Autumnal Walk along Grantham Canal and Denton Reservoir

It’s been a long time since I’ve updated this blog – everything interesting I’ve seen recently has been far from Grantham, and usually in the dark as bat surveys have filled most of my time! So expect some bat related posts in the near future…

September scene

To get going again; this post is just a few photographs from a walk along Grantham Canal and around Denton Reservoir on a sunny, dew-damp September morning. A little bit of everything! It’s sad to see so many of the wildflowers going over, how can autumn be upon us while we’re still waiting for summer to begin? Still, a few flowers are still hanging on:

Black knapweed (Centaura nigra)

Black knapweed (Centaura nigra) is a favourite with the bees and butterflies and a few are still in flower.

Yarrow (Achillea millefolium)

Yarrow (Achillea millefolium) is a native which you may even have growing in your lawn, or one of the ornamental coloured varieties in the flowerbeds. Look out for the feathery fronds of leaves beneath.

Autumn hawkbit (Leontodon autumnalis)

There are several hawkbit (Leontodon spp.) species – I believe this one is the appropriately named autumn hawkbit. They are in the same family as the dandelion – the daisy or compositae family – but are a much finer, more delicate species.

Ragwort (Senecio vulgaris)

Ever-ebullient ragwort (Senecio jacobaea). There seems to be a fair bit of debate at the moment on whether it really is dangerous for livestock, but it’s another brilliant species for invertebrates. Look out for the yellow-and-black striped caterpillars of the cinnabar moth in July and August.

Creeping thistle (Cirsium vulgare)

Creeping thistle (Cirsium arvense) is another species with a long flowering season.

Rosebay willowherb (Epilobium angustifolium)

Rosebay willowherb (Epilobium angustifolium) flowers later in the season and brightens up the countryside, especially around water. This photo was taken beside Denton Reservoir.

Harebell (Campanula rotundifolia)

Harebell (Campanula rotundifolia) is a species I was not expecting to encounter – this was growing within a sheep-grazed field to the south of Denton. It is a delicate flower often found in more dry, nutrient poor grasslands and heathland, Sherwood forest is a good area to spot them. A welcome addition to the day!

The fields look as though they are on fire from a distance as clouds of dust rise like smoke from the combines. With the crops gone and the stubble remaining, it’s a good chance to look for a few arable plants. There are a number of species which are well adapted to arable conditions and are growing rather rarer these days thanks to the intensification of agriculture. Below are photographs of scentless mayweed (Tripleurospermum inodorum) and common poppy (Papaver rhoeas) – not rare but attractive, I especially love the texture of the poppy flower!

Scentless mayweed (Tripleurospermum inodorum)

Common poppy (Papaver rhoeas)

I spotted a fair few birds within the hedgerows and arable margins, it’s getting to the time of year when large numbers descend on the feast of berries which are ripening. Plenty of blackbirds along with mixed-tit flocks, yellowhammers, chaffinches and an attendant kestrel. This stretch of farmland is a great spot for fieldfares and redwings when then arrive for the winter too.


The last few butterflies were still floating and resting in patches of sunlight; red admirals, comma’s and speckled wood all in evidence. Below is a comma (Polygonia c-album) sunning itself on a bunch of ripening blackberries!

Comma butterfly on blackberries

Dragonflies and damsel-flies were spaced out along the edge of the reservoir, the dragonflies jealously guarding their patches. This was my first attempt at a dragonfly in flight, I’m quite pleased with it! I am not 100% confident on the ID but this is certainly a hawker dragonfly, probably a southern hawker (Aeshna affinis) judging by the amount of green on the thorax but please feel free to set me straight if it’s a common!

Southern hawker dragonfly

Denton Reservoir in the ice and snow

Cold and snowy weather can be the perfect time to go and visit larger waterbodies where all the water fowl are often far away – as the ice closes in, they are generally pushed closer together where they manage to keep a small area of clear water where they all then congregate. Whilst I’m sure they aren’t too pleased with the weather, this does often make them easier to see! And if you’re lucky, you might even enjoy the sight of one trying to land one the ice as in the case of the mute swan – this year’s judging by the greyish tinge to the plumage!

Mute swan landing on ice at Denton Reservoir
Mute swan landing on ice at Denton Reservoir (click for a larger quality picture)

Denton reservoir is located in the village of Denton, just outside of Grantham. It can be accessed by footpath from the village and is well worth a visit at any time of year. Lincolnshire County Council have produced a walking route which takes in the reservoir as well as the villages of Denton and Harlaxton – you can download a copy here or pick one up from Grantham Library.

I spotted a total of  nine species at the weekend which are illustrated below.

Mute swan

Mute swans at Denton Reservoir

Tufted duck and Pochard

These two species are quite similar at first glance and you might be forgiven for thinking one was the male and one was the female! The black and white diving ducks, with the little tuft extending back from the head, are tufted ducks whilst the brown-headed pochard is the chap with his head tucked under his wing in the bottom left of the photo. Don’t be distracted by the white-nosed coot’s, they’re featured further down.

Tufted duck and Pochard at Denton Reservoir


Often thought of as a sea bird but often seen inland. Similar to a shag but shags are very rarely seen away from the coast.

Cormerant at Denton Reservoir
Cormerant at Denton Reservoir
Cormerant in flight at Denton Reservoir
Cormerant in flight at Denton Reservoir

Great crested grebe

Often one of the shyer species, this is a good chance to get a good view of them. There are two on the ice and one braving it out on the cold waters with his head under his wing.

Great crested grebes at Denton Reservoir


A species which will be very familiar to most – the males are the brightly coloured chaps whilst the drabber females are dressed in brown. They’re all taking care over their appearance in this photo!

Mallards at Denton Reservoir


These are often quite territoral little creatures for much of the year, even chasing swans away from their patch. Perhaps it’s the sheer futility of being territorial in such a small space which calms them down at this time of year – they all looked to be getting on well.

Coots at Denton Reservoir

Canada goose

Whilst none of these photographs are award winners, this is the worst of them all – it wasn’t until I got back that I realised the camera had focussed a little behind the geese! There are often large flocks of these geese, along with the greylags, but these were the only two when I visited.

Canada geese at Denton Reservoir


Wigeon at Denton Reservoir