Online Content

1. Alonso, Juan C. with Javier A. Alonso and Manuel Quintanilla, "Modeling the Common Crane (Grus grus) Population Wintering in Iberia"

Type:
Document
Date Created:
1986
Collection:
System Dynamic Society Records
Collecting Area:
University Archives
Collection ID:
ua435
Parent Record(s):
8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
Thumbnail Path Ss:
/downloads/7p88d100t?file=thumbnail
System Modified Dtsi:
2020-01-02T18:39:38Z
Description:
A field study carried out during the last seven years on a wintering population of Common Cranes (Grus grus) in Spain allowed us to gather accurate field data on-certain relevant demographic parameters: (a) the size of the Western Palearctic population of this species is estimated to be around 40000 birds, and (b) the age composition in autumn is estimated for 1979-85 to be around 13.5% young. These data enabled us to develop and test a population dynamics model which combines the density- and age-dependent effects on productivity and survival rates. The parameters of the productivity and survival functions were varied within biologically reasonable limits. From the series of possible combinations we selected those that fitted our field data on population size and age structure best. Each variable was then varied to study their influence on the model.