Birds are disappearing from the skies of France. Their numbers have dropped by 33% in the space of 15 years. That decline reflects observations made in other countries across Europe.
At first blush, the reasons given for the frightening decline in bird numbers seems quite reasonable. Both the spread of mono-culture and pesticide use are hammering insect numbers, and since many birds eat insects, then obviously those birds are losing their food sources. And well, of course, they’re dying.
But there’s a glitch in that explanation.
When studies found that insect numbers were falling off the cliff (75% loss), the same conclusions as above were put forward as reasons for the losses. In light of the fact that insect numbers weren’t just dropping in areas of farmland or in areas where pesticides were being used, climate change got kind of thrown in as an afterthought
When broad environmental factors are such that plant growth is accelerated, then the accelerated growth means plants contain more starch than they do protein. And studies have shown that to result in malnutrition, compromised immunity, starvation and death for organisms on the next step of the food chain. In the case of terrestrial life as opposed to submarine life, we’re talking insects.
Two broad environmental factors have been looked at in relation to accelerated plant growth and poorer nutritional value. In one study, extra light was provided to a marine environment to increase plankton growth. It worked. But the zoo-plankton that fed on the phyto-plankton tanked. And the reason it tanked was that although its food source had become abundant, it had also become crap – the zoo-plankton simply couldn’t consume enough of the nutritionally compromised phyto plankton to remain healthy.
And when parallel studies were carried out on land, but this time providing extra CO2 to the environment instead of light, the results were the same. Fantastic growth rates and junk food.
For those who are interested, all the links to studies and articles relating to what you’ve just read are in the original article I’ve linked to above.
But my question is this.
Given that these studies and their results are known, then why, when faced with evidence of rapidly declining populations of species at the lower levels of the food chain, do we tell ourselves somewhat comforting tales about pesticides and mono-cultures ? We know full well that atmospheric CO2 levels are through the roof, and we also know how that affects flora, and by extension, fauna.
I’ll leave you to decide why it might be we’d want to point the finger at secondary causes for life dying away while assiduously ignoring the likely principal cause.