Visitors to the Montrose Basin will have noticed that, while the summer birds are still here, our winter visitors have already started to appear. Along with our residential species, these different groups of birds give the perfect opportunity to compare the different types of wings that have evolved with the different lifestyles.
The Barn Swallow and Common Swifts at the Visitor Centre are perfect examples of high-speed wings. Long, slender and angled this wing type produces very little drag allowing the birds to fly quickly with high manoeuvrability. They are perfect for catching insects in mid-flight and have actually been used by the Air Force as a model for their fighter jets wings. However, this type of wing does need constant movement to keep the individual airborne requiring a relatively large amount of energy.
This is in complete contrast to the soaring wings found on our most famous visitors, the pink-footed geese. Generally broad, this wing type allows larger birds to stay airborne, and birds of prey to carry heavy food items in when flight. The slots at the end of the wings, either known as notches or emarginations, depending on the degree of the slope, help provide greater lift and reduce drag when the air is forced between the gaps. While these wings are usually shorter in size, aiding take-off, a number of birds in this group, including swans, have a higher aspect ratio wing structure and need to taxi to get airborne.
Just take a look out the Visitor Centre’s windows and you’ll see a variety of birds that have the elliptical wing shape. Short and round, with a low aspect ratio, these wings allow for fast take-offs, quick sprints, and tight manoeuvrability in confined spaces such as forest and undergrowth. Seen in the blue tits and tree sparrows, it allows for a quick get-away from predators, and is even found in larger birds such a pheasants. Unfortunately for our passerines, their most dangerous predator, the Sparrowhawk, has also evolved the same wing structure allowing it to chase them through areas other predators can’t reach. While the elliptical wing allows for sudden bursts of speed, it is definitely not designed for long distance travel, and produces the characteristic ‘flitting’ from one spot to another.
A fourth wing type, the high aspect ratio wing, is seen on the long distance travellers, like the albatross. This design results in low loading due to the fact that the wings are much longer than they are wide. This wing type not only allows birds like terns to fly slowly, and hover while fishing, but also produces the characteristic soaring and gliding above the waves seen in seagulls, where the lift from the seas and oceans captured by the wings allows them to glide long distances.
Other interesting things going on at the Montrose Basin Visitor Centre this month are our events:
Sunday 9th September, 2pm – 4pm: Our wetland wildlife.
Family guided walk. Join the Ranger to explore the unique habitat at Montrose Basin. Discover the wide variety of birds living in this wetland area. Meet at the Montrose Basin Visitor Centre, normal admission charges apply.
Friday 14th September, 6.30pm – 9.30pm: After dark.
An evening with the Ranger to discover how surveys are carried out after dark using camera traps. Meet at the Montrose Basin Visitor Centre, adult £3, child £2, members free.
Sunday 16th September, 9am – 11.30am: Bird ringing demonstration.
Find out how licensed ringers catch, examine and ring a variety of birds which visit the reserve and how it can help with conservation efforts. Meet at the Montrose Basin Visitor Centre, normal admission charges apply.
Saturday 29th September, 6.30pm – 9.30pm: Creatures of the night.
Join the Ranger for an interesting evening discovering more about the bats and moths at the Montrose Basin Visitor Centre, adult £3, child £2, members free.
Georgina Bowie, Visitor Centre Assistant