Words from a wildlife expert

On my most recent walk on Tresco we saw wildlife from more than one season. The rain of late seems to have rejuvenated the tiny Orange Birdsfoot, with its bright orange flowers, that only a week or so appeared to have finished for the year, but was back in abundance this week.

On the other hand, we found a group of four Common Redshank on the edge of Simpson’s Field. These waders are a regular autumn and winter visitor to the island but this was the first flock I had seen for several months. Other signs of autumn included at least six Grey Herons and two Teal. The lone Shelduck was also on the Great Pool and is at the end of its breeding season, as they leave the islands at this time of year, only returning in late October/early November. Also breeding on Tresco this year was the continental version of Pied Wagtail known as a White Wagtail, so it was nice to see one on the edge of the Great pool that morning. It’s surprising how hard it has been to see these grey and white birds this summer.

It was also an excellent day for dragonflies as we saw three species. Black-tailed skimmers were almost unknown on Scilly until three years ago when a small population was discovered on Tresco. These have increased since then so that it is possible to see them quite easily during June and early July - most often in the areas around the Abbey Pool and eastern end of the Great Pool. Common Darters, our smallest dragonfly, have been present on Scilly for much longer but it’s always nice to see them as they appear each year in July. Other signs of migration included the Migrant Hawker Dragonflies that were chasing prey on the eastern side of the island that afternoon. They are a reasonably common migrant, but there is a suspicion that they may also be breeding on the islands now. Our only damselfly was not to be forgotten, as we did see one of the delicate Blue-tailed Damselflies near the Great Pool.

The westerly breeze created ideal conditions for the Swallows, a lone House Martin and five Swifts chasing insects over the bushes along the edge of the Abbey Pool. The latter only breed on Scilly on Tresco but are a regular spring and early autumn migrant.

As the day warmed up it proved to be an excellent day for butterflies, with Meadow Browns in the more open areas, Speckled Woods in the more sheltered rides, a few Holly Blues, Large and Small Whites, a scattering of Red Admirals and a lone Peacock Butterfly. Comma Butterfly have only recently colonised the islands so to see six on Tresco that afternoon was my best total – so far!

As we move into autumn the diversity of birds and butterflies should increase as more migrants pass through the islands and the late flowering flora should be starting to show.

Will Wagstaff
July 2023