25th Feb 2021
As we move out of winter and start seeing small signs of spring appearing all around us, it is that time in the year when we start preparing for the biological surveying season. A start was made on this last year but, as with many things, the pandemic put much of what we’d planned on hold.
The first surveying will begin with the arrival of the house martins in March/April. They are incredibly characterful little birds and their constant chatter makes them one of my favourites. They are also extremely agile and graceful in the air and you could while away hours watching them. Often confused with swallows, they have a distinctive white band just above the tail that is not present on the swallow.
They migrate to the UK each spring from southern and western Africa to breed, before returning to Africa for the winter in September/October. I will be keeping records of when the first house martins start to arrive and when they depart. They return to the same nest sites each year, and will use the same nests if they are still intact. This can save them over a week’s worth of work. They build their nests in the corners and eaves of buildings, scooping up mud and mixing it with their saliva to make the nest structure. Here at Abbotsford we had a total of 8 nests that were used last year, located on the main building of Abbotsford overlooking the North and South Court and the Morris Garden. I will be recording how many nests are used this year and how many of the same nests are used as last year. I will also keep a record of how many broods each nest produces, which can be up to three. Over the summer, keep an eye and an ear out for house martin chicks in the nest calling to their parents for food.
Over the summer I will also be carrying out weekly butterfly and bumblebee surveys from the start of April. For each survey, I walk the same transect (survey route) identifying any butterflies or bumblebees I see within 5m to my right and left. Thanks to data collected from a volunteer who carries out surveys of his own on the estate, we have data about our butterfly populations from the last seven years. This is incredibly valuable data and can help us to identify which species may have been in decline over the last decade here at Abbotsford and provides a focus for concentrating our efforts. In my next blog post I will be outlining our plans to develop wildflower areas on the estate and which butterflies we hope to attract with our wildflower planting.