Week 28: Hemel Hempstead Barn Owls

Southern Hawker dragonfly, Bovingdon Brickworks (perched after hunting by the Buddleja)

Southern Hawker, Brickworks

Bramble blackberries, Brickworks

After fledgling Wagtails and nestling Swallows; riverside damsels and hunting dragonflies; meadows of moths and butterflies, I hadn’t got a clue what wildlife wonder I might encounter this week. In my wildest dreams, I don’t think I could have conjured up what transpired.

After months of not feeling up to going out beyond about 6pm, the sunset on Monday evening, combined with improved health, tipped the balance. Box Moor Trust land set against a fiery sky, seemed like a good plan. Of course, the inevitable happened. By the time I got out of the car, the colours had faded and the moment had passed. Still, it seemed a pity to waste escaping the house and so off I set. I debated whether or not to bother with the tripod but decided that if I left it in the car, I was bound to regret it.

I might have missed the sunset but I came across something far more exciting. Over the past month or so, there have been a number of Barn Owl sightings around Hemel Hempstead. On the Box Moor Trust Moth, Bat and Glow Worm evening (27th June), the group had enjoyed watching a bird quartering over the field between Chaulden Lane and the railway bridge. Dan Forder (of Hemel Birding fame) had seen a bird near the M1 Jun 8 on 7th July. And, on Monday evening, as I walked over Trust land, I chanced upon one of these beautiful creatures perched in a tree. It eventually took flight, soared silently over my head and away. Utterly magical and boy was I glad I had the tripod with me! The light was almost gone but I was able to get some ropey video footage before darkness fell. Special thanks to my talented Sister, her choir and the Robin soloist(!) for the backing track. A couple of years ago, on a sultry summer evening, the choir threw open the hall doors as they sang a cappella. Nature joined in. The resulting piece is candid and unique. A male Robin sings his evening song and the choir swells to accompany him.



Having done a little reading about Barn Owls, it seems to me that the females have the right idea. Grab yourself a monogamous mate and sit around all evening whilst he goes off and finds the food. Once eggs are laid, snuggle up inside the nest site, don't bother to build a nest (who needs twigs when regurgitated pellets will do?!), don’t bother to wash, and lap up meals-on-tap from the doting male. Result!

Ten Barn Owl Facts, shamelessly copied and pasted from the internet (with a few minor additions). More facts here.

1. The barn owl was voted Britain’s favourite farmland bird by the public in an RSPB poll in July 2007. 
2. Historically, the barn owl was Britain’s most common owl species, but today only one farm in about 75 can boast a barn owl nest.
3. Barn owls screech, not hoot (that’s Tawny owls). 
4. The barn owl can fly almost silently. This enables it to hear the slightest sounds made by its rodent prey hidden in deep vegetation while it’s flying up to three metres overhead.
5. The barn owl’s heart-shaped face collects sound in the same way as human ears. Its ears are placed asymmetrically for improved detection of sound position and distance, and it does not require sight to hunt. Its hearing is the most sensitive of any creature tested.
6. Barn owls are non-territorial. Adults live in overlapping home ranges, each one covering approximately 5,000 hectares. That’s a staggering 12,500 acres or 7,100 football pitches!
7. It’s not uncommon for barn owl chicks in the nest to feed each other. This behaviour is incredibly rare in birds.
8. In order to live and breed, a pair of barn owls needs to eat around 5,000 prey items a year. These are mainly field voles, wood mice, and common shrews. One of the most unusual feeding records is of a barn owl catching flying hawk moths.
9. Though barn owls are capable of producing three broods of five to seven young each year, most breed only once and produce, on average, only two and a half young. 29 per cent of nests produce no young at all.
10. 91 per cent of barn owls post-mortemed were found to contain rat poison. Some owls die as a direct result of consuming rodenticides, but most contain sub-lethal doses. The effects of this remain unknown.

Barn Owls are a Schedule 1 protected species. It’s fantastic that there appears to be a number of birds locally.


Finally, this week's oak...

And, Dellfield in Summer...

It seems incredible that just 3 months ago, this meadow was carpeted in Cowslips…

Week 24: A Novel Use of Nettles & Family Wagtail

The first week of July and yet, applying my mind is like trying to rouse a tiny dormouse, snuggled up in a downy nest, seeing out the winter. That is to say, the creative juices have run dry. I’m adopting the less is more approach when it comes to words and will perhaps rethink things from week 26 onwards. By that point, the project will have been going for 6 months and might be worth tweaking/reworking/abandoning. Who knows.

Ok, first up, it’s a female Banded Demoiselle.

This one was fluttering around the common nettles by the river, east of Station Road on Harding's Moor. At one point it looked as though it was ovipositing some 15 metres from the river (pardon?!). That had me scratching my head until someone suggested that perhaps the Demoiselle was using the bristles on the nettle leaf to clean itself. That made perfect sense, especially when I noticed that apart from the mating claspers (cerci) and ovipositing appendages (stylus), the damselfly had a foreign object hanging from its rear end (nice!)!

After the Broad-bodied Chasers, I’ve seen an additional 3 species of dragonfly this week on Trust land. A few Emperors (river Bulbourne, Gadespring cress beds and Preston Hill pond), a Southern Hawker around Fishery Moor and a Common Darter (photographed, left) at the Preston Hill pond.

Most noticeable this week, though, has been the number and variety of butterflies out and about. Marbled Whites, Commas, Small Tortoiseshell, Meadow Browns, Ringlets, Red Admiral and Small Whites to name but a few. Add to that, Small and Large Skippers out in good numbers now. I have attempted a Skipper ID comparison (below) from photographs taken at the Brickworks this week.

Small Skipper (Thymelicus sylvestris) (left); Large Skipper (Ochlodes sylvanus) (right)

3 Key Differences

1. Size (wingspan): Small Skipper 27-34mm; Large Skipper (male) 29-34mm, (female) 31-36mm. Their wingspans overlap but the Small Skipper is noticeably smaller in the field.
2. Shading on the wing: Large Skipper - dark shading/patterning on forewing
3. Antennae: Small Skipper - orange/brown rounded tips; Large Skipper - hooked tips. I’ve not found an Essex Skipper (yet) so don’t have to worry about that!

Up on Further Roughdown, I came across a pair of mating Ringlets (Aphantopus hyperantus). Their larval foodplants are grasses [Cock's-foot (Dactylis glomerata), Common Couch (Elytrigia repens), False Brome (Brachypodium sylvaticum), Meadow-grasses (various) (Poa spp.) and Tufted Hair-grass (Deschampsia cespitosa)].

And, near Old Fishery Lane, a Gatekeeper butterfly (Pyronia tithonus) was warming itself, perched on nettles. This is another species that relies on grasses as larval foodplants [Bents (various) (Agrostis spp.), Fescues (various) (Festuca spp.) and Meadow-grasses (various) (Poa spp.). Common Couch (Elytrigia repens)].

Early on in the week, Monday, I think it was, I was walking across Station Moor when I suddenly heard the distressed calls of a Grey Wagtail. I looked up to see a Sparrowhawk lazily flying south, carrying something in its talons. The diminutive Grey Wagtail was in hot pursuit as if its yellow go-faster-stripes were sufficient protection against such a predator. I did wonder if the Sparrowhawk had made off with a young Grey Wagtail. Anyway, on Thursday, I was able to get back to the area and was pleased to discover that, whatever had been going on with the Sparrowhawk, it had not prevented the Grey Wagtail pair from successfully fledging at least 2 youngsters this week by the Fishery Road canal bridge. I’ve put together some video footage of the parents and one of the fledglings. It was a task and a half to capture significant moments when the wind wasn’t gusting and making the footage unusable. Some clips are a little ropey (to put it mildly!) but hopefully that doesn’t detract too much from enjoying the events.



Finally, this week's Oak photograph.