David Beeson, March 2023
Being omnivorous mammals, we can be forgiven for thinking that most animals act in a similar way. But even the slightest thought ensures alternative thinking. Some mammals are fully carnivorous, and some of those feed off decaying meat that would be inaccessible to us without huge risks. Yet, vultures and kites can thrive on that diet. Some whales and whale sharks may feed off the smallest ocean organisms and find enough food to maintain their bodies. The munching mammals, such as deer and cattle, grind their tough plant foods well enough that their gut bacteria and enzymes can eke out enough goodness from doubtful human food. Tapeworms live in oxygen-free conditions within the guts of animals, withstanding the peristaltic waves, stomach acids and gut enzymes.
There is the true story of the American lady (Karen Keegan) who needed a kidney transplant. (I have shortened the story) Her husband was not a suitable match, but what about her children? Now all those were absolutely her offspring, as she had birthed them, and her husband was genetically the father to them all. No mixing up of babies had occurred, yet at least one offspring was proven NOT TO GENETICALLY BE HER CHILD when tested for suitable kidney donors. It took some time for this conundrum to be understood, as you will have thought. It appears that the mother was one of the non-identical twins in the uterus. Non-identical means different genetics. The twin died early in pregnancy and some of her cells were incorporated into the surviving twin, who became a chimera – a mixture of two different individuals. One of the ovaries that developed came from one twin the other from the other. The non-genetic child came from an egg from the dead twin and the other children from her own ovary.
Human chimeras are now well known and, it appears, also that cells can pass across the placenta from mother to child and vice-versa – a further genetic complication.
There are many true accounts of chimeras and I suggest you research the scientific articles available. E.g https://en.wikipedia.org/wiki/Chimera_(genetics). https://www.scientificamerican.com/article/3-human-chimeras-that-already-exist/
The point I’m making is that individual organisms can sometimes be mixtures and that is true for us all. Yes, even you! For within our cells are organelles called mitochondria which are bacteria that have evolved to dwell there and are vital to life. Indeed, we die if we consume sufficient cyanide, but that chemical kills the mitochondria and not our own human metabolism. Mitochondria have their own genetic material (one set, and not the two of humans) and bacterial organelles.
Plant chloroplasts are also invading bacteria that can only live there. Animals and green plants are chimeras, and this ‘living together’ of bacteria and plants and animals is a very different lifestyle.
I find plant parasites interesting and mistletoe is a common plant parasite. Near my home, some deciduous trees appear almost full of leaves over winter being so infested with the evergreen parasite.
Perhaps, mistletoe is best described as a semi-parasite as it uses the host for support, minerals and water and not (as far as I know) for organic food. It is photosynthetic.
There is only one species of mistletoe in the UK but other lands have multiple species, and in South Africa, I encountered an acacia tree with a mistletoe that itself was host to two other different mistletoe species. Almost a plant food chain.
Parasites can generate interesting scenarios. The UK government is attempting to eradicate TB in cattle. One strategy is by killing badgers, that they claim to be carriers of the disease. However, badger researchers do not accept that badgers are the main cause for transmission. Most wild and domestic livestock can carry TB.
Cattle are often moved from farm to farm, and they flow through animal markets. They, like horses, pheasants and sheep, often carry gut parasites. When an animal carries such parasites their immune system is partially shut down by the parasite and, in that situation, the TB test does not work. TB-carrying cattle are being spread from farm to farm. Vaccination against TB is available – use it!
Some time ago TB broke out on one of the UK islands. The badgers there are TB-free. Almost certainly the TB arrived with new cattle that had gut parasites and their TB did not show up on TB-testing. I consider that the UK government is full of non-science people who bow to the hunting / shooting lobby and fail to understand Badger / TB ecology.
Now for something unbelievable …
The Emerald Cockroach Wasp is a beautiful 2cm-long tropical insect. The female seeks out large roaches, and for that, we can all be pleased. Stinging the animal renders it paralysed, and she can then insert her stinger into the animal’s brain and eats off its antennae. The incapacitated cockroach, once the initial sting has worn off is led (like a docile pet) to a burrow. A single egg is then laid and on hatching eats the roach alive.
Bomber Termites are South American insects, and they pack quite a punch. Termites are vegetarian and usually build huge, above-ground, mud structures. They consume tough, cellulose-filled foods and require gut bacteria to release the nutrients. However, inevitably, they are a link in a food chain and need to fight back for the colony to survive. As the Bomber Termite workers become old their jaws wear out and they can no longer harvest suitable foods. They then become colony defenders and can burst open to release highly toxic chemicals (benzoquinones) to kill attackers. Suicidal altruism.
Bagworms are a group of moths, named because their caterpillars build a protective bag of leaves or twigs, not unlike that seen in cased caddis larvae. One European bagworm builds its case of excrement, as does an insect that feeds on my wild betony. The bagworm larvae pupate within their case and the emergent female is wingless. The flying males seek out the females and mate with them still inside this case. She lays her fertilized eggs in the case and dies. Not a lifestyle I would suggest to the ladies reading this!
There is much more about all these organisms on the Internet.
www.nwhwildlife.org is the homepage for 150+ articles on biology, ecology and wildlife.