The survival of the fittest

Long-tailed tit

The long-tailed tit with a mouth full of caterpillars is a timely reminder that nature’s reproduction season is in full swing.  If you’re up during the night feeding a demanding baby, I sympathise with you.  But you’re not the only one finding child rearing hard work.  In the animal kingdom, you don’t have to just raise your kids, you have to make sure they don’t become food for someone else’s.  If that isn’t bad enough, they can’t pop to the shops for supplies.  They’re constantly foraging, often for the whole of daylight hours to find enough sustenance to ensure their young survive.  Baby swallows, for example, need hundreds of flies each day.

Tawny owl

The tawny owl is nocturnal but, because he now has young mouths to feed, ours is waiting in the garden at 9pm even before it is dark, looking for the supper I’ve provided for him for the last 3 years or so. Tawny owls have a varied diet.  They’ll take small mammals, birds, slugs, worms and amphibians.  At daybreak they’ll retreat to the woods and try to remain inconspicuous in order to get some rest.  But when their youngsters are growing, they will need to be fed during the day.   The adult will need to keep one eye open to spot some unsuspecting prey which they’ll catch and deliver to the nest.  Doing this is going to attract the attention of locals who find their presence threatening.  Blackbirds will use their strident alarm call to harass the owl in an attempt to drive it away from the proximity of their own nest.  They’re your typical ‘neighbours from Hell’.

Before the long-tailed tit interrupted proceedings, his caterpillars were trying to make it to the next stage in their life cycle.  When the relative warmth of spring prompted their change from egg to larva, probably the last thing they expected was to become bird food.  But if they knew what we know, it shouldn’t come as such a surprise because animals time their breeding season to coincide with the availability of prey.  Tits and migrant flycatchers, for instance, rely on caterpillars to feed their young but climate change seems to be impacting on this cosy arrangement.  As Spring comes earlier, insect larvae develop earlier.  If these birds don’t keep up to the changing timetables, they miss the metaphorical train and are left on the platform with nowhere to go.  Fewer chicks will survive and here begins the downward trend.

In the animal kingdom, where you are in the food chain impacts your chance of making it to adulthood.  Only apex predators can afford to relax.  One of my trail cams recording activity in a nearby wood regularly shows a passing fox carrying a pheasant or a rabbit.   Even a duck egg will provide some welcome sustenance to fox cubs, but there goes another duckling. 

Red fox

No wonder ground nesting birds like pheasants will lay around 20 eggs because few chicks will survive – the more eggs, the better the chance.  Badgers will take advantage of any convenient prey and only the best camouflaged bird’s nest will escape the attention of avian predators. This is nature.

Spring is, arguably, the best season to study wildlife as the challenges of reproduction and survival combine to present a natural world drama with a plot more intriguing and complex than you could ever imagine.  It’s no coincidence that the lives of insects, birds and mammals are so intertwined.  And it’s a sobering thought that our lives rely so much on the survival of even the smallest of creatures.  Bees, for instance, are perfectly adapted to pollinate plants, helping the plants to grow and multiply.  The vast majority of plants we eat rely on pollination, particularly by bees.  That’s why we should look after them.

Honey bee

This Post Has 0 Comments

Leave A Reply