Demography of marine birds in the Northeast Atlantic: informed parameter values for population modelling

Matrix models are often used to assess and predict the impact of human
activities on wild populations. These models require input values of
demographic parameters, i.e. survival and fecundity. However, empirical
estimates of these parameters are often not available, particularly for
survival. We built matrix population models for 25 species of marine birds
in the Northeast Atlantic. These models were based on long-term monitoring
data on abundance and breeding productivity, collated for an environmental
status assessment under the OSPAR Convention for the Protection of the
North-East Atlantic. We started with literature-based values of
age-specific survival and tuned these values to fit the observed
population growth rate. This database presents tuned values of
age-specific survival for 25 species in four regions of the north-east
Atlantic, a total of 54 regional populations. In addition, we report
modelled generation time as well as the level of breeding productivity
required to maintain a stable population for the same populations.
Practical implication. Our tuned values of age-specific survival should be
used as starting values in future modelling exercises. They represent
means over relatively large scales and long timespans and may need
adjusting to local conditions.

# Demography of marine birds in the Northeast Atlantic: informed parameter
values for population modelling Dataset DOI:
[10.5061/dryad.4mw6m90qn](https://doi.org/10.5061/dryad.4mw6m90qn) ##
Description of the data and file structure This dataset includes
model-derived estimates of demographic parameters for 58 populations of 25
marine bird species in Northwest Europe ### Files and variables #### File:
Model_output_overview_Dryad.xlsx **Description:** Model assumptions,
empirical estimates and model output **Sheet**: Data ##### Variables *
Species * Common name * Scientific name * Clutch size (1 or +1) * Region
(OSPAR Region, see
[https://www.ospar.org/convention/the-north-east-atlantic](https://www.ospar.org/convention/the-north-east-atlantic)) * Assumptions * Age of first breeding (years) * Breeding propensity (proportion) * Base parameter values (from literature). "n/a" for survival indicates that survival of the age class in question was considered equal to adult survival. * Breeding productivity (fledged chicks/pair/year) * S0_base: first-year annual survival probability * S1_base: second-year annual survival probability * S2_base: third-year annual survival probability * S3_base: fourth-year annual survival probability * S4_base: fifth-year annual survival probability * S5_base: sixth-year annual survival probability * SA_base: adult annual survival probability * Source: reference code, see sheet 'References' * Empirical estimates (from monitoring data) * Mean productivity (fledged chicks/pair/year) * n colonies (number of colonies monitored for productivity) * Lambda (annual finite population growth rate, assuming exponential growth) * Tuned parameter values (output from model)."n/a" for survival indicates that survival of the age class in question was considered equal to adult survival. * S0: first-year annual survival probability * S1: second-year annual survival probability * S2: third-year annual survival probability * S3: fourth-year annual survival probability * S4: fifth-year annual survival probability * S5: sixth-year annual survival probability * SA: adult annual survival probability * Model output * B-lambda_1: mean breeding productivity required to stabilize population (fledged chicks/pair/year) * Generation time: estimated generation time of stable population (years) * Comments. "n/a" indicates no specific comment. **Sheet:** References **Variables** * Number: reference code, see variable 'Source' in sheet 'Data' * Reference: citation for published source