Voles and holes in France

 

Gardeners and householders in France are forever complaining about the presence of voles in their gardens, either because of the holes they make or the harm they can cause to plants and vegetables. Any harm they may cause depends on the species, some preferring roots and others seeds, grains, leafy plants and even insects. 

Although there are eleven species of vole in France only a few are of concern to gardeners or farmers. As a general rule these are the Field vole, the Common vole and the Bank vole. The Water vole in its land based form, (known as rat taupier), can have a major impact but they are only present in some regions of France. 

Occasionally some vole species have a population explosion that reaches a peak and then equally as rapidly the populations collapse back to normal or less than normal for a year or more.

What needs to be considered, as always, is the greater good and voles along with wood mice provide the main food source for a large range of creatures and in some cases what amounts to the only food source.

I would think that birds of prey will immediately spring to mind for most people; owls, buzzards, kites and hawks. All will catch and eat voles to some extent and for some they will make up almost 100% of their diet. They are of particular importance for Little owls, Barn owls, Kestrels, Hen and Montagu’s Harriers, all of whom will either not produce eggs or will experience high chick mortality numbers if there aren’t sufficient numbers of voles available. 

Most of the snakes that are found in France regularly eat voles. 

On the mammal front they will be eaten by Foxes, Stoats, Weasels, Badgers, Polecats, Genets, Stone Marten, Pine Marten and European Mink. 

Although it may seem a bit callous, the more voles that are available for mammals and snakes to eat the less pressure there will be for them to eat other creatures that are either less able to produce large numbers of offspring or that are already suffering population declines due to other causes. 

Due to the harm being caused to other non target species the use of poisons, (rodenticides), in the outside environment was prohibited by law in France in 2012. Poisoning to other creatures was being caused either directly with them coming into direct contact with the products or indirectly by the consumption of creatures that had been poisoned.   

Farmers in France can apply to their Prefecture for derogations to enable them to continue with poisoning fields to protect their crops and sadly this has become normal. It’s also not unusual to see dead small birds around animal sheds where poison grain is being used but that’s a different issue. 

These vicious cycles reduce the number of predators for the voles and other rodents and increases the need for poisoning, exactly the opposite of that which is required.

 

Chris

Protected Reptiles and Amphibians in France

The new list of protected reptiles and amphibians in France has for the first time included the four species of Viper, (Vipéridés).

Vipera aspis - Vipère aspic - Asp Viper
Vipera berus - Vipère péliade - Common Adder
Vipera seoanei - Vipère de Seoane - Seoane's viper.
Vipera ursinii - Vipère d'Orsini - Orsini's viper

For far too long these species have been persecuted and killed. This combined with the destruction of their natural habitat has resulted in a serious decline in numbers.

Needless to say this will not in itself prevent the continued harming of these valuable species but will send a signal to those with ears to hear and to those in authority 

LINK TO LEGISLATIVE TEXT

Chris

Sexton or Burying beetles in France

 

Our house is full of places where animals live and overall we are happy with that and it rarely causes any actual harm although occasionally something dies which needless to say can smell a bit.

Fortunately, as always, the natural world is well equipped to deal with any small corpses that are inaccessible, (as they invariably are), and Burying or Carrion beetles are one of the insects that make their living from such things. There are some 20 odd species in France with a total of 30 species in Europe although not all are true burying beetles; some of them eat fungi or rotting vegetation.   

This year in September we were finding Nicrophorus vespillo in one part of our house and I would speculate that they had been on a dead Loir, (Edible Dormouse), probably behind the bath or false wall in the downstairs bathroom, one of the places where they frequently live. These amazing beetles can smell a corpse from a vast distance using the highly sensitive hairs on the ends of their club ended antennae. Having found a corpse, usually that of a small mammal, both male and female set about preparing it for use, sometimes excavating below it to bury it or even moving it if it’s small enough. Hairs or feathers are removed as are any eggs or larvae of other species, (flies etc), and the body is shaped into a ball where the beetles eggs are laid around it. Both parents feed and care for the young larvae when they hatch and this can last for up to 10 days before the young can consume the corpse directly. This feeding of the young larvae by adults is very rare in the insect world and is normally associated with social or colony forming species such as honey bees, wasps and ants. In addition to this unusual behaviour the parents are known to regulate the number of larvae in relationship to the quantity of food available on the carcass by removing and killing some larvae if there is a shortage of food or laying more eggs if there is plenty, thus having larvae of different ages on the same corpse. Larvae pupate in the soil or debris under the corpse before emerging between 20 and 30 days later.

 

Nicrophorus vespillo with mites

As with some other insects, notably some Bumble bee species, these Burying beetles carry with them several species of phoretic mites that use the beetle as transport from one corpse to another. The relationship between these mites and the beetles has generally been thought to be benign but there is extensive research continuing on what the actual relationships and effects are. Needless to say it’s too complicated a subject for me and to go into here but I’ve put a link below and to a great video. 

Chris

LINK Phoretic mites and beetles 

LINK  Video burying beetle at work and larvae