Back on the 16th June (how can six weeks feel like a lifetime away?!) I ran a short half-day course for the RSPB at Wiggonholt Common, part of Pulborough Brooks RSPB Reserve. The remit of the course was to teach a whole load of RSPB staff about heathland invertebrates. This recently restored heathland coming out of pines is fairly under-recorded, so we were likely to get some good records for the site. I used the picture of the Pantaloon Bee Dasypoda hirtipes just to attract your attention, although a nice 'bare ground' species, they are well known from the car park at Pulborough Brooks! Those hind legs are spectacular but I am sure I have seen them somewhere before...
By far the best thing we found was this Dalman's Leatherbug Spathocera dalmanii found by one of the attendees! It's actually my first Sussex example of this species (I have only recorded twice before, once in Hampshire and once in Dorset). It's also only the third Sussex record and the most easterly in the county! Well done.
What I really wanted to do was to show just how few heather specialists occur on a heath. In the table below, I have written a very quick one or two words about the most significant habitat requirements of that species. Now please note these are quick notes and someone is bound to object to the odd detail. So unless I have made a glaring mistake, please don't bother! It's a rough guide and this sort of analysis works by weight of numbers. For those that came on my chalk-grassland invertebrate course, I am working on a similar post but with twice the species, this is taking a little longer than I had hoped.
| Taxon group | Recommended Common Name | Resource |
| Beetle | Ampedus balteatus | Deadwood |
| Beetle | Anoplotrupes stercorosus | Woodland, dung |
| Beetle | Athous haemorrhoidalis | Roots |
| Beetle | Cryptocephalus fulvus | Grassland |
| Beetle | Cryptocephalus parvulus | Birch |
| Beetle | Dasytes aeratus | Deadwood |
| Beetle | Dune Chafer | Roots, sandy soils |
| Beetle | Green Tiger Beetle | Bare ground |
| Beetle | Heather Beetle | Heather |
| Beetle | Hemicrepidius hirtus | Roots |
| Beetle | Luperus longicornis | Generalist |
| Beetle | Malachite Beetle | Deadwood |
| Beetle | Nalassus laevioctostriatus | Deadwood |
| Beetle | Oedemera lurida | Flowers |
| Beetle | Small Heather Weevil | Heather |
| Beetle | Stenurella melanura | Deadwood |
| Beetle | Striped Ladybird | Pines |
| Beetle | Strophosoma melanogrammum | Trees & bushes |
| Beetle | Vine Weevil | Roots |
| Beetle | Welsh Chafer | Roots |
| Bug | Aphrophora alni | Trees & bushes |
| Bug | Evacanthus interruptus | Generalist |
| Bug | Rhyparochromus pini (Nb) | Bare ground |
| Bug | Spathocera dalmanii (NS) | Acid grassland |
| Bug | Ulopa reticulata | Heather |
| Bug | Zicrona caerulea | Leaf beetle predator |
| Butterfly | Green Hairstreak | Gorse/broom |
| Butterfly | Meadow Brown | Grasses |
| Dragonfly | Black-tailed Skimmer | Aquatic larvae |
| Dragonfly | Broad-bodied Chaser | Aquatic larvae |
| Earwig | Common Earwig | Generalist omnivore |
| Fly | Dasysyrphus venustus | Woodland margins |
| Fly | Dioctria atricapilla | Grassland predator |
| Fly | Helophilus pendulus | Wetland |
| Fly | Neoitamus cyanurus | Woodland predator |
| Fly | Scathophaga stercoraria | Dung |
| Hymenopteran | Ammophila sabulosa | Bare ground |
| Hymenopteran | Bombus pascuorum | Flowers |
| Hymenopteran | Cerceris rybyensis | Bare ground |
| Hymenopteran | Dasypoda hirtipes (Nb) | Bare ground |
| Hymenopteran | Formica fusca | Generalist predator |
| Hymenopteran | Honey Bee | Flowers |
| Moth | Beautiful Yellow Underwing | Heather |
| Moth | Brindled Beauty | Trees & bushes |
| Moth | Brown Silver-line | Bracken |
| Moth | Common Footman | Lichens |
| Moth | Endotricha flammealis | Generalist |
| Moth | Silver Y | Migrant |
| Moth | Vapourer | Trees & bushes |
| Orthopteran | Common Ground-hopper | Generalist omnivore |
| Orthopteran | Mottled Grasshopper | Bare ground |
| Orthopteran | Speckled Bush-cricket | Generalist omnivore |
| Spider | Araneus quadratus | Generalist predator |
| Spider | Arctosa leopardus | Bare ground |
| Spider | Cercidia prominens (NS) | Scarce generalist |
| Spider | Evarcha arcuata (NS) | Heather |
| Spider | Evarcha falcata | Generalist predator |
| Spider | Labyrinth Spider | Generalist predator |
| Spider | Mangora acalypha | Grassland predator |
| Spider | Marpissa muscosa | Deadwood & fence posts |
| Spider | Neottiura bimaculatum | Trees & bushes |
| Spider | Xerolycosa nemoralis (NS) | Bare ground |
| Tick | Ixodes ricinus | Mammal parasite |
Of the 63 species we recorded in around two hours, only five (7.9%) were thought to be directly associated with heathers. In total, six (9.5%) had conservation status which is pretty good. So generalists, bare ground species, woodland & scrub and deadwood species ALL outnumber those species that are tied to the heathers. Yet of these, it's only really the bare ground species that fall into what we would call a 'heathland invertebrate'. Not that the others are not welcome. Additionally if we count the acid grassland species and those on sandy soils, that's a total of 14 out of 63 species. So about 22.2% could perhaps be considered 'heathland invertebrates' but this is becoming more subjective as you group the species in this way.
This is a really interesting exercise in showing that a healthy heathland is not just about dense blocks of heather, far from it. A healthy heathland has a wide range of resources held in an intricate mosaic. This is not an easy thing to achieve, and requires careful management to hold these sites, often poised at the point of collapse, so that all of these resources can be present in some amounts all of the time.
No comments:
Post a Comment