photographs Roger Morris Hoverfly Recording Scheme - - PowerPoint PPT Presentation

A new paradigm in biological recording?

Monitoring hoverflies with digital photographs

Roger Morris Hoverfly Recording Scheme

www.hoverfly.co.uk With photographs by John Bridges http://northeastwildlife.co.uk/

What is a hoverfly?

• Order: Diptera (Di –

two; ptera – wings) – the second pair of wings is modified to form the ‘halteres’ – turn and bank indicators.

• Family: Syrphidae

What makes it a hoverfly?

Photo Stuart Ball

The UK Hoverfly fauna

• 283 species (2 confined to

Ireland)

• Adults are recognised as

important pollinators of flowers, but also

• Wide range of larval biology,

including:

• aquatic filter feeders;
• saprophages, including dung, fungi

and decaying wood;

• leaf, stem, root and bulb feeders;
• predaceous upon aphids and other

larvae; and

• associated with nests of bumblebees,

social wasps and ants.

Myathropa florea

Foundations of biological recording

• Victoria County Histories – accounts of species

known from many (all?) counties.

• Journals of Natural History Societies and some

specialist journals.

• County atlases – predominantly botanical and

birds.

• National atlas schemes – with the bar set by

Perring and Walters (Atlas of the British Flora – 1962).

Hoverfly Recording Scheme

• Established 1976
• 1976-1987 two scheme
• rganisers – John Ismay,

followed by Philip

• Entwistle. No scheme
• rganiser from 1997 to

1991 when Stuart Ball & Roger Morris took it on.

• Atlases published in

2000 & 2011 and another due out soon!

Chrysotoxum arcuatum

Traditional administration

• f recording
• Largely voluntary using a network of non-

vocational specialists.

• Central co-ordination and publication by the

Biological Records Centre (formerly Monks Wood and latterly at CEH, Wallingford).

• Local records centres – variable in manpower

and who runs them.

Traditional data capture

• Traditionally – paper based – using record

cards or conventional letters/publication.

• Relied on one or more Recording Scheme

Organiser to interface with the contributors.

• Data digitised centrally at Monks Wood.
• Not all taxonomic groups had (have) a

recording scheme – dependent upon there being a willing and interested specialist.

And then came easy access to powerful computers!

• Database technology.
• Electronic data transfer.
• Shift away from paper-based technology and

towards RS organisers managing the scheme’s data.

• The first paradigm shift!

Data submitted by traditional routes

And then: Digital photography

• Jepson, P. (2005) ‘Natural History Re-

mastered’. British Wildlife, 17(1): 27-31.

• Suggested that Digital photography would

replace traditional recording and the need to retain preserved specimens.

• A second paradigm shift?

New data capture systems

• Web-based facilities to upload photographs.
• Crowd-sourced identification (WAB, iSpot).
• Potential for interactions with a different cohort
• f biological recorders:
• Casual observers with a camera.
• Photographers who want their subject matter named.
• Keen recorders who branch into new disciplines but do not

want to retain specimens.

• Those who want to make a contribution to the state of

knowledge about wildlife but lack the experience to tackle difficult taxa.

Recording hoverflies from photographs

• Started around 2007 but became a major

activity of the HRS by 2009.

• Data extraction entirely by RKAM (at the

moment) from:

• iSpot
• Wild About Britain
• Flickr
• Ipernity
• Picassa
• Other blogs and websites

Basic progress

Yearly data growth

Relative contributions of data sources (Log2)

Scale of individual photographic contributions

Contributors to data sources

Key messages

• There are substantial numbers of people who

take at least a passing interest in hoverflies as a photographic subject.

• Data from such sources have grown in

response to new data capture systems.

• The establishment of the Facebook site and

‘community’ has played a big part in fostering interest and participation.

But ...

• Crowd sourced identification still relies upon a

small number of specialists.

• The UK Hoverflies FB Group relies upon 3

‘resident specialists’ who have many years experience using microscopes and keys.

• Data extraction takes up nearly all of the time
• f one specialist from May to September.

There is no additional specialist capacity!

Lots of data but is it any use?

• Critical review yielded the following

comments:

• ‘Outrageous’ and ‘grossly misleading’ to suggest that so

many species can be identified from photographs.

• ‘Only about 30 species can be reliably identified from

photographs’.

• ‘It is a waste of time extracting data for a few common

and easily identified species’.

• ‘very little scientific value in this paper’.

Let us test the validity of these assertions

• Records so far of more

than 150 species, including several rarities (e.g. Callicera aurata, Callicera spinolae, Eristalis similis, Meligramma guttatum, Meligramma euchromum, Pelecocera tricincta). Critical identifications

• ften checked with

European specialists.

Meligramma guttatum

Is it worth collecting data for ‘common’ species?

• Trend analysis calls for

large volumes of robust data.

• Records of rare species

will always be sparse.

• Commoner species are

therefore often the most useful bellwethers

• f change.

Episyrphus balteatus

Is rarity always what it seems?

• Some species are there

but occur at times when recording is difficult (e.g. Spring) – need more recorders.

• Species’ abundance can

change – what is rare now may not be in 20 years time – need lookouts to spot the change.

Cheilosia grossa – photographic data

Dominant species

• ~ 35 species make up

90% of the dataset.

• Poor coverage of

difficult genera – Cheilosia, Pipizini, Platycheirus and Sphaerophoria.

• But good coverage of

many species that have responded to climate change.

Helophilus pendulus

Uneven recording

Tribe GB Fauna Species recorded % GB fauna in sample Identified records Unidentified records Total records % Identified

Volucellini 5 5 100 886 5 891 99.4 Xylotini 20 14 70 647 11 658 98.3 Eristalini 28 19 67.9 3488 380 3868 90.2 Callicerini 3 2 66 4 4 100 Syrphini 84 45 53.6 3352 1031 4378 76.6 Bacchini 30 15 50 860 291 1158 74.3 Cheilosini 43 17 39.5 634 170 804 78.9 Chrysogastrini 29 10 34.5 108 49 157 68.8 Merodontini 7 2 28.6 188 15 203 92.6 Microdontinae 4 1 25 1 1 100 Pipizini 20 3 15 9 63 72 12.5 Paragini 4 4 Pelecocerini 3

Lessons

• It is a misconception to think that photographers

will only encounter ‘common’ species.

• Increased recorder effort will change perceptions
• f ‘rarity’.
• But, there are limits to what can be achieved

from photography.

• A significant proportion of the fauna is either not

encountered or unidentifiable from photographs.

• The positive message is that a bigger recorder

base can be grown from photographic recorders.

Use of biological records

• Mapping – traditional atlases

BUT – so much more:

• Red lists
• Site-based conservation
• Climate change indicators
• Phenological change
• Aspects of species’ biology
• Pollinator ecology?

So, what sort of data are required?

• High resolution
• Reliable
• Verifiable
• Repeatable

Outcomes 1 - coverage

HRS species per hectad 2014 Photographic coverage 2014 Photographic data species per hectad

Outcomes 2

• Good yearly

data-sets for about 40 species, which can be used to investigate phenological change or differences.

Phenology of Episyrphus balteatus in 2013 and 2014 2013 2014

Outcomes 3

• With sufficient records it

is possible to detect change both within and between years.

• Needs lots of recorders

across the country and for those recorders to be active at critical times.

• Photographers are

different because they will look for all sorts of subject matter.

North Midlands South Phenology of Epistrophe eligans in 2014

Outcomes 4

• Investigating

autumn and winter hoverfly activity.

• There is a lot

more going

• n than we

knew hitherto!

Potential of new working

• Think of a photo as a

voucher specimen – it conveys important data:

• Gender
• Numbers
• Activity record – flower

visits, predation,

• viposition.
• All data need to be

extracted but many recorders don’t do this when entering data onto iRecord.

If you have the data you can do so much more!

Volucella zonaria Male Volucella zonaria Female

And even change people’s lives!

• Create a virtual community with people that

know one another electronically.

• New interests for photographers – at least two

have commented that this new interest has greatly brightened their lives.

• Need to recognise this paradigm as a

challenge for traditional societies – not a threat but a new opportunity.

Conclusions

• We have entered a new paradigm in biological

recording.

• Photography cannot replace traditional specimen-

based recording but it can compliment it.

• In some taxonomic groups it is possible to identify

significant proportions of photographs and to generate valuable records.

• But, it takes time and commitment – we need a new

generation of recording scheme organisers – and more within each scheme to facilitate interactive approaches.

Thank you for listening