2.7 Demographic rates

2.7.1 Gannet

Table 2.7: Demographic rates for the Gannet PVA models

SPA				Survivals
	S0->1		S1->2	S2->3		S3->4		S4->5		SA	PA
Forth Islands		Mean		0.542	0.779	0.859	0.863		0.954	0.954	0.698
Forth Islands		SD		0.084	0.045	0.032	0.039		0.050	0.050	0.071
Flamborough and Filey Coast		Mean		0.542	0.779	0.859	0.863		0.954	0.954	0.795
Flamborough and Filey Coast		SD		0.084	0.045	0.032	0.039		0.050	0.050	0.064
North Rona and Sula Sgeir		Mean		0.542	0.779	0.859	0.863		0.954	0.954	0.662
North Rona and Sula Sgeir		SD		0.084	0.045	0.032	0.039		0.050	0.050	0.082
Fair Isle		Mean		0.542	0.779	0.859	0.863		0.954	0.954	0.695
Fair Isle		SD		0.084	0.045	0.032	0.039		0.050	0.050	0.079
Noss		Mean		0.542	0.779	0.859	0.863		0.954	0.954	0.712
Noss		SD		0.084	0.045	0.032	0.039		0.050	0.050	0.060
Hermaness, Saxa Vord and Valla Field		Mean		0.542	0.779	0.859	0.863		0.954	0.954	0.661
Hermaness, Saxa Vord and Valla Field		SD		0.084	0.045	0.032	0.039		0.050	0.050	0.055
Eggs/pair: 1 (Snow and Perrins, 1998)
Age at first breeding: 5 (Horswill and Robinson, 2015)

Table 2.8: References and comments on demographic rates specified for Gannet PVA models. 'SE' and 'SD' refer to standard error and standard deviation, respectively; “H&R” refers to Horswill and Robinson (2015)

SPA	Demographic parameter	Source	Comments
Forth Islands	PA	Horswill and Robinson (2015)	SPA-specific estimates not available. Eastern UK figures adopted.
	S0->1, …, S3->4	Wanless et al. (2006)	Survival estimates for the Bass Rock colony (time-series: 1959 - 2001). SEs from original reference converted to SDs, following the same approach as Mobbs et al. (2020).
	S4->5, …, SA	Deakin et al. (2019)	Mean and SD derived from averaging over sex-specific adult survival estimates for the Bass Rock colony (time-series: 2010 - 2018).
Flamborough and Filey Coast	PA	SMP (2022)	Annual breeding success data from Flamborough and Filey Coast SPA (1991 - 1998; 2009 - 2019).
	S0->1, …, S3->4	Wanless et al. (2006)	SPA-specific estimates not available. Adopted the same parameter values as Gannet in Forth Islands.
	S4->5, …, SA	Deakin et al. (2019)
Sule Skerry and Sule Stack	PA	Cook and Robinson (2010)	SPA-specific estimates not available. Adopted figures based on data gathered from NW Scotland (Orkney and Shetland), as provided by the NEPVA Tool (Mobbs et al., 2020)
	S0->1, …, S3->4	Wanless et al. (2006)	SPA-specific estimates not available. Adopted the same parameter values as Gannet in Forth Islands.
	S4->5, …, SA	Deakin et al. (2019)
North Rona and Sula Sgeir	PA	Cook and Robinson (2010)	SPA-specific estimates not available. Adopted figures based on data gathered from NW Scotland (Orkney and Shetland), as provided by the NEPVA Tool (Mobbs et al., 2020)
	S0->1, …, S3->4	Wanless et al. (2006)	SPA-specific estimates not available. Adopted the same parameter values as Gannet in Forth Islands.
	S4->5, …, SA	Deakin et al. (2019)
Fair Isle	PA	SMP (2022)	Annual breeding success data from Fair Isle SPA (1986 - 2021).
	S0->1, …, S3->4	Wanless et al. (2006)	SPA-specific estimates not available. Adopted the same parameter values as Gannet in Forth Islands.
	S4->5, …, SA	Deakin et al. (2019)
Noss	PA	SMP (2022)	Annual breeding success data from Noss SPA (1986 - 2021).
	S0->1, …, S3->4	Wanless et al. (2006)	SPA-specific estimates not available. Adopted the same parameter values as Gannet in Forth Islands.
	S4->5, …, SA	Deakin et al. (2019)
Hermaness, Saxa Vord and Valla Field	PA	SMP (2022)	Annual breeding success data from Hermaness, Saxa Vord and Valla Field SPA (1989 - 2019).
	S0->1, …, S3->4	Wanless et al. (2006)	SPA-specific estimates not available. Adopted the same parameter values as Gannet in Forth Islands.
	S4->5, …, SA	Deakin et al. (2019)

2.7.2 Guillemot

Table 2.9: Demographic rates for the guillemot PVA models

SPA		Survivals						Productivity
		S0->1	S1->2	S2->3	S3->4	S4->5	SA	PA
Forth Islands	Mean	0.560	0.792	0.917	0.938	0.927	0.927	0.681
Forth Islands	SD	0.058	0.152	0.098	0.107	0.045	0.045	0.152
Farne Islands	Mean	0.560	0.792	0.917	0.938	0.927	0.927	0.787
	SD	0.058	0.152	0.098	0.107	0.045	0.045	0.141
St Abb's Head to Fast Castle	Mean	0.560	0.792	0.917	0.938	0.927	0.927	0.681
	SD	0.058	0.152	0.098	0.107	0.045	0.045	0.152
Fowlsheugh	Mean	0.560	0.792	0.917	0.938	0.927	0.927	0.681
Fowlsheugh	SD	0.058	0.152	0.098	0.107	0.045	0.045	0.152
Buchan Ness to Collieston Coast	Mean	0.560	0.792	0.917	0.938	0.927	0.927	0.681
Buchan Ness to Collieston Coast	SD	0.058	0.152	0.098	0.107	0.045	0.045	0.152
Troup, Pennan and Lion's Heads	Mean	0.560	0.792	0.917	0.938	0.940	0.940	0.629
Troup, Pennan and Lion's Heads	SD	0.058	0.152	0.098	0.107	0.025	0.025	0.174
Eggs/pair: 1 (Snow and Perrins, 1998)
Age at first breeding: 6 (Horswill and Robinson, 2015)

Table 2.10: References and comments on demographic rates specified for Guillemot PVA models. 'SE' and 'SD' refer to standard error and standard deviation, respectively; “H&R” refers to Horswill and Robinson (2015)

SPA			Comments
Forth Islands	PA	CEH (2018)	Annual breeding success data from Isle of May (2007 - 2016). Historically low productivity in 2007 attributed to difficult feeding conditions and severe weather. Despite being extreme, estimate was deemed accurate and thus used for inter-annual mean and sd calculations
	S0->1, …, S3->4	Harris et al. (2007)	Isle of May survival estimates (time series: 1983 - 2002). SDs converted from SEs presented in the original paper, following the same approach as Mobbs et al. (2020).
	S4->5, …, SA	Jitlal et al. (2017)	Adult survival estimates for the Isle of May colony.
Farne Islands	PA	SMP (2022)	Annual breeding success data from Farne Islands (1986 - 2010).
	S0->1, …, S3->4	Harris et al. (2007)	SPA-specific estimates not available. Adopted the same parameters as Guillemot in Forth Islands.
	S4->5, …, SA	Jitlal et al. (2017)	SPA-specific estimates not available. Used the same parameters as Guillemot in Forth Islands.
St Abb’s Head to Fast Castle	PA	CEH (2018)	Used the same parameter values as Guillemot in Forth Islands. Productivity estimates available in SMP for Guillemot in St Abbs, but for a very short time-series (2015 - 2018). The annual average (0.784) is within values observed in nearby colonies (Isle of May, 0.681; and Farne Islands, 0.787). However, 4 data-points was deemed insufficient to produce a realistic measure of inter-annual variability. Precautionary approach taken by using the lower, and more recent, estimates from Isle of May.
	S0->1, …, S3->4	Harris et al. (2007)	SPA-specific estimates not available. Adopted the same parameters as Guillemot in Forth Islands.
	S4->5, …, SA	Jitlal et al. (2017)	SPA-specific estimates not available. Used the same parameters as Guillemot in Forth Islands.
Fowlsheugh	PA	CEH (2018)	SPA-specific estimates not available. Used the same parameter values as Guillemot in Forth Islands.
	S0->1, …, S3->4	Harris et al. (2007)	SPA-specific estimates not available. Adopted the same parameters as Guillemot in Forth Islands.
	S4->5, …, SA	Jitlal et al. (2017)	SPA-specific estimates not available. Used the same parameters as Guillemot in Forth Islands.
Buchan Ness to Collieston Coast	PA	CEH (2018)	SPA-specific estimates not available. Used the same parameter values as Guillemot in Forth Islands.
	S0->1, …, S3->4	Harris et al. (2007)	SPA-specific estimates not available. Adopted the same parameters as Guillemot in Forth Islands.
	S4->5, …, SA	Jitlal et al. (2017)	SPA-specific estimates not available. Used the same parameters as Guillemot in Forth Islands.
Troup, Pennan and Lion’s Heads	PA	Horswill and Robinson (2015)	SPA-specific estimates not available. Northern UK figures used instead.
	S0->1, …, S3->4	Harris et al. (2007)	SPA-specific estimates not available. Adopted the same parameters as Guillemot in Forth Islands.
	S4->5, …, SA	Horswill and Robinson (2015)	SPA-specific estimates not available. National-level adult survival estimates adopted. SD value taken from the NEPVA tool (Mobbs et al. 2020), which addresses error in value reported by H&R (2015).

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