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

Lichens on ash trees at Londonthorpe Woods

Lichens on ash treeWhen I went to Londonthorpe to look at the winter buds, I noticed how well lichens had already established on some of the ash trees. These are often overlooked but well worth further investigation, especially if you have a little hand lens to help you out!

Definitive identification often involves recourse to complex keys involving chemical tests and microscope work. But don’t let that put you off, the more common species are often identifiable using a simple guide such as the ones produced by the FSC. These show you some of the species you often encounter along with the places you are likely to find them. For example, all three species shown below are found on the ‘Lichens on twigs’ laminated sheet.


Lichens are quite unusual in that they are a symbiosis between a fungi and an algae which are in entirely separate kingdoms – the plant and the fungi. They grow on trees, on stone, on sawn wood and bricks and even at the edge of the pavement where feet rarely tread.

A common myth is that lichens only grow where the air is clean. Whilst it is true that many species are very sensitive and can be used to indicate the quality of the air, there are also species which are quite tolerant of poor air quality and will thrive in fairly grim conditions. This is evidenced by the number of lichens you can find on trees in the busy London parks. All three of the species described below are fairly tolerant of nitrogen and acid pollution so we can’t use them to make any great claims about the cleanliness of Grantham! These are common species and are often the first to colonise new trees, especially smooth barked species such as the ash.

There is lots of terminology associated with lichens – the Natural History museum website has a good glossary. I will introduce a few of the key terms here which we can hopefully expand on with different species in a later post!

Lichens can be categorised as crusteose, those which form a crust upon a surface, foliose which are leafy in nature and fruticose which you could describe as shrubby. The three below show examples of crusteose and foliose species. I will try to add a fruticose specimen in a later post!

Xanthoria parietina

The xanthoria genus of lichens may be the ones you are most familiar with – you can find them in a variety of habitats and they are quite common. This species, Xanthoria parietina, is a foliose lichen and is a good model on which to show the difference between the main body of the lichen, the thallus, and the fruiting bodies, the apothecia. The fruiting bodies in this species are of the ‘jam tart’ variety, named because of their shape. These are where the spores, the reproductive seeds of the lichen, are produced.

Xanthoria parietina on ash
Xanthoria parietina

Leacanora albella

Leacanora are crusteose lichens and are another fairly common group of species which you are likely to come across. This one is differentiated from the very similar Lecanora chlarotera by the colour of the fruits which are white rather than buff. Again, you can see the jam tart like fruiting structures and you can see the difference between this crusteose lichen and the much leafier foliose Xanthoria parietina.

Leacanora albella on ash
Leacanora albella

Lecidella elaeochroma

You might have to look a little more carefully to spot this one, another crusteose species. Depending on the tree you find it on, it may only be the black fruits which give it away – these are often called wine gum fruits. If you look carefully though, you’ll see plenty of established specimens of this lichen on the ashes throughout the plantation, as well as tiny patches which are only just beginning to establish and where only a few black dots are apparent.

Amandinea punctata on ash
Amandinea punctata