Indicators of the presence of different mammal species

Adapted from Armstrong, H. M., Chesterton, C., Currie, F., Kirby, K. and Latham, J. (2003) Developing survey methods to assess over-grazing of upland woods. Report to DEFRA. 35 pp.

N.B. It will be relatively easy to determine the species responsible for the impact in a particular woodland if only one species is present. However, up to 4 species may commonly be impacting, albeit in different seasons. Determining the relative contribution of sheep and deer to the impact will not be possible in most cases.

Browsing is here defined as biting off parts of woody species whereas grazing is biting off parts of non-woody species.

Browsing, grazing and bark damage indicators

Time of Type of bark damage Time of Maximum Forage preferences Maximum year possible /indicators year bark height of Mammal /browsing indicators height of Comments browsing damage damage to bark browsing likely likely All deer Ragged ends to bitten- Browse line (0.5 - 1.5 m high) along lower edge off shoots (always of canopy indicates deer presence if they are in eaten). high enough numbers. Sheep damage very similar to deer damage. Roe deer Herbs, bramble, woody All year 1.1 m Fraying of young trees Spring/ 50 cm Solitary or in small groups in woodland. browse, grass, crops. Summer Sometimes seen feeding in fields. Damage trees and sometimes arable crops. Muntjac Bramble, ivy, All year 1.1 m. Will Fraying of young trees Autumn 40 cm Prefer habitats with dense cover and a high honeysuckle, rose, nibble coppice diversity of shrub and ground layer plant species, hawthorn, sloe and other shoots to about the presence of bramble and a variety of young deciduous trees 1 m from broadleaved trees. and shrubs including ground. Will Can break coppice stems. Can peel bark from coppice shoots. Also walk over the small branches and trees. nuts, fungi, ferns, herbs, top of bendy Will fray tree shelters to 40-50 cm in height. grasses and wild coppice stems to Can damage farm crops. flowers. Do not browse reach the leaves. conifers except in harsh weather. Time of Type of bark damage Time of Maximum Forage preferences Maximum year possible /indicators year bark height of Mammal /browsing indicators height of Comments browsing damage damage to bark browsing likely likely Fallow As for roe – also like All year 1.8 m Fraying of young trees Autumn 80 cm Groups or herds; often shelter in woods and feed deer acorns and mast. in fields. Strip bark from pole stage All year Will fray tree shelters. trees, particularly Norway Damage farm crops, woodland shrubs and ground spruce, Lodgepole pine, flora. larch, ash, willow and beech. Vertical incisor marks down stem. Red deer Grass, heather, crops All year 1.8 m Fraying of young trees Autumn 1.8 m Damage trees and farm crops. trees and shrubs. Stripping (As Fallow) All year Vertical incisor marks down stem Sika deer Grass, heather, trees, All year 1.8 m Fraying of young trees Autumn 1.6 m Groups in dense woodland with mixed fields or shrubs & herbs. glades. Damage woodlands and sometimes crops. Stripping (As for Fallow) All year Vertical incisor marks down stem Sheep & Grass, heather, trees, All year 1.5 m Severe stripping of bark All year 1.5 m Sheep and goat browsing damage is very similar Goats shrubs and herbs. on young to pole stage to deer damage. Ragged edge to browsed trees often leading to tree shoots, which are always death. More likely to be eaten. severe with goats than sheep. Diagonal incisor marks across stem Cattle Ragged edge to browsed 2.0 m Bark rubbing and All year 2.0 m shoots. stripping by cattle can occur on all age classes of tree.

Horses Woody growth not 2.5 m Stripping of bark by All year 2.5 m and favoured horses often leads to tree Ponies death. Diagonal incisor marks across stem. Time of Type of bark damage Time of Maximum Forage preferences Maximum year possible /indicators year bark height of Mammal /browsing indicators height of Comments browsing damage damage to bark browsing likely likely Rabbits Sharp angled, knife-like Winter & 0.54 m rabbits Strip bark to all age Winter/ 0.54 m Rabbits and hares cut on ends of stems or spring – classes (beech Spring branches. Shoots can be Rarely 0.7 m Hares vunerable). Incisor marks 0.7 m Hares left uneaten (n.b. always summer. 3-4mm wide in pairs. left uneaten by hares). Higher in snow Diagonal incisor marks Higher in snow across stem. Grey Strips bark on trees of age April – Bark stripping mainly to base and main stem. Can squirrel class 10-40 years. July ring-bark. Damage at base of tree can be confused Sycamore, beech, oak and mostly with winter bark-stripping of rabbits. pine are most at risk. though Fresh bark can be found at base of tree. Incisor marks 1.5 mm can extend Intensity of damage mainly related to previous wide in pairs usually to mast crop where a good mast year and high spring running parallel with stem September breeding success usually precedes heavy damage or branch. year. Field vole Strips bark on roots or All year lower stem. Bark removed but greater (stripped) in short risk in irregular strips 5-10 mm winter wide with incisor marks 1 mm wide in pairs in the bark around the edge of the wound. Bank vole Will remove buds, Winter Bark removed (stripped) Winter & Can climb trees Less common than damage by Field voles. particularly of pine, in short, irregular strips 5- Spring so damage can usually on restock sites; 10 mm wide with incisor occur up to 4 m. often immediately after marks 1mm wide in pairs planting. in trees to early pole stage. Signs, dung, tracks and sward height

Mammal Minimum height Comments Signs Dung (droppings) Tracks and Pathways of grazed sward Short, blackish, cylindrical and Well used narrow pathways. Roe deer Hair in barbed wire fencing. pointed at one end. Smooth Slots pointed and together at 4 cm surface, shiny when fresh. tips. Hair in barbed wire fencing. As for roe, but larger, with As for roe, but pointed tips Chewed/ thrashed plastic tree Fallow deer striations and less uniform shape more splayed (seen at wet 4 cm shelters. Newly-planted trees pulled for older males. muddy crossings). out of ground. Hair in barbed wire fencing. As for fallow, but larger and As for fallow but more Can occur in large herds on Red deer 4 cm Wallows in wet hollows. more fibrous and brownish. poached pathways in places. moorland. Wool snagged on fences/shrubs. Roundish but angular and Slots rounded at tips. Broader Sheep Newly planted trees pulled out of irregular shape. Smooth surface, and more rectangular than for 3 cm ground. shiny when fresh. deer. Black and white hair snagged on Rocky outcrops, ledges or Goats fences. Newly planted trees pulled out As for sheep. As for sheep. 6 cm caves are required for of ground. shelter. Often sheltered in Roughly torn and pulled up woodlands in winter vegetation. Trampled standing Widely splayed deep slots. where poaching of soil Cattle areas for ruminating. Trampled tall Large round pats. 6 cm Pathways 0.3 m wide. surface around vegetation. Poached areas. Rubbed supplementary feeding trees. stations can occur. Favoured vegetation grazed close to Rarely found in closed Horses Rounded hoof marks. ground. Trampled tall vegetation. Coarse fibrous heaps. 2 cm canopy woodland though can /Ponies Pathways 0.3 m wide. Rubbed trees. occur. Burrows, dunging tumps (large Narrow vegetated pathways. Rabbits Roundish and fibrous. piles of dung). Very short Pad marks evident in 1 cm and hares Deposited in favoured areas. vegetation in patches. snow/frost.