By Steve Westerman, Wharfedale Naturalists’ Society

IN my last Nature Notes I described the activities of oystercatchers, a species of wader that can regularly be seen and heard along the Ilkley section of the River Wharfe.

This month, I thought I would continue the theme and discuss another, smaller wader (length: 19-21cm; wingspan: 32-35cm) that also breeds in the area, but one that is much more difficult to spot – the Sandpiper.

In addition to being rather small, sandpipers are very effectively camouflaged. Their plumage blends in incredibly well with the stony/rocky areas on which they spend much of their time. They have a habit of standing and bobbing their tail feathers up and down.

According to one source, this is called "teetering". Anyway, even with this movement, I still find them difficult to spot. Often the first clue to their presence is their call, a repetitive, rather thin, short "peep".

In flight sandpipers are more obvious, although you’ve still got to be paying attention. They can sometimes be seen flying along the river, usually quite low over the water, but with a slightly erratic motion. Their white wingbars are a good indication (although not foolproof) as to their identity.

As with oystercatchers, when searching for a nest site, sandpipers value quiet, undisturbed areas of the river, usually with stones that shelve to the water, and with a good amount of vegetation.

I think these requirements, coupled with a territorial attitude, mean that there are relatively few nesting pairs around here. It has been suggested that increasing human disturbance may be contributing to a national decline in numbers. Although factors relating to their migration may also be involved.

Early in the season, a pair of sandpipers had, I think, begun nesting along a section of riverbank near Burley weir. One morning I watched as one of the birds was trying, with some vigour, to deter or distract a squirrel.

Unfortunately, the squirrel didn’t seem either deterred or distracted. I couldn’t see the eventual outcome but given that squirrels will occasionally predate birds’ nests and subsequently there was no sign of the sandpipers, I can only guess they had to – or perhaps just preferred to - move elsewhere to try again.

For sandpipers the breeding season can be over relatively quickly. It is not unusual for one of the parents (typically the female) to leave before the chicks have fledged. So, some birds leave the breeding territory in June, with many following in July, and a few who have made a late second attempt at nesting being delayed until early August.