September 2017

It is said that nature abhors a vacuum, and if proof were needed then our partly built pond would provide it.  Filled only with clean rainwater, it had many aquatic bugs in it even before we introduced a few plants into it.  One of the most notable visitors to the pond was a large emperor dragonfly which spent much time laying eggs into the pondweed.  This was several weeks ago, but already I have seen dragonfly larvae swimming about in there.  I have heard it said that dragonflies only live for a few weeks, but that refers only to the adults.  The larvae will lurk on the bottom of a pond for two or three years until the weather is fit for them to emerge as beautiful and aerobatic predators. The larvae are powerful predators that will eat anything from water fleas to small fish.  The adults are also agile predators that will take any flying insect, including smaller dragonflies.

Emporer Dragonfly (Female)

We caught sight of another aerial predator recently as a sparrowhawk flew over ignoring, and ignored by several seagulls as it flew past.  It was also ignored by a large gathering of house-martins and swallows that were flying round the house and landing on neighbouring roofs or telegraph wires.  Swallows and martins have nothing to fear from sparrowhawks which are neither fast enough nor agile enough to catch them.  Sparrowhawks method of catching prey is to use surprise, which they do by swooping low over hedges and fences, taking the prey while it is still perched in a bush or tree.  Swallows and martins are preyed on by a much more agile bird – the hobby, which will accompany swallows and martins as they migrate to Africa.  We assume that the gathering of martins and swallows was to do with migration which they won’t start until the flock is large enough.  A large flock of birds constantly shifting position within the flock confuses predators and just on numbers alone reduces the chance of an individual bird being taken.

Sparrowhawk (Male)

Birds of prey are almost defined by their prey and their hunting methods.  Sparrowhawks swoop, hobbies use sheer speed, and peregrines use that amazing vertical dive at nearly 200 miles an hour.  But there are many birds of prey that adopt more sedate methods.  Walk around Rye Harbour reserve and you are almost certain to see a kestrel hovering and keeping perfectly still waiting for a mouse or vole to stray into the open, the kestrel alerted to its presence by urine trails that reflect ultra-violet light.  The barn owl doesn’t quite hover, but moves very slowly above the ground, relying on silent flight and pale colours to hide it from its prey.

Larger raptors like marsh harriers or buzzards are able to take larger prey like rabbits or weasels which are generally slower moving and easier to see.  They use a swift pounce from slow soaring flight to secure their prey.  One of our largest raptors and one that you are increasingly likely to see in this area is the successfully reintroduced red kite.  How does that catch its prey?  Well, it doesn’t.  It is not a bird of prey, it is a scavenger that, when it is not being overfed by farmers in Wales that charge the public to see them, will take carrion or any other scraps it can find.  The red kite reintroduction has been so successful, that it makes you wonder why it became extinct in the first place.  Perhaps it was persecution by those same farmers who mistakenly saw it as a threat to their livestock.