What's going on with the ash harrier?

Without a doubt, when referring to the ashy harrier (Circus pygargus), we are talking (and we already talked hither), much to our regret, of one of the most threatened birds of prey on a national scale. It is classified in the Red Book of Birds of Spain (2021) as “Vulnerable”, which has led it to be chosen —after several years as a candidate— as the bird of the year 2023, by the Spanish Ornithological Society (SEObirdLife).

This situation has placed this species, the delicate moment it is going through and the uncertainty about its future in the media spotlight. However, he has been working with the ash harrier in the shadows for a long time in a totally altruistic way. In many places in Spain, minimally hopeful results have been obtained.

The reason for this situation is based, among many other reasons, on the radical and rapid transformation that agriculture has undergone, in the case that concerns us, mainly cereals. The intense and increasingly premature heat, the lack of rainfall and the consequent advance of the harvests form a deadly cocktail for our protagonist.

At this point, it is logical to wonder how this affects our previously mentioned ash harrier. Well, we have to know that both the ashen harrier and its counterparts (the pale harrier and, to a lesser extent, the lagoon harrier) nest in the ground, thus taking advantage of the vegetation cover provided by the cultivated fields. The problem, as we have mentioned before, is that these habitats are increasingly decimated by the lack of water, since it rains less and cereal growth is reduced, so it has to be used sooner.

All of this entails several problems:

The harriers don't have enough time to carry out their cock, so these chickens face the risk of being fatally hit by the harvesters.

In the event that this did not happen, the lack of crop cover makes it impossible for chickens to have a stable shade in which to rest and avoid the increasingly extreme heat that occurs during the months of June and July. A large part of them, unfortunately, perish. This cause, without going any further, occurred last year, which was summed up in a lethal combination: scarce rainfall, little vegetation cover and constant heat waves.

This lack of vegetation cover also causes predation problems. The nests are very exposed and are excessively accessible to mammals, including the most common the fox, as well as other opportunistic predators such as other raptors, some mosquitoes or corvids.

To try to counteract all this, many groups and associations, mainly made up of volunteers, work against the clock every summer. Their goal is to save and bring out as many chickens as possible. In a very brief way, this work can be outlined in different phases.

First, the nests have to be located, one of the jobs that requires the most time and effort in the field. Once the breeding areas are located, it is necessary to contact the farmers or owners of the plots where they are located. During this phase, numerous factors will be evaluated, the date of the harvest being the crucial one, and the one that will mark the future of the subsequent work. Because of the early harvest, many of the nests would be left to their fate if no intervention were taken. It is a matter of reaching an agreement with the farmer, either delaying the harvest, or protecting the nest in some way (leaving a stand unharvested, fencing off the nest, etc.), with the mission of avoiding or, at least, reducing the likelihood of predation, and allowing the harvester to visualize and position the nest when carrying out the harvest.

In short, the role of farmers and rural people is key and essential. Fortunately, there is increasing awareness and awareness of the issue at the social level, and, although the truth is that there is still a lot of work to be done, let's hope that in a few years the critical situation of our ashen harrier will be a mere anecdote, which has helped us to learn and realize the capacity for influence that we have as a human being in the environment that surrounds us.

Alfonso Guío, Biodiversity