One of the major agricultural changes which has affected farmland birds in Britain has been the loss of mixed farming.
Arable crops on livestock farms
Livestock farming predominates in north and west Britain and there has been a decline in arable crops.
In these areas, spring crops can be especially important for declining bird species, particularly seed-eating birds such as larks and finches. Arable crops also provide a safe nesting habitat for ground-nesting birds.
Those livestock farmers who produce fodder crops such as spring cereals or turnips are encouraging the survival of declining bird species in their area.
- Arable crops can provide essential food sources for seed-eating birds in predominantly grassland systems.
- Where there is no scope to incorporate any form of arable crop into the farming system, small plots sown with wild bird seed mixtures will be very beneficial.
Wild bird seed mixture
Wild bird seed mixtures are an unharvested mix of seed-bearing crops which will benefit species such as grey partridge and yellowhammer.
Benefits to wildlife
Stubble fields provide valuable winter food for seed-eating birds
Many of the declining farmland bird species are small, seed-eating birds. Their decline has been greatest in those areas of Britain where livestock farming predominates. The stubble which follows spring cereals usually provides abundant food for birds throughout the winter due to the availability of spilt grain and weed seeds.
Fodder brassicas provide valuable weed seeds for winter food
Many small, seed-eating bird species, particularly linnets and twites, depend on the seeds of weeds for winter survival as they are poorly adapted to take spilt grain in cereal stubbles.
Traditionally managed crops of fodder brassicas (such as turnips, rape and kale), where weeds are allowed to persist in the crop and set seed, provide an important habitat for small seed-eaters and other birds like grey partridges. Important weeds include fat hen, charlock and chickweed.
Arable crops provide a nesting habitat for farmland bird species
Vegetation structure is often the crucial factor determining the ability of ground-nesting birds to breed on a farm. Arable crops can provide a suitable breeding habitat for grey partridges, skylarks and buntings. Spring cropping also provides a breeding habitat for lapwings, as well as an improved habitat for skylarks.
Choosing which crop to use
Combination fodder crops
Spring-sown crops are more beneficial than other types as they allow the retention of stubbles which offer food for seed-eating birds throughout the winter.
They also provide bare ground in the spring for breeding lapwings and nesting habitat for skylarks throughout the summer.
Combinable crops generally provide food for seed-eating birds right through from the ripening of the crop to cultivation of the stubble. Such bird species also eat the seeds of those weeds which germinate during crop establishment and after harvesting.
The benefits of whole-crop silage for birds are more numerous with spring-sown than autumn-sown crops, because winter stubble provides a seed source and spring tillage offers nesting habitat for lapwings.
Although this crop is harvested green and drops no seed, whole-crop silage can still be a source of weed seeds for seed-eating birds. In particular, the unripe grain of whole-crop cereals can be a vital food source for bunting chicks, especially when large insects are not available.
There is now a wide range of silage crops in use - these include cereals and mixes of cereals with pulses or brassicas and maize. All but the latter (see below) will provide some seed food during establishment and after harvest, as well as providing nesting habitat for grey partridges, skylarks and buntings.
Maize is not generally that useful to birds as it requires relatively weed-free conditions during its establishment. In addition, its structure makes it unsuitable for use by most ground-nesting birds. Lapwings, however, can nest on the bare ground created during preparation of the seedbed.
You should try to avoid lapwing nests during establishment operations. Condense all operations within one week so any failed pairs can nest again in safety.
If you drill the headland or undersow maize with a seed-bearing crop such as linseed, this may provide seed for birds through the winter.
Root crops and other fodder brassicas
Turnips, kale and other fodder brassicas with high weed populations are particularly important crops for wintering farmland birds. Broad-leaved weeds grow along with the crop and their seeds become available to birds as the crop is grazed or harvested. Birds will continue to find seeds on this land until you turn over the ground.
You may find it necessary to control weeds during crop establishment to get a good yield, but if you can tolerate any weeds that germinate with the crop and leave them to set seed, this will be of great benefit to birds.
Wild bird cover
Wild bird cover using seed crops are particularly useful on livestock farms with no arable crops. You can use these in field corners and on marginal strips. A mix of crops is generally established in spring and maintained for two years.
Kale, cereals and quinoa are particularly useful components for seed-eating birds such as partridges, finches and buntings.
Source: The RSPB