Black-legged seriema (Chunga burmeisteri): A new unsuspected tree disperser in the Dry Chaco

The study was conducted in the Dry Chaco of central Argentina, assessing the seed dispersal role of Black-legged seriemas (Chunga burmeisteri). We collected 42 faeces of C. burmeisteri and found that all of them contained seeds from at least three woody plant species: algarrobo dulce (Neltuma flexuosa), tintitaco (Strombocarpa torquata) and mistol (Sarcomphalus mistol). We were able to compare the germination rates of seeds found in the faeces of C. burmeisteri with control seeds that did not undergo endozoochory only for N. flexuosa. The percentage of germinated seeds was slightly higher in the seeds that were ingested by C. burmeisteri compared to the control group. This study provides the first evidence of C. burmeisteri ‘s role as a seed disperser for dominant trees in the Dry Chaco forest. The discovery is surprising because C. burmeisteri was previously known only for its predatory behaviour. These findings highlight the need for further research on tree dispersal by vertebrates in the Chaco region, considering that dry forests, like the Chaco, are among the most threatened ecosystems worldwide.