Ferbane Wildlife Audit & Management Plan

This is an extract from the recent biodiversity study of the Ferbane area.  Blackthorn Ecology completed a project to record, communicate, manage and enhance wildlife in seven settlements in County Offaly.

The project commenced in January 2013 and ran through September 2013. The project was managed by the Offaly Community Forum with funding from the Offaly Local Development Company.

Click to View full report.

WILDLIFE OF FERBANE
3.1 Overview
A total of 512 plant and animal species have been recorded in and around Ferbane. These
are listed in Appendix A. The habitats present in Ferbane are mapped in Figures 1-4.
3.1.1 Habitats
Ferbane and its environs are blessed with an abundance of high quality wildlife habitats. Few
other towns in Ireland have such a range of habitat types within a kilometre of town centre.
The different environmental conditions provided by the diversity of habitats in the area
significantly increases the number of local plant and animal species.


The most important habitat in the area is Ferbane Bog, a raised bog right on the edge of
town. Ferbane Bog is of international conservation importance because there are very few
relatively intact raised bogs left in Europe or the world. For this reason, Ferbane Bog is
formally designated as a Special Area of Conservation (SAC). Raised bogs are wetland
habitats that depend on rainwater rather than groundwater. The wet and quite acidic
conditions in bogs mean that only a certain specialised suite of plants, mainly mosses, can
grow there.
The River Brosna forms a natural wildlife corridor through town, helped by the presence of native wet woodland along much of it, especially to the east of the town centre.
Native riparian – or riverside – woodland is now rare in Europe, which makes the woodland strips along the Brosna particularly valuable. The river has been dredged in the past to prevent flooding, which has probably led to the loss of riparian wetland habitats in the past. There is, however, a small pocket of swamp and wet woodland that occupies a former river meander a little way to the west of
the Brosna bridge. Other wetland habitats around Ferbane include drainage ditches, which
provide suitable conditions for wetland plants, frogs and invertebrates.
Apart from the River Brosna riparian woods, the rest of the woodlands in Ferbane are
mainly made up of non-native trees, such as beech and sycamore. Although native trees and
woods are generally better for biodiversity than non-native trees like beech, any sort of
woodland cover can usually be good habitat for wildlife. Also, veteran trees of any species
can develop small habitat features, like rot holes, crevices and dead branches, that are of
benefit to nesting birds, roosting bats, and fungi and invertebrates that rely on deadwood
habitats. Most fields around Ferbane are separated by hedgerows, which also provide a sort
of substitute woodland edge habitat. Most hedgerows are composed of hawthorn with
A woodland canopy in Ferbane
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some blackthorn and other shrubs like elder and bramble. Occasional ash and other tree
species can improve the structural diversity, and thus the wildlife value, of hedgerows.
Hedgerows need regular, but not too intensive, management to reach their maximum
biodiversity (see Section 4.1.3).
Most of the grasslands around Ferbane
are agricultural grasslands that have
been more or less improved. There
are also some improved amenity
grasslands, such as lawns, verges and
sports pitches. These grasslands are
of little value for wildlife because they
are highly managed and species-poor.
Semi-natural grasslands on the other
hand support a greater diversity of
grasses and wildflowers and, in turn,
invertebrates and other animals.
Benefits to wildlife are greatest when
grassland plants are allowed to flower
and set seed, which provide nectar and other food for animals. Semi-natural wet grasslands
dominated by rushes, sedges and tussocky grasses are the most abundant type in Ferbane,
including the former Cow Park at Ballylin. One unintended benefit of dredging the River
Brosna is that dry calcareous (lime-rich) grassland now grows on some of the low mounds
of spoil along the riverbank. Unimproved calcareous grasslands are uncommon in Offaly and
can be rich in wildflowers and invertebrates.
In the more built-up parts of Ferbane, old stone walls can be valuable wildlife habitats. The
Brosna bridge and most walls around town are either made of concrete or are too new to
be good habitats. Some walls around the ruined Church of Ireland and adjacent school,
however, support a wide range of ferns, lichens and mosses.
3.1.2 Plants
We recorded a total of 255 plant species in Ferbane, including flowering plants, conifers,
ferns, horsetails, mosses, liverworts and lichens. There are certainly many more present
that we didn’t find! As would be expected, most plant species we found are common in
small towns and rural settings across Offaly. The diversity of different habitat types present
in Ferbane and its environs, however, increases the species richness – or number of species
– of the area. These include many that are characteristic of natural habitats rather than
towns and ordinary countryside, and some of these are detailed in Section 3.2 below.
The most notable plant species we found in Ferbane is squirrel-tail moss, which was
recorded in a sycamore woodland behind the Ferbane business park. Its name comes from
its appearance when dry: it grows with its leaves tightly pressed to the stem, resembling a
squirrel’s tail. It is rare (but not threatened) in Ireland, partly because it is sensitive to air
pollution. The last time it was seen in Offaly was in Geashill in 1903, however, it is likely
that it occurs undetected in other places in the county. It lives on trees with base-rich bark,
like ash and sycamore, and also on limestone rock.
Ferns, white stonecrop and mosses on an old stone wall
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3.1.3 Animals
We recorded 14 species of ground beetles, 4 species of soldier beetles, 5 species of
ladybirds, 39 species of hoverflies, 14 species of soldierflies, 11 species of snail-killing flies, 21
species of bees and wasps, 66 species of butterflies and moths, as well as a range of species
from other insect groups
Two bumblebee species that we
recorded (Bombus lapidarius and
Bombus muscorum) are classified as
near threatened in Ireland. Bombus
lapidarius is sometimes referred to as
the Red-tailed Bumblebee and is a
distinctive black bumblebee with a red
“tail” (although there is another very
rare species, largely confined to the
Burren, with similar colouration).
While this species is still widespread in
Ireland, it has disappeared from much
of the countryside, due to intensive
farming. Bombus muscorum, sometimes referred to as the Large Carder Bee, is an all-ginger
species, distinguished from the common Bombus pascuorum by the lack of black hairs on its
abdomen. It is a scarcer species than Bombus lapidarius, requiring extensive areas of flowerrich
open habitats. It is mainly a coastal species in Ireland, but with clusters of inland records
in areas such as the Midlands bogs and the Burren. We also recorded a solitary bee species
(Nomada panzeri) that is classified as near threatened in Ireland. This is a cuckoo bee which
lays its eggs in the nests of other solitary bee species. There are also cuckoo bumblebees
that are nest parasites of other bumblebees, and we had a tantalising glimpse of what
appeared to be one of these species: Bombus rupestris. This species is a nest parasite of
Bombus lapidarius. It is classified as endangered in Ireland and almost all the recent records
are from the Burren and the Aran Islands. If its presence in Ferbane could be confirmed, this
would be a very significant record.
Perhaps the rarest invertebrate species we recorded was a small, black soldierfly Zabrachia
tenella. This was first recorded from Ireland in 1978 (Speight et al., 1992), and there do not
appear to be any other Irish records of it. However, it is a small inconspicuous and elusive
species, so it is likely to be under-recorded. It appears to be associated with bark beetle
galleries in recently dead pines (Stubbs and Drake, 2001). Several other scarce invertebrate
species were recorded, including three hoverfly species (Epistrophe grossulariae, Melanogaster
aerosa and Portevinia maculata) and five moth species (Bordered Beauty, Clouded Brindle,
Double Lobed, Rustic Shoulder-knot and Small Clouded Brindle).
The ground beetle, hoverfly, snail-killing fly and moth fauna recorded included a number of
species associated with well-developed wetland habitat. These were mainly recorded from
the Ferbane Wastewater Treatment Plant, with some species also recorded in the wet
meadows habitat adjacent to the amenity woodland walk at Ballylin. Of particular note was
the capture of Melangoster aerosa in the Malaise trap at Ferbane Wastewater Treatment
Plant. This hoverfly is associated with high quality acid and alkaline fen habitats. The number
Bombus muscorum
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of individuals caught indicated that there is a localised population established very close to
the Malaise trapping site. Also of interest was the occurrence of the snail-killing fly Sciomyza
dryomyzina. This is a rare species in Britain and has been regarded as a rare species in
Ireland, although recent surveys have found it to be more widespread in Ireland (Gittings
and Speight, 2010).
The TTV bird surveys recorded a total of 39 species, with a few additional species recorded
from the amenity woodland walk area at Ballylin. These were mainly common species in the
Irish countryside. Apart from Grey Heron, no riparian bird species were recorded.
However, access to the river was very limited. The riparian habitat would appear to be
suitable for Kingfisher, but the lack of marginal vegetation would limit its suitability for other
species such as Moorhen and Teal. The wet meadows around the amenity woodland walk
provide good habitat for scrub-associated species such as Whitethroat, Blackcap, Willow
Warbler, Linnet, Lesser Redpoll and Reed Bunting. A cuckoo was also heard calling distantly
from this area in early June. Other observations of interest included a small House Martin
colony under the eaves of the Gallen Priory Nursing Home, with Swifts possibly also nesting
here, and a Treecreeper observed in the linear conifer woodland along the Gallen Priory
access road. While we did not record the species, Barn Owls have been recorded in this
area by NPWS, and a local resident that we spoke to also mentioned the presence of Barn
Owls.
The bat surveys recorded high levels of bat activity in several locations. The ruined church is
a potential roosting site. The structure was inspected in daylight and no obvious signs of
roosting bats were found. However, Common Pipistrelles were recorded flying around the
churchyard at dusk in the August survey, and while they were not directly observed
emerging from the church, it seems likely that they were roosting in this area. In addition to
the ruins of the church, the old school building has high potential for roosting bats. One
Myotis bat (either Whiskered or Natterer’s) was also recorded in the churchyard at dusk,
while Myotis bats were also recorded feeding in the tree-lined edge of the Kilmore Demesne
along the Belmont Road later in the night during the June survey. Whiskered and Natterer’s
Bats have very similar echolocation calls, and cannot be reliably separated using heterodyne
bat detectors. Daubenton’s Bat was recorded along the River Brosna with intense feeding
activity in the section adjacent to Gallen Community School. Daubenton’s Bat is associated
with riparian habitats, where it feeds by skimming low over the surface of the water. It often
roosts under bridges. We also recorded intense bat feeding activity of pipistrelles in the
amenity woodland area at Ballylin, both within the woodland and around the edges of the
woodland. The bats were echolocating at around 50kHz, which is intermediate between the
typical echolocation frequencies of Common and Soprano Pipistrelles, so they could not be
identified to species.
3.2 Local Wildlife Hotspots
The locations of local wildlife hotspots are shown in Figure 5 and in the habitat maps
(Figures 1-4).
Ferbane Bog
Ferbane Bog is a large raised bog adjacent to the town of Ferbane, most of which is owned
and managed by the National Parks and Wildlife Service. Only the edge of the bog is within
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1km from the town centre, i.e. the area considered part of a “town” under the Tidy Towns
competition (Tidy Towns Unit, 2010). Therefore, only species that are found at the bog
edge are listed in the Ferbane Biodiversity Inventory (Appendix A). As a whole, the bog is
relatively intact and of very high conservation value, compared with other raised bogs in
Ireland. A recent survey of Ferbane Bog has found that it is drying out, however, due to the
effects of past drainage and peat cutting (Fernandez Valverde et al., in press). If the drying
process is not stopped, then the unique assemblage of species and their raised bog habitat
will be lost. There are pine trees colonising the edge of the bog nearest Ferbane, which is a
symptom of the bog drying out.
The edge of Ferbane Bog is somewhat
drier than the centre, as is typical with
most raised bogs. Ling heather and
cross-leaved heath are abundant small
shrubs, interspersed with common
and hare’s-tail cottongrasses and the
lovely yellow-flowered bog asphodel.
Bog mosses (Sphagnum) are also
common. Two large lichens are also
prominent, the bushy reindeer lichen
and the striking devil’s matchstick.
At the fringe of the bog proper is a
strip of birch-dominated woodland
with some rusty willow and Scots
pine. More bog mosses as well as glittering wood-moss and common tamarisk-moss can be
found under the trees, alongside brambles, purple moor-grass and other plants of wet, peaty
ground.
River Brosna
The River Brosna is a deep slow flowing river that connects Lough Ennel to the River
Shannon at Banagher. The Brosna catchment is calcareous but also contains one of the
largest areas of peat bog and active peat harvesting in the country, resulting in a major influx
of peat silt and sediment into the river (O’ Reilly, 2002). The dark staining in the water has
also caused a lack of plant vegetation in the deeper areas of the channel such as those in
Ferbane. As noted above, it has been dredged in the past, which has produced relatively
steep sides with little fringing vegetation apart from reed canary-grass on the riverbanks.
Peat deposition arising from harvesting in the wider river catchment and channel dredging
have invariably caused a decline in the condition of gravels for trout spawning. Nonetheless,
it remains a very important river for brown trout that grow very large in the rich waters of
the river. The Ferbane area, however, is more characteristically typical of a coarse fishery
with deeper and slower moving water apart from very localised shallow riffle-glide zones.
While brown trout are known to occur in the River Brosna downstream of Ferbane, roach,
perch, pike and minnow are also present. The pike can grow very large and have been
recorded over 30lbs in the lower reaches of the river. Inland Fisheries Ireland have
recorded Minnow, Perch, Roach, Pike, Eel and Gudgeon in the upper Brosna at Pollagh
(Kelly et al., 2008). The Brosna also has a small spring run of Atlantic salmon that have
Papillose bog-moss
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become rarer in the Shannon system following the construction of dams. Salmon are
anadromous, meaning that they spawn in freshwater and return to the sea to feed and grow.
Fish passes have been constructed on weirs throughout the river to facilitate the passage of
salmon upstream.
Other notable species present in the River Brosna include the white-clawed crayfish that
have been recorded in the river near Ballycumber and Clara upriver. Crayfish are
crustaceans with large claws which they use to feed on river invertebrates and vegetation.
The species is protected. They occur in rivers that are limestone rich, such as the Brosna
but are sensitive to river dredging and physical alterations to river habitat. It is possible that
crayfish occur in the River Brosna at Ferbane given their presence upstream.
The riparian woodlands that fringe the
river in places are made up of ash,
rusty willow, crack willow, alder and
birch, with hawthorn and spindle
growing in their shade. The river rises
significantly in the wintertime, which
means that the lower trunks of the
trees are covered in silt. These
conditions suit a small number of
mosses that specialise in growing on
silty trees, including many-fruited
leskea and red beard-moss.
Characteristic riparian woodland
wildflowers that can be found here
include wood dock, gipsywort and the delicately-flowered remote sedge. Otters visit the
riverside woods, as demonstrated by footprints seen during the field survey.
Elsewhere along the river, the low mounds of spoil dredged from the river are occupied by
semi-natural grassland habitats. Where unmanaged, the mounds are occupied by vigorous,
competitive species, like false oat-grass, creeping buttercup, creeping cinquefoil, bush vetch,
broad-leaved dock and nettles. Rusty willow and alder saplings are regenerating in places.
Where grazed by cattle, a lower, more attractive calcareous grassland has developed,
supporting such lovely plants as quaking grass, lady’s bedstraw and fairy flax.
Apart from the woodland fringe, most of the river floodplain has either been developed or
agriculturally improved. Nevertheless, the range of specialised wetland species recorded in
the invertebrate trapping at Ferbane Wastewater Treatment Plant indicates that welldeveloped
wetland habitat with high invertebrate biodiversity occurs in the vicinity. The
former river meander on the southern side of the river opposite the treatment plant
appears to be the most likely location.
Gallen Wood
At the bend of the River Brosna to the east of town there is a mature beech woodland:
Gallen Wood. The understorey is sparse as a result of the dense shade that beech casts and
also because of cattle grazing. At the woodland edges, some native woodland of hazel, ash
and hawthorn has sprung up. Early spring wildflowers that bloom before the forest canopy
leafs out are present, including lords-and-ladies, wild garlic and the brightly yellow-flowered
Riparian woodlands along the River Brosna
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lesser celandine. Portevinia maculata, a scarce hoverfly species, occurs in this woodland. This
species is a woodland specialist whose larvae develop in wild garlic. Another scarce
woodland hoverfly, Epistrophe grossulariae, was also recorded here.
Ballylin Amenity Woodland and Former Cow Park
Behind the Ferbane business park is a small area of
woodland. The canopy trees are mostly the nonnative
sycamore and European larch, but some
native ash and pedunculate oak trees also grow
here. The woodland is open and grassy with little
or no shrub layer. Typical woodland wildflowers
that can be found here include lesser celandine,
wood dock, lords-and-ladies, wood avens,
germander speedwell and enchanter’s nightshade.
The footpath running through the wood is
bounded on one side by a hedgerow that provides
some needed structural diversity to the woodland
edge. As noted above, the rare squirrel-tail moss
can be found in this woodland. Two ground beetle
species (Calathus rotundicollis and Leistus fulvibarbis)
typically associated with forest habitats were
recorded here. The woodland also appears to be
an important feeding habitat for bats with intense
feeding activity of pipistrelles recorded in and around the woodland in the bat survey.
However, the trees do not appear to be suitable for roosting bats, so it is likely that the bats
are commuting to feed here from a roost site some distance away. Similarly, due to the
condition of the trees, there may be a scarcity of nest sites for hole-nesting bird species.
The former Cow Park adjacent to the woodland is mostly occupied by wet meadows rich in
tussocky grasses, sedges and tall wildflowers. Meadowsweet is abundant, named for its
flowers that smell of sweet, new mown hay. Other wildflowers are either tall, like purple
loosestrife, or climb tall grasses, such as meadow vetchling, tufted vetch and marsh
bedstraw. These wet meadows
support large populations of Réal’s
Wood White, a butterfly associated
with rank meadows, where its
caterpillars develop on meadow
vetchling. This butterfly has the
distinction of being one of the small
number of Irish species that does not
occur in Britain. The meadows also
support good populations of Common
Blue and Small Copper, two other
butterfly species associated with
unimproved grasslands. The flowerrich
character of these meadows is
Ballyvlin amenity woodland
Small Copper (Lycaena phlaeas)
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reflected in the large population of Bombus lapidarius, a near-threatened bumblebee species
(with the possible occurrence also of Bombus rupestris, an endangered species). The damp
character of the meadows is reflected by the presence of wetland ground beetle species
(Agonum fuliginosum and Agonum gracile), although the soil appears to dry out during summer.
The combination of rank grassland and patches of scrub provide good habitat conditions for
a range of scrub-associated bird species.
One formerly disturbed field has recently been cleared and reseeded with a commercial
seed mix by Ferbane Tidy Towns. The plant community there is still developing, but
includes some of the species from the neighbouring meadows that have regenerated from
the seedbank. There are also a few patches of drier calcareous grassland that have
developed on soil disturbed by road construction. These patches can also be wildflowerrich
and include common spotted orchid, lady’s bedstraw and common knapweed.
A drainage ditch lined in places with mature Scots pine trees forms the boundary between
some fields. Fool’s watercress is abundant here; other frequently occurring wetland plants
include water mint, branched bur-reed, great willowherb and yellow iris. Common darter, a
handsome red dragonfly, and some wetland hoverfly species are also found in the area.
Church of Ireland Ruins
Mature lime, beech, Douglas-fir and Lawson’s
cypress trees occupy he grounds of the former
Church of Ireland, now in ruins. These trees, the
surrounding stone walls and the shell of the church
itself all combine to create a surrogate woodland
habitat. In the early spring, the graveyard is full of
wild garlic (also known as ramsons), lords-andladies,
primroses and violets. Inside the church is
vigorous regeneration of ash saplings. More wild
plants typical of woodlands or hedgerows now
growing within the church walls include common
spotted orchid, wild strawberry, germander
speedwell, wood false-brome, hart’s tongue fern,
common tamarisk-moss and common striated
feather-moss. The church also supports a colony
of Jackdaws, and may hold roosting bats (see
above).
A range of mosses, ferns and small plants occupy
the stone walls around the church and the adjoining derelict schoolhouse. These include
white stonecrop, wall-rue and the white hair-pointed mosses wall screw-moss, greycushioned
grimmia and thickpoint grimmia. Many mosses of stone walls have white hair
points on their leaves to help