INVASION OF THE CROCODILES - Rethinking Invasion Ecologies from the Environmental Humanities - page 246

far must a species move, or across what 'natural' ecological barriers, to qualify as
an illegitimate inhabitant of its new environment? I have shown that there is no
scientific basis for defining (or stigmatising) crocodiles as invasive alien species in
northern Australia. However, we should not discount the deep attachments
humans make to places, understood as spaces invested with human sentiment,
cultural associations and memories. According to David Strohmeier, Aldo
Leopold, the great American conservationist, died defending a stand of trees on
his smallholding from fire. Leopold well knew that the trees would regenerate
from this fire, but not in his lifetime (Strohmeier, 2005: 103). We get upset about
changes to what we know, and what we believe should exist in a place, and what
we know is framed within the limits of a human lifespan. If the rivers of our youth
were devoid of crocodiles (after they were shot out), then their return may effect
a very significant and unwelcome change to the reaches and pools we were
accustomed to swim in.
Ecology has taught us, however, to be wary of shifting baselines. We should not
judge what the so-called 'natural' state of any space is, based on how it appeared
when first encountered. We should not judge deviation from that state to be
degradation, or a corruption of the 'natural'. A hard lesson for environmentalists
to learn from the 1980s was how to assess environmental degradation, if according
to developments in ecological theory there is seldom a stable 'natural' baseline to
measure against (Worster, 1994). This is due to 'natural' fluctuations as well as
human interventions, which we increasingly discover were much more widespread
and profound before European explorers and settlers arrived to describe the world
than was previously recognised.
The displacing of the cyclical time of systems ecology has favoured a return to
a historical conception of time in ecology, where irregular natural disturbances
and periodicities of natural variation regain their importance. This implies it is
necessary to investigate the environmental history of an ecosystem (a place, not a
generic space or system) in order to manage it sensibly. Not to discover some
past pre-human (or pre-European) baseline or 'natural state', but rather to recon-
struct histories of major events and shifts, and to help establish what Szabó rightly
emphasises: 'historical range of variability' (Szabó, 2010: 383).
The BBC documentary's assertion that crocodiles are being found 'often in
places where crocs were previously unknown' is vague as to how long crocs were
unknown to inhabit such places (in recent human memory, or a couple of
generations' memory, for instance?). Given the longevity of crocodiles' habitation
of Australia, it is unlikely that crocodilians have not lived previously in these areas.
There were probably crocodiles there before the escalation in hunting in the 1950s.
Interestingly, a letter writer to Melbourne's The Argus newspaper in 1875 argued
that crocodiles were commonly found as far west as the Dampier Archipelago (west
of what is currently regarded as their 'natural' range), and confirmed that (as today)
they were found as far east as the Fitzroy River at Rockhampton ('Australia Felix',
Anon, 1875). Even if crocodiles were not found previously in areas they are now
inhabiting, then they almost certainly were living in these places over their longer