Chafer Grubs

A few days ago I noticed divots of grass and soil turned over on the lawn that fronts to the greenhouses at the Botanic Gardens. I asked and the gardener said it was the work of rooks and crows digging for chafer grubs. I didn’t get an answer yet to my full question, which was that the damage seemed to follow the location of the fairy circles that I saw last year (and the year before that).

Chafer grubs are about 2cm long and are the larvae of the chafer beetle. The grubs feed on the roots of grass plants and then in Spring they surface and emerge as beetles. They swarm and fly into the trees to mate, and then the females come down to lay eggs in the soil. The eggs hatch into grubs and begin feeding. And that completes the cycle.

Gardeners control chafer grubs on lawns by soaking the ground with nematodes. They are microscopic creatures that act as parasites on other insects by releasing bacteria into the host’s body to kill them. The nematode then eats the host.

Shooting and Lead Shot

The animal rights organisation,, Animal Aid, says that around sixty million pheasants and partridges are bred each year in the UK, to be shot. It doesn’t say there are all shot. Some might escape or die before growing old enough to be driven into the air. Or they might escape the guns and live out their lives. Or at least live until the next shooting season.

Wild Justice says that 43 million Pheasants and 9 million Red-legged Partridges are raised and released to be shot.

The Shooting Seasons

The pheasant shooting season runs from the 1st October – 1st February in Great Britain and the partridge shooting season runs from the 1st September – 1st February.

In Northern Ireland the Pheasant Shooting season runs from the 1st October – 31st January and the partridge shooting season runs from the 1st September – 31st January.

Let’s say there are equal numbers shot in Britain and Ireland (probably not) and split the difference and say the season overall runs from 15 September to 31 January – that’s 138 days.

Let’s say that all the birds raised are shot and that an equal number are shot each day during the season – so that’s 430,000 per day. Is that credible?

The Game Shooting Census and Shoot Owner Census is run by GunsOnPegs and Strutt & Parker. For their report in 2018 they surveyed 652 shoot across the UK. From that they extrapolated to the total number of shoots and arrived at 9,000 shoots and 1,724 birds shot per shoot.

That equates to fifteen-and-a-half million birds shot each year during the 138 days of the hunting season.

Lead Shot

Let’s look at the amount of lead shot that is shot into the air. Let’s suppose that every shot bags a bird. It’s unlikely, but let’s go with that.

GunsOnPegs notes the advice of ElyHawk cartridge maker, with the following recommendations.

For November we would recommend the 12 bore Zenith 30g No.6 and the 32g No.5 which are 70 mm (2¾ inch) and have fibre wads. In the Zenith shells the copper coating on the lead reduces the number of deformed pellets and therefore increases the amount of pellets in the pattern. This cartridge has excellent recoil characteristics and keeps things manageable in lighter game guns. 

A pellet of No.6 weighs 1.6 g. So in 30g there are 18 or 19 pellets. Let’s say 18.

A pellet of No.7 weighs 1.28g. So in 32g there are 25 pellets.

Let’s assume that the shooters use 30g No. 6 and 32g No. 7 equally, and split the difference between 18.5 and 25, and say 22.

So with fifteen-and-a-half million birds, that’s 341 million pellets of lead, some of which land up in the pheasants and partridges and a lot of it that ends up on the ground.

And let’s split the difference between 30 and 32g and say that the weight of shot blasted into the air is 31g x 15.500,000, which is 480 metric tons of lead.

According to the Royal Society of Chemistry, lead is widely used for car batteries, pigments, ammunition, cable sheathing, weights for lifting, weight belts for diving, lead crystal glass, radiation protection and in some solders.

And according to the RSC, something less that 60% of lead is obtained from the mineral galena and at least 40% of lead in the UK is recycled from secondary sources such as scrap batteries and pipes.

And according to Statistica, 300,000 metric tons of lead were refined in the UK in 2019. 

Toxicity of Lead

So year on year, 0.16% of the refined lead is spread on the ground by guns. That’s not much as a percentage of all lead refined, but how toxic is 480 metric tons of lead spread out on the ground? 

Does the lead that falls from the guns sit on the ground forever, or is it ground down to dust, or dissolved in groundwater?

When lead comes in contact with moist air it becomes reactive. And especially so when the soil is acidic, as most farmland soil is.

Even a moment’s thought will show the danger, because lead is forbidden to be used in water pipes.

Lead is a cumulative poison. Each year, more lead is blasted from guns to then lie on the ground and be absorbed by birds, animals, and humans,

Lead poisons the neurological system. Children absorb a larger amount of lead per unit body weight and are more susceptible to lead poisoning than adults. The effects include lower IQ, behavioural changes and concentration disorders.

A study this year reported in Medical Express that was published in the Proceedings of the National Academy of Sciences, sampled more than 1.5 million people in 269 U.S. counties and 37 European nations. Researchers found that those who grew up in areas with higher levels of atmospheric lead had less adaptive personalities in adulthood—lower levels of conscientiousness and agreeableness and higher levels of neuroticism.

Osage Orange

Walking along the path in the Botanic Garden that runs more or less parallel to Trumpington Road, we came across dozens and dozens of what looked like yellow-green balls beneath two trees. They looked like versions of yellow tennis balls, only much bigger. The biggest we probably about 20cm (8inches) in diameter.

How hadn’t we seen them before when they were on the trees? How could we have failed to see them?

Mark pulled one apart and we could see they didn’t have a peel or a shell. Rather they were self-contained versions of something like a cauliflower, with the stalks reaching into the middle of the ball, and the surface tightly packed.

Maclura pomifera, commonly known as the Osage orange, horse apple, hedge, or hedge apple tree, is a small deciduous tree with these fruiting bodies. The fruit are inedible to humans and more or less inedible to animals save for black-tailed deer in Texas and fox squirrels in the Midwest. The belief is that they were once the food of a species of animal that is now long extinct.

Their range is in a fairly narrow area of the South West United States.