Surveying for risk not ecology

There is an inherent difference between surveys conducted to increase understanding about the behaviour or ecology of a specific species and the surveys conducted to assess risk or compliance.  The difference is subtle but crucial in sustainable development.

© Janet Hastings | Dreamstime.comGetting it wrong (which happens if the objective of the survey/census is not well articulated) can produce results that greatly misrepresent risk.  The two types can be thought of as subject focussed and hazard focussed surveys.

Let me give you a couple of examples.

Survey type 1 – Subject focussed.

Objective:  to test a hypothesis related to kangaroo diet. An appropriate survey design here would be to survey (or census) all the kangaroos in the region of interest.

Survey type 2 – Hazard focussed

Objective: to determine the number of kangaroo collisions during summer on some stretch of road.  Here, a census of kangaroos would use huge resources, and may produce biased results (not all the kangaroos surveyed go near the road in question, let alone get into an altercation with a car).© Dirkr | Dreamstime.com

Here we require a hazard focussed survey frame, i.e. we would survey (or census) the stretch of road(s).

These examples may be trivial, but a confusion between subject and hazard focussed surveys is a real and overlooked issue in many environmental surveys, particularly those involving rare or cryptic species.

The traditional approach in ecology is to undertake behavioural/biological surveys – to determine features of the species, or their interaction with their environment.  These surveys are usually designed to maximise the observer’s likelihood to actually observe the species.  The more individuals observed, the more data you can collect on morphology, behaviour etc etc etc.

However, in sustainable planning we are interested in determining

• The likelihood of an impact (how many critters will be hit by cars, lose their breeding ground, fly into a turbine, etc?)
• The consequence of an impact (this is done through population viability analysis if the population is geographically isolated, or through various harvest rates for species that range further). 

Determining the likelihood of the impact is akin to determining the impact of a new road on local kangaroo population.  We must focus our surveys on the hazard, not the subject.  This involves stepping away from traditional subject based surveys.

If this is not done, than you may have a wonderful data set filled with observations of species behaviour down in that valley over there, but no insight at all into the risk posed by the road up on the ridge here.  Without that insight, management is impossible and compliance is reliant on subjective assessment.