Moles are the easiest mammal to record – and without you even having to see one!

The signs of mole activity are obvious at any time of year.  The mounds of fresh earth are pushed above ground as the mole tunnels along underneath.

Two things cause a mole to leave its tunnel system.  First is when the young moles are forced to leave home and find one of their own, and second is when it is flooded out.  The moles get back to burrowing as quickly as possible as they are very vulnerable to predation (and to being run over by cars), so are more likely to be seen dead than alive.

Nevertheless, moles hills are signs that moles are around, and are therefore acceptable as records of moles.

So, we should have records of moles from everywhere in the county.  But do we?


Maps can show the distribution of a species, and if there is enough information, can show either density of records or changes over time.  Unfortunately, there are not enough data to show density – that would require systematic recording to mean anything.  Nor are there enough data to show changes over time.  In the above map, the darker the colour, the more recent the record.

But then, I hear you thinking, moles are everywhere, and why should that change?

Studies over the past decade or so from around the world have shown that earthworms are declining at an alarming rate – all due to increased intensity of farming practices, such as the rate of fertiliser and pesticide use, frequency of ploughing, etc.  Both earthworms and moles play a major part in soil aeration, drainage and mixing-in of organic matter.  In many areas, the decline in earthworms has been cited as the reason for the decline in songbirds such as thrushes.  Read more here.

Earthworms form the major part of the diet of moles, so yes, there is the potential for mole populations to change.  But how would we know if it is happening here?

MoleThis graph shows the number of 1km squares in Pembrokeshire in which moles have been recorded each year since 1980 (2017-18 are incomplete).  It tells us two things:

  • moles are around
  • sometimes someone actually makes a note of them and sends it to a recording system.

By the way, I don’t expect you to record every molehill – one record of molehills in a 1km square per year is fine.

I took over as mammal recorder in 1990.  Frustrated by the lack of records (of all mammals in the county), in 1999 I devised a survey form for people to just tick the box of each species seen in their garden in the previous decades – the 1980s and 1990s. Since these records did not have a specific year, they were lumped into 1985 and 1995, hence the higher counts in those years.   You can fill in a form for your garden in 2018 here

From 2007 to 2011 the British Trust for Ornithology were gathering data on birds for a national atlas.  As I (and a few others) traveled around the county looking for birds, I recorded mammals and butterflies too.  This explains a lot of the high record numbers in that period.  The BTO also runs a weekly garden birdwatch survey in which participants can record other garden wildlife as well as birds.  This has contributed to the dataset since 2006.

It is easy to contribute records of mammals, and anything else.

Record your sightings of moles (and any other species you can see around you – try for a minimum of five) on the West Wales Biodiversity Information Centre recording system (if you are in West Wales) or on iRecord.

Add the mammals in your garden (or nearby) to the dataset for 2018 here.  You can also add data for 2017 and 2016 on separate forms.  Your contribution will be very much appreciated.