Mint litter pick

On Saturday 27th April, 7 members of the young church along with parents and helpers, met at The Mint to take part in a litter pick around the city centre. Using council equipment, we collected litter in St Bartholomew’s Cemetery, Cathedral Green, and Northernhay Gardens, before returning to the Mint for some well-earned refreshments. Everyone had fun, and it is certainly something we will consider doing again. Stephen Hardiman

Great Big Green Week Events

The Great Big Green Week (8th-16th June) is a celebration of community action to tackle climate change and protect nature. All over the country thousands of people get involved in locally organised events of various kinds. Exeter events this year:

  • Climate Exhibition from Exeter Science Centre at Killerton. Open daily at 10am. Hands-on exhibits and creative activities on climate change.
  • Medicinal Trees and Shrubs Walk round Streatham Campus. Mon 10th June from 1 to 2.30pm. Led by Dr Anne Stobart, medical herbalist and researcher.
  • Ranger-led themed walks at Killerton. Wed 12th June from 10am-12 noon and 23.30pm; Sat 15th June from 2-3.30pm. 5
  • Sewing the Mossy Carpet at Exeter Phoenix. Friday 14 June from 10am-12.30pm (short visits welcome). Join a participatory creative sewing session with Art and Energy creating the Mossy Carpet.

Knowing Creation, Knowing God :

Knowing the way Poets, artists, philosophers and scientists have long been fascinated by swallows, with their swift but elegant flight and their mud nests stuck under the eaves of houses. But it’s their annual disappearance and reappearance that has most captured “Swallows in flight”. Postcard by A.M. Mailick, 1905. Wikimedia Commons CC PD the imagination. In UK they usually appear in spring, sometimes as early as March, though as Aristotle observed, “One swallow does not a summer make, nor one fine day”.

Aristotle supposed that swallows spend the winter hibernating in holes in trees, while Pliny the Elder suggested they fly to neighbouring countries. These were pretty sensible suggestions compared to some later ones. In 1555 Swedish archbishop Olaus Magnus concluded that swallows hibernate underwater at the bottom of lakes and rivers, a theory repeated by such luminaries as Carl Linnaeus and Samuel Johnson. In the 17th century Charles Morton reasoned swallows migrate to the moon in winter, which while fanciful, did at least introduce the notion of longdistance migration.

It was not until centuries later with the development of bird-ringing in the early 1900s that the mystery of where swallows go in winter was eventually solved. In May 1911 a (not the) John Masefield put a ring round the leg of a swallow in central England, and in December received a letter from South Africa saying the ringed bird had been found in a farmhouse in Natal. So now we know that each spring and autumn some swallows make a 6000-mile trip taking around 30 days; not quite to the moon and back but nonetheless an astonishing feat. Even more astonishing is that around half of swallows each year return to the same nest site. The mystery now is not where swallows go in the winter, but how can they navigate with such accuracy.

Current understanding is that swallows and other migratory birds find their way using a combination of methods. There’s a genetic component; some birds are born to fly in a particular general direction, and if a southwest-migrating bird mates with a southeast-migrating bird, their young will fly in a southerly direction. Birds also navigate using the position of the sun and stars, and they learn landmarks along the route during their first migration.

It has also been known for some time that they utilise earth’s magnetic field, but only recently has it been discovered that there are chemical reactions in birds’ retinas that enable them to “see” the magnetic field. Complex proteins called cryptochromes seem to be involved, but much remains to be discovered. If current theories are correct, it means there are biological sensory systems that can detect stimuli millions of times weaker than previously thought possible. Not only would this revolutionise our understanding of biological sensing; it would generate all sorts of possibilities for new artificial sensors.

Two of the scientists leading this research (Peter Hore at the University of Oxford and Henrik Mouritsen at the University of Oldenburg in Germany) sum it up nicely: “When you next see a small songbird, pause for a moment to consider that it might recently have flown thousands of kilometers, navigating with great skill using a brain weighing no more than a gram. The fact that quantum spin dynamics may have played a crucial part in its journey only compounds the awe and wonder with which we should regard these extraordinary creatures.”

Roger Day