Bittern in the Dearne Valley:

Readers of Nature’s Home magazine, and watchers of BBC’s Autumnwatch will be familiar with one of the star species at RSPB Dearne Valley, the Bittern. And current visitors to Old Moor will notice that the path from the Bus Stop to the Reedbed Hide is not open.  Here’s why.  

In 1997, there were only 11 booming males in the whole of the UK. A key cause of this decline was the drying out and loss of their ideal habitat – the reedbed. So, after extensive research to understand the habitat, diet and breeding conditions required by this illusive bird, undertaken by the RSPB and partners, new management practices were implemented on some RSPB sites, and now the species has made a fantastic come-back. 


A national RSPB-led project, aimed at restoring Bittern habitats, began in 1996 in East Anglia; and then expanded into various UK sites.  Now there are estimated to be around 160 booming Bitterns in the UK.  

At Old Moor, after the initial reedbeds had been established by Barnsley Council in the 1990s, RSPB’s work began in earnest from 2004 onwards.   Old Moor had wintering Bitterns from 1999/00; but, the key exciting milestone is the first breeding, which took place in 2012. 

And now, each Spring, the paths around the reedbed are closed to allow nesting and feeding to take place undisturbed. But you can still get a fabulous view of the bittern from the Bus Stop and the Bittern Hide. This year Bittern have also been sighted over Wath Ings the Field Pools and Bolton Ings.


The process of creating the right environment, providing the right food, and making sure nests were undisturbed has taken years, and there will be more about that in future posts.


Bitterns… and yet more:

The management of the reeds at Dearne Valley has led to fantastic success for Bitterns, but it is also a success for other species too. 

In addition to watching the Bittern, and recording their behaviour and numbers, and spotting some surprises; visitors to Old Moor have also been able to watch Marsh Harriers, who have taken up residence in the same habitat as the Bitterns.  Potentially a beneficiary of the Lockdowns last year, the Marsh Harriers bred in 2020, and seem to have moved in whilst the reserve was closed; the paths were quiet and the food was plentiful.  Having two star species to monitor is a full-time job (more about that in a future post from “the man in the box”!)

And now, the Marsh Harriers are as active as the Bitterns in preparing to raise a new generation of this powerful bird of prey.  And this gives us a brilliant opportunity to compare and contrast the two birds.


Bitterns are bigger than Marsh Harriers – with a length of around 75 cm, compared to 52cm, making them about half as long again. And a Bittern’s wingspan is also slightly bigger than a Marsh Harrier’s, at 130cm compared to 122cm. 

As suggested by the fact they are living in close proximity at Old Moor, their diets overlap. Bitterns have a decidedly “fishy” diet – favouring amphibians, eels, and fish, as well as insects; whilst Marsh Harriers will also eat amphibians, fish, and insects; but they are also partial to small birds and mammals, including rabbits, too! Yum!

But, how both birds feed differs – the Bittern will “fish” in the traditional manner that we might expect long-billed water birds to do – “stalk and stab”; and then fly back with their catch.  

Marsh harriers, in general, like their food to be on the ground and they will target it from above in a sort of drifting and dropping manoeuvre. However, once paired up, the Marsh Harriers can exchange food in mid-air as part of the male providing for the female and young. This is where the male flies near the nest site, carrying food, and calls to the female; and she will then fly up towards him and they manoeuvre so that the male is just above the female. He then “drops” the food for her to catch. This is amazing to see!


More about Marsh Harriers and Bitterns next time.


The reserve, a potted history:

There is no doubt that hosting breeding Bitterns is an amazing achievement for RSPB Dearne Valley. But, like at many other sites across the UK, this didn’t happen by accident. 

Just over half a century ago, the site for the reserve could not have been more different to what it is now. It was an area of poor agricultural land, and a coal stacking area during the Second World War.  It was dominated by shale, scrub, willow, and birch; with some rough wet grassland thrown in. However, even then it provided relief from incredibly hard jobs for a small band of locals who would visit regularly for the birding.

The first key area was largely what is now referred to as Wath Ings (now part of Old Moor).  And over the years, the birders acted to protect the area; they even installed two hides during that time – one on the Willow Pool (now gone), and one opposite the current location of the Wath Ings hide. That hide was famously built in a back garden and transported to Old Moor in 1975 and is still on the site today – although it has moved, and is a bit “matured” now, so not up to modern standards for visitors. But here you can see the birders’ penned sightings from inside the hide!

It was their passion for the area that is often celebrated as starting the green revolution in the Dearne Valley! Without these early pioneers it is highly likely that there would not be an Old Moor reserve.

The RSPB's involvement began in 2003 when they leased Old Moor (including Wath Ings) and Gypsy Marsh from the Council and Environment Agency. Part of Edderthorpe Flash was then purchased in 2004 with the rest gifted to the Society in 2008. This is the only land in the Valley that the RSPB actually own. Later 'acquisitions' have all been long term leases from the Environment Agency with Wombwell Ings in 2005, Bolton Ings in 2006 and both Adwick and Houghton Washlands in 2011. 

The creation of the reserves we see today is the result of many individual and organisational efforts. There are too many to name here but there will be more history in future posts.

Other Species:

Regular visitors to Old Moor will be familiar with some of the other species that also reside in the reeds and benefit from an excellent reedbed habitat; so now is the time to introduce Bearded Tits.  

“Beardies” are small-sized; their length is around 12-15cm and their wingspan 16-18cm – about the size of a Tree Sparrow; and they are often heard rather than seen, but once seen, they are never forgotten.  



Bearded Tits are a recent arrival, first found at Old Moor in 2016 – that’s only five years ago, but they can feel such a permanent part of the reedbed that visitors are sometimes shocked if they don’t encounter them at the height of the Summer and Autumn!!


Their name is a bit of a misnomer. These birds are not actually part of the Tit family, having their own family name of Panuridae; and, as for a beard, well they might actually be more accurately called the “moustached long tailed sparrow” – not quite as catchy though!

Although these beautiful birds can be seen on the reserve throughout the year, without hearing their tell-tale “pinging” it is hard to locate them amongst the reeds. But the “pinging” and the colourful glimpses of these reedbed occupants make visitors smile with delight after a walk around the reeds.  

You might find them eating insects and spiders in the warmer months, but they are a bird so well-adapted to their habitat, that they will eat a different diet during Winter; switching to reedbed seeds and grit to grind the seed down during the colder months.


                                                We will be showcasing another special species next time.


Other birds, flora and fauna to watch out for now in the Valley:

Keep your eyes peeled for waders: Redshank, Common and Green Sandpipers, Lapwing, Avocet, and Oystercatcher.  

And look for all manner of ducks: Mallard, Pochard, and Tufted Ducks to name a few. 

Don’t forget the aerobatic Swift that you may see connect on the wing when they mate.  

And finally, babies are everywhere – Goslings, Ducklings, Coots. Keep your eyes peeled for them! 


Early Summer is a great time for:

DogRose                                  Southern Marsh Orchid            Ragged Robin                      Common Vetch

Gorse, everywhere! (have a sniff, but be careful not to prick your nose, it smells of coconut!)

Brimstone Butterflies along Green Lane


Bank Voles and if you are lucky, Stoat, at Old Moor

Ragged Robin

Common Vetch a member of the pea family.      

And Dog Rose – everywhere


June is also a great time to visit Old Moor and the Dearne as the Dragon and Damselflies emerge from the ponds


                                                            Azure Damselflies emerging from the Toyota pond dipping pond.                                          David Pritchard

And sure enough, the first sighting of a Hobby was only last weekend on June 5th. The Hobby is a specialist Falcon who catch and eat dragon flies whilst airborne. They are summer visitors all the way from Tropical Africa, 1000’s of miles away.

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