delight us with their beauty and springtime singing as well as improving the food supply for the bats we want to encourage.
Numbers of species of Lepidoptera (Butterflies and Moths) associated with different tree species
Data from: Habitat Creation and Repair by O L Gilbert and P Anderson, OUP 1998
Native Oaks 193
Scots Pine 36