An Urban Bioblitz

View of one corner of my urban gardenI’ve mentioned before that I live in quite an urban part of Bristol, and that although it’s a nice area and Bristol is a great place to live, my part of it is pretty much devoid of trees, grass or really anything other than tightly packed houses, cars and concrete.

I am lucky in having a small garden though, and I’ve tried hard to fill it with a range of different plants and to make it a bit more wildlife-friendly. Although I don’t own the house, my friend and landlady has been kind (or foolish?!) enough to let me move things around in the garden and plant what I like.

When I first moved in, the two tiny flowerbeds were covered in loose shale – something I don’t really understand; why have a flowerbed then cover it in stone so nothing grows? As soon as I removed this, wild garlic sprung up, followed this year by foxgloves. I have to wonder how long they’ve been waiting there for their chance to grow! There was also one small bush and a few plants in one corner, and since moving in I’ve planted various fruits and vegetables – with mixed success – and have planted up flowerbeds, pots and hanging baskets with species I hoped would attract bees, butterflies and other insects.

 Foxglove (Digitalis purpurea) Lavender flowers

Trailing lobelia flowersI have to confess that I’ve not done a lot of weeding, so various other plants have found their way in, including a buddleia which I just had to let grow (sorry to my landlady if you’re reading this – I’ll trim it back!).

So, although it’s not the patch of countryside I’d like it to be, at least compared to most of my neighbours’ gardens it’s a veritable jungle.

A Garden Bioblitz

I’ve also talked before about two “Bioblitz” events I’ve taken part in, at Chew Valley Lake and Tyntesfield Estate, both of which aimed to find as many species as possible in a particular area within a certain amount of time.

With this in mind, I decided to try a Bioblitz of my own – this time counting how many species live in my own, very urban, back yard. This was partly out of my own curiosity and interest – wanting to know what’s there and just how much can live in such an urban space – and partly as a way of putting my species identification skills to the test, something I’ll talk more about in a future blog. It was also a good chance for a bit of photography, and with such a tiny garden – really just a few square metres of patio, surrounded on all sides by terraced houses – it was fortunately not too daunting a task.

So, on a sunny afternoon back in July, much to the bemusement of my neighbours, I set out into the wilds of my garden with notepad, field guides and camera in hand to see what I could find.

The species hunt begins…

I started my search with the plants, seeing as these were what were most obviously surrounding me and they were not about to go anywhere. As well as listing those I had planted myself, I tried to identify all the “weeds” (or, as I call them, “wildflowers”), and I also took photos of everything so that I had a record and could use the photos to help identify things later. I also made sure I counted mosses, as well as one of the more interesting finds, a liverwort. The walls and stone plant pots were also home to lichens, although I’m not enough of a lichen expert to identify the different species. Many of the plants I’d counted were showing signs of disease so I tried to note these down too.

Petty spurge (Euphorbia peplus) Willowherb (Epilobium spp)

Liverwort (Marchantia polymorpha) Diseased courgette leaf Lichens on stone plant pot

The plants and lichens done, I moved onto the animal life. I’m always struck by the lack of birds here – I’ve seen plenty of different species around Bristol, yet never a single bird in my garden. There’s no such thing as a dawn chorus here either; the most I’ve heard is one lonely blackbird and the odd gull. There are always gulls flying overhead though, and the occasional magpie, wood pigeon or blue tit further down the road, as well as goldfinches which strangely enough seem to be everywhere. As part of my count, I made a list of species I’ve seen flying over the house (both during the count and at other times), but I didn’t include them in my overall species total – which is a shame as they have so far included 3 peregrines, 2 buzzards, several house martins, swifts and a raven!

There are also no mammals in the garden, not even urban foxes, which do well elsewhere in the city – it’s just too enclosed, with terraced houses on all sides and walls and fences everywhere. However, I felt I should technically include the neighbours’ cats, seeing as they seem to like the garden and are always out there…

Fortunately, although there were no birds, wild mammals, amphibians or reptiles, there were plenty of insects and other invertebrates. I was quite surprised by the number of different bee, wasp and hoverfly species, and there were quite a range of spiders, woodlice, snails and beetles. All got photographed and recorded, and I identified them to species level where I could.

Earthworm Woodlouse

Garden spider (Araneus diadematus) Hoverfly (Sphaerophoria scripta)


So – the result! I wasn’t aiming at an exact, definitive total as there were probably species I missed, I didn’t delve into every nook and cranny, and I wasn’t able to identify everything. I was also never going to be able to include all the fungi, bacteria and other microorganisms.

I did include species I’ve seen in the garden at other times though, and also one or two that have ventured into the house – I’m also still finding new species (if I don’t finish writing this blog soon I’ll probably have a few more to add to the list!) so my count was by no means exhaustive. However, it hopefully gives a rough snapshot of what I’ve found living in my garden this summer.

And the total number of species I counted was…

… 133 !

 Which broke down into:

  • 60 plant species (of which 26 were planted by me or previous tenants)
  • 2 mosses, 1 liverwort and 2+ lichen species
  • 43 insect species (including 2 butterflies, 11 moths, 3 bees, 4 wasps, 5 beetles, 3 hoverflies, 5 other flies, 1 grasshopper, 1 ant and 8 other miscellaneous bugs)
  • 12 arachnid species (9 spiders, 2 harvestmen and a pseudoscorpion)
  • 6 mollusc species (4 snails and at least 2 slugs)
  • 1 mammal (a cat!) – not including the human doing the counting…
  • 4 other invertebrate species (1 earthworm, 1 centipede and at least 2 woodlice)
  • At least 2 plant diseases (possibly fungi)

I’ve also recorded at least 19 bird species flying over the house or in the nearby street at various times, but I did not include these in the total as they don’t use my garden.

A few of my finds:

Crab spider eating aphid Harvestman

 Garden spider (Araneus diadematus) Tunnel web in wall

(Clockwise from top left: Crab spider, Harvestman, Tunnel web in wall, Garden spider)

Snail (Oxychilus spp)  White-lipped banded snail (Cepaea hortensis)

(Left: Oxychilus spp.; Right: white-lipped banded snail)

Comma butterfly (Polygonia c-album) caterpillar on blackcurrant Mint moth (Pyrausta aurata)

Mullein moth caterpillar (Shargacucullia verbasci)(Clockwise from top left: Comma butterfly caterpillar; Mint moth; Mullein moth caterpillar)

Rose chafer (Cetonia aurata) Rose chafer (Cetonia aurata) grub

Ground beetle(Clockwise from top left: Rose chafer; Rose chafer grub; Ground beetle)

Hoverfly (Sphaerophoria scripta)Green bottle fly Common froghopper (Philaenus spumarius)

 (Top: Hoverfly; Bottom left: Green bottle fly; Bottom right: Common froghopper)

I think I was most impressed by the number of spiders and snails – just half an hour digging up some potatoes last week added a surprising three more spider species and a further snail, as well as a second woodlouse species. There have also been a lot of different moths and their caterpillars.

There were also at least two ‘alien’ species (not including any non-native plants), a harlequin ladybird and a thriving colony of girdled snails:

Harlequin ladybird (Harmonia axyridis succinea) Girdled snail (Hygromia cinctella)

My most intriguing finds were these mummified aphids which have been parasitised by a small Praon wasp – the aphids’ bodies are hugely swollen and are attached to the nasturtium leaf by small discs:

Aphids parasitised by Praon wasp larvae

There was also this tiny creature, barely more than a millimetre or so in length, which I found crawling up my kitchen wall. Although not technically living in the garden it was exciting and I felt I had to include it! It’s a type of arachnid known as a pseudoscorpion. It has no tail or sting like true scorpions, but was still managing to look pretty menacing for something so miniscule:

Book scorpion (Chelifer cancroides)

One thing that struck me in doing this mini survey was the fact that it was making me look – properly look – at what was around me. For example, when the identification of a plant species depends on tiny features of its leaves, stems or flowers, you need to have a really close look at things you’d never normally notice. And I suddenly found myself hugely excited at spotting even the tiniest fly.

Something that probably stood out for me most though was that virtually every animal I counted was making use of something I had planted or allowed to grow, soil or compost I had uncovered or provided, or shelter I had created simply by leaving the garden a bit ‘untidy’. The flowers I had planted – including the veg I was trying to grow – were being used by what to me was a surprising number of bees and hoverflies, and every plant species seemed to have different creatures using it, feeding on its leaves or flowers, or simply sheltering on or inside it.

The plants were also supporting species such as aphids which in turn were being eaten by ladybirds, spiders and parasitic wasp larvae, while the various caterpillars, if not food for other things themselves, will hopefully go on to produce moths which in turn could feed local bats and other species.

Honey bee (Apis mellifera) Honey bee (Apis mellifera)

Buff-tailed bumblebee (Bombus terrestris) Hoverfly on rocket flower

There were also signs of nature finding a way to survive in even the most unlikely places, with plants pushing their way up through cracks in the patio or growing on walls. I could have weeded these out to tidy the garden up, but where would the enjoyment be in a bare and barren patch of bricks and concrete?

Escaping strawberry plant Wall-rue (Asplenium ruta-muraria)

Escaped love-in-a-mist (Nigella damascena) growing in patio

Concluding Thoughts

I think it says something about my level of wildlife geekiness that I really enjoyed the challenge of trying to identify even the smallest creatures I found in my mini-Bioblitz. I get a real buzz from each new creature I find – just discovering one more snail species can make my whole day!

I think my conclusions from the whole exercise though are mixed. On the one hand, it’s amazing how much you can find when you really look, and 133 species is a large number to find in an area just a few metres square, in the middle of the urban jungle, mostly during an hour or so one afternoon.

It’s also encouraging that even the smallest actions can have a positive effect on wildlife. For example, I planted a single, small blackcurrant bush which ended up being used by comma butterfly caterpillars. I let a few weeds grow by my back door – bees loved them and they are currently covered in moth cocoons. I let the buddleia grow and although I was disappointed at the lack of butterflies, it was popular with bees, hoverflies, caterpillars and the colourful rose chafer. I took the shale off the flowerbed and a whole range of plants sprang up. Just by providing a variety of plants, I was putting in place the base of the food chain and allowing other creatures to move in.

It’s not only wildlife that benefits either – I get huge enjoyment from seeing bright flowers, smelling the buddleia and seeing all the insects that come to feed on the flowers. And it makes the garden look nice too! The best thing is that you don’t have to spend ages on it either – the most wildlife-friendly gardens are often the ones that are not over-tidied.

Candytuft and love-in-a-mist in flowerbed Hoverfly (Scaeva pyrastri) on buddleia

However, I can’t help feeling that there should be so much more here. The thought I took away from the whole thing was that there is more in my garden than I expected, but so much less than there ought to be.

The fact that just one or two bees or a single butterfly is a cause for celebration surely points to how little there is here in the first place. The birds in particular are conspicuous by their absence – just before writing this I went home to Kent for the weekend and woke up to at least a dozen different species calling and singing outside my window each morning. I would never get that here. Also, stand out in the countryside in the summer and you’re likely to be surrounded by clouds of flies and other insects – where are they all in south Bristol? Something is surely wrong – the question has to be, what?

Garden snail (Helix aspersa)

Urban wildlife declines

There are many issues surrounding the declines in urban wildlife. They include the over-use of pesticides and other chemicals, the paving over of lawns, the cutting down of trees and bushes (forget health and safety – we really need our trees!), a tendency to be over-tidy in our gardens, and doing up our houses so birds are left without nesting sites and bats without roosts. We don’t want to see rainforests cut down, but we’re happy to chop our neighbourhood trees and pave over our wild areas. There’s also the issue of our pets, particularly cats – the friendly cat that visits my garden catches anything that moves and I’m pretty sure is responsible for an almost total lack of grasshoppers this year.

My big question though is why this part of Bristol in particular is so lacking in wildlife, when the city as a whole is one of the greenest in Britain and in other areas has plenty of different species? I think it must be a combination of how densely packed the houses are here and the almost total lack of trees, shrubs or lawns. The gardens are tiny, surrounded on all sides by houses, and separated from each other by fences and walls. In my last house, barely a mile or so away, there were mice, rats, hedgehogs, birds, dragonflies, frogs and even slow worms – I’m sure the difference must be that, small and urban as it was, it had a lawn, pond and bushes, was near to a large park, and was much more interconnected with other gardens.

Slow worm (Anguis fragilis) Large red damselfly (Pyrrhosoma nymphula)

As a zoologist I find a lack of wildlife particularly frustrating and at times downright depressing, but I think it’s important for us all to have a regular dose of nature for our health and mental wellbeing. There’s even a name for the modern lack of contact with the natural world – “Nature Deficit Disorder” – which describes the negative behavioural and developmental effects on children who are alienated from nature.

Something we can all do…

The good news I take from this urban bioblitz though is that it doesn’t take much to improve things for wildlife. You don’t need a big space, and even the simplest acts can have a big effect. I don’t have room here to talk about all the various ways you can make your garden a haven for wildlife, but I’ve given a few links below to some good resources.

There’s still more I could do for my garden too – I don’t have room for a pond, but some small water feature would be good. I’m not convinced putting food out for the birds would help a lot with no birds about – and particularly with so many cats around – but you never know. I could also make sure I plant more native species as it was interesting to realise that about half the plants in the garden were things I had introduced – in my day job I often write about humans introducing non-native species to new areas, and yet here I am in effect doing just that!

Nasturtium flowers Garden spider feeding on honey bee

Also, a final thought – if it takes so little to make the most of what you’ve got and to dramatically improve an area for wildlife, imagine if every garden in my street did the same. Imagine if we planted a few trees. Imagine if a few people dug small ponds. The effects would add up! What I have found from the little I’ve done to my garden encourages me not to give up, that my actions can make a difference – and they make the garden a whole lot more rewarding for me, too.

I would love to know other people’s thoughts on this, so please do get in touch if you have any comments!

You can view a few more photos of the wildlife in my garden on my garden wildlife Flickr pages.

A couple of resources with more information on creating a wildlife-friendly garden:

A bit more on urban wildlife and the wildlife in and around Bristol:

And an interesting article in the Guardian about a bioblitz in a London garden –

20 thoughts on “An Urban Bioblitz

    1. Glad you liked it! I’ve added at least 2 more species to the count in the last week (cranefly and house sparrow, first I’ve spotted anywhere near here) – think I’m a bit addicted now! 🙂

  1. Think this is brilliant! I’ve run a BioBlitz in Corfe Mullen (Dorset) for two years running, with the help of many species experts, Dorset Wildlife Trust & general public. This year in 12 hrs we found over 700 species in our village. I record the wildlife in my garden (mostly the insects & solitary bees in particular) so this idea has really got to me… maybe we could have a “garden bioblitz” day and encourage lots of people to blitz their gardens next year!

    1. Thanks – it’s lovely to get people’s feedback, glad you enjoyed it. 🙂 Wow, 700 is a good total! A garden bioblitz day sounds like a really good idea, it’d be great to encourage people to find out just how much they have in their gardens and also to encourage them to do things to attract more species. Definitely something to look into!

      1. Biggest problem would be people’s knowledge of the wildlife around them. Most people know the basics but ask them to distinguish a honey bee from a mason bee or one spider from another and they could get stuck.

      2. That’s true… Although it would still be a good way of getting people to have a closer look at what lives around them, even if they can’t identify different species, and there’s always online guides and sites such as ispot which are becoming increasingly useful for identification for those who are more interested. I reckon it’s worth looking into, even if it was on a much more ‘basic’ level than a normal Bioblitz.

      3. Yes, we used iSpot for our BioBlitz – most of the county recorders and experts who came are also on there as admins. A great website. They will even let you set up a special tag for your bioblitz see We were also really lucky to be able to use Indicia software from Opal/NBN for our online recording see We’re very lucky that the guy who developed the software lives in Corfe Mullen. Food for thought…. I still really like the idea of Garden BioBlitzs

  2. Love the idea and the blog…
    I helped Jane out with the bioblitzes in Corfe Mullen. One of the great successes in my opinion was that we had lots of experts to hand, so it gave us amateurs a great chance to learn and I’m sure the experts learnt a lot from each other. As a result the data output is reasonably high quality – most of the records can be put down as certain because the tricky ones were generally confirmed by an expert. A garden bioblitz would be a different proposition I think, as it would be hard to achieve the same levels of interaction. iSpot is great but only when something can be photographed well enough to ID, which for some groups is more or less never. BUT, there would a different outcome I think – an increased awareness of the wildlife in our gardens and hopefully some incentive for people to continue gardening in a wildlife friendly way. If it achieves this (and we all enjoy doing it!) then who cares if the data is a bit more “basic”?

    1. Thanks John – sorry I’ve only just had a chance to reply! You’re right that it would be quite different and the data would be of a different quality; I guess as you say it would be a slightly different concept, aimed more at getting people interested and noticing just how much can live in a garden, and perhaps also finding things that they hadn’t realised were there. Hopefully it would also encourage people to try and attract more species too. Plus it’s also really good fun! I definitely think it’s something we should try and get people doing, I mentioned it on Twitter last week and had quite a bit of interest so will look into it some more 🙂

  3. Great, I look forward to it. If you want a hand with the IT side of things I could set up something similar to what we used for the Corfe Mullen BioBlitz to capture records and give feedback – just let me know.

  4. To me a BioBlitz is about public engagement with ecologists and ecological societies, it is about interface with schools and children/teachers. Which is why a big site with different habitats, parking and a base/hub is such a good way. If we wanted to get information back from gardens, I’m not certain calling it a BioBlitz is the way I’d want to go. Here is a thought what about running a BioBlitz one day then leveraging that to run a GardenBlitz the next – giving people somewhere to bring their questions and data.

    1. Thanks David – you’re right, it wouldn’t be quite the same thing as a proper Bioblitz and would lack that engagement between the public and experts. I’m not sure it would even be a case of getting people to count how many species they could find so much as just getting them looking to see what’s there (unless of course they did want to try and count everything!)… But yes an interesting thought to tie it in with a proper Bioblitz so people have somewhere to bring their questions etc.

  5. That was great. I must live really near you, v similar surroundings, and no birds. I used to live in Streatham backing onto a railway cutting and had masses of birds out the back including a regular visit from a great spotted woodpecker and one year a sparrow hawk nesting in the trees just beyond the end of the garden. Here in south Bristol, not a dicky bird. You’ve inspired me to get out in the garden and try this out for myself though – it might help me find something positive in the armies of snails trying to wreck my plants!

    1. It’s a shame isn’t it – I really miss having birds outside. Yes definitely have a go, you never know what you might find! Let me know if you do! Don’t know if you’ve heard about the “Garden Bioblitz” event I’ve helped set up this weekend? We’re running it as a trial event this year but hoping to make it a national event next year – I think we have enough volunteers helping out this time round but if you want to follow what’s happening all the details are on our website at 🙂

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