Since our last post the snowy conditions at Lindisfarne have continued. We have been out and about on the Reserve monitoring birds and there has been a definite decrease of species on site. The numbers of Light-bellied Brent Geese present, for example, have decreased. In partnership with our friends in Denmark, we monitor the entire population of the East Atlantic race of Light-bellied Brent Geese, which is made up of around 7,000 birds.
Light-bellied Brent Geese at Lindisfarne (John Dunn)
It is extremely important not to disturb birds in this severe weather as it is vital that they conserve energy. Walking too close to the tidal areas where ducks, geese and waders feed causes them to take flight, which wastes their energy and causes stress, preventing them from feeding, which can be fatal. In these severe conditions feeding is important to give them the energy to stay warm and not lose weight. It is a struggle to feed when the land is covered in snow and the cold causes die-back of the Eelgrass that the ducks and geese feed on. Please be careful not to cause disturbance when walking on the Reserve and keep dogs on leads to prevent them from going too close to birds. It is also important not to approach birds for photographs. One of the main reasons why Lindisfarne has been designated a National Nature Reserve is to protect its birds, and in this weather their protection is vital.
Snow on the Causeway, Holy Island
An advantage to the frost is that it causes dieback of Pirri-Pirri (the invasive plant species mentioned in previous posts). When Pirri-Pirri gets frost damaged, it breaks apart more easily when livestock trample it, helping to reduce its abundance.
The sheep did a good job of targeting the invasive Michealmass Daisy as well as Pirri-Pirri, both of the island’s non-native species. Creeping Willow is a native species but can become a scrub issue if not controlled, and the sheep also did a good job at grazing it. Through enclosing them within an electric fence, they grazed intensively. The fence-line, enclosing about an acre, was moved around to target the most appropriate areas of the dunes. Because Michealmass Daisy is less widespread than Pirri Pirri, this method had a more significant impact. The below photograph, shows the difference the sheep made to the vegetation compared to the un-grazed on the left.
As well as being able to carefully target specific areas, electric fencing is portable and has minimal impact. The cattle require stronger fencing, but Natural England has chosen the least visually-impinging option possible. When taking the cattle off last week, we brought hurdles onto the island and then took them off – this takes time but is an alternative to a permanent corral, which would detract from the natural landscape of the dunes. We also try to keep signage to a minimum for the same reason.
With this season’s grazing complete, we look forward to May when the dunes are awash with flowering orchids. The blog will be updated with wildflower photos throughout the spring and summer so keep an eye out.