The Greenland White-fronted Goose Anser albifrons flavirostris

The Greenland White-fronted Goose is also experiencing
inter-specific competition, as expanding
numbers of Canada Geese Branta canadensis
from North America colonise west Greenland,
locally displacing the endemic Whitefronts. Wingmoult
has been rarely studied as a critical element
in the life cycle of the Anatidae, yet it is precisely
at this period that competitive interactions between
the two goose species are most apparent
(Jarrett 1999, Kristiansen 2001). The ecological
conditions for breeding White-fronted Geese in
west Greenland are therefore most unlikely to
remain as they are now, and the existing baseline
information will prove invaluable for assessing,
and making predictions about, future population
change.
Having restored the population to more favourable
conservation status of greater numbers and
more stable population trends, the future challenge
is to maintain this status in the face of
greater change and provide solutions to potential
conflict. There is a need to integrate the local
scale with processes at the macro-scale, to assess
local effects and build these into an understanding
of overall population change. In particular,
since we have evidence that there is some winter/summer
segregation, what will be the effects
of changes in the summering areas on the winter
distribution and abundance of the population? To
answer these questions is the challenge for the
immediate future. This will require the use of the
material presented here to develop a forward
strategy for research on this well-described population.
Hopefully, such a synthesis would offer a
useful model for understanding the effects of
complex changes on other migratory bird populations.
Although they are not a major pest to agriculture,
there is, nevertheless, local conflict between these
geese and farming interests in a few wintering
areas, notably in Scotland. Patterns of land-use
rarely stand still, and the changes brought about
in rural land use on the wintering areas in the
last few decades have required that the geese
adapt to major modifications of the habitats they
have exploited over recent periods and over a
longer time span.
Climate change is also likely to be manifest on
the staging and wintering areas. Compared with
20 years ago, we now understand a great deal
more about the biology and ecology of the population
that can assist in developing adequate con-
servation management planning for this singular
race of geese.
In this way, we can offer solutions to some of the
potential conflicts, and provide informed judgements
where predictions would have been impossible
a few years ago. More importantly, we
can use our knowledge and understanding of this
population to make more general inferences about
other species and populations. As our understanding
of the energetics of migration is continually
improved, we can better understand the biological
importance of stopover and wintering sites
used by these migratory birds and the importance
of food quality and quantity, as well as the effects
of disturbance, to the overall fitness of individuals.
As we understand more about how the behaviour
of individuals contributes to their reproductive
output and longevity, so we can make
more informed predictions about how human
activities affect these individuals and scale up to
the potential impacts on the population as a
whole.
The responses of individual organisms are not all
the same, especially in highly social animals such
as Greenland White-fronted Geese, where dominance
hierarchies are well established and extended
familial relationships shape the individual
responses. We need to understand how change
affects foraging and reproductive decisions made
by individuals, and to translate these local-scale
responses through to the impacts at the population
level. Such a process is epitomised by the
recent development of individual-based behaviour
models of the annual cycle of migratory
goose populations (Pettifor et al. 2000). Such models
require detailed information about critical elements
of the annual cycle of the birds, often in
widely differing and remote geographical areas
at different times of the year. So how do we set
about identifying the critical elements and measuring
their effects? Greenland White-fronts are
long distance migrants, flying perhaps 6000 km
in the course of their annual migrations alone, so
the factors affecting their reproduction and survival
(and ultimately their population size) may
be acting in many different ways in different parts
of the globe.
1.4 The flyway concept
By definition, migratory waterbirds have evolved
life history strategies that enable the exploitation
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