Portlick, Co. Westmeath; Bird Survey Report
JULY 2001
Martin Brennan, MSc.
CONTENTS
1.
INTRODUCTION
2. SITE DESCRIPTION
3. SURVEY METHOD
4. COUNT POINTS
5. RESULTS
6. COMMENT
7. RECOMMENDATIONS
8. BIBLIOGRAPHY
9. MAP
1. INTRODUCTION
Portlick,
Co. Westmeath.
Grid Reference: N 04 48; N 05 48; N 05 49
A network of 16 sites countrywide has been selected under the project known as The Millennium Forests the objective of which is to restore or create native woodlands. Portlick is one of them. Ecological surveys are being conducted to establish baseline data which will inform management decision making and provide knowledge for the complimentary educational and promotional aspects of the project. This study of avifauna forms part of that broader ecological survey.
2. SITE DESCRIPTION
Portlick is situated about 5 kilometres north-west of the village of Glassan and approximately 8 kilometres north of Athlone on the eastern shores of Lough Ree. It is at an altitude of aproximately 40 meters above sea level. The site contains a diversity of woodland habitats including ash (Fraxinus excelsior); beech (Fagus sylvatica); mixed beech/Scots pine (Pinus sylvestris); mixed broadleaves; hazel (Corylus avellana); scrub and recently replanted areas. The study area, comprising approximately 52 hectares, is shown outlined in red on the map attached.
3. SURVEY METHOD
The survey was conducted using the point count method. Points were selected to represent the diversity of woodland or habitat types within the study area, subject to the limitations imposed by the requirements of this method - e.g. minimum distance of 200 meters between points. Within the chosen habitats points were randomly selected where the extent of the site so permitted.
Two counts were conducted. These took place between 05.30 hrs and 09.30 hrs on 2nd May and 5th June 2001 respectively in favourable weather conditions.
Two separate recording bands were used at each point:- <30m and >30 meters.
All birds, whether detected by sight or sound (calls or song) were recorded.
Birds in flight, those recorded outside the official counts and the aquatic species are shown separately and are excluded from computation of densities and from other statistical analysis.
Densities are derived from compounding the two counts for each point by taking the higher count for each species at ranges 0-30m and 0 to infinity as used in the IPA system {Blondel, Ferry and Frochot (International Bird Census Committee 1977)} - (Bibby et al 1985).
Abundance is based on recordings within the point - i.e. within the 30m radius.
4. COUNT POINTS
Counts were conducted at seven points within the study plot. As far as practicable these represented the diversity of habitats within the site as a whole and a good spread of locations throughout the entire block. A brief description of the habitat at each point follows. These are specific to the habitats within the 30m radius but would be typical of the habitat generally, with only minor variations expected between any specific points chosen within it.
Point
1.
Mature ash woodland with occasional beech. Hazel, holly (Ilex
aquifolium) and hawthorn understorey, with some bramble (Rubus
fruticosa). Little ground vegetation - some ivy (Hedera
helix) and mosses (Bryophytes).
Point
2.
Mature beech with holly understorey. Little ground vegetation,
but some bluebells (Endymion non-scriptus).
Point
3.
Clearfelled site with occasional spindly ash and hawthorn (Crataegus
monogyna) from former rotation. Very little ground vegetation.
Mainly bare soil with ridges of stumps and brash. Rcently replanted
with oak (Quercus petraea), ash and birch (Betula spp.).
Point
4.
Hazel
woodland with some holly, gorse (Ulex europaeus) and bramble
understorey.
Ground vegetation consisted mainly of bluebells, lesser celandine
(Ranunculus ficaria) and mosses.
Point
5.
Scrub consisting of gorse, hawthorn, blackthorn (Prunus spinosa),
hazel, elder (Sambucus nigra), holly and bramble.
Ground vegetation consisted primarily of bracken (Pteridium aquilium).
Point
6.
Mature beech with some Scots pine. Some hawthorn and willow (Salix spp.) understorey. No ground vegetation.
Point
7.
Mature mixed beech and sycamore (Acer pseudoplatanus) with
some open space. Understorey of hawthorn, holly and brambles.
Ground vegetation predominantly of grasses with lesser celandine
and primrose (Primula vulgaris).
5. RESULTS
Species
Richness
The
number and variety of species varied from point to point and ranged
between 9 and 14 (Table 1). The 7 points give a cumulative total
of 25 bird species. A further 6 (Table 11) were recorded within
the study area outside the formal counts bringing the total number
of bird species recorded in the woodland habitat to 31. (Some
although not recorded at specific points during the counts were
recorded there or in those habitats at other times).
Four species only were recorded at all points - blackbird, chaffinch, woodpigeon and wren - although not all within the inner band.
Taking the total number of bird species recorded at each point the broadleaved woodland sites (Points 1, 2 and 7) displayed the greatest species richness followed by mixed scrub (Point 5). However, by concentrating only those bird species recorded within the inner 30m band this scrub and hazel woodland (Point 5) both improve their positions with the former now showing greatest species richness with ten species - equalling that of the mature woodland at Point 2. The clearfelled area displayed poor species richness, with only three bird species recorded within the 30m band.
Table
1. Bird Species Recorded at Portlick in Summer 2001.
SPECIES |
POINTS |
||||||
1 |
2 |
3 |
4 |
5 |
6 |
7 |
|
| 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) | - |
- |
- |
- |
/* |
- |
- |
| Dunnock (Prunella modularis) | - |
- |
/* |
- |
/ |
- |
- |
| Goldcrest (Regulus regulus) | / |
- |
- |
/ |
/ |
/ |
- |
| Great Tit (Parus major) | - |
/ |
- |
- |
- |
/ |
- |
| Jackdaw (Corvus monedula) | - |
- |
- |
- |
- |
/* |
- |
| Long-tailed Tit (Aegithalos caudatus) | - |
/ |
- |
- |
- |
- |
- |
| Magpie (Pica pica) | - |
- |
- |
- |
- |
/* |
- |
| Mistle Thrush (Turdus viscivorus) | /* |
- |
/* |
- |
- |
/* |
/ |
| Pheasant (Phasianus colchicus) | /* |
/* |
- |
- |
- |
- |
- |
| Reed Bunting (Emberiza schoeniclus) | - |
- |
- |
- |
/ |
- |
- |
| Robin (Erithacus rubecula) | / |
/ |
- |
/ |
/ |
- |
/ |
| Rook (Corvus frugilegus) | /* |
/* |
- |
- |
- |
- |
- |
| Song Thrush (Turdus philomelos) | / |
- |
/* |
- |
- |
- |
/* |
| Spotted Flycatcher (Muscicapa striata) | - |
- |
/ |
- |
- |
- |
- |
| Tree Creeper (Certhia familiaris) | / |
/ |
- |
- |
- |
- |
- |
| Willow Warbler (Phylloscopus trochilus) | - |
- |
/* |
/ |
/ |
/* |
/* |
| Wood Pigeon (Columba palumbus) | /* |
/* |
/ |
/* |
/* |
/* |
/* |
| Wren (Troglodytes troglodytes) | / |
/ |
/ |
/ |
/ |
/ |
/ |
| Number within 30m radius | 9 |
10 |
3 |
8 |
11 |
7 |
7 |
| Total Number | 13 |
14 |
10 |
9 |
12 |
13 |
11 |
(Note: / = recorded inside 30m zone; /* = recorded beyond 30m zone; - = not recorded)
Table
11. Additional species recorded outside formal counts.
SPECIES |
LOCATION |
| Greenfinch (Carduelis chloris) | Sub-compartment 9 |
| Hooded Crow (Corvus corone cornix) | Sub-compartment 1 |
| Linnet (Carduelis cannabina) | Sub-compartment 7 |
| Sedge Warbler (Acrocephalus schoenobaenus) | Sub-compartment 3 |
| Sparrowhawk (Accipiter nisus) | Sub-compartment 15 |
| Swallow (Hirundo rustica) | Sub-compartment 5 |
AQUATIC
SPECIES |
|
| Arctic Tern (Sterna paradisaea) | |
| Black-headed Gull (Larus ridibundus) | |
| Coot (Fulica atra) | |
| Great Crested Grebe (Podiceps cristatus) | |
| Heron (Andrea cinarea) | |
| Lapwing (Vanellus vanellus) | |
| Little Grebe (Tachybaptus ruficollis) | |
| Mallard (Anas platyrhynchos) | |
| Moor Hen (Gallinula chloropus) | |
| Mute Swan (Cygnus olor) | |
| Redshank (Tringa totanus) | |
| Tufted Duck (Anthya fuligula) | |
| Whooper Swan (Cygnus cygnus) |
Abundance
The
most abundant species varied from point to point (Table 111),
but chaffinch and blackbird were the two most abundant species
in the woodland as a whole, being most abundant respectively at
6 and 5 Points respectively out of the 7. While the species shown
were the most dominant it was noticeable that in general they
did not represent a major proportion of the populations at any
point. Rather, all species present were well represented with
minor variations in their relative abundance.
Table
111. The most abundant species at each point.
SPECIES |
POINTS |
|||||||
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
|
| Blackbird | 1 |
- |
3 |
1 |
- |
- |
- |
- |
| Chaffinch | 2 |
- |
- |
- |
2 |
- |
- |
- |
| Wren | 3 |
1 |
- |
3 |
1 |
1 |
2 |
1 |
| Great Tit | - |
- |
- |
- |
- |
- |
- |
1 |
| Robin | - |
- |
1 |
- |
- |
- |
3 |
- |
| Goldcrest | - |
- |
2 |
- |
- |
- |
- |
- |
| Chiff Chaff | - |
- |
- |
2 |
- |
- |
- |
- |
| Coal Tit | - |
- |
- |
- |
3 |
2 |
- |
- |
| Mistle Thrush | - |
- |
- |
- |
- |
3 |
- |
- |
| Willow Warbler | - |
- |
- |
- |
- |
- |
1 |
1 |
| Dunnock | - |
- |
- |
- |
- |
- |
3 |
- |
| Blackcap | - |
- |
- |
- |
- |
- |
3 |
- |
Note:
species are ranked in order of abundance 1 to 3 (1 = most abundant),
where species ranked equally they are given the same number in
the order; - = not recorded.
Density
Bird density for the study area as a whole was 40.13 birds per
hectare.
6. COMMENT
Portlick supports a very rich diversity of bird life. This may be accounted for by the diversity of woodland types, almost exclusively broadleaves, including considerable areas of scrub. It displays good stratification in terms of the mix of habitats - one phasing into the other with no abrupt changes and the presence of some mature trees throughout maintaining a corridor and good vertical stratification. The greater species richness in the woodlands at Points 1 and 2 over that at those at 6 and 7 may possibly be accounted for by the more extensive scale of the former over the latter. The benefit of edge effect, due to the long narrow nature of the property, may also be a factor in the rich diversity of bird species.
Most bird species were generally well represented throughout the property, with the mixed scrub supporting bullfinch, reed bunting and dunnock not recorded elsewhere within the fixed bands. It also provided the only recording of cuckoo, although outside this band. The coal, great and long-tailed tits and treecreeper were confined to mature woodland. Leaving aside the purely aquatic species, the presence of the lake/wetland habitat only added two species to the list of those found in the woodland environment - reed bunting and sedge warbler.
The lake supports a rich diversity of bird life in winter, particularly wildfowl, and in summer attracts migratory species including a number of tern species - all tern species are listed in Annex 1 of the EU Bird Directive. The erection of a hide would enhance the value of the property from a birdwatchers point of view.
7. RECOMMENDATIONS
Maintain the forest as it is.
Ensure that grazing and horse-riding are controlled.
Monitor the mixed scrub in sub-compartments 2 and 3 to ensure that a good mix of species continues to exist and that they are in fruiting condition. Some occasional pruning/coppicing may be required to prevent domination by one or two species and to maintain vegetation layers and structure.
Encourage broadleave scrub along road sides.
Erect a bird hide.
Monitor the shore line for the presence of nesting terns.
Monitor the impact of the forest programme and operations on bird communities.
8. BIBLIOGRAPHY
Anon (Forest Service) - Code of Best Practice - Ireland (2000).
Anon (Forest Service) - Forest Biodiversity Guidelines (2000).
Bibby, C. J.; Burgess, N. D.& Hill, D. A. - Bird Census Techniques (1992).
Fitter, R.; Fitter, A. & Blamey, M. - The Wild Flowers of Britain and Northern Europe (1974).
Higman, S.; Bass, S.; Judd, N.; Mayers, J. & Nussbaum. R. - The Sustainable Forestry Handbook (1999).
Humphries, C.J.; Press, J.R. & Sutton, D.A. - Trees of Britain and Europe (1981).
Mullarney, K.; Svensson, L.; Zetterstrom, D. & Grant, P.J.- Collins Bird Guide (1999).
Mutch, W. -Tall Trees and Small Woods, How to Grow and Tend Them (1998).
Peterson, R.; Mountfort, G. & Hollom, P.A.D. - A field Guide to the Birds of Britain and Europe (1954).
Richards, A.J. - British Birds, A Field Guide (1979).
Sutherland, W.J. & Hill, D.A. (Eds) - Managing Habitats for Conservation (1995).
9.
MAP
Legend
Study area : outlined in red
Count Point : number in yellow circle
