'Wild' honey bees in the lower orchard at Charingworth

Today I was in the 1940s orchard clearing brambles away from the fearsomely shrouded branches of tree 40. I found a surprisingly active colony of honey bees in the south facing base of one of the trees nearby. Honey bees are not actually native to Britain. There are 'feral' populations of the European honey bee, a domesticated form of the bee Apis mellifera that originated in eastern tropical Africa. Beekeepers and orchards have a long history of symbiosis, with the beehives traditionally brought into the orchard in late spring for the blossom. This way the pollination of the blossom is maximised, helping ensure a good apple crop for the farmer and lots of nectar for the bees to make honey with.

I remember that the cavity had had unoccupied combs in it last winter and has clearly been repossessed by the bees. The photo on the left shows this comb in November 2008, with the one on the right taken today. Honey bees are not doing well in Britain currently. They are suffering from a range of new diseases, including the parasitic varroa mite that has spread viruses throughout wild and captive bee colonies.

The press often deal with these issues rather clumsily, confusing the causes of the decline in feral honey bee populations with those of the truly native bumblebee (23 species) and solitary bee (~250 species). The basic reason for the decline in most of our true native bee species has little to do with diseases- agricultural intensification has removed the majority of our species-rich grasslands and thus there are no longer enough nectar-rich plants to support bumblebee colonies and solitary bees (this photo shows a unimproved lowland flood meadow near Bledington, with abundant clover and birdsfoot trefoil). A lack of appropriate nest site habitats is also probably a factor limiting some bumblebee and solitary bee species. I went on a bumblebee walk on Salisbury Plain in August and met Damian who is interested in all these issues and has his own charity dedicated to helping bees.

Conderton, Worcestershire: an orchard of national importance?

Today I braved some fairly angry rain storms to visit a big pear orchard in Conderton (near Tewksbury), Worcestershire. At several hectares in size, several hundered trees and over a century old, there's an awful lot to try and condense into a few photos. It is certainly one of the best orchards I have yet visited and perfectly illustrates the similarity of old traditional orchards to woodland pasture. Indeed, because of it's size and scale I don't expect there are many in the whole county to rival it, especially in terms of habitat diversity and potential for biodiversity. It is begging out for a full species inventory to be undertaken.

That hole was perfect for a Little owl and they love orchards like this one. This is also one of the first orchards I have documented that have had abundant mistletoe (Viscum album) in them. It just doesn't seem to be as common around Charingworth. Misletoe is interesting because it acts like a minature ecosystem supporting six invertebrate species that entirely rely on it.

One of these mistletoe-dependent species is the Mistletoe Marble moth, Celypha woodiana, a UKBAP species. You can detect it by looking for characterisitic damage done by the leaf-mining larvae to the leaves (but alas I did not know this until now and so did not check for it!). The other five species dependent on mistletoe are the weevil Ixapion variegatum (first recorded as a new British species in a Herefordshire orchard in 2000) and four ‘true bugs’ (belonging to the Order Hemiptera): the capsid bug Pinalitus visciola, the predatory Anthocoris visci, the Jumping Plant Louse Psylla visci, and Hypseloecus visci (discovered as recently as 2003 in Somerset).

How about that for a wildlife woodpile? An incredible spread. Fortunately there are also many dead trees that have been left standing as well. The orchard has an incredible range and volume of dead wood; standing, shaded, large logs, full fallen trees and even logs submerged in water. This provides much of the substrate for fungal and microbial decomposition, which is in turn exploited by a whole suite of insects that provide food for all the larger animals.

A lesser stag beetle I found underneath one of the large pear logs pictured.

Orchards often contain other structural features of the landscape preserved around or within them. This one had several very large old ash pollards (and one of field maple). These could house larger raptors and owls and add a different dimension of habitat complexity.

Only whole-dead trees like this provide enough appropriately decomposed wood to support the development of large beetles like the stag beetle, and some species of longhorn beetle and click beetle whose larvae can take seven years to develop.

I'm certainly no lichenologist, but every tree seemed to have a quite varied lichen community and traditional orchards like this are excellent lichen habitats with old trees and low chemical inputs.

What a fantastic orchard landscape that is. I'm betting on Blenheim Orange for the gnarly gentleman in the foreground. It seems to be a real bird haven too, for even though I went without any binoculars, I immediately saw two green woodpeckers take off with their characteristically undulating flight. I spotted many yellow meadow ant hills that they love to feed in. There were also clouds of fieldfare that were pestered by a sharking sparrowhawk at one point. I must make a concerted effort to contact the Overbury Estate and learn more about this special place.

Portabello crossroads orchard, Warwickshire

This is a beautiful orchard associated with an old farm on the Fosse Way in Warwickshire. Many of the trees are well over 50 years of age, including several of considerable girth. The grassland underneath is also very rich in wildflower species.


Note the Selfheal (Prunella vulgaris) in the foreground.

Standing dead trees are a fantastic habitat for insects and birds, but are often tidied away. Leaving them standing preserves this precious contributor to the diversity of your orchard.

One of the larger trees, although I have no idea about the variety...

A Brown Argus butterfly (Plebeius agestis) basking in the sun on the fringe of the orchard. Old orchards are great for butterflies since they combine an open canopy with many of their foodplants and nectar sources, as long as the sward beneath is rich in plant species.

A fantastic open cavity in the massive trunk of a large tree. Perfect access point for saproxylic invertebrates such as stag beetles, certain hoverflies and the Noble Chafer (Gnorimus nobilis). Also potential for bats roosting above.

In half an hour my plant tally for the orchard pasture included:

Selfheal (Prunella vulgaris),
Red Clover (Trifolium pratense- pink, pictured above),
Meadow Vetchling (Lathyrus pratensis),
Agrimony (Agrimonia eupatoria- yellow, pictured above),
Lady's Bedstraw (Galium verum),
Meadow buttercup (Ranunculus acris),
Knapweed (Centaurea nigra),
Red Bartsia (Odontites verna),
Silverweed (Potentilla anserina),
Ribwort Plantain (Plantago lanceolata),
and the grasses,
Meadow Barley (Hordeum secalinum) and,
Meadow Foxtail (Alopecurus pratensis).

Pretty impressive since these were just some of the obvious species that I could identify, indicating that the pasture has had very little inputs from fertilizer or herbicides. This sward greatly increases the ecological 'value' of the site.

I love finding gnarly old trees like this. Nothing worse than the indignity of being propped up.

A bat survey in the Charingworth orchards

This morning I went out into the orchards with my neighbour Andy (pictured above) to survey potential bat roosts. Andy is an ecological consultant and bat enthusiast and has an endoscope for looking into cavities. I had previously located 6 likely looking cavities where there were openings into upwards slanting internal spaces so we went and checked them out...

There are seventeen species of bat in the UK, and 3/4 of these can use trees as roosting sites, each with their own different preferences. They generally prefer roosts that are dark, fairly well insulated, dry, quite humid and away from potential predators such as rats. Finding summer tree roosts is very difficult in places like Gloucestershire due to the number of trees and the fact that buildings often provide more suitable sites. Common pipistrelle (Pipistrellus pipistrellus) is the commonest British bat and the most likely species for the orchard to have as a resident.

Andy using the endoscope to inspect a cavity in the 1920's orchard. Promising potential roosts had very little cobwebs across the entrance or inside as the presence of these is both a deterrent to bats and indicates that the hole hasn't had any animal traffic passing through. Droppings are another giveaway. Sadly we did not find any bats in the trees, but there is great potential for some of the hollow limbs to be used either infrequently by solitary males or for hibernation in the winter. Another survey has been scheduled!

Three examples of the many (9+) woodpecker holes in the orchards. These are also often ideal bat roosts. Noctule bats (Nyctalus noctula) and Daubenton's (Myotis daubentonii) have been known to roost communally in the rot holes that form above old woodpecker nests. Cobwebs in several of the ones we inspected suggested no-one was currently using them.

Rot holes and cavities - a survey

For several days during November 2008 I surveyed every standard and half-standard apple tree to get an idea of the condition of the orchards. I measured the trunk height and circumference of the trees. I also counted and photographed each 'rot hole', 'cavity' and dead limb, since it is these veteran tree features that account for much of the habitat value in traditional orchards.


An example of a 'rot hole'. Great habitat for saproxylic invertebrates including the Noble Chafer, Gnorimus nobilis (a UK BAP species) and many species of fungi . And snails.

An example of what I would call a 'cavity'. It is more of an internal space than a 'rot hole' and often forms where a hollow limb or trunk is accessible through a hole in the bark. Good habitat for a range of cavity nesting birds and bats. You can see some fungal hyphae hanging down inside this cavity- it is in one of the oldest trees and has an entirely hollow trunk, along with several hollow limbs.

Out of a total of 34 healthy and 8 decrepit trees in the 1940s orchard, I found a total of 77 rot holes and cavities (thumbnails above). The average trunk circumference was 160 cm, measured below the lowest branch, illustrating the considerable size of trees in this orchard.

Out of a total of 50 healthy and 3 decrepit trees in the 1920s orchard I found a total of 164 rot holes and cavities. The average circumference was smaller though, at 143 cm. I think the reason this orchard has a greater density of ancient tree features than the one planted in the 1940s is due to the trees being older on average, as well as perhaps having been pruned more intensively being half-standard trees. More veteran tree features = more unusual habitat.

A resident of tree 28, 1920s orchard.