Foraging Behaviour and Population Status of the White-Breasted Cormorant (Phalacrocorax Lucidus) in Lake Hora- Arsedi, Bishoftu, Ethiopia
The present study was conducted at Lake Hora-Arsedi located in Bishoftu town, 47 km south of Addis Ababa. The aim was to investigate the dive duration, pause duration, perching height, foraging band and population status of the white-breasted cormorant (Phalacrocorax lucidus) in the study area. Two sites were selected to carry out the observations. Data were collected from January–December 2014 to include dry and wet seasons mainly based on direct observational methods. Focal observations were carried out on randomly selected foraging cormorants within the two systematically oriented observation sites. A single individual was observed for 20 minutes. Total population count was made at two roosting sites along the shoreline following roost count technique. Roost count was made 15 times at each season. The total number of population during wet and dry seasons was 23 ± 0 .4125 and 33 ± 0.43498. The mean dive duration at site 1 during the dry season was 22.32 ± 0.84 and 30.3 ± 0.75 seconds during the wet season. The mean dive duration at site 2 during the dry season was 25.76 ± 0.68 seconds and it was 39.25 ± 0.96 during the wet season. The mean dive duration at both sites showed significant variation between seasons (P<0.05). Dive duration and pause duration were significantly positively correlated in both sites during both seasons. Dive efficiency ranged from 1.67 to 2.26. Mean perching height ranged from 1.8 ± 0.15 to 2.3 ± 0.25 and the variation was not significant. Mean foraging band ranged from 11.56 ± 0.91 to 22 ± 1.2 m and the variation was significant between sites of the same season (P<0.05) but was insignificant between seasons of the same site (P>0.05).
Baudinette, R.V. and Gill, P. (1985). The energetics of ﬂying and paddling in water: locomotion in penguins and ducks. J. Comp. Physiol. 155: 373–380.
Bernstein, N.P. and Maxson, S.J. (1982). Absence of wing-spreading behaviour in the Atlantic blue-eyed shag (Phalacrocorax atriceps bransfieldensis). Auk 99: 588–589.
Betre Alemu (2000). Rehabilitation of Hora-Arsedi catchment. Debre Zeit Agricultural Research Centre, Debre Zeit, Final report.
BirdLife International (2008). "Phalacrocorax carbo". IUCN Red List of Threatened Species. Version 2009.1. Accessed July 09, 2009 at http://www.iucnredlist.org/details/144638/0.
Blackwell, B.F. and Krohn, W.B. (1997). Spring foraging distribution and habitat selection by double-crested cormorants on the Penobscot River, Maine, USA. Colon. Waterbird. 20: 66–76.
Boldreghini, P., Santolini, R., Volponi, S., Casini, L., Montanari, F.L. and Tinarelli, R. (1997). Variation in the use of foraging areas by a cormorant Phalacrocorax carbo wintering population: a case study in the Po delta. Ekol. Pol. 45: 197– 200.
Carbone, C. and Houston, A.I. (1994). Patterns in the diving behaviour of the pochard (Aythya ferina): a test of an optimality model. Anim. Behav. 48: 457–465.
Casaux, R. (2004). Diving patterns in the Antarctic shag. Waterbirds 27: 382–387.
Cooper, J. (1986). Diving patterns of cormorants (Phalacrocoracidae). Ibis 128: 562–569.
Debout, G., Røv, N. and Sellers, R.M. (1995). Status and population development of cormorants (Phalacrocorax carbo carbo) breeding on the Atlantic coast of Europe. Ardea 83: 47–59.
Dewar, J.M. (1924). The Bird as a Diver. Witherby, London.
Gremillet, D., Argentin, G., Schulte, B. and Culik, B.M. (1998). Flexible foraging techniques in breeding cormorants (Phalacrocorax carbo) and shags (Phalacrocorax aristotelis): benthic or pelagic feeding? Ibis 140: 113–119.
Hatch, J., Brown, K., Hogan, G. and Morris, R. (2000). Great cormorant (Phalacrocorax carbo). BNAO 553: 1–20.
Hoffman, W., Heinemann, D. and Wiens, J.A. (1981). The ecology of seabird feeding flocks in Alaska. Auk 98: 437–456.
Johnsgard, P.A. (1993). Cormorants, Darters, and Pelicans of the World. Smithsonian Institution Press, Washington.
Kooyman, G.L. (1989). Diverse Divers. Springer-Verlag, Berlin.
MacArthur, R.H. and Pianka, E.R. (1966). On optimal use of a patchy environment. Am. Nat. 199: 603– 609.
Mesele Yihune and Afework Bekele (2010). Diet and activities of pied kingfisher (Ceryle rudis) in Lake Hora-Arsedi, Debre zeit. Ethiop. J. Biol. Sci. 9(2): 117–125.
Mohr, P.A. (1961). The geology, structure and origin of the Bishoftu explosion craters, Shoa, Ethiopia. Bull. Geophys. Obs. Eth. 2: 65–101.
Owre, O.T. (1967). Adaptations for locomotion and feeding in the Anhinga and the double-crested cormorant. Assoc. Field Ornithol. 41: 165–167.
Rippey, B. and Wood, R.B. (1985). Trend in major ion composition of five Bishoftu crater lakes. SINET: Ethiop. J. Sci. 8: 9–29.
Santoul, F., Segura, G. and Mastrorillo, S. (2004). Environmental determinants of great cormorant (Phalacrocorax carbo) distribution in small man-made waterbodies – a case study of gravel pits in southwest France. Hydrobiologia 528: 179–186.
Schmid, D., Gremillet, D.J.H. and Culik, B.M. (1995). Energetics of underwater swimming in the great cormorant (Phalacrocorax carbo sinensis). Mar. Biol. 123: 875–881.
Smith, R.L. and Smith, T.M. (2003). Elements of Ecology. Cummings, San Francisco.
Sutherland, W.J. (1996). Ecological Census Techniques. A Handbook. Cambridge University Press, London.
Watanuki, Y., Ishikawa, K., Takahashi, A. and Kato, A. (2004). Foraging behaviour of a generalist marine top predator, Japanese cormorants, in years of demersal vs. epipelagic prey. Mar. Biol. 145: 427–434.
Williams, J.G. and Arlott, N. (1980). A Field Guide to the Birds of East Africa. Collins, London.
Wittenburger, J.F. and Hunt, G.L. (1985). The adaptive significance of coloniality in birds. Avian Biol. 7: 1–78.