geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Modelling the daily food requirements of wintering great cormorants: A bioenergetics tool for wildlife management


, : Modelling the daily food requirements of wintering great cormorants: A bioenergetics tool for wildlife management. Journal of Applied Ecology 40(2): 266-277

1. Great cormorants Phalacrocorax carbo, Linnaeus are large piscivorous birds which occur in Asia, Australia, Africa, Europe and North America. Their European breeding population has increased by at least 15% per annum over the last 15 years, reaching a total of c. 200 000 pairs in the late 1990s. There are concerns that this increase is adversely affecting freshwater fish populations throughout Europe, but real assessment requires a detailed knowledge of cormorant food requirements. 2. The daily food intake (DFI) of great cormorants has been measured during the breeding season, but little is known about DFI in winter when these poorly insulated birds experience consistently low temperatures. DFI is likely to vary widely according to abiotic and biotic conditions, making predictions about impact particularly difficult. 3. We modelled DFI for great cormorants wintering at Loch Leven, Scotland, using behavioural data recorded via radio-tracking of free-ranging individuals, metabolic measurements obtained from captive birds, and published data. DFI was estimated to be 672 g day-1 (predicted maximum range 441-1095 g day-1), values similar to DFI of great cormorants breeding under temperate conditions and of other aquatic bird species. 4. During winter great cormorants at Loch Leven decreased their average dive time and increased dive efficiency (higher proportion of time spent underwater). They nonetheless spent 130 min day-1 in the water and allocated more than a third of their daily energy budget to diving. 5. Synthesis and applications: In view of the need for the sound management of cormorant populations, we present a general bioenergetics model, based on simple behavioural and dietary inputs, that computes an estimate of DFI outside the breeding season for a range environmental conditions and habitats.

US$19.90

DOI: 10.1046/j.1365-2664.2003.00806.x


Other references

Nielsen, H., 1990: "Achieving Health for All": a framework for nutrition in health promotion. Achieving Health for All, a document released by Health and Welfare Canada, is a framework for nutrition in health promotion. Specific examples of the nutrition implications of the framework's challenges, mechanisms, and strategies are presen...

Trombly, C.A., 1992: Deficits of reaching in subjects with left hemiparesis: a pilot study. Therapy to restore functional movement of stroke patients is based on assumptions about the deficits that occur in motor control as a result of stroke. Success has been limited, perhaps as a result of insufficient information concerning the charac...

Montel, John E., 1983: Mexican government tackles tough economic problems. Foreign Agriculture 21

Thumm, K.; Mahony, M., 2002: Hatching dynamics and bet-hedging in a temperate frog, Pseudophryne australis (Anura: Myobatrachidae). Embryonic development to the time of hatching was found to vary within and between clutches of the red crowned toadlet, Pseudophryne australis. Hatching occurred over many developmental stages, from 24 to 36 (modified Gosner stage). The time taken...

Allgayer, B.; Berger, F.; Reiser, M.F., 2012: SPECT/CT: technical innovations - options for clinical use. Der Radiologe 52(7): 607-607

Ferrier, P.E., 1966: Stability of sex chromosome mosaicism in man. American Journal of Human Genetics 18(6): 614-615

Cuny, M.; Milet, M.; Hayes, D.H., 1979: Strain-dependent variation of the protein composition of Tetrahymena ribosomes. Febs Letters 101(1): 77-84

Tufenkji, N., 2006: Application of a dual deposition mode model to evaluate transport of Escherichia coli D21 in porous media. 1 Controlled laboratory-scale column deposition experiments were conducted using a well-characterized mutant of the Escherichia coli (E. coli) K12 strain to obtain insight into the mechanisms that give rise to the observed deviation from classical...

Heiss Georg A.; Dullo Wolf Christian, 1997: Stable isotope record from recent and fossil Porites sp. in the northern Red Sea. Coral Research Bulletin 5: 161-169

Slezak, H.; Haddad, R.; Scholda, C., 1994: Pathogenesis of secondary glaucoma after intraocular silicone oil administration. There are various causes of increasing ocular tension after vitrectomy and intraocular silicone oil filling; it is reported on a new type of postoperative secondary glaucoma. A 56-year-old man with flat anterior chamber and secondary glaucoma afte...