In addition to pressures stemming from habitat loss and degradation, direct exploitation,
poisoning, and other forms of persecution, cranes are subject to several other
broad anthropogenic threats, including:
Human interference or disturbance
Interference or disturbance by people can be an indirect cause of reproductive
failure and mortality in cranes. Such interference can occur in any phase of the
cranes’ life cycles, but is most critical during the breeding season, when adults
are establishing territories and nesting birds and young are most vulnerable (Winter
1991, Ma and Su 1991, Bylin 1987). Encroachment upon or disturbance of crane nests
renders eggs and young birds more vulnerable to predation.
Warfare and political instability
Warfare and political upheaval have had negative impacts on many crane species.
Because cranes are present in or migrate through many political “hotspots”—including
the frontiers of hostile nations—they have often been influenced by human conflicts.
Cranes (and other species) can be affected in various ways: through direct mortality,
disturbance, and habitat loss and degradation; through the taking of birds to
meet subsistence needs (which is also a major problem under famine conditions);
and through the inability to enforce laws, manage protected areas, and conduct
research (Barzen 1991, Archibald 1992c, Beilfuss 1995).
Lack of effective legislation and administration
Lack of effective legislation and conservation administration is a general threat,
especially in developing countries where the legal and political framework to
support conservation is often weak. In some countries, laws are either lacking
or inadequate to protect cranes and their habitats. Ineffective management of
protected areas is a threat in many regions. Finally, the lack of cooperation
among different agencies at the local, national, and international levels can
be an obstacle to effective coordination and implementation of crane conservation
plans.
Lack of knowledge and public support
In general, cranes are well studied relative to other taxonomic groups. Nevertheless,
important gaps in scientific knowledge about their populations, populations dynamics,
life histories, migratory patterns, habitats, and ecological relationships remain.
This is especially true for the lesser known and more remote species and populations
(mainly the Siberian, Hooded, White-naped, and Black-necked Cranes). Such gaps
in scientific knowledge hinder accurate assessments of their conservation status
and needs. At least as important as the gaps in technical knowledge, however,
is the lack of knowledge and support among elected officials, agency personnel,
and other leaders in different sectors of society, as well as among educators
and the local public (Archibald et al. 1981).
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