Flying like a Starling on Prozac
Footprints in the snow indicated there had been more people this way than I had expected. In the cold dampness I imagined none had stopped by the flock of grazing sheep. The Jackdaws drew my attention. Walking on straight mechanical legs they had a superiority lacking amongst the Starlings. Smaller and out numbered, 8 to 14, they scurried between the clumps of grass.
They moved slowly east to west across the field. Quarrelsome, none of them wanted to be last and ran to be ahead of the group. First to whatever tasty treat lurked out there. Occasionally, they would fly up a short distance, wheel round and feed somewhere new. At these times it was a loose flock each bird provided with space. They would land and begin to run in a new direction.
A hungry kestrel flew down the lee of a hedge. It was not seen too late by the Starlings. Flying up in a tight group they stayed above the falcon. Tight turns as each bird moved in relation to its neighbour. No bird taking the lead they glided down when they felt the danger had gone.
There are two groups that should cause concern. Home grown birds that find it hard to find a house which has not been improved with plastic fascia boards. These in effect say don’t nest here, above gardens from which leather jackets, larvae of Daddy-long Legs Craneflies, are removed by lawn treatments. The second group being those from Eastern Europe arriving in huge numbers and forming evening spectacles above their reedbed roosts.
Like with many migrant insect feeding birds there is a widening gap between the day-length that triggers a bird to migrate and the local temperatures when it gets to its nesting sites. Here for many the insect larvae are already bigger than what they would normally feed newly hatch chicks. Whilst there is optimism that birds can adapt, up to a point. They face other environmental stressors.
Just outside my patch is a a water treatment works. Whilst I have not found Siberian Chiffchaff which seem to drip from these premises in the South, Starlings do find this place really attractive feeding. Unfortunately, water treatment works are not designed to filter out medically prescribed drugs. Once they have been around your body they go through your kidneys and via your bladder and on via a toilet to a water treatment works. Any invertebrates living in this soil are bathed in a medical cocktail. Hungry Starlings are not picky eaters. Remember the ones earlier who have just been feeding around sheep droppings containing breakdown products of veterinary drugs.
Researchers at University of York have shown that worms growing in these environments have high levels of fluoxetine; Prosac to you and me. This chemical was shown to have an impact on feeding behaviour. Rather than having a large meal early after the roost eat to meet their energy requirements during the day and a big meal before going to roost they snack all day, but don’t start feeding as early and finish a long time before going to roost. So in winter they do not meet there energy requirements. This will impact on their winter survival.
After a while my eight Starlings took flight; purposeful, heading West. I would love to think that I saw them again down at the roost at Blaydon, but I will never know. At 4.15 small groups flew in tight balls of a few hundred that circled around the lake and pulled in others like iron filings to a magnet. This aggregation pulled out towards the rugby ground and disappeared from sight. Looking back at the lake new groups were arriving swirling and riding high in the air as Sparrowhawk flapped and glided into this open space. Individuals were lost as specks of dust amongst a growing storm.
The groups merged, coalesced and poured down into the reeds like smoke being drawn into a bottle. They performed this all in silence; as though they had never been there at all.
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