Grizzly Bears, Orcas and more - in a Day?

 

Grizzly Bears (above) and Orcas (aka Killer Whales), the two wildlife stars of Canada's Pacific Northwest, were top of my 'must see' list for a trip to British Columbia this summer. But what was the best way to guarantee sightings of both?  

The Great Bear Rainforest (link here) holds one of the largest populations of Grizzly Bears on Canada's west coast. It is an area of scenic splendour, where the Coast Mountains plunge from high icefields down densely forested slopes to fjord-like inlets that penetrate deep into the mountain massif. There are few settlements and no road access. Getting into this landscape requires either boat or floatplane while accommodation options are limited to a small number of wilderness lodges. None of this comes cheap.

September is the peak season for grizzly sightings when the bears hang around river mouths to feast on the annual salmon run. But the need to stick to UK school holidays meant that we had to travel earlier in the summer. Could we justify the expense of a lodge stay at a time when bears might be harder to find?

A bit of online research provided the answer. Sea Wolf Adventures is a First Nations-led tour company that runs day trips from Port McNeill at the northern end of Vancouver Island over the Johnstone Strait, through the pine and spruce-clad islands of the Broughton Archipelago and right into the heart of the Great Bear Rainforest. As well as offering the chance of a Grizzly Bear encounter, these boat tours seek out the area's marine life highlights, of which Orcas top the bill. The chance to score my two top wildlife goals in a single day was too good an opportunity to miss.

Vancouver Island from the Broughton Archipelago

Port McNeill is a small working port with only a few places to stay or eat. Our base here was the Black Bear Resort Hotel (link), a decent motel just up the hill from the village centre, while the Devil's Bath Brewing Company down by the harbour (link) provided excellent pizzas, a good range of craft ales and a generally nice vibe. Both are recommended.

0630 on a Friday morning saw us down at harbour waiting to get checked in the Sea Wolf Adventures office. The sun was shining and the sea was still: it was a lovely morning. A quick waterfront wander produced the startling sight of two Bald Eagles perched on an electricity pylon. Apparently, this is a normal morning occurrence at Port McNeill. Although these birds are common on Canada's west coast, seeing them so close-up was a special moment. Regal is the word.

Bald Eagle - Port McNeil, Vancouver Island BC

Back at the office we discovered the rest of the party donning life jackets and filling travel mugs with coffee. We met our host (Hannah) and driver (Mike), who led us down to the pontoons and onto the boat, where we shamelessly bagged the two front seats. Mike explained later that the Mayumi, named for his daughter, had been custom-built for the company; two huge outboards gave it some serious thrust when he fully opened the throttle, and it covered the miles with ease.

Mayumi at the dock in Port McNeill

After slowly navigating out of the harbour, Mike set a course for the islands of the Broughton Archipelago on the far side of the Johnstone Strait. The islands form a maze of waterways, along which we cruised slowly looking for bears on the shoreline. There were none to be seen, but a Humpback Whale feeding close inshore near a narrow passage called The Blow Hole came as a surprise; the coastal waters are deep here, even very close to the shore. 

Humpback Whale diving close to the shore - Broughton Archipelago

After passing through the Blow Hole, Mike decided to head up to Knight Inlet and we were soon battling up this arrow-straight fjord at some speed into a stiff wind. Things got a bit bumpy. You might think that these land-enclosed waters would be sheltered, but the mountains here seemed to funnel the wind right towards us.  The skies were overcast and gloomy, a stark contrast to the sun that had been shining over the Johnstone Strait. But these mountains attract the clouds - and the rain. This accounts for the forests' rich understorey vegetation, including berry-bearing bushes like Salal much favoured by bears, as well as the abundant epiphytes that have made their home on tree trunks and branches.

Conifer forests on the shores of Knight Inlet, BC

Mike was on the radio and it’s clear (with hindsight) that he’d been a tipped-off about a bear sighting. After some distance, and about two hours into the boat ride, he aimed the boat at a rocky promontory and slowed down the engines: our first Grizzly Bear was foraging down by the water's edge, an adult female with two cubs (but only one cub visible in the image below). She's also the one pictured in the image at the beginning of this blog post.

Grizzly Bear mother and cub - Knight Inlet BC

From a distance, the adult bear looked just like one of the larger rocks on the shoreline, albeit a rock that was moving. But as we moved closer more detail was revealed. Mike took the boat in slowly and suggested that we might like to get out on deck. I didn't need telling twice, and made a bee-line for the forward hatch. I was soon perched above the bow as the boat came closer towards the rocky shore. 

The Grizzly Bear cub on the left has spotted something ...

The cubs were constantly moving about, also searching for food, although they will be fed on their mother’s milk for up to two years. These ones were probably around 6 months old; cubs are born in the den during the winter months. I loved the way that one cub stood up on its hindlegs, giving a sharp stare to the nearby gulls (above). All three bears seemed unfazed by our presence.

We spent about a quarter or an hour bobbing about getting views of this our first bear family, before another boat appeared which was our signal to head off to avoid overcrowding. The bears didn’t even seem to notice our departure. Mike started to retrace our route westwards down Knight Inlet but stopped after about ten minutes and slowly pulled in towards the shore again. This was bear family number two, another female (below), also with two cubs, occupying a separate territory to the first female. Mike said that this (second) female was the daughter of the first one. And she did look a bit younger and less, well, grizzled than the first adult bear. Grizzlies can live a long time, up to their 30s.

The second Grizzly Bear mother - Knight Inlet, BC

Neither adult bear looked exactly big or chunky, probably because spring and summer have provided them with comparatively short rations. Bears survive remarkably well during hibernation, being able to subsist without food or water for six months by relying on fat reserves and recycling their fluids. During the summer they feed on berries and can scavenge carrion as well as hunting birds and small mammals. But for coastal bears such as these the big feast comes in September with the salmon run, their big chance to stock up before hibernating.

Grizzlies are part of the larger Brown Bear Ursus arctos species which also occurs in Europe and Asia (and originally in parts of North Africa). Brown Bears are classed as being of ‘least concern’ in conservation terms, given their (very) large range and a stable population that may now be increasing in some areas. However, the IUCN’s population estimate (110,000 individuals) is massively less than the 200-250,000 previously estimated in McDonald et al (2002) so it’s not all good news, and some of the more isolated populations of Brown Bears are clearly in trouble. This doesn’t seem to be the case for the Great Bear Rainforest, which (as best I can find out) is home to around 6,000 Grizzly Bears out of some 20,000 in Canada. (Please let me know if more detailed figures are available.)

For completeness, here’s a photo (below) of the second Grizzly mother with her two cubs. We spent ten minutes watching them move slowly over the shoreline rocks before Mike backed the boat away and we resumed our return ride down Knight Inlet.

The second Grizzly Bear mother with both cubs - Knight Inlet, BC

We were pleased with these sightings but one more Grizzly Bear encounter remained in store. Back in the labyrinth of channels through the Broughton Archipelago, Mike navigated us to a sheltered cove next to Bowers Island. Some movement at the forest edge revealed the presence of a lone Grizzly (below), almost certainly a male given its hefty bulk, staring out of the gloom. (I'm blaming the distance and low light levels for the poor quality of the image below).

Male Grizzly Bear seen at a distance!

We sat in the boat waiting to see if he would come out any further. The bear stared straight at us and gave what looked like an exploratory sniff before turning on its tail and stalking slowly back into the forest’s shadows. Oh well - you can't have everything.

It was time to move onto the second phase of the day's explorations, so Mike turned the boat towards the Johnstone Strait heading for Blackfish Sound which, as its name might suggest, is a happy hunting ground for Orcas. That colloquial (and biologically inaccurate) term can equally apply to Humpback Whales, which are also present there. First, however, it was lunchtime, and we stopped for half an hour in another rocky bay, where a Wandering Tattler fly-by (below) was another new entry on the holiday bird list. Wandering Tattlers breed in the far north – Alaska and eastern Russia – but winter down both sides of the Pacific as far south as Chile and Australia. Their ‘wandering’ tag is well justified. (ID note: the thin white stripe above the eye separates Wandering Tattler from the two yellowlegs species, while the absence of a white rump in flight rules out the two dowitchers).

Wandering Tattler - Blackfish Sound, BC

Out on Blackfish Sound the number of seabirds was increasing, and amongst the many gulls (mostly Glaucous-winged and Short-billed) were many good numbers of auks, including the bizarrely-billed Rhinoceros Auklet, another new species for me. The photo below shows the weird horn-like extension sticking out of the top of its bill: technically this is part of the rhamphotheca (a new word for me) which is the keratin sheath that covers the bill's central bone. The horn is only present in breeding adults and is shed each year, like the colourful sheath on a breeding Puffin’s bill.

Rhinoceros Auklet - Blackfish Sound, BC

But our attention was quickly diverted from the auks: our first group of Orcas (below) was up ahead.

Orcas - Blackfish Sound, BC

There were four in the group, keeping very close together. Judging by the dorsal fins, they were two older adults and two younger individuals. The Orcas around Vancouver Island have been the subject of intensive scientific study. This reveals that two main types of Orcas can be found in these coastal waters - Residents and Transients. As might be expected, the Residents stay around here all year round, feeding mainly on fish. In contrast, the Transients - which are a bit larger, with slightly different markings - are more mobile, following and hunting marine mammals. Our Orcas here were Residents, and a study of the most recent photo-catalogue (Towers et al, 2020) meant that Mike and Hannah were able to identify the individuals concerned - namely matriline (the name given to these small female-led groups) number A23.

At this point a second group of Orcas came into view (below). This included an individual with a distinct notch in the back of its dorsal fin. The photo-catalogue, which can be downloaded online, identifies it as female A55, who was born in 1987. Orcas can be very long-lived, with females as old as 90 recorded in the wild.

Two of the second group of Orcas.

Female Orca A55, with notched dorsal fin.

We spent almost an hour watching the two groups of Orcas. At first, I didn’t notice that a massive cruise ship had loomed up behind us, heading south. It seemed a grotesque intrusion into such a peaceful and beautiful scene. Mike moved our boat to one side while the Orcas made off in the other direction. The cruise liner bombed past us at speed and disappeared quickly. I could see very few people on the decks or cabin balconies: were any of them aware of the presence of the Orcas?

It was time for us to move on, but we soon picked up an observer that surfaced close to the boat ...

Steller Sea Lion - Blackfish Sound, BC

One of the largest sea lions, Steller Sea Lion is found on both sides of the northern Pacific. Apart from size, and this was clearly a big beast, the key identification feature for Steller is the pale, almost yellow, colour body which contrasts with the dark limbs - seen below giving us a cheeky wave.

Steller Sea Lion waving a flipper.

Steller Sea Lion

And that was almost the end of the show. After a brief detour past the settlement at Alert Bay, where Mike gave us a bit of the history of the First Nations and their battles with authorities to protect their culture and way of life, we made the short crossing back to Port McNeill. 

Sea Otter - Port McNeill, BC

But there was a final wildlife highlight: a single male Sea Otter (above) was having a snack just outside the breakwater of Port McNeill harbour. Further south on the Pacific coast, these engaging animals are easily (and famously) seen in California's Monterey Bay - see my blog post about them here - where they are present in good numbers.

The fortunes of Vancouver Island's Sea Otters haven't been quite as rosy as their Californian cousins. Originally hunted to extinction for fur, the species was reintroduced to the island in the late 1960s with 89 otters brought down from Alaskan waters. Numbers have since grown significantly, with over 3180 counted in 2005 - the most recent data that I can find (Nichol, 2005). The relocation site was on the Pacific Ocean side of the island (the opposite side to Port McNeill), and that is where the bulk of the Vancouver Island population remains. Mike and Hannah told us that only single males have so far made it around to the Port McNeill area. It's heartening to know that their distribution is still spreading, and hopefully some females will turn up in due course.

And that was that. We went back to the office, handed back out life jackets and travel mugs, and said our farewells. It had been an epic day of wildlife watching. What really stood out, apart from the diversity of species, fantastic scenery and sense of being in a wilderness, was the opportunity to spend a time watching charismatic animals doing their thing in a relaxed and hassle-free way – for both them and us. And that, really, is unbeatable. 

Huge thanks to Mike and Hannah of Sea Wolf Adventures!

References:

McDonald, D. ed. (2006) The Encyclopedia of Mammals. Oxford: OUP.

Nichol, L.M. (2007) Recovery potential assessment for sea otters (Enhydra lutris) in Canada. Fisheries and Oceans Canada, Science.

Shirihai, H. and Jarrett, B. (2006) Whales Dolphins and Seals: A Field Guide to the Marine Mammals of the World. London: A&C Black.

Sibley, D. (2003) Field Guide to the Birds of Western North America. London: Christopher Helm. (Indispensable!)

Towers, J., Pilkington, J., Gisborne, B., Wright, B., Ellis, G., Ford, J and Doniol-Valcroze, T. (2020) Photo-identification Catalogue and Status of the Northern Resident Killer Whale Population in 2019. Nanaimo: Fisheries and Oceans Canada.

 

Exploring Costa Rica's Undiscovered Wetland

Pinnated Bittern - Medio Queso

Mention Costa Rica as a birding destination and you'll quickly start hearing about cloud forests like Monteverde and the Dota Valley or lowland rainforests like La Selva and the Osa Peninsula. But it's not all about forest birding - Costa Rica boasts some fabulous wetlands packed with an enticing range of birds and other wildlife. The most famous include Palo Verde National Park, sited in the otherwise dry forests of the north east, and Caño Negro up in the north, which drains over the border into Lake Nicaragua.

But there's another wetland near the Nicaraguan border that is much less well known, and far more accessible than Caño Negro. This is Medio Queso, which bafflingly translates as 'half cheese'.  Only a short drive east of Los Chiles, the last town before the Nicaraguan border, the wetland is reached by a road that starts near the local airport and, at the time of our visit, ended next to a new bridge (still being built in late 2024) across the Rio Medio Queso. A small dock beside the road is the starting point for a boat ride that explores these productive marshes.  

Medio Queso - relaxed wetland birding

Boat trips have provided some of my tropical birding highlights, and our visit to the wetlands of Medio Queso was no exception. The weather was hot, still and sunny as we cruised under the bridge and headed north along the main channel. The expansive view towards the hills of Nicaragua (above) was a refreshing contrast to the crowded forest trails that we'd experienced over the previous few days. 

Although excellent for birds, the Medio Queso wetlands are not protected – apart, oddly, for the small part over the border in Nicaragua, although you wonder what that means in practice. Our guide, Pat O'Donnell, had done his best to put the place on the Costa Rica birding map, and the presence of boat, boatman and local guide were encouraging signs. (There's more on Medio Queso in Pat's blog - link here).

Northern Jacana - Medio Queso

Water levels were high, and Pat was concerned that it might be harder to locate the key species. As it turned out, we did pretty well. This Northern Jacana (above) gave wonderfully close views. I love jacanas. For me they are a definitive bird of tropical wetlands, effortlessly balancing on lily pads in their hunt for a watery meal. Northern Jacanas look especially smart, with their yellow frontal shield and cool chestnut and black two-tone livery.  Northern Jacana females hold a territory containing up to four males (the technical term is polyandrous) and may be juggling several pair bonds at the same time. Males do most of the parental jobs like incubating eggs and brooding chicks, although females will step in to help at times. Very good of them, I’m sure.

Pinnated Bittern posing at Medio Queso

The jacana was only the start. The boat's passage startled a Pinnated Bittern (above and at the top of this blog post) which was stalking through the shallows. It flew off down the channel in front of us and landed a couple of times before being displaced again as we approached. In the end it gave up and flew off to one side. Pinnated Bitterns share the tendency of their Eurasian cousins to sit silently in reed beds, so getting a clear sight of one like this was very satisfying. The species has an oddly disjointed distribution, being found in various corners of the Neotropics including southern Mexico; a strip across northern South America; and an area including northern Argentina and Paraguay. It is absent from the Amazon basin.

Least Bittern - Medio Queso

A bit of a commotion on the boat announced the sighting of a Least Bittern (above). The guidebooks will tell you that this is an uncommon species in Costa Rica that is difficult to see because of its habit of skulking in dense vegetation. Well, this one was positively showy. In the Birdlife/HBW Checklist (which is the one I follow) Least Bittern is in the same genus (Ixobrychus) as Europe's Little Bittern, which it kind of resembles, and Australia's Black Bittern, which it doesn't. The bird's diminutive size isn't obvious from the above photo, but I can tell you that this is a seriously small heron. 

Neotropical Cormorant - Medio Queso

Rather more common, this Neotropical Cormorant (above) was nicely perched on a cecropia branch. (All of my other sources say ‘Neotropic’, but I’m sticking to the Checklist spelling.) The default cormorant for Central and South America, this species ranges from Texas down to Patagonia. 

At this point there was a burst of excitement as a low shape chugged over the waterway some distance ahead of us - my first Sungrebe. Not a great sighting, and no decent photograph, which is not ideal for a 'lifer' bird, but its characteristically long profile lying low in the water was distinctive enough. Sungrebes are bird oddities, sitting in the same small family as the Finfoots (Finfeet?!). They have a wide distribution across the Neotropics, so I'm sure that a better encounter will come along in the future. But life would dull if every bird sat up nicely for a photograph, wouldn't it? (Wouldn't it??)

More obliging was this Green Heron (above) eyeing up some movement in its riverside tree. It took me a while to be certain of the identification, as it differs from most of the other Green Herons that I’ve seen. This is because it's a juvenile, which is lighter and more streaky than the adult. The dark cap is a bit of a give-away, as is the white stripe below the eye. 

Anhinga - Medio Queso

Nearby, a snake-necked Anhinga (above) sat on the top of another riverside tree, surveying the marshy landscape. Also seen here, but not photographed were Slaty Spinetail, Scissor-tailed Flycatcher, Green-breasted Mango and a Purple Gallinule (below), which was having a bit of a skulk behind some watery vegetation. Think of a large, blue Moorhen and you've got the general idea. 

A Pied-billed Grebe sat at a distance with two young; also here were Snowy and Great White Egrets, Mangrove Swallow, Variable Seedeater and a neat little Common Tody-Flycatcher (below - this photo is actually from Pocosol a couple of days previously). 

Common Tody Flycatcher - Pocosol

Two Little Blue Herons flew over, followed by a flock of Red-winged Blackbirds. A White-throated Crake (below) chugged speedily across the river, white throat not visible. These are Costa Rica's most common crakes, being found in most wetland areas.

White-throated Crake moving at speed - Medio Queso

Yellow-breasted Crake - Medio Queso

Getting good views of birds like crakes is the mark of a successful wetland visit, and here at Medio Queso we were favoured by a second species - the Yellow-breasted Crake (above). This started to stalk away at speed over the lily pads when it caught sight of us, so the field marks are not all easily seen. But you can just make out the black stripe through the eye.

Spectacled Caiman - Medio Queso

It wasn't only birds. This Spectacled Caiman (above) has the sort of smug expression that says ‘I am in a good place for a caiman to be’. Limitless prey and plenty of cover. Although a common species in the Neotropics, it's always good to see one. The presence of the small crocodilians always seems to make a wetland seem all the wilder, even if they are considerably less dangerous than some of their larger cousins.

We had seen Groove-billed Anis on the previous day’s drive up to Los Chiles, but it was good to get a better look at one sitting near the watercourse (below). The grooves in the bill are just about visible here.  Although in the cuckoo family, Anis are communal breeders rather than brood parasites. Females nest together and share duties of feeding and incubation.

Groove-billed Ani - Medio Queso

Now the boatman turned around, and we puttered back under the bridge where we’d begun, continuing on to explore the channel to the south. Several stands of mature trees flanked this section of river, and a number of smaller birds were added to the list: Thick-billed Seed-finch, Canebreak Wren, Orchard Oriole, Barred Antshrike and Rose-breasted Grosbeak. And I realise that I've forgotten to mention this flying Roseate Spoonbill (below) seen earlier in the day; it was quite distant, so my photo doesn't do it justice. They are (literally) brilliant and startling additions to the wetlands of the Neotropics.

Roseate Spoonbill - Medio Queso

The morning had warmed up and raptors were starting to appear. A hawk (below) circled above us, before diving down into the reeds. There was some debate about what it was: Pat suggested White-tailed Hawk, which was confirmed when it flew up again. The single dark band at the tail end is diagnostic; the mopre common Short-tailed Hawk, which has a similar head pattern, has lighter bars on the tail. Also, the wing shape – this is broad and pointed, with a relatively straight trailing edge. Short-tailed Hawk has a more rounded trailing edge. White-tailed Hawk has two colour phases: this was the more common light morph. But it was surprising to see it here because Medio Queso is out of the range shown in the field guide. Very much a species of open lands rather than the forest.

White-tailed Hawk - Medio Queso

The hawk was a suitable way to sign off a magical morning of relaxed wetland birding. The next day we would be back on the rainforest trails - but that's another story.

References

Garrigues, R. and Dean, R. (2014) Birds of Costa Rica (2nd ed). London: Helm

Link to purchase Pat O'Donnell's guidebook How to See, Find, and Identify Birds in Costa Rica

Know Your British Lizards!

 

Britain doesn't have many lizards, so surely it's not difficult to work out which species is which? Wrong! I sometimes get confused, and I know that I'm not alone. It doesn't help that lizards don't always hang around to give you a good view. Too often, you only see a flash of movement or catch a glimpse of a tail vanishing at speed under a rock or into a bush. 

Anyway, as a budding reptile surveyor  I've been trying to learn the key identification features that separate Britain's lizards. In doing so I have relied heavily on the two field guides mentioned at the end of this post, strongly supported by guidance and training from experts including Sue Searle, Howard Inns and Rick Sharp. My notes have somehow ended up as this blog post, which I hope that you find useful too. The photos are all my own.

It's also worth knowing that Amphibian and Reptile Conservation, who do much to conserve and promote Britain's reptiles, have prepared a useful (and free) online reptile identification guide which covers snakes as well as lizards. It can be downloaded from their website (link here). 

I'm focusing here on four species: three lizards that look like lizards - Common (or Viviparous) Lizard Zootoca vivipara (pictured at the top of this blog post), Sand Lizard Lacerta agilis and the non-native Wall Lizard Podarcis muralis - as well as the legless Slow Worm Anguis fragilis. I've included Wall Lizards because they have become well-established in a number of mainly coastal sites in the south of England - many of which are in Dorset where I'm based - see my blog post here.

I've concentrated on features that can be distinguished by the field observer, ideally with a photograph, rather than anatomical details that require an 'in-hand' examination such as femoral pores and supraciliary granules. For most of us this is simply impractical, and for Sand Lizards it would be illegal without a licence, as that species is protected in the UK - so don't even think about picking one up! I'm sure that most of us would rather avoid disturbing these lovely creatures in any event.   

The Slow Worm is probably the most common of all our reptiles, being found right across mainland Britain. Having no legs, it can be clearly distinguished from our other lizards, looking in the first instance more like a snake. But on closer inspection you'll see that they have a less slender and more chunky profile than our three native snakes, as well as a distinctly Common Lizard-like head. 

Slow Worms are the most likely lizards to turn up in a back garden. If they arrive in yours then count your blessings and try to maintain a patch of undisturbed long grass and a few bushes for them. Compost heaps go down particularly well.

Slow Worm (male) - Dorset

The photo above shows a male Slow Worm. These are usually a uniform light brown colour sometimes dotted with startling blue spots. In contrast, the females tend to have darker sides and/or a dark stripe along the back (the dorsal or vertebral stripe) - see below. 

Slow Worm (female) - Dorset

The dark sides and dorsal stripe are also characteristic of juvenile Slow Worms. However, these will (unsurprisingly!) be much smaller than adults with brighter and more clearly defined markings. The dorsal stripe on juveniles often ends in a dot next to the head, as in the example below.

Slow Worm (juvenile) - Dorset

Right, onto lizards with legs. These are more tricky, but at least they do look like lizards.

First, the magnificent Sand Lizard. 

Sand Lizard male - RSPB Arne, Dorset

Sand Lizards are the most distinctive of Britain's legged lizards. (I did a blog about them last year, which you can find here). The key distinguishing features are set out below, but please be aware that Sand Lizards are a strictly protected species, so keep your distance and avoid disturbing them or their habitat.

• Sand Lizards are larger than either Common or Wall Lizards, with a total length of up to 25cm rather than 22cm (Wall Lizard) or 20cm (Common Lizard). Not that this helps with smaller individuals!
• Sand Lizards usually have two white or cream-coloured streaks down the back (dorsal streaks) - see the photo below.
• The spots on male, female and juvenile Sand Lizards are usually ocellated, meaning that they have a lighter ("eye-spot") in the middle. This is a key feature that is not present on Wall Lizards, although you need to look carefully at the spotting on female Common Lizards especially when they are flattening themselves while basking in the sun.
• As my photos show, male Sand Lizards usually have striking green flanks. However, females are brown all over, dotted with ocellated spots (no photos - apologies). But beware! Male Wall Lizards can also show green, which gets brighter during the breeding season (see the photo later in this blog post) and you can occasionally see green Common Lizards. However, in both cases, any green on Common and Wall Lizards extends across the back, while on male Sand Lizards it is restricted to the sides. 
• Sand Lizards are generally more heavily built, or "chunky", than Common or Wall Lizards.
• The final point to bear in mind about Sand Lizards is that in Britain they have a limited distribution, being confined generally to heathland in Dorset, Hampshire and Surrey along with sand dunes near Southport, Merseyside. They have been more recently introduced to sites in Devon, Cornwall, Berkshire, North Wales and Kent (possibly more). However, I'm not aware of any British locations where Sand Lizards co-exist with Wall Lizards.

Sand Lizard (male) - RSPB Arne, Dorset

Next, Common Lizards. These are also known as Viviparous Lizards, as they give birth to live young rather than the egg-laying Sand and Wall Lizards, but I'm using Common Lizard in this blog for simplicity. Like Slow Worms, the range of Common Lizards extends in theory (and on the distribution maps of many field guides) across the whole of mainland Britain. But in practice they are more scarce, and may be absent from large areas of intensively farmed land or built development. Generally, they favour undisturbed and open landscapes such as heaths or downland; in the former setting, their range overlaps with that of Sand Lizards although Common Lizards tend to prefer damper and grassier places while Sand Lizards are happier in drier areas dominated by heather and gorse.  

Common Lizard - Higher Hyde Heath, Dorset - showing re-grown tail

Distinguishing male and female Common Lizards is far less easy than for Sand Lizards. Males are generally more speckled, while females tend to look more stripey. I think that the photo above is probably a male, given the flecked pattern on its back, but the obvious light-coloured stripes give me some pause for thought. Nobody said it would be straightforward! (If the belly is visible, which it isn't in this image, then things get easier: males have a yellow-orange underside, while females are a plainer beige colour below.)

So, what are the key identification features that distinguish Common Lizards from Sand and Wall Lizards? As noted above, both Sand and Wall Lizards have very restricted distributions in Britain. If you are not on lowland heath or coastal dunes then you are highly unlikely to be looking at a Sand Lizard, while Wall Lizards tend not to stray far from their known colonies, which are mostly in Southern England (see here for more details). However, if you are in an area of possible confusion then the following may help:

• Compared to Sand Lizards:
• Common Lizards generally do not show any green colour, but if green is present then it will be right across the back and not confined to the sides. It will also usually be less vivid than the green of a male Sand Lizard.
• Any spots on Common Lizards will usually not be ocellated, so will appear as white flecks rather than dark spots with a central white "eye". 
• Common Lizards are smaller and more slender, with much less bulky heads than Sand Lizards (see photos below).

Common Lizard - head 

Sand Lizard - head

Wall Lizard - head

• Compared to Wall Lizards:
• Common Lizards tend to be slightly smaller than Wall Lizards, although this is not always obvious and you very rarely (i.e. never!) see both species side-by-side to compare.
• The markings on Common Lizards are generally either speckles (including patches of white) on the males or light-coloured stripes on the females, while Wall Lizards usually have more mottled markings (see photo below).
• Common Lizards have a blunter snout than the more pointed snout of Wall Lizards. This is just about apparent in the respective head photos above, but in the field I find that I need either a very  good look at the lizard or a decent photograph.
• Although by no means definitive, Common Lizards tend to be seen in flatter, grassy areas, while Wall Lizards are usually not far away from a vertical rocky habitat: they are well-named. Even though the Wall Lizard photographed below was basking on leaf litter, it was less than a metre from a large south-facing stone wall.

Wall Lizard showing mottled pattern - Abbotsbury, Dorset

Finally, this brings us to Wall Lizards. Strictly these are called Common Wall Lizards, as there are a wide variety of wall lizard species across Europe (see Speybroeck et al., 2016), but I've deleted the "Common" in this blog for reasons of clarity, given the risk of confusion with Common Lizards.

Wall Lizard male with bright colouration - Abbotsbury, Dorset

The main identification features that distinguish Wall Lizards from Sand and Common Lizards have already been described above, so there's no need to restate them again in detail. The important thing to remember is that the colouration of Wall Lizards is very variable, and males of the populations of southern England can have either green or brown backs depending upon where the original introduction was sourced (generally green from Italy and brown from France). Colour alone is generally not a reliable way of separating Wall Lizards from Common Lizards, although a useful tip is that some male Wall Lizards show a blue patch on the side of the belly - see the example below from Portland, Dorset. As far as I'm aware this is not a feature found in Common Lizards.

Wall Lizard male with brown back and blue sides to belly - Portland, Dorset

Anyway, I hope that this is helpful - do let me know if I've made any errors or if anything isn't clear. I intend to update this post as I get more field experience with these species.

Postscript: For the sake of completeness, I should add that there is a further lizard species on British soil - the (Western) Green Lizard Lacerta bilineata, which as well as being a native of Jersey, an island that also hosts native Wall Lizards but no Common Lizards, has a longstanding introduced population in Bournemouth of all places. Western Green Lizards are large (up to double the size of a Sand Lizard) and truly spectacular. I have yet to get a decent photograph of one, but in compensation here's a magnificent (and very similar) Eastern Green Lizard L. viridis that I photographed in northern Greece. Enjoy!

(Eastern) Green Lizard - Lake Kerkini, Greeve

References

Inns, H. (2009). Britain's Reptiles and Amphibians Wildguides. Especially useful, as it focuses upon the few British species (plus introductions).

Speybroeck, J. et al. (2016) Field Guide to the Amphibians & Reptiles of Europe (British Wildlife Field Guides) London: Bloomsbury. Frankly, this is rather daunting given the much greater diversity of lizard species on the continent and the taxonomic complications of some groups (such as Iberian Wall Lizards). But it's good to see the British species in their wider context.