May is the month in which badger cubs start venturing above ground and can be found playing close to the sett. Often the first sign of their emergence is patches of flattened bluebells. Fox parents are still busy supplying food for their rapidly growing cubs, which may now start accompanying them on foraging trips. As the cubs grow, they hone their hunting skills by play-fighting with their littermates. These games can be so absorbing that the young foxes will sometimes come within a few feet of a quiet observer. There are also young stoats and weasels to be found this month, sometimes seen travelling in family groups. Their dancing play is mesmerising to watch and it has been suggested that they use this to “hypnotise” rabbits, allowing them to get within striking distance.
Hedgehog courtship gets into full swing this month, with a male circling an initially unwilling female as she huffs and headbutts at his side. I’ve witnessed this a few times in my garden; in one case it went on for the best part of two hours, while on another night it lasted for only about 40 minutes before the female relented and the two wandered off together. Hedgehogs gestate for about a month, so the first litters usually start appearing towards the end of June. If you’re gardening over the next few weeks, please take a minute to check long grass for sleeping hedgehogs before mowing or strimming.
Late May is also when deer begin giving birth to their kids, calves and fawns (depending on species). In my experience, roe are the first to drop their kids, with red and sika calves and fallow fawns following shortly afterwards. Chinese water deer, again in my experience, tend to be later, dropping their fawns in late June or early July. Muntjac can breed throughout the year. In the event that you come across a baby deer lying in the vegetation, please do not touch it. It is perfectly normal for mothers to leave their young hiding among tall grass and bracken during the first couple of weeks after birth, and it is very rare for a mother to abandon her offspring. Every year many deer fawns are taken into wildlife rescue centres by well-meaning but uninformed members of the public who think the youngsters need help. Intervene if the deer is injured, but otherwise do not touch the fawn and just leave it where you found it; its mother will be nearby.
If there was a lot of squirrel activity in your local park at the start of the year it’s a fair bet that there will be squirrel kittens around soon, as winter mating typically leads to kittens born in late April or early May. Underground, the mole breeding season is coming to an end, with most females having already given birth, although the young won’t be seen above ground for another month or so. Many brown hares will have had their first litter by now – females average three litters per year during a breeding season that runs from February to October.
Finally, it’s a good month for rabbit-watching. May is a peak month for rabbit pregnancies and most colonies will have youngsters in residence now. Despite appearances to the contrary, rabbits are highly territorial and use scent to mark out the boundaries of their core areas. Each population (colony) of rabbits is subdivided into several distinct groups. These normally consist of four or five unrelated males (bucks) guarding up to about eight, generally related, females (does), although the social system varies from pairs to up to 20 individuals, depending on the population density.
The group will maintain a core area, typically around a breeding warren, that will be boundary-marked with scent and defended against neighbouring colonies. If the scent doesn’t deter intruders, rabbits will fight. Before any direct physical contact is initiated, however, the aggressors will use a suite of body language to convey their intentions. A rabbit with ears upright and facing forward, for example, is relaxed, but when the ears turn outwards it indicates they’re annoyed or tense, while ears facing backwards is a sign that the rabbit is about to attack. A flicking of the back feet is also used to signal annoyance, while high-pitched squeals and the thumping of a back foot are used to indicate alarm. Fights involve combatants jumping and twisting while each attempts to bite or scratch the other. Dominant males from adjacent social groups within the same colony will maintain their territory using another series of displays, including parallel running along, and scraping the ground at, the boundary.
In a fascinating article in BBC Wildlife back in 2007, University of East Anglia rabbit biologist Diana Bell described how new social groups form through “social budding”. When the number of females in the current group exceeds about eight, some of them start restricting their activities to the edge of the territory and it becomes progressively more difficult for the dominant buck to defend both groups. At this point, an immigrant buck challenges for dominance of the tearaway does and a new social group is born within the colony. Dr. Bell also noted that if the dominant buck is lost from the group, the testes of a fortunate subordinate will dramatically increase in size within a few days and he will take over.
Rabbits – and particularly young rabbits – are a powerful draw for predators, so it’s worth finding a secluded spot by your local rabbit colony and sitting and waiting; odds are it won’t be long before a fox, weasel, stoat, buzzard or, come dusk, badger arrives.
May is a good month for listening to birds as well as watching them, with the unmistakable call of the cuckoo, the chirruping whistle of the nightingale, the bubbling churr of the nightjar, and the treacly spring song of the blackbird to lift your spirits. Whitethroats are busy singing away on gorse and heathland here in the south, as are Dartford warblers. There’s plenty of song from robins, dunnocks, wrens and chiffchaffs too. Tawny owlets can be found branching now, while most other owl species will be feeding nest-bound chicks. The Barn Owl Trust’s website has a good guide on what to do if you find an owlet out of the nest. Please remember that tawny owlets are very precocious and will branch at a young age, so just being out of the nest is not necessarily an issue.
Depending on how spring began, weather-wise, many garden birds may already have produced their first brood. There should be a few goslings and ducklings to be found now, and great crested grebes will either be in the final stages of incubation or carrying their humbug-striped chicks around on their backs, so keep an eye out if you visit your local lake or pond.
Most people will have noticed that swifts, martins and swallows are now back in the UK. Personally, I love to hear the summery sound of swifts screaming overhead as I walk to work. Swallows in particular have a rich mythology in Britain. In spring our ponds and pools are alive with swallows gathering mud for their nests. As they collect mud they leave small pits on the bank of the pond and this is probably the source of early theories that swallows and martins hibernated in muddy burrows around ponds. The mystery of where these birds go in winter wasn’t solved until a swallow chick from a Staffordshire porch nest was ringed in May 1911 by John Masefield and netted by chance on a farm in Roodeyand, South Africa, some 6,000 miles away, during December 1912.
In the south of Britain, May heralds the arrival of chiffchaffs, redstarts and tree pipits, with blackcaps, willow and wood warblers following shortly after. Other ambient species include stonechats, skylarks, hobbys, winchats, lapwings, geese, turnstones, and spotted flycatchers.
Reptiles & amphibians
All our reptile and amphibian species are active during this month. Frogs and toads have finished breeding now, with most spawn having hatched. If you have tadpoles in your pond, keep an eye out for them starting to develop back legs, the buds for which appear before those for their arms; this signals a sharp increase in protein requirement and their diet switches to a meat-based one. Newts may still be spawning and this is easiest to watch at night with the aid of a torch.
While the breeding season has come to a close for our amphibians, things are just getting started among our reptiles. A male adder’s priority upon coming out of hibernation is to produce sperm in readiness for the emergence of the females later in the spring – hence he’s spent the past two months basking without feeding. The males will now have left their hibernacula (the places in which they overwinter) and will be actively searching for females with which to mate. Early May is a good month to see adders dancing (a fight in which two adult males intertwine, each trying to push the other down) and mating, the male and female curled up together.
May is also the start of the sand lizard breeding season and the males are at their most vibrant, sporting a bright green and brown marbled pattern. Unfortunately, sand lizards are a rare sight in the UK and currently restricted to a few isolated areas of sandy heathland in Dorset, Hampshire and Surrey as well as the sand dunes of Wales and Lancashire.
If you’re coast-bound this month, keep an eye out for the world’s second largest fish species; the basking shark, so named because early observers mistook its slow surface swimming while feeding for basking in the sunshine. Historic records put these fish anywhere up to 15m (49ft), but most of the empirical data we have suggest 10m (33ft) is likely to be closer to the maximum size and very few animals (i.e. fewer than 10%) recorded in British waters exceed 8m (26ft). These marine leviathans appear to be attracted to UK waters for two reasons: breeding, with reports of courtship behaviour (including nose-to-tail following, with the female in the lead) off the UK between May and July, and feeding. Basking sharks are highly migratory and while we once thought them to hibernate on the ocean floor during the winter, satellite tagging has now shown that they move widely, following the plankton blooms on which they feed.
Towards the end of spring an area of warmer water from the Atlantic ocean pushes its way into the cooler coastal waters off southern Britain. Warm and cold waters mix in an area known as the Ushant front, where high nutrient levels promote phytoplankton growth. When phytoplankton bloom, so too do its predators (i.e. zooplankton; largely calanoid copepods). When the conditions are calm, these critters form visible ‘planktonic slicks’ on the surface; it is these blooms that the basking sharks are attracted to. Consequently, baskers are generally first seen in the western English Channel and the southern Celtic sea during May. During ‘invasion’ years, shoals of several hundred animals can be seen off the coast, although numbers vary considerably year to year, largely in accordance with sea surface temperature rather than, as might have been assumed, zooplankton density. Shark sightings start in south-western England (prime spotting sites include the Lizard peninsula, Penzance, and Falmouth), with the sharks moving north into the Irish Sea and up to the Firth of Clyde and Sea of Hebrides as the summer progresses.
The appearance of butterflies is dependent on a suite of factors, including landscape changes, the prevailing weather conditions and how warm/dry last year’s summer was. Pearl-bordered fritillaries and the elusive purple emperor butterfly should also be on the wing this month.
Wolf spiders are abundant now, although most will be without egg sacs. If you’re in your garden after dark on mild nights this month and have a patio or any brick piles, look around carefully with a torch for the impressive pale pink-orange woodlouse spiders hunting their namesakes. A few other species to keep an eye out for this month include maybugs (aka common cockchafers), the elongate green and gold-spotted green tiger beetle, soldier beetles, nest-building wasps, hoverflies, well-armoured Minotaur and stag beetles, and the variously decorated longhorn beetles.
Pond-life is very busy at this time of year, and a dip into your local pond should reveal such delights are whirligig beetles, pond skaters, the great pond snail, and diving beetles as well as the ferocious dragonfly nymphs and water scorpions.
Slugs and snails hibernate when temperatures drop below about 5 Celsius (41 F), so they’ll now be active across the country. The average British garden is estimated to be home to about 20,000 slugs in late spring, and there’s little evidence that there’s much gardeners can do to reduce that. One study found that even removing several thousand slugs from a garden over the course of a year had no significant impact on the number found the following year. Generally, it seems that warmer winters and wetter summers are likely to allow slugs and snails to remain active throughout the year. It will be interesting to see whether a boom in slug and snail populations bodes well for their predators, such as slowworms, thrushes and glowworms.
Plants & fungi
Bluebells are at their best this time of year and there should be plenty of fruit blossom. Dog violet and campion add a splash of purple and pink, respectively, to our meadows and roadside verges this month, while wood sorrel, forget-me-nots and celandine provide the white, blue and yellow. May is also a great time for orchid-spotting, with early spider and bird’s-nest orchids, the dazzling-pink lady orchid and the aptly-named early purple orchid in bloom.
If you’re heading for the coast this month, spring squill, English scurvy grass and common thrift (or ‘sea pink’, above) are among the plants on display. Fungi-wise, keep an eye out for glistening ink-caps, false deathcaps, chicken of the woods and large parasol mushrooms.