David Bennett

If it were a blackbird like nearly all other blackbirds, then it would be all black, with a yellow beak. It is leucistic, which means an animal that has whitish fur, plumage, or skin due to a lack of pigment. Its shape and its beak says that it is a blackbird, but it is about ten percent bigger than a blackbird – unless the white areas are throwing of my sense of size. The last time I saw and photographed a leucistic blackbird – not far from here and a smaller bird – I wrote the following:

it is said that the reduction of pigment in leucistic birds causes their feathers to weaken and be more prone to wear. Leucistic birds are usually more conspicuous, which puts them more at risk from predators. There is also evidence that leucistic birds might be less acceptable to potential mates.

Well, yes and no. Being an hereditary deficiency, if the problem were that serious you would have thought that leucistic birds would have died out with no one to carry the defective genes.

A sign by the Giant Redwood (Sequoiadendron giganteum) in CUBG contains the following:

Carbon Offsetting
How many of my international flights could this tree offset?

CUBG has over 1,600 trees in its collection, with this being the largest.

This old Giant Redwood (Sequoiadendron giganteum), planted in the mid 1800s, locks a lot of carbon away in its wood. The amount of above ground carbon stored in a tree is a function of its wood density, height and stem diameter. Each year that a tree grows, it locks away more carbon into its wood. Although we mostly think of trees as carbon sinks, many become a carbon source in the later stages of their life due to decay. This 32 m giant redwood tree has a diameter of 190 cm and a wood density of 0.51 grams per cubic cm. Its above ground biomass has been calculated at 29 tons. It therefore stores 13.6 tons of above ground carbon.

This is equivalent to 49.9 tons of CO – that’s the same amount of CO, emitted by 8 people taking one return flight from London to Sydney in economy class.

It has taken this tree over 150 years to grow to this size and most don’t ever get this big!

It’s plain to see that offsetting flights by simply planting trees is not a sustainable solution to the problem. Nevertheless, tree planting is still beneficial, not only because of the additional CO, taken up by each new tree planted, but also for the biodiversity they are able to support. A single oak tree supports over 284 different insect species.”

Comment

Yes, we must reduce emissions, not least because along with CO and CO2 we are pumping out pollutants that are damaging everyone and everything they touch. But perhaps planting trees is more beneficial than the notice suggests. How about planting one hundred million trees? Eden Projects alone has planted over eight hundred million trees. And they are by no means the only charity planting trees worldwide. That scale of planting changes weather patterns, increases rainfall, stabilises the land. Look at the strip of forest either side of the Panama Canal for the effect of forests on climate.

Saw two foxes today at Cambridge University Botanic Garden. They were just a few feet from people standing watching them. A mallard couple in the stream didn’t seem to feel any need to move as the foxes came to the edge of the water.

One of the foxes had longer fur and was a little bigger than the other, but both were small. Were they are male and a female, perhaps? Young siblings perhaps?

More Chafer Grubs

On another topic, there were lots of fresh divots of grass and soil turned over on the main lawn – more crows after chafer grubs. From the number of divots of disturbed grass and soil, there must be a lot of. chafer grubs.

Cherry Tree

Also at Cambridge University Botanic Garden today, a Yoshino Cherry (Prunus x yedoensis) in bloom. The flowers are white when they are out, but tinged with pink when the buds are closed or just opening.