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Individual study: The scarce large blue butterfly Maculinea teleius moves shorter distances than the dusky large blue butterfly M. nausithous, following reintroduction at the Moerputten Nature Reserve, Noord Brabant, the Netherlands

Published source details

van Langevelde F. & Wynhoff I. (2009) What limits the spread of two congeneric butterfly species after their reintroduction: quality or spatial arrangement of habitat? Animal Conservation, 12, 540-548

Summary

The scarce large blue butterfly Maculinea teleius and the dusky large blue M. nausithous were reintroduced at the Moerputten Nature Reserve, Noord Brabant, the Netherlands in 1990. Both species rely on the great burnet Sanguisorba minor and ants of the genus Myrmica as larval hosts. This study measured the spatial distributions of the new butterfly populations for ten years following reintroduction.

Eighty-six scarce large blues and 70 dusky large blues were released on meadows in the nature reserve in July 1990. The reserve and surrounding road verges were surveyed for these butterflies at least once a week during their flight period each year from 1990 until 2000. The presence or absence of butterflies was recorded in 587 randomly chosen 1 m2 plots, each containing at least one great burnet plant.

Ants (attracted using sugar cube bait) and vegetation cover, including the number of great burnet flowerheads, were also recorded in each 1 m2 plot.
 
The butterfly population sizes were estimated by marking and recapturing individuals in five or six monitoring years for each species.  
 
After the peak flight period, road verges and ditch edges in the surrounding area were also searched for large blue butterflies.

The scarce large blue increased in numbers to an estimated population size between 100 and 300 from 1995 to 1997. From 1993 onwards, the species was restricted to a single meadow where it was released.

The dusky large blue increased in numbers from 1992 to 1995. The estimated population was 592 in 1996. The population deserted the reintroduction site and settled on an old railway embankment in the nature reserve and on nearby road verges from 1993 onwards.
 
For both species, suitable 1 m2 plots further away (up to 922 m) from occupied plots had a lower probability of being occupied in a given year.
 
The dusky large blue covered longer distances, colonizing plots up to 442 m away from the nearest occupied plot (median distance covered 42 m), while the scarce large blue colonized plots only up to 263 m away (median distance 9.8 m).
 
The authors argue that scarce large blue conservation should focus on enhancing local habitat quality, and dusky large blue conservation should focus on building networks of suitable habitat, for example along road verges.
 
 
Note: If using or referring to this published study, please read and quote the original paper, the abstract of which can be viewed at: http://www3.interscience.wiley.com/journal/117969966/home?CRETRY=1&SRETRY=0