Cape Sable Seaside Sparrow - Life Cycle Parameters

Default Life Cycle Parameters in the Cape Sable Seaside Sparrow Individual Based Model (SIMSPAR)
Life Cycle Parameter Default Value in SIMSPAR
Maximum Age 5 years
Juvenile Mortality 0.40 per year
Adult Mortality 0.40 to 0.42 per year
Nesting 7 days
Walking Age 23 days
Fledging Age 33 days
Inter-brood rest period 3 days
Clutch Probability (Size:Probability) 2 eggs:0.16/ 3 eggs:0.48/ 4 eggs:0.36
Sex Ratio (Male:Female) 0.5:0.5

A number of life cycle parameters influence the sparrow's populations dynamics within the model. Each breeding season, the model determines if any individuals are greater than 5 years of age. If they are, these individuals die off since it represents the physiological limit placed upon their longevity. At each time step, the model randomly chooses a number of adults that die based on an annual probability of 0.40. Juvenile mortality, a linear density-dependent model that ranges form an annual probability of 0.40 to 0.42, is determined by the number of successful territories in the juvenile's nesting cell. At the minimum density of one nest per cell the mortality rate is minimal and at the maximum nesting density the juvenile mortality is maximal.

The nesting cycle and its interval lengths are based on field data (see Lockwood, et al., 1997, Wilson Bulletin 109: 720-731). The sex ratio of juvenile birds is assumed to be 50/50 and the clutch size varies according to a set range of probabilities.



Long-term Hydrology