The Greenland White-fronted Goose Anser albifrons flavirostris

irds were picked up dead or dying away from
their normal haunts (Ruttledge & Ogilvie 1979,
Fox & Stroud 1985). Large numbers of albifrons
also died of starvation that year, but there was no
evidence of range contraction for this population,
which is less winter site-loyal and feeds more on
agricultural grasslands (Beer & Boyd 1964).
Even where flush runnels and the pool and hummock
topography are abundant as surface features,
their extent (and therefore the extent of cotton
grass and other favoured peatland food species)
represents a tiny fraction of the entire bog
biotope. Furthermore, by definition, their distribution
is highly patchy, so any herbivore exploiting
such a resource would be expected to show
appropriate behavioural and feeding ecology
adaptations. For example, because both Eriophorum
angustifolium and Rhynchospora alba are only
locally abundant, foraging could rarely take place
in large flocks, since no one area could support
more than 10-20 foraging individuals for prolonged
periods. The broken topography of blanket
and raised mire systems makes approach by
potential terrestrial predators (such as Fox Vulpes
vulpes) relatively simple. Hence, shared vigilance
would be expected to favour the cohesion of small
groups defending feeding patches rather than
lone foraging individuals prepared to risk predation
as the costs of gaining access to interference-free
foraging opportunities and maintain
high intake rates. On the other hand, the locally
restricted, patchy but rich food resource would
have precluded the development of large flocks
typical of other subspecies of Anser albifrons exploiting
open grass swards.
For the reasons considered above, the subspecies
was probably always highly restricted in its wintering
distribution. Oceanic mires with conspicuous
surface patterning reach their southern limit
in Britain and Ireland (Lindsay 1995, Lindsay &
Immirzi 1996), and those in Scandinavia to the
east and north are frozen in winter rendering the
food inaccessible to the geese. In recent centuries,
the wintering range is unlikely to have been very
different from that today, and the habitat signature
that defines their distribution would have
always been highly limited in extent, even allowing
for widespread loss of boglands as a result of
Man’s activities in the last 500 years.
Heavy exploitation by Whitefronts may locally
remove all Eriophorum shoots, and the plant may
take a year or more to recover to levels of biomass
20
prior to goose exploitation (Hupp et al. 2000,
MS24). This also has consequences for the way in
which a herbivore should exploit the feeding resource,
since exploitation of one feeding patch in
year t may render this area a poor foraging area
in year t+1 and perhaps even in t+2. Hence some
knowledge of the spatial arrangement of this
patchy feeding resource and the location of alternative
feeding sites (that can be used in successive
years) might also favour a social system that
involved learning by young members of a group
about alternative feeding sites (linked perhaps by
a common night-time roost site).
The geographical distribution of the Greenland
White-fronted Goose may always have been
highly restricted, limited by a rich feeding resource
that sustained the geese throughout the
winter, the distribution of which was highly
patchy, both in time and space. This presumably
favoured high site fidelity and the “cultural” accumulation
of knowledge as the most effective
means of exploiting the bogland biotopes. This
in turn resulted in low densities of these specialised
herbivores concentrated in relatively small
pockets of habitat. If the Greenland White-fronted
Goose was confined to bogland habitats in this
way, it seems likely that the population would
always have been extremely limited in its range
and abundance by the nature of its habitat.
2.4 Changes in habitat and abundance in
the 20 th Century
Given the waterlogged nature of their habitat, and
the inaccessibility of many of their winter haunts,
the Greenland White-fronted Goose wintering
habitats were probably left largely untouched
until the mid 19 th Century, with many peatland
areas unmodified well into the 20 th Century. Despite
the need for fuel from peatlands, domestic
turbaries were unlikely to have extracted peat by
hand at a rate that would have threatened the
goose habitat. Indeed, there is evidence from at
least 5 different Welsh, Islay and west of Ireland
wintering sites, that abandoned hand-cut peat
diggings perpetuated feeding habitat for Greenland
White-fronted Geese, by creating the wet
floating Sphagnum lawns from which the food
plant Eriophorum can be most easily extracted (Fox
& Stroud 1985). Furthermore, despite the pressure
of human densities on the land that resulted
in the creation of 'lazy beds' in the most extraordinary
situations in the highlands and islands of