Avian Conservation and Ecology - Écologie et conservation des oiseaux: Evaluating the Small Population Paradigm for Rare Large-bodied Woodpeckers, with Implications for the Ivory-billed Woodpecker

Table 1. Minimum, maximum, and intermediate input values used in perturbation analysis for a stage-based population model that predicts extinction rates of large-bodied woodpeckers. Instantaneous rate of population growth (λ) represents the expected population trajectory in the absence of stochasticity in the model.

	Mean				Variance

Parameter	Δθ^a	Min.	Interm.	Max.	Δθ^a	Min.	Interm.	Max.	Data sources

Initial number of adults	1	5	17	30	-	-	-	-	Tanner 1942
Fecundity	0.039	0.67	1.06	1.65	0.002	0.0022	0.0160	0.051	Tanner 1942, Bonar 2001, Mattsson and Christensen, unpublished data
Annual adult survival rate	0.008	0.7	0.8	0.9	0.004	0.0076	0.0394	0.096	Bonar 2001, Loehle 2005, Mattsson and Christensen, unpublished data
Population growth rate (λ)^b	-	0.93	1.22	1.64	-	-	-	-	= S + F * 0.5 * S

^aConstant used in fine-scale perturbation analysis (See Appendix 1).
^bCalculation of female population growth rate is based on fecundity (F: number of female fledglings/adult female) and annual survival (S). The calculation also assumes that juvenile survival is one-half of adult survival, and females can breed 1 yr after they hatch.