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Feeding ecology of Common Guillemots on Lundy: feeding-trip duration
Feeding ecology of Common Guillemots on Lundy
Summary

The only published data on feeding-trip durations 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 feeding-trip durations on Lundy were shorter than those on Skomer.


Table 1: Median feeding-trip durations on Lundy (Preliminary data)

	Median	Timed 	Total 	Timed	Watch 	No of 	
                Feeds   Feeds   /Total  Length  Watches

2015	33m54s	20	79	25%	2h	10	
2014	23m10s	31	77	40%	2h	13	
2013	--m	24	74/104	32%	2h	14 of 26 *subset of data
2012	21m25s	16	52	31%	2h	11
2011	40m	2	17	18%	2h	3
2010	38m	9	28	32%	2h	5
2008	37m	5	30	17%	2h	8	

1986	28m	84	 [210]	40%	4h	5	Hatchwell, et al. (1992)
1985	26m	77	 [275]	28%	4h	10	Hatchwell, et al. (1992)


Table 2: Frequencies of feeding-trip durations on Lundy 2014-2008 (Preliminary data)

                2014	2013	2012	2011	2010	2008	Total
  0 - 10m       3		1				4
 10 - 20m	10		4		1		15
 20 - 30m	7		4		3	1	15
 30 - 40m	1		1	1	2	2	7
 40 - 50m	2		3	1		1	7
 50 - 60m	3		1		2		6
 60 - 70m	2				1		3
 70 - 80m	1		1			1	3
 80 - 90m	2		1				3
 90 - 100m							0
100 - 110m							0
110 - 120m							0
	        31	0	16	2	9	5	63

Timed feeds 2015

 0: 
 3: 16m03s, 16m43s, 18m20s
 5: 22m53s, 23m10s, 27m56s, 28m33s, 28m45s
 3: 31m13s, 32m09s, 35m42s
 2: 40m57s, 47m12s
 1: 56m37s
 3: 62m34s, 67m27s, 68m24s
 1: 77m02s
 1: 85m35s
 0:
 1: 109m32s
==
20 Mean duration of timed feeds = 44m50s, median duration = 33m54s

Timed feeds 2014

 3: 06m25s 07m45s 07m48s
10: 11m15s 11m47s 13m47s 15m29s 15m59s 16m03s 16m10s 16m43s 17m18s 18m41s
 7: 20m01s 21m42s 23m10s 23m21s 26m07s 27m48s 27m54s
 1: 36m24s 
 2: 40m57s 49m28s
 3: 53m40s 55m44s 57m10s 
 2: 63m35s 63m40s
 1: 78m43s
 2: 87m20s 88m23s
==
31   Mean duration of timed feeds = 32m55s, median duration = 23m10s.

Timed Feeds 2012

 1: 8m12s
 4: 12m56s 13m30s 15m02s 18h02s
 4: 20m30s 20m36s 21m24s 21m26s 
 1: 34m42s
 3: 41m46s 46m47s 48m48s
 1: 52m16s
 0: 
 1: 79m46s
 1: 80m13s
==
16 Mean feeding trip duration = 33m30, Median feeding trip duration = 21m25s


Untimed feeds 2014

10: +00m08s +01m44s +02m28s +03m01s +03m20s +03m28s +04m22s +07m32s +07m33s +09m09s
 9: +13m20s +13m33s +14m52s +15m01s +15m25s +15m37s +18m06s +18m08s +19m32s
 4: +21m26s +23m01s +26m26s +28m11s
 6: +30m49s +30m58s +34m10s +37m33s +37m12s +38m50s
 3: +41m27s +45m33s +46m53s
 1: +52m27s
 4: +60m52s +60m55s +61m01s +65m45s 
 2: +77m22s +77m38s 
 0:
 2: +92m46s +98m12s
 2: +101m36s +104m41s 
 2: +110m50s +117m42s
 1: +120m50s
==
46

Untimed Feeds 2012

 4: +5m31s +5m46s +6m13s +8m22s
 5: +10m31s +10m47s +12m13s +14m29s +17m16s
 2: +20m33s +26m08s
 6: +30m43s +31m30s +31m46s +34m40s +35m18s +39m41s
 3: +44m39s +45m33s +45m51s
 4: +53m11s +55m18s +57m43s +58m10s
 2: +61m29s +64m54s
 2: +71m39s +78m42s
 1: +88m48s
 1: +96m57s
 1: +100m28s
 3: +110m58s +112m +117m29s
 2: +121m49s +126m
==
36



Articles on the feeding-trip durations 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.

      Foraging trip durations:
      Lundy 1985, median 26 minutes from 77 trips of recorded length (28% of total feeds from 4 hour watches).
      Lundy 1986, median 28 minutes from 84 trips of recorded length (40% of total feeds from 4 hour watches).

    • [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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