Mention has been made on these pages of the efforts made in recent times to improve the reserves value to amphibians and reptiles. Back in the spring a number of the recently dug ‘amphibian pools’ had frog spawn in them for the first time. Although some late frosts didn't help the frogs cause, certain pools hosted tadpoles and over time froglets were seen as miniature facsimiles of their parents.
The pools in question are hydrologically separate from other water bodies making fish colonisation more tricky and fish removal relatively easy. Fish can have a dramatic impact on amphibians as many view tadpoles as an easy and nutritious snack and will often go on snacking until there are no more tadpoles remaining to be snacked upon.
One of the many amphibian pools created over the past two winters.
A couple of weeks ago we had a toad wandering beside a pool, Anne has found newts occupying one of the new pools and in the past week both Nick T and I have seen grass snakes on their ‘grass snake’ piles (logs and vegetation) - a promising sign and possible evidence that these targeted habitat alterations are paying dividends. As grass snakes are primarily hunters of amphibians we would expect to see their numbers increase alongside that of their favoured prey and it appears that this is indeed the case, which is one of the more gratifying elements of this job - from planning to realisation.
The presence of vegetation piles besides water offer manifold grass snake benefits. As well as refugia for the snakes, the decomposing vegetation generates heat to incubate their eggs. Over the next few weeks ‘bootlace’ hatchlings will be emerging and slithering-forth into their wider watery world - so it may be that our otherwise unprepossessing piles of rotting reed are worthy of closer inspection henceforth!
A coiled grass snake.
Possibly the greatest allure of wildlife watching is the tangible sense of anticipation for what may lie around every corner - of possible new species to encounter or new behaviours to witness from more familiar characters. The scene below was photographed by regular (almost resident) visitor Dan Dench and probably falls into the latter category as, to my knowledge, a fox taking to birdwatching is an entirely new phenomenon.
Strangely the moorhen seems either unaware or unconcerned by the cunning ones intense predatory gaze - or perhaps a summer spent avoiding the clutches of our marsh harriers have provided a sense of perspective, enabling it to view a mere fox with a world weary shrug of the shoulders?
Many thanks to Dan for the photograph.
We have recently received a couple of enquiries about the why's and wherefores of cattle on the reserves as it can appear incongruous to have hulking great bovines trampling and munching their way through our precious reserves.
The cows on Radipole and Lodmoor through spring, summer and autumn maintain a low diverse and varied sward to the benefit of a wide array of wildlife, from invertebrates to birds and mammals. If unmanaged the grassland will become ‘rank’ which essentially means a few vigorous plants dominate, benefitting relatively few invertebrates and the shorter sward required for ground nesting birds and wintering waders and wildfowl is not provided.
Our fantastic residential volunteer Irene - at one with the herd. She is Spanish and it is fiesta season which may possibly explain why they are cowering beneath the willows!
Mechanical control with tractor mounted equipment can maintain a low sward height but does not promote the tussocks, (micro scale hillocks which act as invertebrate refuges) which cattle produce by preferentially grazing more palatable vegetation types and by poaching the soil with their hooves – which also adds areas of bare soil for certain insects to exploit. Mechanical cutting is more intrusive and made difficult by the ground conditions across much of the site. That said we do mechanically manage hard rush as it is too coarse for even our hardy herd and this is undertaken outside of the nesting season.
Cattle are also charged with the responsibility of grazing pool margins thus maintaining open water where otherwise marginal vegetation would encroach, ensuring feeding opportunities for sight feeding fishers such herons, kingfisher, egrets and bittern. Obviously there exists the possibility of ground nests being trampled but the benefits far outweigh the cons as there would be far fewer nests were it not for the cattle maintaining a rich and varied sward.
Our cattle are owned by Peter Broatch of Eweleaze Farm ( http://www.eweleaze.co.uk/ ) in Osmington and are organic Aberdeen Angus - a famously hardy breed, well able to cope with the rigours of wetland life and not too fussy about the vegetation upon which they are forced to dine.
As the single splendid sun has so ardently refused to shine this season the thousands strong bursts of floral sunshine that brighten-up our verges are now all the more welcome - offering a smattering of golden summery hews on even the dullest of dreary days.
Fleabane is in full flower now - where allocation has been made for it to compete with less diminutive herbage - and is finding favour with a diverse array of invertebrates. It is the primary nectar source for the Small Copper and a secondary nectar source for no fewer than seventeen other British butterfly species which emphasises its great importance. The nectary (from where the nectar is collected by insects) is shallow making it of particular value to insects with short proboscises. It is altogether less popular with certain parasitic insects as it boasts insecticidal properties and the vapour from the burning of its dried leaves was once widely used to repel fleas – hence the name 'Fleabane'.
Fleabane with small tortoiseshell.
Also of a cheerily yellow disposition are the St.John's Wort (Hypericum) family comprising common, square-stemmed and tutsom on Radipole. Certain of the 100's strong St.John's Wort family are cultivated and used in herbal extracts for the treatment of depression - so not only does it appear bright and happy but it contains natural brightness and happiness! Conversely St. John's sap is photosynthetic and can cause skin to blister on contact when in direct sunlight, a fact true also of many of our umbellifors (carrot family), most notably hogweed - making verge management a mildly edgy pursuit.
Square-stemmed SJW - bright and delicate enough to lift any minor malaise.
Tansy (Tanacetum vulgare) is more notable on the drier paths of Lodmoor, (in particular the south path adjacent to the promontory) but certain specimens add their distinctive spongy texture to Radipole too. Tansy is often referred to by the colloquial name 'Golden Buttons' which the photo shows to be rather apt. Again it has had a long and varied history of medicinal uses dating from at least ancient Greece and has been used to treat rheumatism, worms, boils and in the Middle Ages to promote abortion.
The golden button, flowerheads of Tansy.
As noted before in these pages the management of our verges is probably the biggest drain on reserves staff time at this time of the year. Although occasionally laborious it is very rewarding as the paths are garlanded with a diversity of colourful botany that they would not otherwise boast if managed in any other fashion. This is of particular appeal to the great diversity of insects as well as our two legged visitors escaping Weymouth’s holidaying hoards.
When so intimately associated with the management of the verges we are able to note the fluctuations in abundance of particular plant species and at the moment both purple loosestrife and angelica are unusually widespread, which is pleasing to me as they represent my joint favourite wild flowers. There must be a some environmental trigger to these boom years and the sun and moon have metaphorically been in alignment from angelica’s perspective as not only are there a massive abundance of them but many are veritable sky scrapers.
Unusually both these species are noticeable within the reedbeds this year probably as a joint result of the parasitic insects that have robbed the reed of its vitality and the unusually dry conditions allowing them to get a footing amongst moisture loving fragmites.
Angelica is a member of the carrot (umbellifer) family and has been used as a herb through the centuries. Legend has it that it's name is derived from an angel that revealed Angelica to be a cure for the plague although history tells us that the success of this was (at best) limited.
Purple loosestrife also has a long and varied history in medicine and herbalism. It has proven anti-bacterial properties and as such was prescribed by medieval herbalists to staunch bleeding, as a gargle for sore throats and to cure mouth ulcers. It has also found application in the treatment of food poisoning, diarrhoea, dysentery and cholera - the purple panacea of Radipole’s verges!
Purple loostrife to the right of greater willowherb - also flourishing this summer which is good news for our local elephant hawkmoth population as their main larval food plant.
Nb. In the event of contracting dysentery or cholera please contact your physician rather than self-medicating with our native herbage.
P.S. Apologies again for the recent dearth of blogging, once again the system was beset by disruptive digital gremlins foiling our good intentions at every turn. Normal service appears to have resumed so tune in soon for more botanical revelations!