OTTENS HJ, WIERSMA P & KOKS BJ (2013) Winter food for farmland birds in Groningen and Drenthe. LIMOSA 86 (3): 192-202.
Modern agricultural fields have little to offer for wintering
birds, which has resulted in dramatic declines in numbers.
Since 2008, in the provinces of Groningen and Drenthe, in
the northern Netherlands, many volunteers have monitored
winter birds in agricultural fields. The aim was to quantify
the effect of winter food fields (WF fields), a newly introduced
method of agri-environmental nature management. These
0.5 to 2 ha fields are sown with various cereals and other
seed bearing plants with the aim to offer food for wintering
birds such as Yellowhammer and Skylark. In 2012, 238 ha of
WF fields were established in the two provinces. The number
of species reported was higher in WF fields (64) than in control
fields (41). Also, numbers present were much higher in
WF fields than in controls (maximum numbers: 255 vs. 55). The
most numerous species were Greenfinch and Yellowhammer,
making up 63% of all birds. Numbers, including those of
vole consumers, were highest from November to February,
except for Skylark, which peaked during the migratory seasons.
Bird numbers increased with WF field size but densities
declined as fields became larger. Lower temperatures led to
higher numbers of finches, buntings and vole eaters. Snow
depth was positively correlated with number of finches,
buntings, sparrows and gallinaceous birds and probably also
of larks and pipits.
Our results show that WF fields are of great importance to
birds wintering in agricultural fields. We hypothesize that
the recent increase in numbers of Yellowhammers breeding
in East Groningen may have partly resulted from these management
efforts. For Skylarks, however, a positive effect
may be limited by the presence of shrubs and trees, which
are important for most other birds.
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