Many mammals, by their nature, are scarcely seen at Paxton Pits--but they are there! For most species, the best chance is around dawn or dusk, since many are nocturnal. We'd appreciate any records of sightings.
Otter (Howard Birley)
Rabbits are the most frequently seen species, especially in the open, sandy areas near Hayden Hide. Brown hare, on the other hand, is scarce, with a maximum of four at any one time around the northern pits, though they could go undetected on the surrounding farmland. There are probably several family groups of foxes, especially on the farmland around the northern lakes, with animals often resting on the banks of Heronry North on sunny winter days. Stoats and weasels are enigmatic at Paxton, and we receive only occasional reports of both. Badgers are present, but scarce, with infrequent signs of them and even fewer sightings. We had a report of a roe deer in 2002, but this is the only record ever. At least two species of bat occur at Paxton, the noctule and the pipistrelle (though this has recently been 'split' into two species, which call at different frequencies, and it will require some ultrasonic surveys to determine whether we have both).
Three introduced species occur around the Pits. Muntjac deer are seen regularly, though probably occur at low density. Grey squirrels are seen regularly in the mature trees between Heronry and Sailing Lakes, as well as in village gardens. Mink, also from North America, have been present around the reserve for two decades, but anecdotal observations suggest that they are less common than just five years ago. Two theories have been put forward: the increase in otters in the Ouse catchment (which may out-compete the mink for food), and Aleutian disease, a virus that can kill up to 98% of young mink and leave the adults in poor health.
Paxton's most popular mammal, and one that every visitor wants to see, is the otter. Poor water quality in the Ouse Valley meant that the species was locally extinct for 30 years, but in 2002 and 2003 occasional sightings suggested that it might be making a return. To encourage them, volunteers built an artificial holt (an otter home) on the east bank of Heronry North, viewable north from Kingfisher Hide (look on the right hand bank and you should see the entrance pipes).
Sightings have increased, with increasing evidence for several animals being present, and in February 2007 breeding was confirmed with the welcome record of a female and two small cubs.
Building the otter holt (Jim Stevenson)
Of the small mammals, surveys have confirmed the presence of harvest mouse at the Pits, which is good news as they are declining nationally. Water shrews were also surveyed in 2000 and were found in two areas. Short-tailed field voles are found in all areas of coarse grass, and are found every year on the Sailing Lake islands by conservation work parties. We also know, from field observations, that wood mouse and brown rat are present around the lakes, the latter seen occasionally on the bird tables.