The Management Plan for the National Park highlights several areas that require specific projects. Some of them are outlined below.
Goosander Nestbox Scheme
Goosanders are mainly summer migrants to Ireland with small resident populations occurring in Wicklow, Donegal and Co Down. Goosanders are at the western limit of their breeding range in Ireland. Wicklow is the only known breeding site for this species, although there have been records of breeding in Co Donegal up until recently.
Goosanders nest mostly on inland waters. They choose unpolluted, deep lakes and rivers bordered by old trees. When ready to breed, female goosanders usually seek out a suitable cavity in old broadleaved trees, but they have been known to use rock cavities or holes in river banks. Nests may be lined with moss, plant material and down from the females breast. They lay between mid-March-April and clutch sizes are between 7-14 eggs. The female begins incubation once the clutch is complete, the male leaves the female immediately after incubation commences. After 30-34 days the eggs hatch out. The chicks remain in the nest for only a day, where after they jump out of the nest and follow the female to the water. The young are excellent divers and can move quickly but are unable to fly for 60-70 days. There is only one brood per year. Goosanders feed mainly on fish (eels, salmon and trout), but will also feed on small crustaceans and even frogs. Goosanders prefer fast flowing rivers with sand or pebble substrate. They can swim deeply and with considerable speed.
A nest box scheme for Goosanders has been operational in Wicklow Mountains National Park since 1995. The nest boxes were erected in an attempt to provide suitable alternative nesting areas for Goosanders, to maximise the chance of breeding. Nest boxes are located in bank side trees at a height of 3-8 m. The nest boxes are lined with moss or bark chippings and are cleaned out every year. The boxes are routinely checked between April – end June each year.
The breeding success of this species has improved since the provision of nestboxes, although numbers are still very low. In 2008, only 3 of the 11 nestboxes had breeding attempts, and only 1 nest box successfully produced young. In 2009, it is proposed to move some of the nestboxes that have never been used in the hopes of finding locations more favoured by the birds. It is also hoped to put up more nestboxes and to cover a wider area.
Redstart & Wood Warbler Survey
The Redstart (Phoenicurus phoenicurus) and the Wood Warbler (Phylloscapus sibilatrix) are both rare migrants and breeders in Ireland. They are amber listed, meaning they are species of medium conservation concern. Both species are closely associated with the oakwoods of County Wicklow. Glendalough, Glenmalure, Luggala, and Rathdrum have some of the best stands of sessile oakwood in the county and all have regular sightings.
In 2007, nestboxes were put up in the Glendalough oakwoods and Clara Vale Nature Reserve for redstart, by NPWS staff. The species is known to have adapted well to nestboxes in Wales. In 2008 the National Park staff started to survey Redstarts and Wood Warblers with a view to obtaining baseline data and details on their relative abundance.
The redstart is a declining species throughout Europe. This decline may be due to changing rainfall patterns in the Sahel, which is affecting wetlands for migratory birds moving along the African – Eurasian flyways. Other possible contributory factors may include modern forestry causing a decrease in nesting holes and increased competition for natural nesting holes from other species such as the tit family.
The redstart is a rare migrant to Ireland. Redstarts are found in Ireland between April and September, with the peak time to hear their calls from mid-May to mid-June. They breed in deciduous and mixed woodland, and nests in tree holes. They feed on insects, in particular, beetle larvae, butterflies and spiders. Males are colourful, and display the red tail and under-wing, when trying to attract a female. The female lays 6-7 eggs, incubation is 13-14 days and the young fledge after 16-17 days. They can have up to two broods in one season. They breed at one year. The maximum recorded age is 6 years and 9 months.
The wood warbler is the brightest and biggest of the 3 leaf warblers that occur in Ireland. (The other two are the chiff chaff and the willow warbler.) It is considered, a rare migrant in Ireland, arriving in mid-April until August. They winter in sub-Saharan Africa. Its breeding distribution stretches from the Pyrenees Mountain range, north to Lapland, south to southern Italy and east to the Balkan peninsula. Its range in Ireland is most likely limited by lack of suitable forests. They can be found in mixed woodland and tend to like oak forest with minimal undergrowth. They require a shady closed canopy for foraging, sparse low ground for nesting, and a lower canopy for singing and display. This combination means that they will occupy different forest types. They feed on insects and other invertebrates. Wood warblers have a low site tenacity, changing its breeding areas from year to year, which can result in localised fluctuations. Breeding in Ireland was first proven in 1968, in Co.Wicklow.
Males arrive back after winter first to set up territories, often in the same area that they were raised. The singing male flies from branch to branch within his territory. The females build domed nests, usually made of leaves, grass, moss and bracken and lined with fine grass and hair. The female lays 5-7 light blue eggs, incubation usually lasts about 13 days, juveniles fledge after about 13 days. The female can have up to two broods in one season.
In 2008, four sites were surveyed within the National Park and adjoining Nature Reserve – Glendalough woods, Derrybawn woods, Camaderry Woods, and Rathdrum Rd woods. It was hoped to visit each site 4 times between 15th April and 15th June, but in the event, two sites only received 3 visits, and one site only received one visit. Each visit involved walking a transect between first light and 9.30 am, recording calls.
No redstarts were heard at any of the sites during the survey visits. In fact, according to Birdwatch Ireland, 2008 was not a good year for redstarts. Redstarts were only heard by their members calling once in Glendalough and not at all in Rathdrum Woods during the nesting season.
Wood Warblers were more in evidence, and were recorded by surveyors on four of the visits.
It is hoped to continue this survey in future years, to give staff a greater idea of the population dynamics within the Park. Ideally, the survey will be broadened to include other woods within the Park..
Char Release Project
The Arctic char is a cold climate salmonid species which occurs in nutrient poor, oligotrophic lakes in the west of Ireland and Wicklow. It is thought to have occurred in Glendalough in the past but is no longer found there. It may have been wiped out due to mining activities and the resulting pollution. The species may still occur in Lough Dan.
In January 2009, a re-introduction project began in consultation with the Irish Char Conservation Group. Environmental conditions in the Upper Lake were monitored continuously to ascertain that conditions would now be suitable for the fish. This monitoring process is continuing throughout the project. At the same time, genetic studies of existing Char populations throughout Ireland identified the Char in lough Cloon, Co. Kerry, as being the most suitable candidates genetically for this project.
Three thousand Char ova (eggs) were translocated from Lough Cloon into the Upper Lake at Glendalough. In January 2010, more eggs will be translocated from the same location, to supplement the previous year’s re-introduction.
The spawning period for char in Lough Cloon takes place in November and December. Eggs are collected & fertilised in December, but spawning is temperature dependant and the lake is monitored to identify when the spawning begins. Once the ova have been fertilised, they are transported in special incubation boxes to Glendalough, where they are seeded on previously identified Char spawning areas.
In January 2009, a count of the dead eggs post planting, revealed that there was a 77% hatching rate.
The project fully adheres to the guidelines detailed by the IUCN(World Conservation Union) for re-introductions.
Deer Survey & Cull
With the extinction of their only natural predator, the wolf, deer numbers are very high throughout the Park. This leads to over-grazing of many habitats, in particular the sensitive native woodlands. Each season deer are surveyed and then culled according to the results.
Grouse Management (Powerscourt Paddock)
Red Grouse are particularly dependent on a suitable habitat for optimal breeding and survival rates. The grouse within the Powerscourt Paddock area of the Park are surveyed annually and the habitat is being managed for grouse, with a programme of heather flailing and burning.