Absolutely Conkers

A horse-chestnut tree leaf with the typical markings of miner moth Cameraria ohridella

Rejoice, for it is that time of the year once again, when the horse-chestnut trees are fully loaded with their shiny deep red bullets and conkers fall from their tired branches onto our heads, before rolling on the wet ground and bouncing gracefully over a bed of brown leaves.

We have spent quite some time observing and filming these trees recently, and our collection of conkers is starting to take over the house. It is sufficient to say I have even found conkers rolling through my bedsheets as I went to sleep...

As we followed the browning of the leaves and the falling of the conkers, we couldn't help but worry as we observed the destructive work of the tireless horse-chestnut leaf miners (Cameraria ohridella). These are very small moths that on the larval stage feed on the tree leaves, burrowing or mining their way through the green, and leaving streaks of brown destruction on their path.

Holding strong against the assault of miner moths

Once the caterpillars grow to full size (which is a mere few millimetres), they cocoon and emerge as micro-moths, which we could observe in millions during the past weeks, flying around the sad looking trees and shrivelled up leaves. These parasites are not lethal to the trees, but they cause their premature ageing, meaning the horse-chestnuts that are infested tend to shed their leaves and conkers as early as the end of August.

A quick search for these leaf-mining caterpillars and we discovered that they were first observed in 1984 in Macedonia. Since then, they quickly colonised new trees and new countries, and they are currently found living and thriving on horse-chestnuts of most European countries. As far as we could observe, every horse-chestnut tree in Bologna is affected but, to our surprise, when we inspected some trees in Hamburg a week ago, we couldn't find trace of their presence. The leaves of these healthy trees were still radiant and green and the chestnuts were strong, big, and heavy, still dangling from the branches.

A freshly fallen conker, in all her shiny and smooth beauty

But it looks like apart from a few healthy trees in northern Europe, the moth is spreading, and there isn't much we can do about it. What this means is that we'll have to get used to smaller and earlier conkers, and that rather than being a typical autumnal event, we'll have to get used to seeing conkers rolling at our feet as we walk back from the beach, at the end of summer. It's good news for the little birds though, as we found blue, great and coal tits, as well as black birds and thrushes, literally feasting on the larvae at the top of the trees. A welcome and hearty snack in preparation for the long, rainy autumn that will soon arrive.

Not the healthiest leaves, but still attractive in the first light of dawn

Nick, Oropendola Productions

Welcome to the Oropendola Blog!

Hello World, Before starting off this journal, we thought we'd take the chance to quickly introduce ourselves and the Oropendola Blog.

Who are we and what is all this about?

Excellent question, let us try to articulate a good enough answer. We are Greta and Nick, two science graduates, wildlife enthusiasts, conservationists, camera maniacs, sound recordists and insect lovers who make films about animals. So, I guess we can call ourselves wildlife filmmakers, or at least that's what we are aspiring to be.

Recently we have dedicated a considerable amount of our time (and sweat) to filming insects and recording their fascinating sounds in the wild. We spent nearly two months doing this, in two locations within the Amazon, and it would be an understatement to say it was an incredible experience.

Now we're back at base, in the north-west of England, with the intention to keep exploring the sounds and the wildlife of this wintery land and edit the footage acquired in South America.

So this, the Oropendola Blog, will be our journal, where we'll share our passion for wildlife sound recording and filming, and a few stories about our past, present and future adventures.

And if you're wondering what on Earth an Oropendola is or means, well, here it is, in all its feathery glory:

Oropendola by its nest in Salvacion, Manu National Park, Peru.

The distinctive and captivating call of the Oropendola was one of the first sounds we heard as we entered the rainforest, and one of the last to accompany us as we left. It was also one of the most common bird calls in general and we could hear it pretty much everyday, from dawn to sunset. As if  singing wasn't enough to attract our attention, a striking yellow tail and beak made it one of the easiest birds to spot in the canopy, as was the utterly bizarre nest it builds, shaped like a teardrop or a pendulum (hence the name) hanging from the trees. After so many weeks in the company of this magnificent bird, we often find ourselves missing its songs. But luckily for us, we have many hours of sound recordings from the rainforest, and the Oropendola features in most of them. Here's a short snippet of one... can you hear its calls?