Birds: why you should not approach nests

Reducing as much as possible the impact of humans on nature is one of our priorities when we are in the field. Observing wildlife in its natural environment is compatible with ethical behavior, responsible and respectful of the environment. All you need to do is follow a few basic rules when going out into the countryside.

Bird protection takes precedence over observation

In the mountains, by the sea, in the plains or in the forest, whatever the natural environment, it is imperative to keep in mind not to approach a nest or an aerie (name given to the nests of birds of prey) within several tens of meters (or even several hundred meters for some species). Observing a nesting site too closely can cause real disturbance to birds. This is why it is necessary to adapt our behavior to the tranquility of the place and systematically prefer the protection of individuals to the quality of the photos, for example.

Preserve nesting and the environment

There are two aspects to staying away from nests. The first concerns reproduction (read the paragraph below). Any disturbance or disturbance that would occur around a nest during the nesting period is likely to cause its abandonment by its occupants and consequently the failure of a reproduction attempt.

The other aspect concerns the direct environment of the habitat. During observation periods, care must be taken not to leave traces of its passage - do not modify the vegetation, for example - so as not to lead predators to the nest, or that the latter is exposed to the elements. In practice, these precautions are difficult to follow in a completely natural environment, but in a natural environment "managed" by humans, it is preferable to take the paths provided for this purpose.

Slow reproduction

In order to better understand why it is essential not to disturb birds, let us dwell for a moment on their reproduction process, and in particular that of raptors. This is particularly slow, with most species only giving birth to one individual per year. Add to this a late sexual maturity that only occurs at the age of 4 to 6 years for large raptors. The disturbance can thus be all the more important for so-called "specialist" species (which can only thrive under certain environmental or feeding conditions), such as the Bearded Vulture. This bird does not reach sexual maturity until between 5 and 8 years old.

Leaving the nesting site

The observer should always pay attention to the behavior of the birds. If the subject is in an alert position (which can result in freezing or hiding, read below) then it is time to freeze or gently retreat. Note that even outside the breeding season, any disturbance can impact the general behavior of the animal (including the way it feeds) and that in the event of involuntary disturbance, the walker must completely leave the area and do not come back the same day.

Warning distance and escape distance

Certain benchmarks make it possible to establish the degree of disturbance that can be caused during a trip in the field. First, there is the alert distance which corresponds to the moment when the bird ceases its activity to observe the source of disturbance and / or it will itself give the alert to its fellows. Then there is take off or escape distance, or the number of meters separating the disturbing element from the bird when it flees. Both vary depending on the species. The Golden Eagle, for example, is particularly fierce: its alert distance is around 400 meters and its escape distance is 225 meters. Conversely, nightjar, whose general hue allows it to go unnoticed, has a reduced flight distance of around ten meters. Cited in a number of environmental studies, the work of M. Ruddock and D.P. Whitfield (published in 2007) identified the warning and flight distances for 25 species of birds. Their study constitutes an international reference in the matter, used as well by the public authorities as by the keen observers. 

The 5 rules to follow

The ideal is to find out beforehand about the most favorable observation periods depending on the species studied or the site you are visiting. But whatever the subject, place or conditions, simple and inescapable rules must be respected while keeping as an absolute priority the protection of birds and their natural environment. Here are the main ones:

1. First of all, as developed above, never disturb the bird in its activities and do not approach the nests.

2. In the event of involuntary proximity to a nest, remember to step back without looking at the animal, take some distance and not come back for several weeks to allow the individuals to finish nesting.

3. Adopt slow movements and be as discreet and silent as possible.

4. When it comes to equipment, opt for neutral-colored clothing, if possible cut from materials that avoid friction noises. Also, bring a good pair of binoculars to keep your distance, as well as a notebook and pencil to record your observations.

5. In the case of the observation of rare specimens, choose wisely the interlocutor with whom you will share the information.

The best is still to rely on experienced guides who are familiar with the terrain and the actions to adopt depending on the species observed!

Boris Toulayrou

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References:  

• observatoire-rapaces.lpo.fr 

• ornitho79.org 

• European science foundation (eurapmon.net) 

• bet-barussaud.fr (bureau d’étude environnemental)  

• linternaute.com