Thursday, 21 May 2015

Cygnets & Ducklings

It is very challenging for an aquatic bird to raise young on the Ock.  In the water they face threats from otters, mink and pike, if they stray onto land they face predation from stoats, foxes and uncontrolled pet dogs and from the air there is the permanent threat of kestrels and buzzards

Yet despite these risks, a pair of swans have managed to raise three young cygnets.

Swans normally have large broods of 8 to 10 cygnets, so this pair may have already lost a large a large proportion of theirs.

Whilst it is unlikely that all three will survive, at least they have two attentive parents who will do their utmost to care and protect them, unlike this lonesome duckling.

With no parents or siblings it has either been abandoned or it's relatives have been predated leaving it will very little chance of it surviving the night, yet alone to adulthood.

Saturday, 16 May 2015

Sophie the Stegosaurus

The Natural History Museum in London is famous for it's dinosaurs, yet it's most iconic, Dippy the Diplodocus in the entrance hall is actually one of ten plaster casts of a dinosaur in Pennsylvania and it now has a rival - Sophie the stegosaurus

Named after the daughter of the benefactor who helped pay for it, this young dinosaur (whose gender is actually unknown) is 85% complete is the most complete stegosaurs yet found.

And it makes a mesmerising display in the Earth Hall when entering via Exhibition Road.

Sophie is a Stegasarus stenops and belongs to the group of dinosaurs known as the stegosaurs which are defined by their heavy body armour and defensive tail spines.
Sophie isn't the only stegosaur at the Natural History Museum, located across from the vast display of itchyosaurs are the fossilised remains of a Dacentrurus armatus:
Whilst not as impressive as Sophie - consisting of only a pelvis, vertebrates, femur and the defining tail spine -  it is the first ever stegosaur to be described and whilst Sophie was found in Wyoming in 2003, this one found in Swindon in 1875.

Dinosaurs of the British Isles by Dean Lomax:

Thursday, 7 May 2015

Top Ten Tips for watching water voles:

In a comment to a previous post, Becky asked the following question:

Any tips for the best time of day to look for water voles

And whilst I answered the question in the comments section  I thought the subject of finding and watching water voles warranted a longer post, so I have compiled this list of top 10 tips to finding and watching water voles:

1. Identify Habitat
Perhaps the most important thing for spotting water voles is to identify is suitable place where they may live.  As the name suggests water voles inhabit water courses, but many sites are not suitable as they require steep banks to burrow into, such as these local water vole habitats.
The bank itself does not have to be too deep, about 10cm is the minimum, hence water voles can be found in water courses with comparatively shallow banks such as the Oxford canal (near Jericho) and the river Thames (near Chimney Meadows).

Vegetation is very important to water voles, - sedge, arrowhead and water crowfoot are some of the river plants that grow in rivers and streams and provide excellent opportunities to watch them swim across the river to feed:
Along the river bank, long grasses provide an additional source of food and bedding as well as cover from predators, and for the determined water vole, there are always nettles.

Unfortunately the ideal water vole habitat - steep banks and plenty of vegetation - does not always make a good place to watch water voles, like this ditch in north east Abingdon, where there is a very strong water vole population, but it's virtually impossible to see them.

2. Look for field Signs:
Having identified suitable water vole habitat, the next stage is to identify if water voles inhabit the area and there are three key field signs to look for - burrows, latrines and feeding.
The most obvious sign of water vole activity are burrows, these can be close to water - with grazed lawns or further up the bank:


Unfortunately the existence of burrows is not sufficient to prove there is an active water vole population, these burrows may have been caused by a now extinct colony or created by another animal - such as  Signal Crayfish (invasive crayfish introduced in the 1970's) that are notorious for burrowing and causing damage on river banks.
Therefore, it is often necessary to find other field signs as well.
Like a lot of mammals (badgers and otters included) water voles use their faeces as form of communication to indicate the existence of a vole's territory and are known as latrines.
Although they can be tricky to spot, when seen they are very distinctive - small, black (sometimes green) and ovoid (often described as looking like tic-tacs).

The third key field sign are the characteristic feeding plies -  vegetation (usually grass or sedge) with their ends cut at 45 degrees - and are easily identified when spotted, 

The combination of all three should mean there is an active water vole population

3. Look out for predators
Whilst they are bad news for the water voles, the presence of predators can be indicative of a water vole population.
The sight of an owl or a kestrel flying above the river can mean there are water voles present.  And the presence of rats can make water voles more active during daylight, hence making them easier to spot.

Whilst they normally eat fish and amphibians, herons are also known to eat the occasional water vole (, so if one is stalking a ditch, which doesn't seem to have a large fish population then it might have learnt of the presence of water voles and there is one currently stalking the lower Ock, where there is a high water vole population at the moment.

The nadir for all water vole spotters is the evidence of American Mink, a single female can wipe out an entire colony. 
Depsite their fearsome reputation, they are shy creatures and are really seen, so the most obvious indication of their presence is their dark, twisted, foul smelling faeces (known as a scat).

4. Listen
Even when water voles can't be seen, they can often be heard - a rustling in the vegetation, the nibbling of sedge (water voles are surprisingly loud eaters) and the distinctive plop made when they dive under the water if inadvertently disturbed can indicate the presence of water voles.

5. Look for them in spring:
Water voles do not hibernate and are active all year round, indeed I have seen them in the snow in winter ( ) and are most active during their breeding season which runs from April to September.
I have found the best time to spot water voles is in spring - especially April and May - when the breeding season has started and the first generation are leaving their burrows and themselves looking to breed as well.
Surprisingly, as the population continues to expand they can be harder to see.  Perhaps due to the younger generations seeking new territories, the increase in population may attract predators and perhaps the biggest factor for decreased water vole sightings is the increase in riverside foliage making it a lot harder to see the river and the banks.
As this graph of my average water vole sightings along the Ock over the previous 4 years shows:

6. Look in the morning and evening:
During the breeding season water voles are active day and night, but maybe because they are avoiding predators I have found the best time to see them is either early morning (7 to 9am) or early evening (6pm to 8pm)

7. Do water vole surveys:
I first leant about water voles through doing the BBOWT surveys - these have several advantages for a would-be water vole spotter - the opportunity to attend a training day to learn about the field signs and understand water vole habitat; an opportunity to explore areas which would normally be out of bounds; and the chance to meet fellow surveyors.
More details on the BBOWT water vole recovery project can be found at:

For those who don't live in the three counties, other wildlife trusts and organisations may offer similar survey opportunities.

8. Visit a water vole reserve:
Several places have introduced water voles into safe suitable habitats including WWT Slimbridge ( and WWT London Wetlands Centre ( and can provide excellent viewing opportunities - if you are not distracted by the other wildlife.
But on my visits I have never actually seen any water voles.

9. Go on a water vole safari
For those wanting to take photographs of water voles photographers Ian Greene ( and Terry Whitaker (!/p/workshops-and-tuitio) run workshops with highly photogenic water voles in photogenic locations.
Unfortunately I have not had the opportunity to attend any of these courses, so cannot make a personal recommendation on them.

10. Be patient:
A key skill I have learnt whilst watching water voles is to be patient, even if there are plenty of signs of them and it is early evening on a warm spring evening, there is no guarantee of actually seeing a water vole.
But with a lot of patience, sometimes many weeks, all it takes is one glimpse of these charismatic creatures to know it has been worthwhile.

Whilst waiting, there are plenty of other things to enjoy along a river, I have also seen kingfishers (, a great white egret ( even otters (
- all whilst failing to see water voles.