Some of this year’s tadpoles

Dear Readers, I have sometimes noticed that although most of the tadpoles in my pond are tiny frogs by now, there are still some tadpoles, who seem to have not gotten the memo about that metamorphosis business. I always wondered what would happen to them – would they just die when winter comes, or would they just complete their growth in the spring? So, I had a little dig around in the literature to see what I could find out.

A 2016 study by Walsh et al found, that in Common Frogs at least, the main factors for growth were food availability and temperature. Low temperatures lead to slower growth, and I’ve often noticed that tadpoles tend to congregate in the warmer, sunnier, shallower parts of the pond. Furthermore, whenever I’ve reared tadpoles in an aquarium they were several weeks ahead of their siblings who were in the colder conditions of the pond. As you might expect, lots of food equals faster growth too, so a warm spring, which tends to promote the growth of algae ( a tadpole’s first food once the contents of its egg have been ingested) should lead to fast development and soon the patter of tiny webbed feet. In the Common Frog, the normal period from hatching to leaving the pond is about fourteen weeks, but this is much slower in cold, high-altitude ponds, such as those in the Scottish Highlands.

So far, so good. But then I read this enigmatic sentence in an earlier paper by Walsh et al”

In addition, the decision on whether to over‐winter as a tadpole appears to be made relatively early in the season (Walsh et al., 2008)

So, at some point in the spring, tadpoles seem to ‘decide’ whether to go hell for leather for development, or to take their time in the hope that things are better during the following spring. But it can’t be as simple as this – if I look closely at my tadpole population there is a wide range of different sizes and developmental stages. One explanation is that there is only a limited supply of food in any given pond. Some tadpoles will start off with a size advantage, and these will hog the food supply and grow quickly. Once they’ve become froglets and left the pond, there will be more left for the remaining tadpoles, but quite possibly not enough for them to complete development before winter comes. Furthermore, there is some evidence that overcrowding in a pond leads to the tadpoles producing a hormone which inhibits growth until the concentration of animals goes down.

The real danger for a tadpole is if it develops into a froglet at a time when there is no insect food for it to eat, so if metamorphosis can’t be completed before the end of summer, the tadpoles will remain as tadpoles and hibernate at the bottom of the pond until spring. At this point, they’ll have an advantage over any new tadpoles, and should be able to grow into froglets with the whole of summer before them to fatten up.

The variation between tadpoles that develop quickly, and those that stay put as tadpoles for a full year, illustrates how adaptable these supposedly ‘simple’ animals are, and how advantageous such plasticity could be, enabling the offspring from a single mating to have two very different paths through life.

Dear Readers, the ivy is in flower in my favourite front garden just along the street, and the pollinators are going mad. I stood with my camera for about fifteen minutes, watching the comings and goings, and while there don’t appear to be any ivy bees yet, there are absolutely masses of honeybees collecting pollen. Clearly, the hives are still active, probably over on the local allotment, and you can see how full the pollen baskets on the legs of this worker bee are (the little yellow bobbles at the side).

It’s not just honeybees though, there are a fair few flies about. Many of them are the greenbottles that I wrote about last week, gathering in a bit of pollen, but there are also batman hoverflies (so called because of the ‘batman logo’ on their thorax). I wrote about these rather handsome flies here, and was glad to make the species acquaintance again.

And then there’s this handsome wasp mimic hoverfly – I am unsure of species, but I do know that it’s a male, because there is no gap between his eyes. The batman hoverfly was a batman and not a batwoman for the same reason.

I’ve pointed out the wonderful self-seeded verbena along the street, and was pleased to see a) that the man with the weedkiller hasn’t been past recently and b) the common carder bumblebees are fuelling up.

And finally, you have probably noticed that the spiders are getting fat enough to notice now. I haven’t had any house spiders (yet) but this orbweb spider has made a web in the front window, just above a window box full of Mexican Fleabane. I imagine that she’ll get plenty of sustenance from the pollinators who pop in, and it’s hard to begrudge here. In fact, I’m quite pleased to see my new windows being gradually colonised by invertebrates, just as the old ones were.

Orb web spider (Araneus diadematus)

I know that some of you have had lots of ivy bees about in the garden in previous years (including the amazing lawn of Philip Buckley, who was kind enough to share some photos and video of his garden last year), so do let me know if you’ve seen any of these guys – there are lots of images here and here. I think the ivy might be flowering a little early this year, so I’m a bit anxious about whether there will be any left when the ivy bees hatch – it will be interesting to see what else the bees find to feed on. At least there’s a fair bit of sedum still around, at least here in London.

Total Lunar Eclipse from March 2025 (Photo By Marcus Humberg – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=161997046)

Dear Readers, today (Sunday 7th) a total lunar eclipse will be visible across Europe, Africa, Asia and Oceania (sorry, North and South American readers) – for those of us in the UK (and the rest of Europe) the eclipse will be visible when the moon is rising. According to the BBC website, totality (when the moon is completely blocked from the sun’s rays by the shadow of the earth) occurs at 7.11 p.m. UK time, but we won’t be able to see it until it rises above the horizon at 7.33 p.m. It will be quite low down in the eastern sky – advice is to find a clear view of the horizon, which may involve getting up high if possible. However, while the moon only looks red at totality (it’s sometimes called a ‘blood moon’ because the blue light from the sun is scattered by the earth’s shadow, leaving just the red light) it will still look pretty strange until about 10 o’clock. Let’s hope for clear skies for at least some of us. Apparently it should be pretty splendid  in the South West (hello, Cornish friends!) and the East of England, but the weather forecast looks pretty good for East Finchley as well, so fingers crossed!

Lunar Eclipse Sequence (Photo by By pedrik – Lunar eclipse sequence, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=43795378)

This is not my first rodeo when it comes to lunar eclipses – there was one when I used to live in a flat in Islington that was only visible when I hung out of the second floor window. Unlike solar eclipses, lunar eclipses are not actually that rare (the next one will be on March 3rd 2026, so chin up if you miss this one!) but they are always a reminder, for me at least, that the engine of the universe continues in spite of all our troubles and worries, and somehow that is quite reassuring.

Fingers crossed that some of us, at least, will be able to see it! Let us all know!

Dear Readers, it might be the end of summer, but the sunflowers at East Finchley tube station are making sure that there’s a last blast of sunshine. Even after a torrential downpour on Thursday they were attractive the bees, and I’ve no doubt that, given half a chance, the birds would be after the seedheads as well.

On this particular flower, there was a common carder bumblebee at the seven o’clock position, and a honeybee at one o’clock, still collecting pollen for the hive. I’ve mentioned before that common carders are some of the last bumblebees on the wing in the autumn – you might see the occasional queen buff-tailed/white-tailed bumblebee foraging before winter hibernation, but generally most of them are now either dead or already hibernating. If you have any ivy near you, keep an eye open for ivy bees, who should just about be hatching from their underground nests.

Ivy bee

Back to the common carder bumblebee, though – different bumblebee species are able to access different food, because they have tongues of varying length. The common carder is a long-tongued species, which means it can access the nectar in flowers which have a long ‘neck’. In sunflowers, each of the florets in the middle is actually a separate flower, so there’s plenty for the bees to feed on. In fact, the way that the florets are arranged is the most mathematically efficient way to pack the seeds into the seed head. They form a series of interconnecting spirals which are successive Fibonacci numbers, and at this point my brain explodes, so any mathematicians out there please pop elucidation in the comments!

Anyhow, I would like to say thank you to the volunteer East Finchley Gardeners who keep the pots on the station platforms full of sunshine. It certainly made my day!

McVitie and Jaffa asleep on the sofa…

Dear Readers, I feel I would be remiss if I didn’t give you a quick update on McVitie and Jaffa, my RSPCA foster kittens. They now have the run of most of the house, and are causing the usual kitten-related havoc – my poor houseplants are being pruned as all the dead leaves that I should have cut off already come flying off every time the kittens run through the ‘jungle’.Fortunately they’re only interested in the dead leaves.

And also in. the knitting….

…and the furniture…

….and the laptop. It’s a miracle that I ever get the blog done at all.

The kits are now on 50 percent ‘normal’ kitten food and 50 percent sensitive tummy food, and so far no explosions. The kitten with the white chin is a real cuddle bunny, while the other one is rather more circumspect, but they both go to sleep on the sofa beside me now, which is rather lovely.

As anyone who has ever lived with kittens will know, they only really have two speeds – manic and unconscious. Apart from one of them having a slightly dodgy tummy, they will be perfect for a lively household – even when strangers come to visit, they will hide for about two minutes before being overcome with curiosity. Fingers crossed someone else will fall in love with them! I will miss them, but they really need a permanent home. And then it will be onto the next cats! If you’ve ever thought about fostering, I would really recommend it – it’s such an introduction to the sheer variety of personality in cats. These two are probably my eightieth and eighty-first foster cats over the past twenty years, and I promise that no two cats are the same, once you get to know them.

I love Seamus Heaney. His poems are always both closely observed, and about much more than than what they seem to be about.

Blackberry-Picking

By Seamus Heaney
for Philip Hobsbaum

Late August, given heavy rain and sun
For a full week, the blackberries would ripen.
At first, just one, a glossy purple clot
Among others, red, green, hard as a knot.
You ate that first one and its flesh was sweet
Like thickened wine: summer’s blood was in it
Leaving stains upon the tongue and lust for
Picking. Then red ones inked up and that hunger
Sent us out with milk cans, pea tins, jam-pots
Where briars scratched and wet grass bleached our boots.
Round hayfields, cornfields and potato-drills
We trekked and picked until the cans were full,
Until the tinkling bottom had been covered
With green ones, and on top big dark blobs burned
Like a plate of eyes. Our hands were peppered
With thorn pricks, our palms sticky as Bluebeard’s.

We hoarded the fresh berries in the byre.
But when the bath was filled we found a fur,
A rat-grey fungus, glutting on our cache.
The juice was stinking too. Once off the bush
The fruit fermented, the sweet flesh would turn sour.
I always felt like crying. It wasn’t fair
That all the lovely canfuls smelt of rot.
Each year I hoped they’d keep, knew they would not.

Wasp Spider (Argiope bruennichi) Photo by Oliver Kane

Dear Readers, you might think that most of the spiders that crop up in the UK are ‘a bit boring’ compared to those found in the tropics, but have a look at this beauty! This is a female Wasp Spider, found in Long Lane Pasture here in Finchley – the site is right next to the North Circular Road, but punches well above its weight in terms of plants and wildlife, largely due to its amazing volunteers.

Female Wasp Spiders are pretty much unmistakable – the one in the photo looks enormous, but actually they only grow to about 15mm long. The males are much smaller, and are very easy to miss.

The webs are also pretty distinctive: they contain a cross made of a different, more robust kind of spider silk. This helps to stabilise the web, and one theory is that this ‘stabilimentum’ is used because the main prey of the Wasp Spider is grasshoppers, which are pretty robust and vigorous insects. The patterns made by the stabilimenta are also thought to reflect UV light in a way that attracts prey to the web.

Wasp Spider web showing stabilimentum (Photo By Charles J. Sharp – Own work, from Sharp Photography, sharpphotography, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=61573410)

Wasp Spiders are mainly found in grassland, but seem to be fairly adaptable – my friend L found the spider in the photo below in gorse at Thorpeness.

Impressive as the Wasp Spider is, her relatives in other parts of the world have taken colouration and web design to a whole new level.  Have a look  at some other spiders in the Argiope genus below…

Argiope flavipalpis from Ghana (Photo By Charles J. Sharp – Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=149790284)

Argiope sp in Tanzania (Photo by By Muhammad Mahdi Karim – Own work, GFDL 1.2, https://commons.wikimedia.org/w/index.php?curid=7164693)

St Andrew’s Cross spider (Argiope keyserlingi) from Australia (Photo By Summerdrought – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=72803212)

Back to ‘our’ Wasp Spider. As is usual with spiders, mating is a bit of a tricky affair – the female will eat the male spider given a chance. In order to avoid this, male Wasp Spiders hang around waiting until the female has had her final moult – at this point, her jaws are still soft so she can’t murder her mate. However, the male will try to ‘plug’ the female, to prevent other males from mating with her – to do this, he uses one of his pedipalps to position the package of sperm. Pedipalps are those ‘boxing glove’ appendages that you sometimes see next to the head of the spider. Once in place, the pedipalp breaks off, preventing other males from mating. However, the male spider has only two pedipalps, so only two chances of passing on his genes.

As the female can also only mate once, due to the ‘plug’, she produces a lot more eggs than you would expect for a spider of her size – as she will only ever have one clutch, it’s important for her to ensure that at least some survive. Eggs are laid inside this rather elegant egg sac, which gives them some initial protection.

Wasp Spider egg sac (Photo by  Bj.schoenmakers – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=21007077)

Interestingly, Wasp Spiders, which were once confined to the very south of England, seem to be moving north – global warming is shuffling everything up, and it will be interesting to see where these fascinating arachnids eventually end up. Do let me know if you’ve spotted any¬

Dear Readers, many years ago (in 1984 to be exact) I was working as an accountant at Fitch and Co, a rather trendy design consultancy based in Soho. One of the perks of working there was that we had a cassette player (later replaced with a CD player). As I sat right next to it, I had some control over what we played – we featured a lot of Prince, Madonna, Ultravox, and the band of one of the guys who worked there, which was called ‘Gay Bikers on Acid’. If you’ve never heard of them, I am not surprised.

Every so often, though, I would try to inject a touch of something more calming, and on would go ‘Songs of the Humpback Whale’. Sadly, my fellow finance bods were not so impressed, especially when it got to the bits of the recording that sounded like giant farts, and so it was soon back to Roxy Music. However, I have always found the recording both moving and inspiring – to think that we share the world with such creatures fills me with awe.

The recordings were collected by cetacean scientist Roger Payne, who heard the recordings of Frank Watlington, a marine engineer who had recorded the eerie wailing sounds of the deep ocean. When Payne listened to them, he realised that the ‘songs’ repeated over time. He also discovered that all male Humpbacks in a given ocean sang the same song, but that it changed subtly every year.

Payne released the album in 1970 (so I was late to the game), and it quickly went platinum. It’s still the highest-selling environmental album of all time. In 1972 the ‘Save the Whales’ movement kicked off, leading to a ten-year global moratorium on whale hunting in the same year, followed by a complete ban on commercial whale hunting in 1986. We know that a few countries still hunt whales for ‘scientific’ purposes (I’m looking at you, Norway, Iceland and Japan) but overall a number of whale populations have grown, though, as we don’t know how large the original populations were it’s difficult to know how many whales there once were. I do know that Moby Dick describes whale pods so huge that they could crush whaling boats through sheer numbers, and Melville was a close observer of whaling.

Payne describes how he came to devote his life to whales.

“In the late 1960s he heard on the radio that a dead whale had washed up on Revere Beach (near Tufts University where he was working) so he drove out to see it. He found that souvenir hunters had already hacked off the flukes from the dead porpoise, somebody had carved their initials in its side, and a cigar butt had been stuffed into its blowhole. He later said “I removed the cigar and stood there for a long time with feelings I cannot describe. Everybody has some such experience that affects him for life, probably several. That night was mine.”

In addition to be a founder of the whale conservation movement, Payne went on to hypothesize that blue whales and fin whales can communicate across whole oceans using sound, a theory that has subsequently been proved. One of his last campaigns was to free captive orca Lolita from Miami Seaquarium, so she could be relocated to an ocean sanctuary in the Salish Sea. Sadly, Lolita, who had been in captivity for 53 years, died before she could be moved.

Payne died aged 88. 5 days before his death, an essay published in Time magazine had this to say:

“As my time runs out, I am possessed with the hope that humans worldwide are smart enough and adaptable enough to put the saving of other species where it belongs: at the top of the list of our most important jobs. I believe that science can help us survive our folly.”

You can listen to ‘Song of the Humpback Whale” here.

You can also hear Payne’s second album, which includes the songs of blue and right whales along with humpback whales here