Ig. Henderson et al., Summer bird abundance and distribution on set-aside fields on intensive arable farms in England, ECOGRAPHY, 23(1), 2000, pp. 50-59
The abundance and distribution of breeding birds were compared on paired fi
elds comprising one set-aside Bald and one crop field, on 11 intensive arab
le farms in eastern and western England. A single observer made four visits
to all set-aside and clop fields between April and July and recorded all b
irds seen during standardised counts and transects.
Rotational and non-rotational set-aside supported higher densities and more
species of birds than fields of wheat, brassicas, root crops and seed rye.
These differences in density, between set-aside and crops, were evident ac
ross a suit of species including waders, gambirds, pigeons and passerines a
nd were particularly marked on rotational set-aside. The majority of specie
s recorded in fields away from boundaries would have been feeding rather th
an nesting there and higher bird densities on set-aside compared with adjac
ent arable crops probably reflects greater food abundance in the former.
The study is the first to demonstrate a clear habit preference for set-asid
e by a wide range of bird species throughout the breeding season and it all
ows a number of recommendations to be made concerning the development of co
st effective agri-environment measures. The fact that the majority of birds
utilised the outer 5 m, or in some cases 20 m. margin of the field suggest
s that many of the benefits of whole held set-aside may be derived from mar
ginal strips. A slight, but not significant preference for rotational over
non-rotational set-aside suggest such margins should be managed to maintain
a patchy, relatively diverse sward of arable plants. A key feature of set-
aside is the scale at which it has been incorporated into the arable landsc
ape. Agri-enviromental schemes will only provide similar national benefits
if they are implemented on a wide scale in such as way as to promote high u
ptake by farmers.