Diving Into Dung

Red-billed choughs became extinct in Kent more than two hundred years ago because of changes in farming practices and persecution. Now, following several years of preparation and hard work, these charming birds are about to be released onto the cliffs around Dover once more.

Red-billed chough on Herefordshire Beacon. Photo by gailhampshire on Wiki Commons cc-by-2.0

On the back of this imminent reintroduction, a flurry of ‘Diving Into Dung’ workshops are being held in our area to increase awareness and appreciation of dung beetles which will form an important element of the newly-released birds’ diet. But, having attended one of these workshops this week, we now realise that these beetles are also of vital importance to farmers and in fact to us all.

The workshop was held at a farm overlooking Dover and the classroom was very atmospherically located in the barn. There were a mix of people attending – some were land managers like ourselves but others were vets and farmers.

Our makeshift lecture theatre in the barn at Broadlees Farm near Dover.

Sally-Ann Spence has spent the last thirty years studying dung beetles and it was impossible not to be drawn in by her enthusiasm and compelling talk about dung beetle biology and ecology and what they require to thrive and do their crucial work. As well as that, she farms livestock herself, using her farm to further research dung beetle-friendly farming practices whilst proving that it is possible to make a farming profit at the same time as cherishing these animals.

Sally-Ann’s box of pinned British dung beetle specimens and identification charts. A microscope is generally needed to get down to species level

In other areas of the world, competition for herbivore dung is so intense that some dung beetles are ‘rollers’ – making a dung ball and rolling it away it away to keep it for themselves. We do not have that level of competition for dung here and there are no British ‘roller’ species. Our species are either ‘dwellers’ or ‘tunnellers’.

A single cow produces 9 tonnes of dung each year and each sheep produces 800kg and, unless all of this vast quantity is quickly broken down, it will sit in the fields and reduce the area that is available for grazing. The beetles tunnel around the dung improving soil aeration, water infiltration and carbon sequestration, as well as reducing the methane that is released into the atmosphere by dung fermentation. If the dung contains seeds, these are taken underground by the beetles and effectively planted. In addition, as well as the choughs, all sorts of other animals eat the adult beetles and their larvae such as little owls, kestrels, hobbies, songbirds, lizards, snakes and badgers.

Britain has been slow to realise the importance of dung beetles in the ecosystem and the dosing of livestock with insecticides has resulted in toxic, insect-free dung that sits in the fields for ages.

After lunch, we went out into the sheep fields to look for dung beetles.

The farm is close to the iconic aerials that stand proud above Dover. Built in 1936, this was once a Chain Home radar station but these days the aerials transmit FM radio to the whole of Kent.

There is also a circus in one of the farm’s fields at the moment:

Sally-Ann demonstrated the different methods of surveying for dung beetles:

Unfortunately we did not find a single dung beetle – an indication that the sheep on this farm had probably been given treatments such that their dung was toxic to the beetles – this was a very salutary demonstration of what the problem is.

Our meadows lie to the north of the chough release site but are sufficiently close that, with the correct management such as grazing parts of them with sheep perhaps, they might be of use to the birds. Indeed, some choughs were briefly released last year and John the bird ringer saw a pair fly over the meadows the very next day.

Not sure how our resident crows would feel about their more colourful cousins, the choughs, visiting? I presume they would not be pleased:

My feeling is that blackbirds and thrushes did not have a good breeding year here with the hot June coming just when they were trying to get worms out of the ground to feed chicks. But this week I did finally have a sighting of a lovely chick out with its dad:

This next photo is an unusual angle of a sparrowhawk which really shows what long legs they have:

A second brood small blue butterfly on the wing in the meadows this week:

Its caterpillars eat the ripening seed of kidney vetch and are cunningly disguised to look like a seed pod:

The caterpillars are usually widely spaced and you could expect to search many plants before finding one. But because there is so little kidney vetch this year, they are much more concentrated – amazing that there are two in a single flower here:

Second brood brimstones are also out and about now:

I think these are small tortoiseshell caterpillars in our nettle patch. I certainly hope they are anyway because we haven’t seen one of these adult butterflies this year and it would be good to know that one has flown through and even stopped by to lay some eggs:

Also on the nettle patch was this harlequin ladybird, Harmonia axyridis (f. succinea). These invasive ladybirds have been out-competing and actually also eating the larvae of our native ladybirds since they arrived in Britain from Asia in 2004. I understand from Sally-Ann Spence, an expert in all sorts of beetle, that their pathogens are starting to catch up with them now and that the rampant harlequin populations we have been experiencing here recently are coming more under control – great to hear some good news.

The harlequin and one of our much lovelier native ladybirds – a seven-spot:

When I first saw this fly in the meadows a few years ago I was confused because its abdomen seemed too small for the rest of it:

It is only when you see it in profile do you realise what’s going on and that most of its abdomen is curled under. It is a really sinister-looking fly:

It is a female ferruginous bee-grabber, Sicus ferrugineus, and she will be laying her eggs onto bumblebees I’m afraid.

In the wood, the marjoram glade is just coming out into flower and, with perfect co-ordination of both timing and colour, is now alive with day-flying mint moths:

The roving camera has moved to look at a second bird box to see if dormice have moved in now that the birds have finished nesting. It seems that this box also has dormice in it:

But the camera has caught a bat at the entrance of the box as well:

Many of these ‘woodcrete’ boxes have ridges built into their ceilings so that bats can cling on and roost within, cohabiting by day with whatever else might be in the box. It is a lovely thought that this box almost certainly had great tits or blue tits nesting in it back in the spring and now it has dormice and bats using it. We have resolved to put up more boxes this autumn because they seem to be making such a difference.

Parent and cub
Two cubs out on their own
Always an absolute treat to see a tawny owl

I finish today with a beautiful view of the white cliffs of France from the top of the second meadow this afternoon. Yesterday we had 25mm of rain but today the sun has returned and the sea is looking almost Caribbean-turquoise.

3 thoughts on “Diving Into Dung

    1. Being stuck for a suitably witty reply, I’ll just have to say wouldn’t it be fantastic to get a chough on the trail cameras, or maybe even into the bird ringers nets – that would be the highlight of their ringing year. But maybe I’m getting carried away because they haven’t even been released yet…!

  1. Or, as they might say up north when confronted with the prospect of spending life up to your beak in dung, “chuffing heck!” Joking apart, it’s good news. They’re lovely birds.

Leave a Reply