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Feeding ecology of Common Guillemots on Lundy: provisioning rates
Feeding ecology of Common Guillemots on Lundy
Summary

The only published data on provisioning rates on Lundy is by Hatchwell et al. (1992). In 1985 and 1986, they conducted a comparative survey of feeding ecologies on Skomer and Lundy finding that provisioning rates on Lundy were higher than those on Skomer.


Table 1: Provisioning rates on Lundy (Preliminary data)

Date    Feeds   Chick   Feeds/  Feeds/  Feeds/
                hours   c.h     c.4h    day

2016	 48	204	0.235   (0.94)
2015	 72     218	0.330   (1.32)
2014	 61     214	0.285   (1.14)
2013    106     288     0.368   (1.47)
2012     65.5   261     0.251   (1.00)
2011     17      81.5   0.2     (0.8)
2010     35     100     0.35    (1.4)
2008     40     202     0.198   (0.8)

1986                            1.76    6.00    Hatchwell, et al. (1992)
1985                            0.87            Hatchwell, et al. (1992)

  • Provisioning rates in 2016 Provisioning rate of 0.24 feeds per chick hour
    (48 feeds / 204 chick.hours = 0.94 feeds per chick per 4 hours).
  • Provisioning rates in 2015 Provisioning rate of 0.33 feeds per chick hour
    (72 feeds / 218 chick.hours = 1.32 feeds per chick per 4 hours).
  • Provisioning rates in 2014 Provisioning rate of 0.29 feeds per chick hour
    (61 feeds / 214 chick.hours = 1.14 feeds per chick per 4 hours).
  • Provisioning rates in 2013 Preliminary provisioning rate of 0.37 feeds per chick hour
    (106 feeds / 288 chick.hours = 1.47 feeds per chick per 4 hours).
  • Provisioning rates in 2012 Preliminary provisioning rate of 0.25 feeds per chick hour
    (65.5 feeds / 261 chick.hours = 1.00 feeds per chick per 4 hours).
  • Provisioning rates in 2011 Preliminary provisioning rate of 0.2 feeds per chick hour
    (17 feeds / 81.5 chick.hours = 0.8 feeds per chick per 4 hours).
  • Provisioning rates in 2010 Preliminary provisioning rate of 0.35 feeds per chick hour
    (35 feeds / 100 chick.hours = 1.4 feeds per chick per 4 hours).
  • Provisioning rates in 2008 Preliminary provisioning rate of 0.2 feeds per chick hour
    (40 feeds / 202 chick.hours = 0.8 feeds per chick per 4 hours).

Articles on the provisioning rates of Lundy's Common Guillemots

  • Hatchwell, B.J., Birkhead, T.R., Goodburn, S.F., Perrins, J.M. & Jones, S.E. (1992) "Chick diets and food intake of nestling Common Guillemots Uria aalge: an inter-colony comparison" Seabird 14:15-20
    • Summary The feeding ecology of Common Guillemot chicks at two colonies, Skomer and Lundy Islands, situated 75km apart in the south Irish Sea was compared over two years. The diets of chicks varied significantly between colonies, with Lundy chicks fed on smaller prey than those on Skomer. However, chicks were fed more frequently on Lundy so the estimated daily energy intake was similar at both colonies. Parents on Lundy made shorter foraging trips than on Skomer. Chick diet and foraging ranges indicated little overlap in foraging areas. Fish fed to chicks were generally of higher quality than those used for display.
    • [notes]

  • Birkhead, T.R., Goodburn, S.F. & Hatchwell, B.J. (1986) "Feeding Ecology of Common Guillemot Chicks on Lundy" Annual Report of the Lundy Field Society 1985 36:25-26
    • Summary Following a long period of decline, several guillemot Uria aalge populations in the south Irish Sea have recently shown an upward trend in numbers. At present the reason for this change in fortunes is not known, but one possibility is that a change in the marine environment has made food more available to guillemots. As part of an attempt to examine this, we have compared several aspects of the guillemot's feeding ecology at three Irish Sea colonies during the chick rearing period. Information has been collected from Skomer Island, Dyfed, Great Saltee, Co. Wexford and from Lundy. Here we present the results from Lundy made between 17th-28th June 1985 about 100m south of St Mark's Stone on the west coast of the island. All observations were made between 1400-1800h BST.
    • [notes]

  • More articles on Lundy's Common Guillemots

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