September, the month of Paseriformes

The month of September is subject to constant change, variations that are reflected in our field trips. Autumn is beginning to break through, and most of the migratory birds, well into the month of August, have begun to move to their wintering quarters. Many of the summer birds of prey that come to the peninsula in order to reproduce—such as bumblebees, ashy harriers, alcotans, kestrels, black kites, booted eagles and snake eagles—or other birds belonging to different groups —such as black and white storks, nightclubs, carracas, bumblebees, etc .— are already starring in the great spectacle of migration to the peninsular south. That's why we say September, the month of passerines.

However, while we say goodbye to all these species, we welcome others that either arrive in our territory during their journey, since they must necessarily cross it to reach their destination, or come to spend the winter in a sedentary way. These are species that are called “wintering birds”, made up of a large number of groups, such as Nearctic waders, gulls, anatids, some raptors, or some passerines, among others.

This time, we will delve into the latter, the passerines, since they are the soundtrack of our field days. In addition, this season is precisely the ideal time for some of them.

Let's start with the omnipresent flycatchers, differentiating two species: the gray flycatcher and the cerrojillo flycatcher.

They are two very grateful and visible species, since they flood the boundaries and fences of the plots that limit the tracks on which we travel, as well as undergrowth areas, oaks, urban parks, etc.

We continue with another of the flag species, in this case, the very showy and elegant royal red coloris, a species that can be observed throughout the month of September, with a little luck, in practically all the natural habitats in which we move during our field days.

Another species worth noting, although it is a little more difficult to detect due to its somewhat nervous and fleeting behavior among the vegetation, is one of the commonly called mosquito nets, in this case, the musical mosquito net, which is especially abundant feeding on the borders of farmland during this autumn season.

In addition, we are going to highlight three species that are also very grateful, since they use terminal, tall and colorful roosters, thus making it easier for us to detect them. The first is the northern tarabilla, with that characteristic white “eyebrow”. This bird reproduces in some areas of the north of the peninsular, showing up in the rest during the spring season and, above all, the autumn season.

The gray collalba, however, reproduces throughout practically our entire territory, but it is during the month of August and September when it carries out its dispersive migratory movements, and we receive individuals from Northern Europe as they pass to the south.

Finally, it is also worth mentioning the common shrike, a summer passerine that we can find in wooded and, above all, shrub masses, which stands out in a very peculiar way. During the month of August, there is an explosion of this species, juveniles come out of the nests and there are field days when you find dozens and dozens constantly demanding food from their parents. During the month of September, their migratory movements begin, and the trickle of specimens is not as exaggerated as in the month of August, although we can still see them here, preparing for their long journey to sub-Saharan Africa.

In short, the world of passerines is very wide. We could spend a lot of time talking about these small protagonists of some of our fieldwork, not to mention many other species such as airplanes, swallows, swifts, whales, blackbirds or washerwomen, but the intention is to introduce a little more to some of the characteristic species in this autumnal passage to their wintering grounds.

Alfonso Guío, Biodiversity