The owls of north Cambridge: The species hanging on – and the ones that have gone

Nature Notes: Bob Jarman talks about owls seen in the north of the city.

My family moved to Harding Way in Arbury in spring 1956. I can vividly remember my first night there. We had stayed with our Uncle Sam in Haddenham while my parents moved, and he delivered my brother and me to our new home that evening.

Uncle Sam was a tough 5ft 6in’ ex-paratrooper who had been captured by the Germans after the failed Arnhem drop by British Airborne Forces. He had a handlebar moustache.

From that very first night we heard the screech of barn owls from what is now the Carisbrook/Tavistock Road development. At that time it was abandoned allotments and before that a military training range. We once found an unused shell and recklessly tried to detonate it by leaning it against a brick and hitting the detonator with a spade until my father saw what we were doing and called the bomb squad. They sealed off the street.

We used to sink jam jars overnight in the soil up to their lip and often caught slow worms. The grizzled skipper butterfly was common, but is now a county rarity.

Following the development of Carisbrook/Tavistock Road, the barn owls moved out onto the agricultural trials ground of the National Institute of Agricultural Botany (NIAB). There they hunted over the fields and along the Histon Road/Huntingdon Road footpath until the building of Darwin Green. I thought that would be the end of the barn owls. Viable hunting territory had been built on.

I was wrong. The barn owls have simply moved further out again, and a pair now occupies a territory on the farmland closer to Girton. The number of barn owls must have diminished over the past 60+ years, but the species is still there.

When I was working at the NIAB I was told that a brown owl had been caught in protective netting and was being kept in a cardboard box before release. “Probably just a tawny owl” I said “but I’ll take a look”. I opened the box and was astonished! It glowered at me with orange eyes and had prominent feathery ‘ear’ tufts. It was a rare long-eared owl. Long-eared owls are strictly nocturnal. None was seen again.

Little owls had a difficult time. Like the long-eared owl they were occasionally caught in protective nets. One roosted for many years in dense ivy that grew over a redundant pumping station. They settled in a quiet corner of the trials ground for many years until building work disturbed them. Unlike the barn owls, they have not returned.

But more owls were to come. The NIAB sold the land that is now Darwin Green, and it was left fallow for eight years before the builders moved in. In the winter of 2015/2016, the farm director told me he had seen an owl. “Probably a barn owl” I said. “OK” said Mark “but there were four of them.”

Four! An immediate visit confirmed what I now suspected – short-eared owls! Leaving the land fallow had enabled voles and mice to increase and that had attracted four short-eared owls to take up residence over the winter. Short-eared owls are day-time hunters and often associate in groups; in the 1960s up to 25 roosted in fenland between Fulbourn and Teversham. This was unusual – short-eared owls in Cambridge! A few days later a “ring-tail” hen harrier joined the owls.

What of the last species of owls, the tawny owl, in this part of north Cambridge that is being intensively developed for housing? They are a nocturnal woodland species but are heard regularly along Huntingdon Road. These are probably young birds that have dispersed from nest sites in south Cambridge, on the Backs and college gardens, and are looking for a breeding territory. They rarely stay around.

What does this owl story tell us? The Royal Society for the Protection of Birds says we have lost 38 million birds in the UK over the last 60 years due to the loss of their habitats and food sources. Barn owls are hanging on in the northern edge of the city but it is unlikely long-eared, short-eared and little owls will return.