The Little Bustard Tetrax tetrax is one of the most endangered species in E
urope. The French populations breeding in cultivated areas have suffered a
drastic decline during the last 20 years and have disappeared from several
locations. In a political context, where management agreements are develope
d under EU agri-environment regulations, it has become urgent to identify t
he ecological requirements of this species, to predict its response to envi
ronmental changes and to suggest management tools, such as promotion of ben
eficial farming practices. Despite the fact that many studies have describe
d the habitat of the Little Bustard, quantitative data are lacking. We meas
ured habitat use in relation to availability in a cultivated plain in weste
rn France in 1995. Habitat use by the Little Bustard differed significantly
from habitat availability. Some crops, such as oilseed rape and cereals, w
ere avoided. Sunflower crops were used by Little Bustard males, but were av
oided by females. Females used set-aside to a greater extent than males. Ha
bitat diversity was significantly greater around the centre of male activit
y than in randomly selected areas. These differences were found for areas w
ithin a radius of 100 and 200 m around centres of male activity but not for
those with a 300 m radius. Vegetation height was one of the most important
variables for calling males, as low vegetation is needed to detect and be
detected by conspecifics. The most important variables for females are food
resources and, to a lesser extent, predator avoidance. For these reasons,
recent changes in land use on arable plains are likely to have different ef
fects on males and females. Conservation measures should take into account
these differences, the importance of the scale of measurement and should in
corporate specific ecological requirements.