Unintended consequences of good fences

Robert Frost wrote, “He says again, ‘Good fences make good neighbors.’” (Source)

I wonder which fences and which neighbors he really meant. In an early post about Mark and Delia Owens’ experience in Botswana, the impact of fences on the wildebeest migrations were mentioned – a horrific consequence killing 10s of thousands of migrating animals. They either starved to death, died from no water or were caught in fences. All to protect human domesticated animals for food.

Photo source – Anthropocene

Anthropocene Magazine came out recently with a scientific report on the genetic consequences of fences that disrupt and / or end the great migrations of Wildebeest in East Africa. The article was based on the solid science found in this article, Liu, et. al. “Introgression and disruption of migration routes have shaped the genetic integrity of wildebeest populations.” Nature Communications. April 12, 2024. While fences are probably the greatest risk to migrations, roads and railroads are also highly disruptive. Migrations of 100s of thousands of animals hardly exist today, regardless of the nature shows one can see on TV.

Vast wildebeest herds once swept across large swathes of eastern and southern Africa’s savannas. But that annual migration has disappeared in many places. Today the only remaining epic migration route passes from the Masai Mara plains in Kenya south to Tanzania’s Serengeti.

Anthropocene Magazine

Not only have the migrations mostly ended (killed) due to barriers to food and water, the genetic health of the non-migrating animals is being compromised.

The analysis revealed that the DNA of wildebeests that continue to migrate looked different – and healthier – than their non-migrating brethren. They showed more genetic connections between animals living far apart, greater diversity and less inbreeding, the scientists reported last week in Nature Communications.  For the animals that don’t migrate, their genetic shortcomings will likely “lead to lower survival, reduced fertility and other negative effects on fitness,” says Xiaodong Liu, a postdoctoral researcher at the University of Copenhagen who worked on the study.

Anthropocene Magazine

It is not just wildebeest either.

The genetic consequences of isolated populations created by fencing have been illustrated elsewhere, such as South African elephants that lost their tusks over several generations.

Anthropocene Magazine

These consequences are directly caused by human activity. They can also be generalized beyond Africa.

The findings are more evidence of the toll taken by the wildlife-blocking infrastructure we are spreading across the landscape. The lessons could also extend beyond Africa’s wildebeests to other migrating grazers, such as reindeer. “The study shows us that wild animal species, for whom migration is an essential part of their biology, struggle to survive in an increasingly human-dominated world, unless special attention is paid to preserving their old and natural migratory routes,” said Heller.

Anthropocene Magazine

Here’s the rub. Are humans that selfish? Or, do we make decisions for short term gain without fully comprehending both intended and unintended consequences of our plans and actions. Were / are fences the only way to achieve the objective, or were they the easiest, cheapest and most expedient regardless of the consequences to our animal neighbors on this earth?

Surely seems to me, that good fences only make better human neighbors built on the deaths of millions of animals who share our earth – and who knows the unintended consequences of disappearing migrations and genetic health of those highly reduced populations – to the earth, to other animals, including humans?