national trust – Grantham Ecology

Heather Colletes bees

September 8, 2016September 9, 2016Grantham Ecology2 Comments

August is a fairly spectacular sight in the Peak District – up away from the arable fields, the heather turns the landscape pink and purple amongst the gritstone. Such a vast resource does not go un-tapped by the natural world and one solitary bee in particular has evolved to exploit the nectar wich underpins this aesthetic abundance.

The heather colletes bee – *Colletes succinctus*

This beautiful little solitary bee is known as the heather colletes – Colletes succinctus. These are slightly smaller than a honeybee but have a similar banded pattern to their abdomen. They are a member of the colletes family – known as the plasterer bees.

These sandy paths, studded with gritstone and lined with heather, offer ideal nesting sites for the heather colletes bees with open substrate for burrows and a plentiful food source just next door.

One of the first misconceptions about solitary bees is that you will find them in isolation. Where the conditions are right however, many species of these bees form dense nesting aggregations. The ‘solitary’ epithet refers to the fact that they do not partition roles in the same way as the social honey bees, such as workers and queens. As we walked the sandy soils of the National Trust‘s Longshaw Estate, we saw these little bees feeding on the heather – their bodies curled almost foetally around the flowers – and soon started spotting their nesting holes too!

At first we saw a few holes here and there, but soon we were coming across dense aggregations of the pencil-sized nesting burrows. Much to the bemusement of a group of American tourists hiking up to the tor, I spent the next 20 minutes on my knees watching their coming and going – the video below shows some their entering and leaving their nesting holes.

The males emerge a little before the females, who themselves appear in August to co-incide with the flowering of the ling. I watched the females leaving their holes and flying up to the heather in whose roots they were nesting. Here they gather nectar and also pollen to stock the larders of their nesting burrows. The females layer their burrows with pollen and then lay their eggs which overwinter as pre-adults (eggs to larvae) to emerge the following summer.

Heather colletes bee emerging from a nest burrow amongst the heather roots

The males hang around the nesting burrows and mate with the females as they fly to and fro – sometimes a mating ball will form where several males will attempt to mate with a single female, grappling together until one wins out. I did not manage any good images of this behaviour, although I would recommend a read of Phil Gate‘s Guardian Country Diary piece which has a cracking photograph of the mating bees.

As the weather warmed up, the previously empty holes increasingly revealed their inhabitants which responded to the changing conditions and began to pop out

One thing which was noticable was the difficulty the bees had in keeping their footing on the loose, sandy soil. Often they would slip and fall, or otherwise engage their wings just to stay positioned on the ground. Coupled with their propensity for nesting on bare ground, an opportunity often afforded by well-walked paths, it much be a feat of engineering to maintain the integrity of these burrows in such substrate. The video below shows a couple of such incidents in slow motion:

I took a few more slow-motion videos of their flight as they enter and leave their nesting burrows. They would often land close to their burrow and the look around a while before successfuly locating their hole. I wonder how they know which is their entrance, amongst so many others. From watching other mining bees prviously, they seem to use landmarks in such a way that adding or removing something from the immediate vicinity of the entrance, such as a twig or leaf, can leave them apparently unsure about their home.

Just a few clips of them leaving in slow motion to finish off! As always if you want to find out more about a bee species in the UK, including these heather colletes, I would suggest checking out the BWARS species accounts and Steve Falk‘s Flickr page including images and the text which accompanies the images in his excellent book.

Things to do in January Number 3: Grasses in the snow

January 23, 2013January 23, 2013Grantham Ecology2 Comments

Snow changes everything, if only for a few days. You can walk through the fields and see exactly who has been where – in which spot the blackbirds have chosen to dig for food, which gap in the hedge the rabbits run through, where the heron stalks along the canal in the early morning. Here’s a slightly unusual one but it struck me how obvious all the grass seed heads are when walking through the snow up to Belmount Tower. Usually half the battle with grass ID can be spotting the distinctive heads against the mass of green and brown around them but they stand out beautifully against the white. Here are a few which should be easy to see!

Cock’s foot – Dactylis glomerata

So called because of the spur which you can see at the base of the seed head, this grass is a common find where management isn’t too heavy. In this case, it is doing well in a field with a low level of sheep grazing but roadsides, wastegrounds and field edges are other good places to find it.

Crested dog’s tail – Cynosurus cristatus

This is a common, tufted perennial grass which is finer than some of the more boisterous grasses such as the cock’s foot above or the tufted hair grass below. Its distinctive feature is a line which runs from top to bottom and, a little like a parting, the seed grows one way or the other. This is distinct from some other similar grasses which grow all the way around in a cylindrical cone, a little more like a pipecleaner.

Tufted hair grass – Deschampsia cespitosa

This grass is large and imposing, growing in a tussock and sending its seed heads up and out a metre from the base. Its leaves are a good give-away if you’re in doubt – squeeze the blade between thumb and finger and you will find that it runs smoothly in one direction but drags with impressive friction if you try it the other. This grass is generally found in damper ground – this could be alongside rushes in a marshy grassland or simply a part of the field where the water collects.

Purple moor grass – Molinia caerulea

I think that this grass is purple moor grass – another large, tussock-forming species which can be up to a metre tall. Like the tufted hair grass, it is often found in slightly damper locations and is most commonly associated with acidic habitats such as moorlands, as the name suggests.

Common bent – Agrostis capillaris

This is a common grassland species which is likely, along with crested dog’s tail, to be one of the main constituent species within this field. It has a fine, spreading panicle (the term for the entire cluster of flowers) and likes nutrient poor conditions. Again, its prevalence will be down to the right level of management (grazing) to keep the nutrients low.

The official grassland managers (with voluntary assistance from the rabbits and deer of course)

Where to see bluebells near Grantham

May 17, 2012Grantham Ecology2 Comments

There are a few woods around Grantham where you can go and see wild bluebells. I saw a few plants flowering as early as the end of March when we had the week or two of glorious weather, but the majority are looking beautiful now in May.

Belvoir Woods, accessed by footpath from Stathern, a village several miles to the west of Grantham, is a good location to see carpets of bluebells within the woods – this is where the photographs on this page were taken. The map below shows where within the woods the largest abundances can be found.

Belton House, the National Trust property to the north-east of Grantham also has them in their woodland beside the river. You need to pay entry to get into the house and gardens unless you are a National Trust member (but, it goes without saying, it’s well worth it!)

Location of Belton House, just outside Grantham

This Sunday, the 20^th of May, Harlaxton College will open its woods to the public to see the bluebells there. The college is based at the large manor just outside Harlaxton, visible on the left of the A607 as you leave Grantham heading west. The college is an outpost of the American University of Evansville. Access is through the village and the woods are open between 1pm and 3pm.

Location of Harlaxton Manor, just outside Grantham

For other locations of bluebell woods, why not check out the National Trust’s Bluebell Map here.

For more info on the difference between native and Spanish bluebells, have a look at my recent post here.