Our series of blogs featuring 70 species to spot at Minsmere continues this week with another common species, albeit one which may be overlooked by many visitors. To do so, though, risks missing out on the chance to spot another popular species, especially during the winter.
Our species of the week is alder, and it's the main food source for siskins. Alders are medium sized trees that are often associated with wetland edges such as riverbanks and reedbed edges or with damp woodland. In fact, the latter is often referred to as alder-carr woodland. In spring and summer, alder's large, dark rounded leaves are quite distinctive, but it's in the winter that these trees are probably most easily identified. The reason is that they are covered in tiny cone-like catkins - a feature that is unique to alder.
Alder catkins by Ian Barthorpe
Alders are easy to locate in some parts of the reserve, such as at the pond (as you can see from the photo above), between South Belt Crossroads and Wildlife Lookout, and between Island Mere and the Rhododendron tunnel.
Being able to identify our common trees is very useful as some birds, insects and fungi are particularly closely associated with only one or two types of plant. In the case of alder, for example, it's the favourite food for siskins. These tiny yellow-green and black finches are perfectly adapted to take advantage of the seeds within the alder cones. Their relatively long slim bill allows them to reach the seeds whereas chaffinches and greenfinches, for example, can't reach into the crevices within the catkin.
Male siskin feeding on alder catkins by Les Cater
Minsmere's alders have certainly been attracting siskins in good numbers over the last few weeks, with flocks of between 50 and 150 birds seen in various areas, but especially near South Belt Crossroads. These flocks may also contain a few goldfinches, or occasionally a lesser redpoll or two, as well as blue tits. The flocks are often first located by the birds' calls, as siskins tend to be quite vocal birds.
You may also sometimes see siskins coming to the feeders outside the visitor centre, or perhaps you are lucky enough to have them visiting your garden. We attracted a small flock to our garden last year. They haven't returned yet, but perhaps they are waiting for the Big Garden Birdwatch over the weekend of Saturday 27 to Monday January before they make an appearance.
A female siskin feeding on peanuts, with a greenfinch for comparison. Photo by Chris Gomersall (rspb-images.com)
While we haven't seen any siskins on the visitor centre feeders yet this winter, they have certainly been attracting large flocks of blue, great, coal and marsh tits, chaffinches and goldfinches, as well occasional visits from a nuthatch or great spotted woodpecker. With so many small birds around, it's perhaps not a surprise that a beautiful male sparrowhawk fancied his chances of a meal this morning. I think he missed, but unfortunately I was too slow to get a picture of him sitting on the handrail of the steps.
There's plenty of other interesting wildlife to spot as you stroll around Minsmere too. The glaucous gull was on the Scrape again this morning, along with a few dunlins, snipe, redshanks and curlews, a pair of tufted ducks, five pintails and large flocks of wigeons, gadwalls, teals, mallards, shovelers and shelducks. A single goosander was at Island Mere, where bearded tits, bitterns and marsh harriers are all regular. An otter was seen from Bittern Hide this morning, and three were in the pools near the North Wall sluice. Stonechats are regular along the dunes, bullfinches in the North Bushes, and green woodpeckers on Whin Hill. Add to that the regular grey squirrels and muntjacs at the visitor centre and many other commoner species, and you're certain to see something interesting if you visit.
Finally, there are a few plants to spot, as well as the alder. Gorse is perhaps the most obvious plant, while winter is a good time to swot up on your tree ID by using bark, buds and seeds as clues. What other plants can you identify in winter? While autumn may be the best time to see fungi, some species are present in winter too, and we recently found a few clumps of yellow brain fungus (Tremella mesenterica), as i the photo below. They certainly brighten up a dull day.