Bird Survey Report
JULY
2001
Martin Brennan, MSc.
CONTENTS
1.
INTRODUCTION
2. RESULTS
3. GENERAL PRINCIPLES
4. COMMENT
1.
INTRODUCTION
As
part of a broader ecological survey of the network of 16 sites
which constitute the Peoples Millennium Forests a detailed study
of avi-fauna was conducted in those six which are designated as
candidate National Heritage Areas or proposed Special areas of
Conservation. These are:
1.
Rosturra, Co. Galway
2. Muckross, Co. Kerry
3. Portlick, Co. Westmeath
4. Cullentra, Co. Sligo
5. Rossacroo, Co. Kerry
6. Ballygannon, Co. Wicklow
The
study was conducted during the summer of 2001 using the point
count method. A summary of the findings follows together with
a brief discussion and an outline of the broad principles governing
the management of forests in the interest of their bird populations.
It outlines the ideal strategy. In managing the forests to fulfil
a range of other objectives certain compromises will be necessary,
however, these principles should form the backdrop against which
the plan is developed, as they tend to satisfy other ecological
requirements also, and are the basis for the sustainable management
of the forest generally.
A more
detailed stand-alone report on each individual site is attached
with specific recommendations pertaining to that site.
2.
RESULTS.
Bird
species richness varied from site to site and ranged between 21
and 31 species (Table 1), giving a cumulative total of 44 species
for the six sites. The variation is influenced by a number of
factors, including the nature of the woodland, diversity of tree
species, composition and range of habitats. In general mature
broadleaved woodland supported the greatest bird species richness.
Clearfelled sites displayed low species richness, and scrub was
shown to be a valuable habitat in terms of the range of species
which inhabit it.
Additional
species associated with an adjacent aquatic habitat in two particular
sites are listed in Table 11.
Table 1. Bird species recorded at each site in Summer 2001.
|
SPECIES
|
SITES
|
| |
1
|
2
|
3
|
4
|
5
|
6
|
| Blackbird
(Turdus merula) |
/
|
/
|
/
|
/
|
/
|
/
|
| Blackcap
(Sylvia atricapilla) |
/
|
/*
|
/
|
-
|
/*
|
/
|
| Blue
Tit (Parus caeruleus) |
/
|
/*
|
/
|
/
|
/
|
/
|
| Bullfinch
(Pyrrhula pyrrhula) |
/*
|
-
|
/
|
/*
|
-
|
-
|
| Chaffinch
(Fringilla coelebs) |
/
|
/
|
/
|
/
|
/
|
/
|
| Chiff
Chaff (Phylloscopus collybita) |
/
|
/*
|
/
|
/
|
/
|
/
|
| Coal
Tit (Parus ater) |
/
|
/
|
/
|
/
|
/
|
/
|
| Cuckoo
(Cuculus canorus) |
/
|
-
|
/
|
/
|
/
|
-
|
| Curlew
(Numenius arquata) |
/
|
-
|
-
|
-
|
-
|
-
|
| Dipper
(Cinclus cinclus) |
-
|
-
|
-
|
-
|
-
|
/*
|
| Dunnock
(Prunella modularis) |
/
|
/*
|
/
|
/*
|
/
|
/
|
| Grasshopper
Warbler (Locustella naevia) |
/
|
-
|
-
|
-
|
-
|
-
|
| Goldcrest
(Regulus regulus) |
/
|
/
|
/
|
/
|
/
|
/
|
| Great
Tit (Parus major) |
/
|
/
|
/
|
/
|
/
|
/
|
| Greenfinch
(Carduelis chloris) |
-
|
-
|
/*
|
-
|
-
|
-
|
| Grey
Wagtail (Motacilla cinerea) |
-
|
/*
|
-
|
-
|
-
|
/*
|
| Heron
(Ardea cinerea) |
-
|
-
|
-
|
-
|
-
|
/
|
| Hooded
Crow (Corvus corone cornix) |
-
|
/*
|
/*
|
-
|
/*
|
/*
|
| Jackdaw
(Corvus monedula) |
/
|
-
|
/
|
-
|
-
|
/
|
| Jay
(Garrulus glandarius) |
/*
|
/*
|
-
|
/
|
-
|
/
|
| Linnet
(Carduelis cannabina) |
-
|
-
|
/*
|
-
|
-
|
-
|
| Long-tailed
Tit (Aegithalos caudatus) |
-
|
/*
|
/
|
/*
|
-
|
-
|
| Magpie
(Pica pica) |
-
|
-
|
/
|
-
|
-
|
/*
|
| Mallard
(Anas platyrhynchos) |
/*
|
-
|
-
|
/
|
-
|
/*
|
| Meadow
Pipit (Anthus pratensis) |
-
|
-
|
-
|
/
|
-
|
-
|
| Merlin
(Falco columbarius) |
-
|
-
|
-
|
-
|
/*
|
-
|
| Mistle
Thrush (Turdus viscivorus) |
/
|
/
|
/
|
/
|
/
|
/
|
| Pheasant
(Phasianus colchicus) |
/
|
/
|
/
|
/
|
/
|
/
|
| Raven
(Corvus corax) |
-
|
-
|
-
|
-
|
/
|
/*
|
| Reed
Bunting (Emberiza schoeniclus) |
-
|
-
|
/
|
/
|
-
|
-
|
| Robin
(Erithacus rubecula) |
/
|
/
|
/
|
/
|
/
|
/
|
| Rook
(Corvus frugilegus) |
/
|
/
|
/
|
/
|
/
|
/
|
| Sedge
Warbler (Acrocephalus schoenobaenus) |
-
|
-
|
/*
|
-
|
-
|
-
|
| Siskin
(Carduelis spinus) |
/*
|
-
|
-
|
/*
|
/
|
-
|
| Snipe
(Gallinago gallinago) |
/*
|
-
|
-
|
/
|
-
|
-
|
| Song
Thrush (Turdus philomelos) |
/
|
/
|
/
|
/
|
/
|
/
|
| Sparrow
Hawk (Accipiter nisus) |
-
|
-
|
/*
|
-
|
-
|
/
|
| Spotted
Flycatcher (Muscicapa striata) |
-
|
-
|
/
|
-
|
-
|
-
|
| Swallow
(Hirundo rustica) |
-
|
-
|
/*
|
-
|
-
|
/*
|
| Tree
Creeper (Certhia familiaris) |
/
|
/*
|
/
|
/
|
/
|
/
|
| Willow
Warbler (Phylloscopus trochilus) |
/
|
-
|
/
|
/
|
/
|
/
|
| Woodcock
(Scolopax rusticola) |
-
|
-
|
-
|
/*
|
-
|
-
|
| Wood
Pigeon (Columba palumbus) |
/
|
/
|
/
|
/
|
/
|
/
|
| Wren
(Troglodytes troglodytes) |
/
|
/
|
/
|
/
|
/
|
/
|
| |
|
|
|
|
|
|
| Number
of species recorded during counts |
22
|
12
|
25
|
22
|
20
|
22
|
| |
|
|
|
|
|
|
| Number
of species recorded outside counts |
5
|
9
|
6
|
5
|
3
|
7
|
| |
|
|
|
|
|
|
| Total
Number of Species |
27
|
21
|
31
|
27
|
23
|
29
|
Note
1: / = recorded during official counts; /* = recorded outside
counts; - = not recorded
Note
2: Site Nos as follows:- 1 Rosturra; 2 Muckross; 3 Portlick; 4
Cullentra; 5 Rossacroo and 6 Ballygannon.
Table 11. Acquatic Species recorded at Portlick and Cullentra.
|
SPECIES
|
PORTLICK
|
CULLENTRA
|
| Arctic
Tern (Sterna paradisaea) |
/
|
-
|
| Black-headed
Gull (Larus ridibundus) |
/
|
-
|
| Coot
(Fulica atra) |
/
|
/
|
| Cormorant
(Phalacrocorax carbo) |
-
|
/
|
| Great-crested
Grebe (Podiceps cristatus) |
/
|
-
|
| Heron
(Ardea cinerea) |
/
|
/
|
| Lapwing
(Vanellus vanellus) |
/
|
-
|
| Little
Grebe (Tachybaptus rufcollis) |
/
|
-
|
| Mallard
(Anas platyrhynchos) |
/
|
-
|
| Moor
Hen (Gallinula chloropus) |
/
|
/
|
| Mute
Swan (Cygnus olor) |
/
|
-
|
| Redshank
(Tringa totanus) |
/
|
-
|
| Tufted
Duck (Aythya fuligula) |
/
|
-
|
| Whooper
Swan (Cygnus cygnus) |
/
|
-
|
| |
|
|
| Total
Number |
13
|
4
|
Density
Densities
varied, and ranged between 22 and 40 birds per hectare (Table
111). The age and composition of the woodland influenced density,
with for instance, extensive clearfelled areas where density was
low, reducing overall density in the forest.
Table
111. Bird Densities.
|
Location
|
Density
in Birds Per Hectare
|
|
Rosturra
|
36.4
|
|
Muckross
|
24
|
|
Portlick
|
40.13
|
|
Cullentra
|
27.2
|
|
Rossacroo
|
22.4
|
|
Ballygannon
|
34.3
|
3.
GENERAL PRINCIPLES
In
the context forest management, with the objective of optimising
or enhancing its value for avi-fauna, the principal must be to
satisfy the birds' requirements throughout the seasons. These
are a food supply, shelter/perching, suitable nesting sites and
ideally water.
Diversity
of age class. The forest may not have the potential to satisfy
all of those requirements at each stage of the cycle, or may only
satisfy the requirements of a limited number of species at a particular
phase before the maturing woodland results in their replacement
by species better adapted to those developing conditions. A diversity
of age class will thus result in a greater diversity of bird species
by combining all species associated with each stage, (e.g. ground
nesters at establishment stage - pipit, followed by scrub species
before canopy closes - dunnock, and canopy dwellers in the mature
crop - tits).
Diversity
of tree species. Individual bird species have adapted to living
in particular forest environments. Thus for instance siskin are
found in conifer or alder woodland, warblers generally in scrub,
and treecreepers in predominantly broadleaf woodland. A diversity
of tree species will thus result in greater bird species richness.
This can be achieved by planting pure crops or stands of mixed
species. In the context of the Millennium Forests where the restoration
of oak woodland, for instance, may be an objective, planting of
pure stands may be desirable. However where such planting is not
required mixed woodland generally appears to support a greater
diversity of bird life. A mosaic of species connected by corridors
such as roads or rides offers a good alternative.
Diversity
of habitats. Birds have adapted to living in specific habitats.
Thus, a wetland within a forest encourages species such as reed
bunting and sedge warbler, as well as being the location for drinking
and bathing for all other inhabitants of the wood. Open spaces
and scrub attract warblers and stonechat; stone walls attract
tits; buildings swallows and possibly barn owls. An effort should
thus be made to incorporate as much habitat diversity as possible
into the overall forest design for optimum bird species richness.
Management.
Routine management should be employed to enhance the forest environment
for birds - it need not be unnecessarily tidy, fallen branches
and dead wood should be left where they pose no threat, broken
branches should be left un-pruned as they may provide nesting
holes and ivy provides food and nesting places. If the forest
environment is right it will attract those birds which would be
expected to inhabit it, without recourse to artificial means.
Forest
Operations. Forest operations should be carried out when they
have least impact on breeding and nesting birds - outside the
nesting season. Consultation with the local Duchas Conservation
Ranger and Birdwatch branch should take place in advance of any
operations to ascertain if any rare or protected species inhabit
the site.
Monitoring.
In the longer term all sites should be monitored to assess the
impacts of the forest programme and strategies on the avian communities.
4.
COMMENT
None of the count points in this study were located on roads or
rides. However, both from the location of the actual points and
from the locations of the bird species recorded (whether within
or beyond the fixed band), it is clear that they are important
in terms of diversity. Woodland edges, (not just the external
edges but divisions between compartments, along roads, rides and
drains/streams) where a margin of scrub and young broadleaves
existed, combined with the open areas associated with them, provided
suitable habitat, particularly for warbler species - blackcap,
chiffchaff and willow warbler. It was noticeable that where such
a margin was absent, specifically at the edge of conifer woodland
these species were poorly represented. Willow and birch scrub
phasing into the taller trees and denser woodland was particularly
suitable for these species. The provision of or facilitation of
scrub development is recommended. It may be necessary to implement
a programme of phased coppicing of such scrub in the longer term
to maintain good structure and optimum conditions.
Edge
effect. The value of edge effect is generally well recognised,
but underutilized in the forest environment. Its benefit can be
internalized by planting or encouraging the development of a margin
of scrub and young broadleaves along roads and rides. The value
of scrub in terms of bird life is significant. This is clear from
the results of the study and particularly in relation to the Portlick
site. In developing the scrub margin the main crop should be retained
well back so that there is space for a phasing from open space
to herb, scrub and canopy. This need not be uniform so that in
places, particularly in smaller blocks, the forest can close over
roads to create a forest interior environment and generate diversity
along the road.
Scrub.
Scrub, as well as providing suitable habitat for a range of species,
provides valuable autumn and early winter feeding for birds, particularly
thrushes, including the migratory redwing and fieldfare. It can
also support extremely high densities of birds as well as affording
good cover for roosting. A range a native, berry-producing species
are invaluable in this regard - hawthorn, blackthorn, elder, holly
and bramble. Gorse also is a valuable scrub species and ivy enhances
the environment for birds, but should be controlled. Planting
of clumps of such scrub is recommended, together with berry producing
trees such as rowan, whitebeam, wild cherry and yew. A programme
of phased or rotational cutting of the scrub may be necessary
in the longer term in order to maintain patches at different stages
of growth.
Open
space. It appears that there is no provision to retain or
develop open spaces within any of the forests studied. They enhance
the forest environment in terms of diversity of herb vegetation,
insect life and ultimately avi-fauna. Combined with the beneficial
edge effect and developed in association with margins of broadleaf
along roads and rides they have potential to enhance biodiversity
withi the forest. Road junctions, bends or edges present opportunities
for such habitats.
It
was of note that compared to afforestation sites previously studied
the reforestation sites were generally unsuitable for ground nesters
such as meadow pipit and skylark due to the lack of or unsuitability
of ground vegetation and its structure. Monitoring would provide
useful information in this regard.
If
there is a need to enhance the forest environment for particular
bird species nesting boxes can be erected. While these have potential
to enhance conditions it should not be necessary for the more
common species, although it should not be discouraged. However,
it is an approach which might more appropriately be adopted in
particular circumstances such as an experimental/research project
or as an attraction/educational feature for the public. There
is the added work, little as it may be, of monitoring, cleaning
out and maintaining the boxes. This approach is best suited to
rarer species such as raptors, where the objective is to attract
them to a forest and assist them in becoming established, by providing
suitable nesting sites which might otherwise be absent. Published
literature on this subject is scarce. Where such species are known
to exist it is an approach worth exploring and pursuing - e.g.
osprey, an occasional visitor to Lough Ree.
In
conclusion the development of a management plan which incorporates
the above principles and formulates strategies to implement them
will enhance the forest environment for birds and improve the
biodiversity value of the forest generally.
