RttIoP: Feeding ecology of Common Guillemots on Lundy

Summary

Feeding ecology of Common Guillemots on Lundy: provisioning rates

Feeding ecology of Common Guillemots on Lundy: parental attendance

Parental attendance, R Statistics 2012-2016

Parental attendance, 2012-2016

Parental Attendance vs Provisioning Rate, 2012-2015

Feeding ecology of Common Guillemots on Lundy: productivity

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

Feeding ecology of Common Guillemots on Lundy: chick diet

 year |  2014 |  2015 |  2016 | total

05h45 |  4/33 |  ./.. |  ./.. | .4/.33
06h00 |  9/63 |  ./.. |  2/27 | 11/.90
06h15 |  8/86 |  ./.. |  2/45 | 10/131
06h30 |  7/86 |  6/49 |  7/83 | 20/218
06h45 |  3/55 |  8/73 |  4/75 | 15/203
07h00 |  4/72 | 10/98 |  6/75 | 20/245
07h15 |  7/97 |  5/73 |  1/64 | 13/234
07h30 |  5/97 |  9/86 |  5/102| 19/285
07h45 |  1/45 |  5/73 |  2/92 | .8/210
08h00 |  0/21 | 11/98 |  2/66 | 13/185
08h15 |  0/11 |  4/85 |  1/19 | .5/115
08h30 |  0/11 |  3/49 |  2/19 | .5/.79
08h45 |  ./.. |  0/12 |  ./.. | .0/.12

Data collection:

Feeding ecology data was collected on the following days:

        For video recordings of the St Philip's Stone (StPh) provisioning ledge,
                numbers of chicks (c) and feeds (f) are shown as follows: .c.f
                eg. for 21/06/2014, 10c10f means 10 chicks and 10 feeds.

        Leap
        Year
Provisioning    2008            2010    2011    2012    2013    2014    2015    2016

09/06	08/06	.			.	.	.	StPh	.	StPh	160
10/06	09/06	.		JeCo	.	v	613+,v	.	.	.	161
11/06	10/06	.			.	3c2f	.	StPh	.	.	162
12/06	11/06	.			.	4c4f	.	.	3c3f	.	163
13/06	12/06	.		3c1f	.	.	.	StPh	.	2c2f	164
14/06	13/06	.			.	10c3f	StPh	.	StPh	.	165
15/06	14/06	.		7c8f	.	.	.	.	10c8f	.	166
16/06	15/06	.			.	.	1c1f	3c2f	.	4c1f	167
17/06	16/06	.			.	.	1c2f	.	.	.	168
18/06	17/06	.		7c1f	.	11c14f	4c3f	6c6f	12c7f	9c5f	169

19/06	18/06	.			.	11c9f	6c5f	.	.	.	170
20/06	19/06	.		JeCo	12c1f	.	6c4f	10c7f	.	10c10f	171
21/06	20/06	.	JeCo	7c8f	13c1f	11c10f	.	10c10f	12c9f	.	172
22/06	21/06	.			13c7f	.	.	.	.	.	173
23/06	22/06	.			.	.	.	.	12c7f	10c5f	174
24/06	23/06	5c2f			12c4f	.	8c9f	.	12c8f	.	175
25/06	24/06	5c2f		6c5f	.	.	8c5f	.	12c10f	10c3f	176
26/06	25/06	.			.	.	8c6f	.	.	.	177
27/06	26/06	.			8c5f	.	8c6f	.	12c9f	9c4f	178
28/06	27/06	.		7c5f	.	9c4f	8c8f	.	.	9c5f	179

29/06	28/06	.			v	9c3f	.	11c2f	13c7f	9c2f	180
30/06	29/06	9c1f	GrFa		.	        8c4f	11c7f	StPh	.	181
01/07	30/06	9c4f	GrFa		JeCo	9c7f	9c5f	11c7f	.	9c5f	182
02/07	01/07	9c3f			.	9c4f	9c6f	11c5f	13c7f	9c1f	183
03/07	02/07	.	GrFa		.	7c0f	9c8f	12c7f	.	9c5f	184
04/07	03/07	.			.	.	.	12c7f	.	9c1f	185
05/07	04/07	9c9f		4c3f	.	7c3f	9c5f	.	.	.	186
06/07	05/07	.			.	.	8c6f	11c9f	5c	.	187
07/07	06/07	.			.	.	7c3f	.	.	.	188
08/07	07/07	.	GrFa		.	.	7c5f	8c4f	.	.	189

09/07	08/07	9c2f		1c1f	.	2c0f	7c5f	.	+3c	.	190
10/07	09/07	.			.	1c0f	6c2f	.	.	.	191
11/07	10/07	8c0f			0c	.	5c7f	2c4f	.	.	192
12/07	11/07	8c12f		v	.	v	3c2f	.	.	.	193
13/07	12/07	.			.	.	.	.	.	.	194
14/07	13/07	8c2f		2c	.	.	.	1c4f	.	?c0f	195
15/07	14/07	5c1f			.	.	3c4f	.	.	.	196
16/07	15/07	.			.	1179	3c1f	.	1c	.	197
17/07	16/07	.			.	.	.	1c0f	.	.	198
18/07	17/07	.			.	.	3c2f	.	.	?c?f	199

19/07	18/07	1c		0c	.	.	.	.	.		200
20/07	19/07	.			.	.	.	.	.		201
21/07	20/07	.			.	620	2c2f	4+	.		202
22/07	21/07	.			.	.	.	.	.		203
23/07	22/07	.		v	.	.	2c0f	.	.		204
24/07	23/07	.			.	73	.	.	.		205
25/07	24/07	.			.	.	.	.	.		206
26/07	25/07	.			.	.	.	.	.		207
27/07	26/07	.			.	.	.	.	.		208
28/07	27/07	.			.	.	.	.	.		209

Provisioning    2008            2010    2011    2012    2013    2014    2015

Results

Feeding ecology of Common Guillemots on Lundy: provisioning rates

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).

Feeding ecology of Common Guillemots on Lundy: parental attendance

Parental attendance in 2015 Mean time that both parents were at nest site was 12.29% (=27h02m00s/220h00m00s).
Parental attendance in 2014 Mean time that both parents were at nest site was 19.94% (=45h04m11s/226h00m00s). There was only one case of a chick being left unattendended by both parents - on 3rd July "Neolithic" was left for 4m34s after a fight dislodged its parent from the ledge.
Parental attendance in 2013 Mean time that both parents were at nest site was 15.19% (=36h08m35s/238h00m00s).
Parental attendance in 2012 Mean time that both parents were at nest site was 9.75% (=19h18m32s/198h00m00s). Chick "F" was left with allo-brooders (Pair G) on 28th June. Chick "N" was left unattended on at least two days 2nd & 4th July.
Parental attendance in 2011
Parental attendance in 2010
Parental attendance in 2008

Parental Attendance vs Provisioning Rate, 2012-2015

Feeding ecology of Common Guillemots on Lundy: productivity

Productivity in 2015 In 2015 there were 19 focal sites on my St Philip's Stone survey ledge. There were 17 active sites and 2 regular sites. 13 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of 68%. Of these 13 chicks, at least one failed post fledging.
Productivity in 2014 In 2014 there were 16 focal sites on my St Philip's Stone survey ledge. Site H was unoccupied this year, perhaps due to the severe storms of winter 2013-14. There were 15 active sites and one regular site. 12 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of 75%. Of these 12 chicks, at least one failed post fledging.
Productivity in 2013 There were 14 active sites and at least 3 regular sites. 10 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of no more than 59%. Of these 10 chicks, at least 3 failed after 15 days, either through chick lost or post-fledging failure.
Productivity in 2012 There were 11 active sites and at least 6 regular sites. 11 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of no more than 65%. Of these 11 chicks, at least one failed after 21 days.
Productivity in 2011 There were 15 active sites and at least 2 regular sites. 12.5 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of no more than 74%.
Productivity in 2010 There were at least 17 focal sites. 8 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of no more than 47%.
Productivity in 2008 There were at least 17 focal sites. 9 sites produced chicks that either fledged, or were of fledging age (+15days old) when last seen. This gives a productivity of no more than 53%.

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

Feeding-trip duration in 2015
Feeding-trip duration in 2014 31 timed feeds out of 77 (40.26%). Mean duration of timed feeds = 32m55s, median duration = 23m10s.
Feeding-trip duration in 2013 Preliminary data - 11 timed feeds out of a subset of 42 (26%). Mean duration of timed feeds = , median duration = 30m.
Feeding-trip duration in 2012
Feeding-trip duration in 2011 Preliminary data - 2 timed feeds out of 17 (18%). Times: 38m & 42m.
Feeding-trip duration in 2010 Preliminary data - 9 timed feeds out of 28 (32%+-19%). Mean duration of timed feeds = 29m07s, median duration = 38m.
Feeding-trip duration in 2008 Preliminary data - 5 timed feeds out of 30 (17%). Mean duration of timed feeds = 41m24s, median duration = 37m.

Feeding ecology of Common Guillemots on Lundy: chick diet

Discussion

Conclusion

Acknowledgements

References

Recent articles on Lundy's Common Guillemots

Anderson, H.B., Evans, P.G.H., Potts, J.M., Harris, M.P. & Wanless, S. (2014) "The diet of Common Guillemot Uria aalge chicks provides evidence of changing prey communities in the North Sea" Ibis 156:23-34
Davis,T. & Jones, T. (2012) "Birds on Lundy: a summary of fieldwork and results from the National Bird Atlas 2007-2011" Journal of the Lundy Field Society 3:99-110
[notes]

Wheatley, S. & Saunders, N. (2011) "Cliff nesting Seabird Productivity on Lundy 2010" Annual Report of the Lundy Field Society 2010 60:67-74
[notes]

Wheatley, S. & Saunders, N. (2010) "Cliff nesting sea bird productivity on Lundy 2008" Journal of the Lundy Field Society 2:85-90
[notes]

Dalrymple, S. (2008) "Cliff nesting sea bird productivity on Lundy 2007" Journal of the Lundy Field Society 1:41-46
[notes]
Journal of the Lundy Field Society 1

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