<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Although the Ferruginous Duck <italic>(Aythya nyroca)</italic> has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).</p></abstract>

Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).

Diurnal feeding strategies of the Ferruginous Duck <italic>(Aythya nyroca)</italic> in Lake Tonga (Northeastern Algeria)

Laboratory of Ecobiology of Aquatic and Littoral Environments

Laboratory of Dynamics and Biodiversity (USTHB), USTHB, FSB

Laboratory Ecology of Terrestrial and Aquatic Systems

Laboratory of Ecobiology of aquatic and littoral environments

Ornis Hungarica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Diurnal feeding strategies of the Ferruginous Duck  in Lake Tonga (Northeastern Algeria)

Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present...

Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

Published Online: Jul 27, 2019

Page range: 85 - 98

Received: Sep 18, 2018

Accepted: Dec 15, 2018

DOI: https://doi.org/10.2478/orhu-2019-0005

Keywords
El-kala, foraging behaviour, near threatened species, energy budget, Anatidae, wildfowl

© 2019 Khalil Draidi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

Published Online: Jul 27, 2019

Page range: 85 - 98

Received: Sep 18, 2018

Accepted: Dec 15, 2018

DOI: https://doi.org/10.2478/orhu-2019-0005

KeywordsEl-kala, foraging behaviour, near threatened species, energy budget, Anatidae, wildfowl

© 2019 Khalil Draidi et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
El-kala, foraging behaviour, near threatened species, energy budget, Anatidae, wildfowl