Lesser Black-backed Gull (graellsii & intermedius)

(last update: May 17 2015)

LBBG 1cy: Body mass increment and wing length in juvenile LBBG

This page contains two plots to illustrate the variation and pace in growth rate for juvenile LBBG in a year with food shortage (1992) and food abundance (1993) at Terschelling. We also included the plot for Europoort (1992) to illustrate the similarity with Terschelling, the same year.
We used these graphs to allocate some juveniles, of which the exact hatching date was not confirmed by field observations. Although not exact to the day, these plots allow classification of juveniles in one of the actegories we used:
- Category I: hatched before June 10
- Category II: hatched between June 10 and June 20
- Category III: hatched after June 20

Plots from: Spaans A L, Bukacinska M, Bukacinski D, Swelm N D v. 1994. The relationship between food supply, reproductive parameters and population dynamics in Dutch Lesser Black-backed Gulls Larus fuscus: a pilot study. IBN Research Report 94/9, Wageningen,The Netherlands.