# CSIC: each of four European vulture species and red kite keeps its own bacterial community, 155 birds sampled

- Published: 2026-11-12 04:43 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: vulture microbiome, scavenging birds bacteria, CSIC vultures study, Pyrenees vultures, bearded vulture, griffon vulture, red kite, PNAS microbiome
- URL: https://realtech.media/news/rt-e299586d13b3987daaf6ddc1_csic_each_of/

**A study of 155 wild birds in the Pyrenees found that species, not shared carrion, best explains differences in bacterial communities: 18% of variation versus 9% for body site.**

![CSIC: each of four European vulture species and red kite keeps its own bacterial community, 155 birds sampled](https://realtech.media/media/2026/11/121b7ffbac6751ec.jpg)
*xataka.com*

Researchers from the Pyrenean Institute of Ecology (IPE-CSIC) and the Game Resources Research Institute (IREC) analysed the microbiome of 155 wild birds in the Pyrenees, according to csic.es. The birds belonged to the four European vulture species and the red kite. The results were published in PNAS. The authors report that each species maintains its own bacterial community even when several species feed on the same carcass and are exposed to the same microorganisms [1].

Samples were collected from free-living birds between 2017 and 2022. Most birds were captured in Aragon, the rest in Catalonia and, to a lesser extent, in the Basque Country. The species studied were the bearded vulture (Gypaetus barbatus), griffon vulture (Gyps fulvus), Egyptian vulture (Neophron percnopterus) and cinereous vulture (Aegypius monachus), plus the red kite (Milvus milvus), a raptor that eats carrion but not exclusively [1].

## Species and body site

The team sampled four body sites: the face, mouth, trachea and cloaca. Bacterial DNA from each sample was analysed to identify which bacteria were present in each site and species. Species was the strongest factor in microbiome composition, explaining 18% of the differences between samples, compared with 9% attributed to body site. The two factors interact, so differences between species depend on the anatomical region [1].

Each body site also hosts its own community. In the cloaca, bacteria of the digestive tract predominate, while on the face and in the trachea environmental bacteria and those associated with the respiratory system are more abundant. The red kite shows the same organisation by body site, but with a composition of its own [1].

## Age and open questions

Sampling covered all ages, from nestlings to adults. In the bearded vulture and Egyptian vulture, chicks had less diverse bacterial communities that differed from those of older birds. According to the authors, this indicates the microbiome forms as the animal grows and begins to eat carrion. Sex had little influence [1].

"Mere exposure to a microorganism is not enough for it to become established and persist in the body," said Michael Wink of Heidelberg University [1].

The study identified which bacteria are present in each species and body site, but not what they do. The authors say future work will examine their activity to determine whether the bacteria help digest carrion, neutralise toxins or protect against pathogens. They add that the findings could eventually support health-monitoring tools for these birds [1].

## Sources

1. [csic.es](https://www.csic.es/es/actualidad-del-csic/los-buitres-mantienen-bacterias-propias-de-cada-especie-pesar-de-alimentarse-de-la-misma-carrona)
2. [xataka.com](https://www.xataka.com/ecologia-y-naturaleza/buitres-mantienen-su-interior-bacterias-propias-cada-especie-a-pesar-que-se-alimentan-carrona)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-e299586d13b3987daaf6ddc1_csic_each_of/