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Pienkowski:Impactof tourismon coastal breedingwaders
The impact of tourism on coastal breeding waders in
western and southern Europe: an overview
M W Pienkowski
Pienkowski,M. W. 1992. The impact of tourism on coastal breeding waders in western and
southernEurope:an overview. Wader Study Group Bull. 68: 92-96.
This briefoverviewis an amendedand updatedversionof a discussionpaper that originally
appeared as Pienkowski(1984). Since much of its contents remain relevant, and since it was of
restrictedcirculationin its originalform, it is reproducedin this volume. The paper summarises
the variousways in which human recreationalpresenceon coasts duringthe summercan affect
breeding waders, lists possible protectionmeasures, and outlinestopics where further work is
needed. In its originalform the paper was intended to stimulateworkshopdiscussionof the
issues; many of its questions remain largely unanswered.
M.W. Pienkowski,Joint Nature ConservationCommittee, Monkstone House, City Road,
PeterboroughPE1 1JY, U.K.
INTRODUCTION
Plover C. alexandrinus(Dybbro1970). More recently
Prater (1989) has noted that most of the remaining
breedingpopulationof Ringed Plovers in southern
and eastern England are now restrictedto areas
such as nature reserves that are protected from
Many coastal conservationproblemsare relevantto
waders simplybecause these birds happen to use
areas whose habitat is changed by man. Impactson
breeding birds often arise because touristsare attracted
to many areas becauseof their naturalfeaturesof which
waders may form a major part. Any problem that arises
may be less concernedwith changesin land use in
areas that are of major concern for winteringwaders
(see e.g. Davidsonet al. 1991) than with too many
people wishingto visit areas as they are, and thereby
changingthem.
human disturbance.
wide-scalechanges are, however,almost impossible
to obtain althoughcorrelationalevidence may be
very strong (Hilden 1983).
Reduction of breeding density. A review of earlier
work, together with new observational and
experimentalstudies(De Roos 1981) has
demonstrateda depression,by the presence of
Althoughthere has been some work in this field, much
does not appear to be generallyavailable.The main aim
of this paper is thereforeto draw togethersome of the
currentknowledgeand to discusswhat furtherwork is
needed, but it does not attempt a comprehensive review
of the subject.Accordinglythe paper consistsbasically
of headings which may serve to focus attentionon these
two general points.
Proof of such man-induced
tourists,in nestingdensitiesof Oystercatcher
Haematopus ostralegus,Kentish Plover (see also
Schultz& Stock this vol.), Curlew Numenius
arquata, and Redshank Tringa totanus in northern
areas of the Netherlands,especiallythe islandof
Vlieland.
.
Reductionin breeding productivity.Evidence of
this is more difficult to obtain but there is some
SOME SUGGESTED
PRESENCE
EFFECTS
OF HUMAN
Increased leisure time, wealth, private transportand offroad vehicles
have tended to increase
the number and
relevant material. For example, the only simple
correlates of nestingsuccess by Ringed Plovers at
Lindisfarne National Nature Reserve, north-east
England, were distance from public access and
frequency of visits by tourists(Pienkowski
1983b).
frequencyof touristvisitsto many coastal areas in
Europe. Three main related effects on waders have
been suggested. These are:
SOME
1. Reductionin breedingrange e.g. of Ringed Plover
Charadriushiaticula(Parslow 1967) and Kentish
The presence of touristscan influencebreedingwaders
in various ways, as set out below.
92
FORMS
OF POTENTIAL
IMPACT
Pienkowski:Impactof tourismon coastal breedingwaders
1. Habitatchange. For example, erosionof dune, beach
and saltmarsh habitats by people and especially by
vehicles.
2. Disturbance:at feeding sites used by adultsduring
layingor incubation;of incubation;or when adults
are with young. Unintentionaldisturbanceby tourists
of beach-nestingbirds is common (e.g. Pienkowski
1984; Buick & Paton 1989; Melvin et al. 1991) and
may also occurin other habitats.ShelducksTadoma
tadoma, for example, nesting in rabbitburrowsin dunes may not returnto their nests if
peopleare presentin the general area. Males of the
same species defend feeding territorieson nearby
inter-tidalareas to allow rapid uninterruptedfeeding
by the female,whichperformsall the incubation.
Human presenceon these areas can totallyprevent
feeding,sinceother territorialbirdspreventfeeding
in other areas (Pienkowski& Evans 1982).
3. Egg collecting.This stilloccursdespitebeing illegal,
except under special licence, in most countries.
effects may differ somewhat accordingto the behaviour
of the people. In addition,frequency of visits and
durationsof stay appear to be two importantelements.
HABITAT
TYPES
The extent of likely problems as well as suitable
protectionmeasures may differ considerablyin the
various coastal habitats, as described below.
Tidal flats. Tidal flats probably present fewer
problemsthan some of the other coastal habitats
because
nests do not occur here and the habitat is
not greatly used by tourists,especiallyin the mudd•er
areas. Some public usage does, however, occur,
particularlyon small coastal areas and sandy parts
of the foreshore. In these places there is potentialfor
disturbanceto feeding adults and young (see
above).
,
Saltmarshes, brackish marshes and salt-pans. L•ke
tidal flats, in many places these areas are not
greatly used by the public, but they can attract
large numbers of birdwatchers and birdphotographers.All these habitats, even the higher
and infrequently inundated tidal marshes, can be
important breeding areas for waders (see e.g.
Davidson et al. 1991).
5. Introductionof dogs. The presenceof dogs
accompanyingtouristsincreasesmany of the effects
of humanpresence.Dogs may use scent-trailsfor
findingnests, as well as chasing young.
,
Sand and shingle beaches. Waders breeding in this
habitat are under the greatest pressure of
disturbancefrom recreationalcoastal use (see
above).
6. Attractionof potentialpredatorsinto the general
area. This may occur as a resultof easily accessible
food such as picnicwaste (Melvin et al. 1991) or
even throughthe deliberatefeeding of speciessuch
as gulls.
,
4. Tramplingof eggs or young.As mostwaders rely on
the camouflageof their eggs and young as a major
element of defence against predators,and as young
tend to crouch to avoid detection, accidental
tramplingis a commonfeaturewhere there are many
human visitorsto a nesting area.
Sand dunes and links. Like beaches, these areas
can suffer from being highlyattractive in their own
rightto tourists,as well as often being used for
access to adjacent beaches. In additionsuch areas
are very vulnerableto direct habitatdamage from
erosion induced by visitor pressure.
7. Unwittingaid to predators.The presenceof humans
can cause increased
movement
to and from the nest
by incubatingbirds.There are some indicationsthat
predatorsmay take advantage of these increased
movementsto locate nests (e.g. Pienkowski1984).
Under normal circumstances, many waders remain
on the nest when avian predatorsare the sole
immediatethreat since their body camouflageis
effectiveat concealingthe locationof the nest. There
is also some evidence that the presence of humans
in the rearingareas of young Shelducksmay
indirectlylead to increaseddepredationof ducklings
(Pienkowski& Evans 1982).
These effects on breeding waders are often caused by
general holiday-makersat the shore, but can also be
caused by birdwatchersor bird-photographers.
The
SOME
POSSIBLE
PROTECTION
MEASURES
Measures designedto protectbreedingwaders in
coastal habitats fall into seven broad categories, as
follows.
Enforcementof legal measures and public
education. The former is mainly of importancein
connectionwith egg-collection.In most areas this
is, however, only a minor problem. Public education
can also be of benefit in dealingwith egg-collecting
where it is a problem. It is also valuable in drawing
attentionto a wider publicthat birds do nest in
the areas in which the touristsare using for
recreation.
93
P•enkowski:Impactof tourismon coastalbreedingwaders
2. Exclusionof vehicles,dogs, etc. These may be
usefulmeasuresthat can be put into effect without
causing major interferenceto publicaccess. In some
areas it may be possibleto make provisionfor limited
vehicle access for disabledpersons,and for guidedogs for the blind.
3.
1983). The destructionof predatorsis, however,
generallyundesirable.Becausethe eggs of waders
oftenform only a minorpart of the diet of such
predators(e.g. Pienkowski1984), protectionof the
nest may be a more generallyappropriatemeasure.
In the case of birdsnestingon a peninsula,electric
fencinghas provedto be an affectivetechniquefor
preventingaccess by groundpredators(Forster
1975).
Public exclusion from small areas of colonial
breeding.
4. Public exclusionfrom larger areas of dispersed
breeding.
Habitat manipulation.Habitat manipulation
presentsanotherway of enhancingthe breeding
successof coastal breedingwaders. An example
5. Redirectionof publicaccess. This groupof measures
•s consideredtogether, since exclusionof the public
(where necessary) often works better and is more
comes from Lindisfarne
Thus the use of nature trailsdirectingmembersof
the publicto only part of a sensitivearea have
proved usefulin many situations.
that RingedPloversnestedfar more denselyin
areas where much shingle (which is closely
matched by egg camouflage)was presentthan
where the groundwas predominantlysand
(Pienkowski& Pienkowski1989). Since the number
Protectionof coloniallybreedingspecies is obviously
somewhat easier than dispersed breeders. Such
are often used to restrict access to
of breeding Ringed Plovers has decreased in
recent years as the covering of sand has
vulnerablebreedingseabirdcolonieswhere such
measuresat the sametimebenefitbreedingv•aders
increased,the potentialmay exist for reversingthis
trend by addition of gravel.
such as Ringed Plovers.
Many waders present rather different,and often
larger, problemsas their breedingdensitiesare low
and requireprotectionor access restrictionon large
areas. An interestingsituationoccursalong parts of
the coastsof Germany and the Netherlandswhere a
strip of brackishmarshlandoccurs between a pair of
sea-defence dykes. In many places these marshes
are importantbreedingareas for speciessuch as the
Avocet Recurvirostraavosetta and many parts are
designated as nature reserves. Good views of these
marshesare availablefrom roads runningalong the
dykes and birds appear to become accustomed to
the presence of people on the roads.
Beaches, and to some extent dunes, are probably
the mostdifficultareas in whichto provideeffective
protectionof large areas for dispersedbreedingbirds
since there are high levels of demand for public
in
have tended to support earlier views that the
nesting density of Ringed Plovers is determined
largely by the ease with which predatorscan find
nests (Pienkowski 1983a,b). These studies found
positive if those interested can view the birds
concerned, and see the reason for the exclusion.
measures
National Nature Reserve
north-eastEnglandwhere recent habitatchanges
SOME ASPECTS
WHERE
FURTHER
STUDY IS
NEEDED
,
Experimentalwork e.g. on the exclusionof various
agents. A great number of features have been
identifiedas possiblefactorsaffectingthe breeding
successof many wader species (e.g. Pienkowski
1983a, Hotker1991) butthere has been ratherlittle
experimentaltesting. If managementtechniquesare
to be attempted,a good understandingof the various
interacting'natural'and human-inducedprocessesis
desirable to avoid wasted effort.
,
Experimentalwork on possiblemanagement
techniques.This can developfrom 1 above, to
assessthe methodsthat are most economically
effective and that cause minimum restrictions on the
tourist access to such areas, as well as for those
public(see e.g. Melvin et al. 1991).
particularlyinterestedin naturalhistory.
o
6. Compensatoryexclusionor destructionof predators.
The destructionof nest-predatorssuch as Crows
Corvuscoronehas sometimesbeen justifiedon the
grounds that their populationsmay have been
increased by human activities.This appears to be
the case in an attempt to improvethe breeding
performanceof Oystercatchersin Greece (Goutner
94
Identificationof changes due to 'natural'factors.
Furtherresearchis needed here to avoid attributing
disturbanceeffectsto man, and then tryingto
overcome them, when other more natural factors are
responsible.Several problems can be identified:
a. many coastal habitatsare subjectto fairly
rapid natural change (e.g. Parslow 1967;
Pienkowski:Impactof tourismon coastalbreedingwaders
Evans & Pienkowski1984); and in some
cases these are probablybeing exacerbated
by currentlyrisingglobalsea-levels (e.g.
Davidson et aL 1991);
b,
in Europe many wader species are at the edge
of their ranges.This impliesthat they may rely
naturallyon immigrationfrom the more central
pads of their ranges, so observed changes are
not necessarilythe result of local processes.
Peripheral populationsare, however, of
great importancesince they ensure the
maintenanceof range and distributionof the
species, a keystoneof international
conservationeffort (see e.g. Hotker 1991);
and
c. many of the speciesconcernedare migrants,
so that processesacting elsewhere outside
the breeding season may be affectingtheir
population,for example by loss of wintering
habitat (e.g. Goss-Custard& Moser 1988).
4. Identificationof sets of habitats required by
particular species for breeding. As indicated above,
combinations of habitats in close association may
be needed for successfulbreeding by waders.
These may include different habitats for feeding by
adults, as nest-sites and for rearing the young.
Local study is necessaryto identifythe sets of
sites which must be considered as single units.
Similarly, the areas that harbour the greatest
concentrationsof birds may not always be the most
productive. For example, a study of Shelducks
(Pienkowski & Evans 1982) found that the densest
breeding areas appeared to be the least favoured
and that these were the least productiveof young.
Dispersed breeders produced more young, some of.
which recruited into the dense populations which
were probably not self-suppporting.Conservation
activity was, however, concentrated at the sites
holdingdensest Shelduck populations,partly
because
the above situation
had not been known
but possiblyalso because concentrationsof birds
made a more interestingspectacle for members of
conservation organisations.A similar situation in
which many wet grasslandbreedingwaders in
Europe now appear to be breeding with
unsustainablylow productivityis describedby
Beintema (1991 ).
5. Gatheringof existinginformation.One further
problemis that some of these studieswhich have
alreadybeen undertakenhave beenfundedlocally
or on a very smallscale and have not subsequently
been published.One of the objectivesof this volume
is to collatesome of this previouslyinaccessible
information.
REFERENCES
Beintema, A.J. 1991. What makes a meadow bird a meadow bird? In
Hotker, H. (ed.), Waders breedingon wet grassland. Wader
Study Group Bull. 61, Suppl:3-5.
Buick,A.M. & Paton, D.C. 1989. Impactof off-roadvehicles on the
nesting success of Hooded Plovers Charadrius rubricollis•n the
Coorong Region of South Australia.œmu89: 159-172.
Davidson,N.C., Laffoley,D.d'A., Doody,J.P., Way, L.S., Gordon,J,
Key, R., Pienkowski, M.W., Mitchell, R. & Duff, K.L. 1991.
Nature conservation
and estuaries in Great Britain. Nature
ConservancyCouncil, Peterborough.
De Roos, G.T. 1981. The impactof tourismuponsome breeding
wader species on the Isle of Vileland in the Netherlands'
Wadden Sea. Ph.D. Thesis, MedelingenLandbouwhogeschool
Wageningen 81-14.
Dybbro,T. 1970. The KentishPlover(Charadriusalexandrinus)as a
breedingbird in Denmark. Dansk Ore. Foren. Tidsskr.64: 205222.
Evans, P.R & Pienkowski, M.W. 1984. Populationdynamics of shorebirds.In J. Burger& B.L. Olla (eds.), Shorebirds.Behaviourof
marine animals, Vol. 5. Plenum Press, New York.
Forster,J.A. 1975. Electricfence to protectSandwichterns against
foxes. Biol. Conserv. 7: 85.
Goss-Custard,J.D. & Moser, M.E. 1988. Rates of change in the numbers of dunlin,Calidrisalpina,winteringin Britishestuaries•n
relationto the spreadof Spartinaangefica.J. AppliedEcology
25: 95-109.
Goutner, V. 1983. The breeding ecology of the Oystercatcher
HaematopusostralegusL. in the Evros Delta, Greece. Wader
Study Group Bull. 39: 45-46.
Hilden, O. 1983. Recent populationchanges of waders in Finlandand
their causes. pp 13-16 in P.R. Evans, H. Hafner & P. L'Herm•te
(eds.), Shorebirdsand large waterbirdsconservation.
Commissionof the EuropeanCommunities,Brussels.
Hotker, H. (ed.) 1991. Waders breedingon wet grassland. Wader
Study Group Bull. 61, Suppl.
Melvin, S.C., Griffin,C.R. & Maclvor, L.H. 1991. Recovery strategies
for Piping Plovers in managed coastal landscapes.Coastal
Management 19:21-34.
Parslow,J.L.F. 1967. Changes in status among breedingbirds in
Britain and Ireland.
Brit. Birds 60: 97-123.
Pienkowski,M.W. 1983a. The impactof tourismon coastal breeding
shorebirdsin western and southernEurope:an introductionto
general discussion.In P.R. Evans, H. Hafner & P. L'Hermite
(eds.), Shorebirdsand large waterbirdsconservation.
Commissionof the European Communities, Brussels.
Pienkowski,M.W. 1983b. Habitatspecialisationin breedingshorebirds:a defencestrategyagainstegg-predation?WaderStudy
Group Bull.39: 50.
Pienkowski,M.W. 1984. Breedingbiologyand populationdynamicsof
Ringed Plovers Charadriushiaticulain Britain and Greenland
nest-predation
as a possiblefactor'limiting
distribution
and timing of breeding. J. Zool. London202:83-114.
Pienkowski,M.W. & Evans, P.R. 1982. Breedingbehaviour,producbvity and survival of colonial and non-colonial Shelducks Tadorna
tadoma.
¸mis
Scand. 13:101-116.
95
Pienkowski:Impact of tourism on coastal breeding waders
Pienkowski, M.W. & Pienkowski,A.E. 1989. Limitationby nesting
habitat of the densityof breedingRinged Plovers Charadrius
hiaticula: a natural experiment. Wildfowl40:115-126.
96
Prater, A.J. 1989. RingedPlover Charadriushiaticulabreeding
populationof the United Kingdomin 1984. Bird Study 36:
154-159.