Butterfly Monitoring: experiences with citizen scientists

Chris van Swaay,

De Vlinderstichting / Dutch Butterfly Conservation

Butterfly Conservation Europe

Statistics Netherlands (CBS)Thousands of volunteers

Why Butterfly Monitoring?

• Butterflies are good indicators for biodiversity, attractive, easy to count;

• After birds the second group that offers possibilities for large scale trend detection with the help of volunteers, both on a local, national and European level.

• And it’s fun!

Why volunteers?

Counts made by volunteers help the conservation of butterflies directly by:

• Collection of local data on changes in the trend of butterflies, which can be used immediately for conservation at the local level;

• Combined on a higher level the results can be used to in nature conservation of a state or country;

• On a European scale it helps directing conservation efforts.

The start

• Ernie Pollard started the first BMS in the UK in 1976

Count a transectof 5 m wide in sections of 50m

Simple method:Counts are made in a 5x5x5m box

Online recording

Easy access to all your transects

Easy and fast input

From national trends to a European trend

0

25

50

75

100

125

150

175

1990 1994 1998 2002 2006 2010

Inde

x (fi

rst

year

=100

)

FranceThe NetherlandsSpain - CataloniaUnited Kingdom

0

20

40

60

80

100

120

1990 1994 1998 2002 2006 2010

Inde

x (1

990=

100)

+ 9 other countries

European species trends

0

20

40

60

80

100

120

1990 1994 1998 2002 2006 2010

Inde

x (1

990=

100)

0

20

40

60

80

100

120

140

160

1990 1994 1998 2002 2006 2010

Inde

x (1

990=

100)

0

50

100

150

200

250

1990 1994 1998 2002 2006 2010

Inde

x (1

990=

100)

European Grassland Butterfly Indicator

0

20

40

60

80

100

120

140

1990 1994 1998 2002 2006 2010

Butterfly Conservation Europe / Statistics Netherlands

Volunteers

• With the help of volunteers it is possible to do butterfly monitoring in an affordable way;

• It gives a basis for the protection of butterflies in our society: “Our butterflies in the nature reserve next to our village are doing bad/better/well!”

• But most of all: it is great fun!!!

How to find volunteers

How to keep volunteers

• Butterfly magazines• Butterfly days• Websites• Take them seriously

Make work easy: a manual to support the volunteers

• Detailed description of the transects and counts;

• What to do when there are problems?

• Each year a report with results is distributed to all participants

Keep volunteers motivated: annual report to the recorders

• Results• News• Features

Example Catalunya

• >50 sites• Rich in species• Catalunya takes

own responsibility

• Financial support from Junta

Catalan butterflymonitoring magazine Cynthia

Number of transects in NL

Overview over German butterfly

transects (November 2007)

Butterfly pictures

Butterfly pictures taken by transect walkers; ordered by geographical region (available online)

Quality of the recordersand their data

• Strict controll of the data• Check distribution with

atlas data• Check of flight period• With online recording

this can be done immediately

• Paper input is checked in winter

• Support and ‘controll of the controllers’ by CBS (Statistics Netherlands)

Special attention to difficult species

• 1976: start of the first Butterfly MonitoringScheme in the UK

• Well founded by many scientific papers• Now at least 3000 transects in 15 countries• Every year our European volunteers

count once around the world (40.000 km)!• The Dutch BMS alone generates 200 000

records each year

Butterfly Monitoringavailable and routinely collected

Butterfly MonitoringSpatial coverage

• New countries join in every year

• Most of them done on a routine basis