Autumn is my favourite season. It is a season of change, and change is good. The last remnants of summer slip away into a cooler atmosphere, with bright, fresh days of red berries, fungi and frost. Whilst some view autumn as a season of death, it really is only a necessary dormancy, as a means to survive the coming winter. The ability of trees to effectively cut off their own supply of nutrients and retreat into themselves is a remarkable feat, and ensures their survival. Their leaves undergo a change that makes them fall to the ground, as they cannot be retained throughout the cold, dark winter months. This carpet of leaves makes a superb habitat for many ground-dwelling animals and insects. The change in the leaves also has the most beautiful visual consequence, as the elimination of chlorophyll reveals the other pigments in the leaves, turning them into different shades of yellow, orange, red and gold.
Something else remarkable that happens at this time of year is the mass migration of millions upon millions of birds. Spring and autumn are the two points of the year when migratory birds are on the move, either to their breeding grounds in the spring, or to their wintering grounds in the autumn. Ospreys are just one example of a bird that moves on for the change of the season.
The reason that birds migrate is essentially based on food, not temperature. Birds whose food source does not decline during the colder months are usually sedentary, and don’t migrate. It is a lot of effort to do so, and there has to be a good reason. A lot of people ask why the Ospreys bother to come back to England when it’s clearly warmer in West Africa, but the truth is it’s not the warmth that they go there for, it is the abundance of food. In the spring, the abundance of food is here at Rutland Water – they know this, and they know they have plenty of time during the long days of summer in which to catch enough fish to feed their families.
Whilst autumn marks the end of some things, such as the breeding season of Ospreys, it also marks the beginning of others. One example is the influx of wildfowl that descends upon Rutland Water for the winter months. Rutland Water Nature Reserve is famous for its wintering population of wildfowl, notably Gadwall and Shoveler, but also Wigeon, Tufted Duck, Teal, Pintail and Goldeneye, as just a few examples.
If you have been down to Shallow Water hide on the Lyndon Reserve recently, you will have noticed a massive movement of Wigeon and Tufted Duck arriving in Manton Bay. These ducks will have travelled many miles from their breeding grounds in Northern Russia. They come together as large flocks on their long journey south, and when on their wintering grounds are highly gregarious and reside together in large numbers.
When studying the migration of our satellite-tagged Osprey, 30(05), we are always struck with awe that such a feat is possible. Even more astonishing is that other birds, much smaller and more delicate than Ospreys, take on similar or even longer migrations than they do. Sand Martins, for example, are also a summer visitor to England, and they winter in a similar area to Ospreys, therefore travelling a similar distance, and they are tiny little birds! At this time of year, Sand Martins and other hirundines are gathering in huge flocks, preparing to migrate together.
The Arctic Tern is a species which holds the record when it comes to long migrations. This bird has an extraordinary migratory habit of travelling from its breeding grounds in the Arctic, all the way to the Antarctic – the shortest distance between the two being 20,000km (12,000 miles). Travelling this phenomenal distance and back again each year means these birds see more daylight than any other creature on Earth.
The art of migration is a humbling thing. We can never hope to equal these incredible animals in their amazing abilities. We can merely observe with awe. Whilst we may try to decipher the technicalities of migration, it is something that we will never ever truly comprehend. That, in a way, makes it even more amazing. Knowing how everything works takes the wonder out of life.
The following quote, taken from the book “Living on the Wind” by Scott Weidensaul, in my opinion, perfectly describes bird migration:
“Propelled by an ancient faith deep within their genes, billions of birds hurdle the globe each season, a grand passage across the heavens that we can only dimly comprehend and are just coming to fully appreciate”.