[Pollinator] New publication about dingy skipper butterfly (Britain)

[Kimberly Winter]

Interesting article about butterfly conservation:

GUTIÉRREZ, DAVID (2005)
Effectiveness of Existing Reserves in the Long-Term Protection of a 
Regionally Rare Butterfly.
Conservation Biology 19 (5), 1586-1597.
doi: 10.1111/
j.1523-1739.2005.00210.x

Abstract:
The importance of unprotected habitats for the persistence of species in 
reserve networks is likely to be high for species living in highly 
fragmented habitat in which regional persistence depends on metapopulation 
processes. The dingy skipper butterfly (Erynnis tages) is a regionally rare 
declining species in Britain. In the Creuddyn Peninsula (North Wales), it 
inhabits patches of its host plant, Lotus corniculatus L., growing in 
lightly grazed areas in sheltered microhabitats, and its regional 
distribution is dominated by metapopulation processes. In this area, 16 
(61%) out of 26.20 ha of dingy skipper habitat are located in reserves. The 
remaining unprotected habitat is mostly located in wasteland areas 
vulnerable to urban development. Using a metapopulation model, the incidence 
function model, I evaluated the extent to which the persistence of the dingy 
skipper in the landscape could be guaranteed with the existing reserve 
network. According to model projections, the dynamics within the reserve 
system were relatively stable when the unprotected habitat remained, with a 
maximum of 4% simulation replicates going extinct in a 100-year time frame. 
When unprotected habitat was completely removed, however, the dynamics in 
the reserve network became markedly unstable, with an increased extinction 
risk ranging from 15 to 36%. We calculated a relatively simple measure of 
"patch importance," the colonization potential, for each patch. The 
incidence function model predicted that for low and medium levels of 
regional stochasticity ( value from 0 to 0.2), protecting only a relatively 
small number (four to six) of large and well-connected patches (high 
colonization potential) in addition to the existing reserves would be enough 
to decrease notably the extinction risk of the dingy skipper metapopulation. 
The number of patches needed to be increased (11 patches) for high levels of 
regional stochasticity (= 0.3). My results suggest that long-term 
persistence of a regionally rare butterfly in a reserve network may depend 
on the presence of unprotected habitat. For a more realistic estimate of the 
efficiency of reserves for protecting rare species, conservation biologists 
should consider incorporating metapopulation dynamics in their evaluations 
of persistence in existing reserves.

~Kim

Kimberly Winter, Ph.D.
Coordinator, North American Pollinator Protection Campaign
E-mail: NAPPCoordinator at hotmail.com
Internet: www.nappc.org
Ph: (301) 219-7030

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