I have been looking at suitable mixes for wild bird cover crops and somebody has recommended including red clover. What do you think about that? I am told that skylark would feed on it. What about effects on crop structure and "foragability"?
There are pros and cons with clover. It is easy to establish, fairly inexpensive, it is attractive to a range of insects (some of which are a useful food source to other species) and it can last several years with little or no maintenance.
However, traditional Clovers have large saucer-like leaves that will collect water (including dew) and act like a reservoir in the early morning. If young, downy chicks forage in such areas they can easily become wet and cold, inducing further stress.
I believe that the important thing with any game mix is to keep the proportions of any ingredient in balance with the job one is trying to do. For a pollen-rich mix aimed at benefiting birds, I would include a little clover (preferably a traditional red type) but also include Trefoils which have narrow blade-shaped leaves that do not hold water very well and provide many similar benefits to the clover. The other important factor is management as the most used areas of these crops are round the edges. These can be maximised by planting in long strips rather than blocks, or by a regular cutting programme to provide different densities and different flowering times.
I would just try to avoid a thick carpet of clover, unless you keep bees!!