It’s an odd year (you can say that again - the editor). The winter has been warm and wet there is no arguing with that, so warm in fact that many species are struggling to tell when in the year they are.Some species are very early, the Toothwort at Taf Fechan for example is flowering weeks earlier than usual but I haven’t seen a single Hoverfly yet this year, I have records for both Eristalis tenax and Eristalis pertinax from mid-February last year.
You have to wonder why; I suppose the question is why is warmer winter weather such an issue? Why, when the weather has been so seemingly benign am I seeing fewer Hoverflies?
Warmer isn’t better. This is on the face of it is a strange statement, a dichotomy even when put in the context of the warmth loving tropical species that is Homo sapiens who dream of winter holidays in the sun, but warm winters are a real problem if you happen to have evolved to hibernate.
Hibernation is dangerous; it’s an exquisite balancing act of extreme consequences it’s certainly not just going to sleep. Hibernating animals can only store a finite amount of energy to keep them alive and warm weather keeps waking them up. The problem is that waking up uses energy, in some cases a lot of energy, energy they cannot replace because there is very little or no food to replace it with.
This applies to Bats especially but it also applies to many other species of animals, not all of whom hibernate in the true sense of the word but also have to live on winter’s knife edge of life or death.
This also applies to my overwintering Hoverflies and other insects like Butterflies; warmth at the wrong time means continued activity without available food. Did fewer Hovers survive the warm winter?
Another issue is abnormally early flowering plants, which are nice for us, or a mere curiosity, but not really for the plant that expends energy on producing flowers only to have very few or no active pollinators to serve it.
This has a knock on effect throughout the year as insect numbers peak at the wrong time for nesting birds that rely on a steady source of food for energy expensive growing chicks and for those overwintering animals that have fewer fruits and nuts to eat as the flowers weren’t pollinated.
It’s all very worrying.
Graham Watkeys (Taf Fechan Volunteer Warden)