Rats

I know I promised an article about establishing wild flower margins but its a bit late in the year to sow them now so I thought I would wait until next year... If you can't wait that long then let me know by leaving a comment.Thanks.

Instead I have decided to talk about rats, specifically.....

....Are rats ruining your attempts to increase farmland bird numbers?

I've heard that you're never more than 3 feet from a (brown) rat*. Sitting here in my office with my dog next to me that seems highly unlikely but it was certainly true for a farmer who recently contacted me about a rat infestation in his wild bird seed mixes.

Driving around his field one night he was astonished to see hundreds of rats running amok in the considerable areas of triticale,  (a wheat /rye hybrid cereal), barley and quinoa. These are sown annually for corn bunting to nest in during the summer and other farmland birds to eat through the winter as part of his Higher Level Stewardship Scheme. I too was shocked to see the amount of damage the rats had done; pulling over the heads of the cereal in order to get to the grain and numerous holes and rat runs in the hedge bottoms surrounding most of the fields. This was despite shooting over 1000 rats earlier in the year.

Cereal dominated wild bird seed mixes should be sited away

from buildings so not to encourage rats

Unfortunately wherever you have grain you can get rats. Even simple bird feeders in your garden can cause a problem as I found out last year with rats as big as cats gambolling under my feeders in broad daylight. So what you might say, isn't it all part of our diverse native fauna? Firstly they are not considered native as the first record of them in Britain is from 1700s when they reputedly came  ashore from ships from the Far East via their landing ropes. They can do immense damage to buildings with their sharp teeth which grow continuously; they can gnaw through concrete, strip insulation wires off cabling causing electrical fires; they transmit leptospirosis via their urine and they eat almost anything including birds' eggs, chcks and most grisly of all,  the feet of live chickens brooding their eggs. As they are such agile climbers its not just ground nesting birds who are at risk. They are prolific breeders who can have up to 100 young in a year. For most people, ignoring them and allowing them to 'do their thing' isn't an option as they can have such a considerable impact on our lives.

The most common way to control rats is through use of poison or rodenticide. The majority of commercially available rodenticide products to control rats contain one of several anticoagulants, some of which are now subject to resistance in local populations.There is also the serious issue of secondary poisoning of raptors, foxes, badgers etc picking up poisoned carcasses. This is a complex subject which I won't go into here, there is excellent coverage in

http://www.naturalengland.org.uk/Images/ratcontrolguidelines_tcm6-11216.pdf



Monitor any hoppers for rat activity

 Trapping, shooting, using terriers and phosphine gas are other methods of control which should be explored. Removal of the food source is always stated as essential in any rat control regime, particularly using rodenticides. This is difficult where wild bird seed mixes and cover crops are concerned. Rats love cereal, which forms the basis of most rodenticides. There are cob free varieties of maize available for game cover strips and also wild bird seed mixes without cereal, focusing on kale, linseed, quinoa and millet. It is essential that rat populations are monitored and control is part of the farm's annual timetable to keep a lid on populations, particularly around buildings, where there tends to be a wider range of rodenticides available to use. Hopper feeding regularly causes problems so monitor these areas regulalry and bait runs with products suitable for use outdoors.

In the case of the farmer who contacted me, he is being issued with a derogation from Natural England to top his unharvested cereal so shooting is easier and is considering use of phosphine gas and possibly changing the composition of his wild bird mixes. Happily he remains committed to conservation and is determined to tackle this unwanted problem.

All photos copyright of Tracy Adams.


* There are 2 species of rats found in Britain, the black rat (Rattus rattus) which is rare, driven out of most of their former habitat by the brown rat (Rattus norvegicus) which is extremely common. This article deals with the latter.