A post revisited — BMAD

A post revisited — BMAD

Humans are fickle creatures. Yet, as David Hume, the Scottish philosopher, figured out over 250 years ago, we are driven by our passions far more than reason. It can take an unearthly level of persuasion to alter a passionately held view even if there is irrefutable evidence. And many a time the view prevails.

This story about conservation in the face of scientific evidence makes the same point…


It is often said that the end cannot justify the means. This adage comes for the logic that an immoral act is an immoral act irrespective of when it occurs or for what reason.

The other day I witnessed an argument that left me thinking how this is adage is rarely applied.

The discussion began over a conservation problem that is becoming widespread in the eucalyptus forests of eastern Australia. Mature canopy trees are dying from infestations of sap sucking insects that proliferate to reach huge numbers sufficient to defoliate the tree. This explosion of insects and damage to leaves happens where a bird species, the bell miner, is abundant.

Rather than eat the insects, bell miners eat the sugary lurps that the scale insects use to protect themselves – it is a little like harvesting, for the insects regrow the lurp that covers them and the birds come round again.

Bell miners are aggressive birds and chase away other species. This lowers the predation rate on the insects that, over time, means more insects. The insects feed on the leaves that eventually succumb. When the trees lose too many leaves they die back. The process has been given an acronym BMAD; bell miner associated dieback.

Bell miners do well in disturbed forests because they like the dense undergrowth that comes when a forest is altered by fire, logging or other human interference.

Once established the best way to slow the spread of BMAD is active management involving the removal of shrubs. This means suppression through mechanical means, sometimes fire or, more usually, the application of herbicides.

These are drastic interventions of the kind that the conservation movement opposes with religious fervor. Only BMAD is far worse. So even among the ardent conservationists it has been accepted that intervention to remove shrubs is necessary. It is acceptable to manage with interventions of herbicide a habitat that was disturbed.

All good so far. The argument came of over the next issue.

Someone made the comment that ecologically endangered communities could be managed for improvement.

‘No, no, no you cannot do that’ was the indignant cry. ‘You cannot mess with an EEC, you just can’t.’

It was seen as a morally abhorrent suggestion. If something is designated as endangered it is suddenly untouchable.

But why not actively manage? Is it not exactly the same as the intervention proposed to tackle BMAD. In that thorny issue the end justified the means. But the same means cannot be applied to an EEC.

So in the real everyday world we have selective morality.


Let’s just rephrase this outcome.

A Threatened Ecological Community is determined as such by a Scientific Committee that sits in a room in a city and decides a given vegetation type is rare enough and its integrity and longevity threatened enough to meet a set of listing criteria. The committee members review evidence and decide if there is sufficient threat to list the vegetation on a list of habitat types at risk of extinction.

This appraisal confers some protection where the habitat type exists in the landscape. More critically it confers that protected status in the mind of the conservation manager who could contemplate active management for lurp control but not in a habitat that the evidence said was threatened with extinction. That had to be left to be as it is, even if the habitat was degrading and on it’s way out.

No amount of evidence could shift this view. Ironic given the process of listing is supposed to be science based and objective.

Selective morality is not exclusive to environmentalists but they are very good at it. In a way they have to be because there are few options in a world built and driven by profit. They are forced into leaving alone habitat that will degrade in the absence of active management because management is associated with negative outcomes.

Their passion for protection drives them far harder than any amount of reason.

David Hume’s ghost cannot resist a chuckle

Cubitermes sankurensis

Cubitermes sankurensis

Peer reviewed paper series

Dangerfield, J. M. (1990). The distribution and abundance of Cubitermes sankurensis (Wassmann) (Isoptera; Termitidae) within a Miombo woodland site in Zimbabwe. African Journal of Ecology, 28(1), 15–20.


Early in 1987 all efforts to finish my doctoral thesis seemed fruitless. The data were in and the structure agreed with an array of supervisors delivering comments and instructions all taken on board. I recall that the first few chapters were written and re-written any number of times before they were deemed satisfactory. The process was rigorous and arduous as each chapter was given painful birth. I was over it.

A choice was needed to fight or flee the adversity. Such moments happen to everyone at points in their lives. I don’t recall the exact day but the decision happened to cease prevarication, lose the perfectionism excuses, and push the thing over the line. It worked. Within a couple of months my thesis was submitted for approval and for the first time I realised what can be done when the brain actually pays true attention to a task.

Much later I also found out that you couldn’t force this focus. It comes on its own when it’s good and ready. Uncannily, but only if you let it, focus arrives in plenty of time to meet deadlines.

The problem with the burst of energy on my thesis was that I finished it. Now it was time to find something to do with all the education.

NHM South Kensington

The Natural History Museum in South Kensington is a true wonder. It has some startling public galleries with homages to the Victorians who established and built its edifices and its reputation. You can feel very small standing beneath the blue whale skeleton and minuscule in front of the marble statue of Charles Darwin.

What the public don’t see and very few visitors will know is that the building also houses biological specimens from every corner of the globe. These vast collections are all immaculately curated and stored in thousands of drawers and jars in rooms that smell of naphthalene. This wealth of biodiversity is the raw material for systematics, the branch of biology that deals with classification and nomenclature.

Among these many specimens are termites.

For a week in the late summer of that thesis year my eyes were glued to a microscope trying to find the teeth on the left mandible of major soldiers. Thanks to an uncanny alignment of the stars my immediate future was to be as a postdoctoral researcher at the University of Zimbabwe, the opportunity of a lifetime. And what else could a soil ecologist study in Africa than termites. They have, after all, eaten the continents architectural heritage and ruined any number of crops.

So here in the corridors that the public don’t see, I was doing my homework, cramming for a taxonomy test like no other and, thankfully, meeting some taxonomists who would be a huge help when it mattered.

My focus was the fungus growing species, the Macrotermes, whose soldiers have mandibles big enough to be sutures on wounds and whose workers build mounds literally the size of a house. So it was inevitable that the first research was on the soil feeding species Cubitermes sankurensis that was not on my homework list and builds soccer ball sized homes.

‘The distribution and abundance of Cubitermes sankurensis (Wassmann) (Isoptera; Termitidae) within a Miombo woodland site in Zimbabwe’ is not the most erudite contribution to ecological science ever made. In fact, it is a huge surprise that it was published at all.

A few mounds were mapped and the number of termites estimated by correlating mound dimension with the number of termites counted in soil cores taken from a sample of mounds. Around 1,000 termites per square meter, the numbers said but what this actually meant it was hard to say. There was no evidence at all really.

It is hard to know how many peer-reviewed papers are like this one. Nothing obviously wrong and yet little, if any, knowledge gained.

There were plenty more termite mounds to measure and later work produced more useful information than no obvious pattern between vegetation structure and the distribution of termite mounds.


By the way, for those sharp-eyed naturalists the header image is, of course, not Cubitermes but a species of Odontotermes, a fungus growing genus, that needs the wide vents to keep the fungus garden moist.