January 2021

I find it fascinating that some animals specialise in eating some very strange things. I hope you will be equally fascinated. For example, cuckoos specialise in eating hairy caterpillars! These are caterpillars that have evolved poisonous hairs to stop animals eating them, but cuckoos have evolved the ability to be resistant to the poison. Similarly, giant pandas specialise in eating bamboo, which contains significant amounts of cyanide precursors, that could kill a human.

It is also extraordinary that huge anteaters can survive on eating tiny ants and termites. Also, the honey buzzard – a large bird of prey, similar to rabbit-eating common buzzards – actually survives on eating bees and wasps! Owls often swallow quite large rodents whole. The massive bird of prey called lammergeier or bearded vulture – eats large mammal bones by carrying them to a high altitude, drops them onto hard rocks, which breaks them, then flies down to eat the sometimes very large pieces of bone, whole. One was seen in Sussex recently.

Many fish-eating birds, such as herons, sometimes catch quite large fish and swallow them whole and it is possible to see the fish slipping down the inside of their skinny neck as a large bulge. Incidentally, herons will sometimes resort to hunting and eating moles in the same way if frosty weather freezes over their favourite hunting water.

Two favourite foods eaten by badgers are earthworms and hedgehogs. In turn, favourite foods consumed by hedgehogs include slugs and snails. Moles also specialise in earthworms. Bluetit nestlings can eat up to 100 caterpillars per day. One sparrowhawk can eat 10 bluetits in one day. Some butterflies glean essential salts from dog faeces.

Plant nutrition is equally fascinating as a large tree can consume about 15 grams of carbon per day in the form of carbon dioxide and goes on to produce 10 times more oxygen during the day (as providential waste) as they consume for respiration during the night. Using water, trees use the carbon to make carbohydrates such as sugars and cellulose. The waste oxygen is then available for all life, such as us, to breathe.