The impact of feeding by Chilean flamingos (Phoenicopterus chilensis) on the meiofaunal assemblage of a tidal flat

ABSTRACT

The impact on the meiofaunal assemblage of the bioturbation caused by Chilean Flamingos (Phoenicopterus chilensis) feeding on the tidal flat at Caulín, southern Chile was investigated. The flamingos walk in circles in shallow water, moving their feet up and down in order to suspend the sediment which is then filtered through the lamellae in their beaks in order to capture their prey. Which component of the benthos the flamingos are targeting has yet to be unequivocally determined. Meiofauna are one potential food source as they are extremely abundant at the site and the filtering capacity of the flamingos could potentially retain meiofauna. Two possible hypotheses concerning the impact of flamingo feeding activity on the meiofaunal assemblage were tested: hypothesis 1 that the flamingos are feeding on the meiofaunal assemblage, and hypothesis 2 that the flamingos are displacing the meiofaunal assemblage over short distances. Meiofaunal samples were collected on four occasions (autumn, winter, spring and summer) using a randomized block design to include four levels of bioturbation: centre, ring, border and undisturbed. Meiofaunal abundances increased in sediment processed by the flamingos compared with adjacent unperturbed sediment. The results support hypothesis 2 that the flamingos are displacing the meiofauna and not feeding on them. Thus, the impact of flamingo feeding activity on the meiofaunal assemblage at Caulín is to increase small scale spatial (<1 m) heterogeneity in a background distribution that is already significantly heterogeneous.

RESPONSIBLE EDITOR:

• Haakon Hop

KEYWORDS:

• Bioturbation
• Chile
• flamingos
• meiofauna

Acknowledgements

This research contributed to the undergraduate thesis of Jaen Mayorga. Thanks to Dr Alejandro Buschmann and Dr Patricio Manríquez for their constructive critiques of the first draft of this manuscript. This paper is dedicated to the memory of Dr Sandra Cifuentes (1971–2009).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by Proyecto Interno Formación de Investigadores, Universidad de Los Lagos [grant number FISE07/12].