Ballygannon, Co. Wicklow; 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. MAP

 

1. INTRODUCTION

Ballygannon Wood, Co. Wicklow.
Grid Reference: T 18 89

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. Ballygannon 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

Ballyganon is situated approximately 1 kilometre north of the village of Rathdrum in County Wicklow. It is at an altitude ranging between 130 and 200 meters above sea level in the valley of the Avonmore river. The site contains a diversity of woodland habitats including semi-natural oakwood; mixed broadleaves; Scots pine; Norway spruce and sitka spruce. The study area, comprising approximately 56 hectares, is shown outlined in red on the map attached. It forms part of a more extensive area of forest.

 

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 09.45 hrs on 10th May and 10th 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 and those recorded outside the official counts 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 9 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.
Dense young woodland of mixed oak (Quercus petraea), birch (Betula pubesces) and holly(Ilex aquifolium) - approx 5 - 6 meters tall - with bramble (Rubus fruticosa) and ground vegetation of woodrush (Luzula spp.)and grasses (Graminaea).

Point 2.
Pure mature Norway spruce (Picea abies). No understorey. Little ground vegetation except for mosses (Bryophytes) with occasional woodrush and bilberry (Vaccinium myrtillus).

Point 3.
Mature Scots pine (Pinus sylvestris) with occasional birch. Some holly and hazel (Corylus avellana), and bramble understorey. Ground vegetation of woodrush, bilberry and occasional fern (Filiscopsida).

Point 4.
Birch woodland - 20 to 25 feet tall - with some holly understorey and occasional bramble. Ground vegetation of woodrush and mosses with considerable areas of bare ground.

Point 5.
Scrub comprising birch, holly, gorse (Ulex europaeus) and bramble.

Point 6.
Mature oak woodland with low density tree cover - individual trees with much open space. Occasional beech. Bramble and some holly with ground vegetation of woodrush and ferns.

Point 7.
Low density oak woodland. Bramble and some brash. Ground vegetation of woodrush and grasses with areas of bare soil.

Point 8.
Similar to Point 7.

Point 9.
Mixed woodland of oak and Norway spruce with some holly understorey. Some fallen dead wood. Ground vegetation of woodrush, ferns and bluebells, with considerable areas devoid of ground cover.

 

5. RESULTS

Species Richness
The number and variety of species varied from point to point and ranged between 8 and 14 (Table 1). The 9 points give a cumulative total of 22 bird species. A further 7 species, three of which are associated with the river environment (Table 11), were recorded within the study area outside formal counts, bringing the total number of bird species for the entire property to 29. Chaffinch and wood pigeon were recorded at all locations. Wren, robin, song thrush, blackbird and blackcap were each recorded in at least seven of the nine locations.

Based on bird numbers within the fixed 30 meter band mixed oak/Norway spruce woodland recorded the greatest number of species (9) followed by young mixed oak and birch woodlands in equal place with 8 species. The low-density oak woodland recorded only 3 or 4 species at each location.

Table 1. Bird Species Recorded at Ballygannon in Summer 2001.

SPECIES
POINTS
 
1
2
3
4
5
6
7
8
9
Blackbird (Turdus merula)
/
/*
/
/
/
/*
/*
-
/
Blackcap (Sylvia atricapilla)
/
/*
-
/
/*
/*
/
-
/
Blue Tit (Parus caeruleus)
/
-
-
-
/
/
-
-
/
Chaffinch (Fringilla coelebs)
/*
/
/
/
/
/*
/*
/
/
Chiff Chaff (Phylloscopus collybita)
-
/*
-
/
-
-
-
-
-
Coal Tit (Parus ater)
/
/*
-
-
/*
/*
/*
/*
-
Dunnock (Prunella modularis)
-
-
/
-
-
-
/
-
-
Goldcrest (Regulus regulus)
/
/
/
/
/*
-
-
-
/
Great Tit (Parus major)
/*
-
-
/*
-
-
/*
-
/
Heron (Ardea cinerea)
-
-
/*
-
-
-
-
-
-
Jackdaw (Corvus monedula)
-
-
-
-
-
/*
-
-
-
Jay (Garrulus glandarius)
-
-
-
-
-
/*
  
-
-
Mistle Thrush (Turdus viscivorus)
/*
/*
-
-
-
-
-
/*
-
Pheasant (Phasianus colchicus)
/*
/*
/*
/*
-
-
-
-
-
Robin (Erithacus rubecula)
/
-
/
/
-
/
/
/*
/
Rook (Corvus frugilegus)
-
/*
-
/*
-
/*
-
-
-
Song Thrush (Turdus philomelos)
/
/*
/*
/*
/
-
/*
/*
/
Sparrow Hawk (Accipiter nisus)
-
/*
-
-
-
-
-
-
-
Tree Creeper (Certhia familiaris)
-
-
-
-
/*
-
-
/
/
Willow Warbler (Phylloscopus trochilus)
-
/*
/*
/
/
-
-
-
/*
Wood Pigeon (Columba palumbus)
/*
/
/
/*
/*
/*
/*
/*
/*
Wren (Troglodytes troglodytes)
/
/
/
/
/
/
/
/
-
                   
Number within 30m radius
8
4
7
8
6
3
4
3
9
Total Number
13
14
11
13
11
11
10
8
11

(Note: / = recorded inside 30m zone; /* = recorded beyond 30m zone; - = not recorded)


Table 11. Additional species recorded outside formal counts.

SPECIES
LOCATION
Hooded Crow (Corvus corone cornix) Compartment 13901N
Magpie (Pica pica) Compartment 13902I (Sub 10)
Raven (Corvus corax) Over Compartment 13902I (Sub 4)
Swallow (Hirundo rustica) Feeding over river
Dipper (Cinclus cinclus) Nesting in river bank
Grey Wagtail (Motacilla cinerea) Nesting along river bank
Mallard (Anas platyrhynchos) On river


Abundance
The most abundant species varied from point to point (Table 111). However robin, wren and chaffinch constitute the most abundant species in the woodland as a whole. Wren and robin were the most abundant in the low-density oak woodland and in the young oak. The Norway spruce and Scots pine sites had similar species with goldcrest the most abundant. Warblers were the most abundant in birch, and great tit and treecreeper in the mixed oak/Norway spruce.

Table 111. The most abundant species at each point.

SPECIES
POINTS
 
1
2
3
4
5
6
7
8
9
Robin
1
-
-
-
-
2
2
3
2
Wren
2
3
2
2
-
1
1
1
-
Blackbird
3
-
2
-
-
-
-
-
3
Goldcrest
-
1
1
-
-
-
-
-
-
Chaffinch
-
2
-
-
3
-
-
2
-
Wood Pigeon
-
3
3
-
-
-
-
-
-
Blackcap
-
-
-
1
-
-
3
-
-
Willow Warbler
-
-
-
3
2
-
-
-
-
Blue Tit
-
-
-
-
1
3
-
-
-
Dunnock
-
-
-
-
-
-
3
-
-
Treecreeper
-
-
-
-
-
-
-
3
2
Great Tit
-
-
-
-
-
-
-
-
1

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 total study area was 34.3 birds per hectare.

 

6. COMMENT

This site as a whole displayed good species diversity reflecting the diversity of woodland types, with a predominance of broadleaves. Compartment 13902I is a well integrated forest with a considerable amount of broadleaved scrub along roads, although absent on the western (road) side of the block of Norway spruce. Compartment 13901N on the other hand lacks diversity, except at the south-eastern and eastern ends, with the remainder comprising low density oaks of a uniform age. This latter habitat recorded only 3 or 4 bird species within the fixed band at each location, although these cumulatively represented seven bird species, including only one of the tit species - blue tit. Both coal tit and great tit were recorded outside the band in this habitat. The mixed oak/Norway spruce woodland in this compartment, by contrast, recorded 9 species within the 30 meters band.

While records of wood warbler have been made in county Wicklow it was not recorded on this site during the study. Duchas Conservation Ranger, Cathal Stockdale, has no record of it for this location.

While up to 17 bird species were recorded in this pure oak woodland they were at very low densities. The natural process of regeneration will in time improve the situation, and any replanting and management programme will also have an impact. This might be a suitable location for the erection of nest boxes if it is decided to enhance conditions for specific species. It is an interesting site and alternatively, or combined with the nest boxes, could be the subject of a more detailed research project.

The young oak and birch woodlands both recorded the highest species richness on this site, with both supporting broadly similar species. The birch, however, was inhabited by chiff chaff and willow warbler which were absent from the oak. Conversely oak had blue and coal tit which were absent from birch.

The stand of Scots pine in Compartment 13902I hosts a small heronry. Four nests were evident, two of which successfully produced young. The others did not appear to be active, although there was a dead chick in the branches beneath one. They may have been abandoned or may be nests from the previous year.

Sparrowhawk may nest in sub-compartment 3. They were heard calling, though not seen, on a number of occasions, nor was a nest was found.

The presence of dipper on the river indicates good water quality. The river bank may need protection to stabilize it and to protect and provide dipper nesting sites. Planting of occasional willow and alder should be considered where conifers and other vegetation have been removed.

Bird density was high given that the low-density oak wood constituted a large proportion of the total site, reducing overall density.

 

7. RECOMMENDATIONS

Minimum intervention in Compartment 13902I.

Protect and stabilize the riverbank where extraction has occurred by planting broadleaves such as weeping willow and alder - some to overhang the river. It will protect the bank for dipper which nest here.

Retain some open areas in Compartment 13901N.

Encourage scrub development along roads or plant clumps of scrub at chosen locations in this compartment.

Compartment 13901N is a possible location for erection of bird boxes if such a project is desired.

Monitor and protect the heronry in the pine wood.

Monitor sub-compartment 3 for sparrowhawk and protect.

Monitor the colonization process in Compartment 13901N or develop a research project here.

Monitor the impact of the forest programme and operations on bird communities.

 

8. MAP

Legend
Study area : outlined in red
Count Point : number in yellow circle