Conservation Biology of Lycaenidae (Butterflies) - IUCN

Increasing human recreational activities constitute another
serious threat to many habitats all over the world and the
following list, while far from exhaustive, gives some idea of the
range of habitats involved:
• coastal sand dunes in California are threatened by off-road
vehicles and trampling;
• alpine heathlands and meadows in Europe and southeastern
Australia are threatened by the construction of ski-lifts,
runs, access roads, car parks and resort accommodation and
facilities;
• Pacific islands habitats are threatened by the proliferation of
golf courses and by the exotic vegetation often introduced;
• mangrove swamps in eastern Australia are threatened by
coastal resort development.
In many cases these recreational activities involve the
degradation of particularly sensitive habitats which tend to
support isolated, relict and often taxonomically discrete
populations of lycaenids and other insects.
Examples could be multiplied several-fold, but the principle
is well established, and the vital importance of suitable habitat
and resources for conserving small animal and plant populations
should not need further emphasis.
Pollution
The effects of chemical pollution on lycaenids are difficult to
assess, but a number of declines of particular species in Europe
have been attributed in part to atmospheric pollution, including
acid rain. Such pollution is likely to affect the well being of
sensitive foodplants and a wide spectrum of invertebrates
associated with vegetation. Likewise, pesticide drift may cause
occasional hazard, both in agricultural and forest environments.
Exotic introductions
No significant information is available on the deleterious effects
of exotic taxa on native Lycaenidae in many parts of the world.
The introduction of Dutch Elm Disease into Britain, with
consequent large scale demise of Ulmus trees, led to a reduction
in the numbers of the Whiteletter Hairstreak, Strymonidia walbum
(Knoch). Similarly, the introduction of myxomatosis to
Britain in the 1950s resulted in a drastic reduction of the
intensity of rabbit grazing on chalk grasslands, with a resultant
reduction in the numbers of several butterfly species, such as
Lysandra bellargus (Rottemburg) and Maculinea arion. In
New Zealand, Gibbs (1980) noted the trend towards decline of
Zizina oxleyi (Felder & Felder) in parts of the South Island
through hybridisation with the invasive Australian Z. labradus
(both are sometimes treated as subspecies of Z. otis (F.) (Figure
3)). Claims that hybridisation with the introduced Strymon
melinus Hübner could threaten the Avalon Hairstreak, S. avalona
(Wright), on Santa Catalina Island, California, need further
investigation (Wells et al. 1983).
In a rather different interaction between exotic and native
species, Brown (1990) reported that the widespread Leptotes
marina (Reakirt) had adapted well to urbanisation in North
15
America with its range expansion largely due to a 'switch' to a
South African larval foodplant (Plumbago auriculata), which
is used widely in freeway landscaping and as an ornamental.
Furthermore, larvae associate closely with the introduced
Argentine ant, and the prime nectar source for adults is a
Brazilian tree. Leptotes thus has benefited from the presence of
several different exotic species.
Conservation of Lycaenidae
The major sequence of needs in order to effect conservation
programmes for any form of terrestrial wildlife is as follows:
i) Documentation and education, to increase awareness at all
levels and as a mode of communication between informed
scientists and those who make practical decisions over
priorities for land use;
ii) Detection of habitats supporting either critical faunas or
single notable or vulnerable species which merit protection
and the promotion of their continued protection in existing
National Parks and other reserves;
iii) Investigation of the limits and/or wisdom of legislative
protection for particular taxa or habitats, as an interim
measure whilst additional documentation is obtained, and
iv) Autecological studies of selected taxa as a basis for
formulating sound management plans, a step which can
come only from a basis of substantial research rather than
haphazard extrapolation and which is, therefore, costly.
v) Investigation of techniques for captive rearing, in case of
need for ex situ conservation, or translocation. This should
not be seen as a replacement option for in situ conservation.
The information contained in this volume has hitherto been
scattered through a wide range of reports (of varying degrees of
formality and distribution) and scientific papers. In dealing
with such a diverse group of insects, this book cannot be as
definitive as 'Threatened Swallowtail Butterflies' (Collins and
Morris 1985), but the examples given reflect a growing number
of detailed studies on lycaenids and concern over their
conservation. It represents a useful starting point for the
development of conservation programmes for the Lycaenidae
and should help to focus attention on groups or geographical
regions in need of urgent attention.
Public awareness
Most conservation projects to date have been species orientated
and many of these have done much to improve public awareness
of the threats to lycaenid species. The potential for
reintroductions is demonstrated well by the recent project
involving the successful liberation of the Large Blue, Maculinea
arion L. in Britain. This case is discussed in detail by Elmes and
Thomas (1992) and by New ('Large Blues', this volume).
Attempts to introduce the continental subspecies of the Large
Copper, Lycaena dispar, into Britain, are of long standing
(Duffey 1977 and this volume). Both projects highlight the