Wednesday, 28 March 2012

28th April River Dodder Clean Up

River Dodder Clean Up 
Date:Saturday 28th April, meeting point at The Dropping Well Pub Car Park at 10am.

The IWT Dublin Branch Conservation Team got their feet wet to celebrate National Spring Clean Month this April by putting our words into action and taking to the bankside to clean up a section of Dublin's River Dodder, making it a friendlier place for man and wildlife alike. Many sections of this river have been dramatically affected by the floods last year, so this effort was well needed and sorely overdue. As the picture shows some unusual helpers also came along to join the IWT volunteers!

21st April Booterstown Marsh

Time and date: Saturday 21st April, 11:00
Meeting point: Outside Booterstown DART station

A goodly number of IWT members turned up for this event led by Conn Flynn, our Conservation Officer, who was ably assisted by birding enthusiast Arthur Doyle. Before walking around the sanctuary Conn talked about the importance of the marsh for birdlife and he also gave us a brief account of its interesting, somewhat chequered, history. The site which is protected under EU environmental legislation is described by some as a unique patch of wilderness within the confines of the city of Dublin.

Beside different species of waders (among them Redshank, Greenshank, Godwit) and ducks (teal, mallard) we spotted a pair of swans, some Brent Geese, a number of Grey Herons, two Little Egrets, a moorhen as well as some common urban species (Wren, Tit, Finch). We even noticed a swallow busily collecting mud for its nest. Altogether a most pleasant outing.   


Monday, 26 March 2012

15th April Bird Watching on Bull Island

On Sunday 15th of April about twenty IWT members turned out on the Causeway road on Bull Island for an event led by Sean Hogan, an experienced birdwatcher. The North Bull Island is a UNESCO Biosphere Reserve, RAMSAR site and a Special Area of Conservation. Sean had some telescopes on standby and those present got to see and identify Bar and Black-tailed Godwits in their reddish-brown summer plumage, Shelduck, Mallard, Little Egret, Teal, Curlew, Heron and Brent Geese among others.

Sean was a mine of information, and even those who thought they knew a thing or two about birds learned a lot that they did not know before. For example, unlike other ducks, Shelduck lay their eggs in burrows and later each year leave their chicks a hundred at a time in a 'creche' with one of the adults while the others head off to a safe offshore sandbank to moult their feathers. Sean also talked about the Little Egret which is a recent arrival to our shores, only having started to breed in Cork in 1997. Since then it has spread north through Ireland and can be seen regularly around Dublin Bay. The Bull Island and other tidal estuaries like it are a huge source of protein for seabirds, especially in winter. In fact each square metre of mudflat contains more protein than the equivalent size of rainforest! (Photos courtesy of Niall)

Sean in the blue wooly cap shows us the shelduck 

Sean also had some advice about binoculars and telecopes. The rule of thumb for binoculars is that when you divide lens size by magnification the result should be more than 5 e.g. lens size of 42 and magnification of 8. The crucial factor is the amount of light that the lens let in. A decent pair of binoculars can be got for about €100 - 150 and it is important to take the time to try out different kinds to find the one that suits, as each person's preference is different. Regarding telescopes good options are zooms lens with magnification of 20 to 60 or alternatively a wide angle fixed lens of about 32 magnification. A good one won't be got for less than € 200 and the sky is the limit for the more expensive ones.

The best guide books are 'Complete Guide to Irish Birds' or 'Pocket Guide to the Common Birds of Ireland' , both by Eric Dempsey, or the 'Collins Bird Guide to birds of Britain and Europe'

After seeing the birds of Bull Island the group crossed over to St. Anne's Park to hear some birdsong. Coal tits, wrens, robins and blackbirds were heard, and for a few moments there was great excitement when it was thought that woodpeckers had arrived in the park! Alas it turned out to be Grey Crows pecking at the branches of a nearby tree to get building material for a nest. Despite that minor disappointment the group went away very happy with what they had seen and heard, and a lot more knowledgable.

Saturday, 3 March 2012

6th March Green Drinks - Green Roofs

Tuesday 6th March saw the monthly Green Drinks talk in Messrs Maguire, 2 Burgh Quay, Dublin 2. The topic this month "Green Roofs and living walls and their potential to reduce rainfall runoff and attenuate stormwater flood events". The presentation was given by Sadhbh Ní Hógáin, who is a Structural Engineer with an MSc in Architecture. Her past work ranges from design engineering to academic research to domestic refurbishments, and she has recently studied how to construct green roofs, and their benefits to society, industry and the environment.

Green roofs have many benefits. Their major benefit is to reduce the rapid runoff of rainwater from roofs by storing the water in the soil or gravel, and releasing it slowly. This helps to prevent flooding in urban areas, which is becoming a greater concern due to global warming. As well as reducing rainfall runoff, they help to improve air quality by bringing plants into the city areas and they also have a major biodiversity benefit by providing habitats for wildlife such as insects and birds. Green roofs also improve energy efficiency by providing insulation to the building beneath them. All these benefits are shared by green walls, but there is generally less of an effect with them, due to the limitations of a vertical surface.

Green roofs come in various forms. They can be simply a low maintenance thin layer of gravel which will support low growing plants such as sedum, and which only need an annual weeding to keep them working; or they can be a more ambitious affair with shrubs and even small trees, which can act as a rooftop garden or green haven in the 'urban jungle'. Provided the proper support has been built into the roof by a qualified engineer, there is no danger of roofs collapsing under the weight of soil or other material.

Green roofs originated in Iceland, where the inhabitants simply covered their roofs in green turf to provide insulation in the harsh environment. Since those humble beginnings, green roofs are rapidly being adopted in their various modern forms around the world as an essential part of the move to a more sustainable lifestyle.
(Images from Sadhbh)

Green Roof from Iceland where the concept began

Cross Section of green roof

Cross Section of Green roof