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Today, 26 February 2026, the CJEU has delivered its ruling in Case C-131/24, VIRUS (I). This is a case which considers the deliberate disturbance of wild birds as prohibited by Article 5(d) of the Birds Directive, arising from the construction and operation of a new road in Austria.
The judgment of the CJEU in VIRUS (I) is linked to matters I wrote about in February 2025, following an important Opinion delivered by Advocate General Kokott in Case C-784/23 Voore Mets (Birds, Cats, Buildings, Turbines – the concept of “deliberate” acts of harm under the Birds Directive | LinkedIn). That case related to the deliberate killing of wild birds, prohibited by Article 5(a) of the Birds Directive, and the deliberate destruction of and damage to their nests and eggs, prohibited by Article 5(b).
By way of recap, Article 5 of the Birds Directive provides:
“Without prejudice to Articles 7 and 9, Member States shall take the requisite measures to establish a general system of protection for all species of birds referred to in Article 1, prohibiting in particular.
- deliberate killing or capture by any method;
- deliberate destruction of, or damage to, their nests and eggs or removal of their nests;
- taking their eggs in the wild and keeping these eggs even if empty;
- deliberate disturbance of these birds particularly during the period of breeding and rearing, in so far as disturbance would be significant having regard to the objectives of this Directive; and
- keeping birds of species the hunting and capture of which is prohibited”.
Article 5 protects all wild birds in the EU, including those species that are the most abundant. Paragraphs (a), (b) and (d) of Article 5 of the Birds Directive prohibit ‘deliberate’ acts of harm, which the Court in Voore Mets ruled as including where such harm is a foreseeable outcome of a proposed course of action, even if it is not the aim of the activity or project concerned.
Article 9 provides for a highly restrictive derogation from those prohibitions. Indeed, it appears from the CJEU’s rulings in Voore Mets and VIRUS (I) that it is easier to obtain a derogation to permit harm to strictly protected, vulnerable and rare species of animal under Article 16 of the Habitats Directive than it is to obtain a derogation to permit harm to commonly occurring birds in the wild that are not a conservation concern.
In any event, on 1 August 2025 the CJEU ruled in Voore Mets that the protection of all wild birds by paragraphs (a) and (b) of Article 5 of the Birds Directive is not conditional on or otherwise proportionate to the conservation status of the species of bird concerned.
In this most recent ruling today, 26 February 2026, the CJEU has ruled in Case C-131/24, VIRUS (I), that the protection of all wild birds from disturbance otherwise prohibited by Article 5(d) of the Birds Directive is conditional on the conservation status of the species concerned.
The CJEU’s ruling follows on from the Opinion of the Advocate General Kokott on 18 September 2025 that disturbance of birds prohibited by paragraph (d) is subject to a significance qualifier as regards the conservation status of the species of bird likely to be disturbed: “in so far as disturbance would be significant having regard to the objectives of this Directive”.
The VIRUS (I) case involves a length of new road in Austria that was considered likely, without mitigation, to cause construction and operational noise disturbance impacts on ground-nesting birds (skylark, partridge and quail) and forest-nesting birds (middle-spotted woodpecker) in the vicinity of the proposed road. With mitigation in the form of (a) seasonal limitations, restricting works to certain periods in the year, and (b) enhancement habitat, the preservation and management of 6.6 hectares of old trees in the vicinity, the project was considered likely to disturb individual specimens of the species nearest the source of disturbance, but over the longer term and in the wider vicinity, there was no likely disturbance impact on the species at a population level as a whole.
Experts appointed by the national Court to give their opinion as to the effectiveness of the mitigation could not rule out that individual specimens would be disturbed by construction and operational activities, including noise, in the short to medium term. This gave rise to several questions referred by the national court, to which the CJEU has now replied in today’s ruling.
First, the CJEU has confirmed that it is permissible to take account of the mitigation measures when deciding whether disturbance is likely to occur in breach of Article 5(d) of the Birds Directive.
Second, it is necessary to ensure that the mitigation relied upon is effective, and the Court is entitled to rely on the expert opinion of the Court-appointed experts, provided their opinion and advice is grounded in best available science, is reasoned and justified. Published scientific documentation is not required as evidence of effectiveness as such scientific documentation may not exist.
Third, Article 5(d) prohibits disturbance at a population level. Disturbance of an individual specimen of the species is not prohibited unless the species is so rare or vulnerable that the disturbance of even one or a small number of specimens of the species is sufficient to pose a risk to the population of the species as a whole.
Conclusion
The CJEU’s ruling today in VIRUS I is more pragmatic than the Court’s previous ruling in Voore Mets.
In effect, the conservation status of the bird species likely to be affected by a project will be relevant where there is a risk of disturbance to one or more specimens of the species, but not where there is a risk of killing one or more specimens, or of damage to their nests or destruction of their eggs. With respect to the killing or damage, impact on even one individual is prohibited by Article 5, irrespective of the status of the species of that specimen.
With respect to disturbance, it will only be prohibited where disturbance of one or more specimens would be considered significant having regard to the species’ conservation status at a population level.
This is useful clarification for developers and decision-makers alike.
