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All you need to know about frog spawn

Jess Price

Conservation Officer

frog spawn / dichohecho / Foter / CC BY
frog spawn / dichohecho /† CC BY

Maybe itís the memory of long summer days spent watching tadpoles, or the excitement of seeing perfect miniature frogs develop from a clump of jelly, but I love frog spawn and so do a lot of other people. Running the Sussex Wildlife Trustís wildlife information service, I know that come early spring the frog spawn questions come rolling in thick and fast. People worry that theyíre doing the wrong thing for their spawn and Iím more than happy to help, so hereís some key points to remember.

Know your species

First things first, itís important to know what you are dealing with - frogs or toads. This is actually very simple to find out. Frog spawn is always laid in clumps, whilst toad spawn comes in long chains like strings of pearls draped over pond weed and submerged plants.

toad spawn / Neil Fletcher toad spawn / Neil Fletcher

Donít fret over numbers

It is important to know that as long as you havenít introduced additional frogs into your pond, there is no such thing as too much spawn. Unfortunately itís a tough life for a tadpole - they have a number of natural predators and are susceptible to various amphibian diseases. Because of this, female frogs lay thousands of egg each year and only a tiny fraction of them will survive to adulthood. Your pond may contain a big black mass of writhing tadpoles, but this is how it is meant to be. Just kick back and enjoy watching these amazing amphibians.

Leave them be

Donít move spawn or tadpoles into a different pond, as this can spread non-native plant species and amphibian diseases. Ponds that already contain spawn may not be able to support the increased population, and ponds that donít have any spawn are unlikely to be suitable for frogs - if they were suitable, the spawn would already be there.

There are many reasons why a pond may not contain frogs, and one of the most common explanations is newts.

Newts and frogs are not mutually exclusive, but they do tend to have a bit of a boom-bust relationship. Newts eat tadpoles, so ponds with lots of newts tend to have fewer frogs. This isnít always going to be the case though. A decrease in frogs means a decrease in tadpoles and that can lead to fewer newts. Then, frog numbers will start to increase.

This doesnít always happen, it may just be that your pond is more suitable for newts than frogs. This isnít a bad thing, newts are awesome too and their habitat is just as important as frog habitat.

The right environment

Sometimes you get spawn, in fact you get massive clumps of it, and then nothing happens - the spawn fails and turns to mush. It is frustrating when this happens and unfortunately it can sometimes be hard to find a reason for it. More often than not, though, it is down to the pond. The two things that all spawn desperately needs to develop properly are light and warmth. You need to let the sunshine in to your pond for tadpoles to thrive.

frogs / Paul Stevens frogs / Paul Stevens

Comments

  • Dave Jones:

    01 Mar 2014 16:23:14

    FAO Jess Price.

    Hi Jess. Just read your post about frogspawn. Have a question: just moved to Western Australia and now have a lovely big garden with a large pond. I have recently added a pump so that there are various water features adding O2 to the water and there has been an explosion (literally) of tadpoles which is wonderful to see.

    The pond is in two parts with a shallow end and a deeper end which are separated by 3 tunnels connecting each end.

    When we arrived 4 months ago, there were some very large tadpoles (some 10cm long), but in much lesser numbers. Since literally draining the pond (to add some lights and waterfeatures), the tadpole population has exploded but I have seen no spawn whatsoever! I can’t understand this as like you, as a kid, my dad would get a load of frog spawn and we would marvel at how the tadpoles emerged and slowly changed to frogs.

    In my pond, the new small tadpoles seem to have just appeared! Could the frogspawn be in the darker areas under the tunnels? (I would doubt this as I was in these connecting up water pipes). It’s surely not possible to produce tadpoles without spawn so what’s happening?

    I’d be really grateful for your help and advice.

    Just spend a lovely hour watching the tadpoles feeding off the green/black algae around the pool while being watched by at least 3 cute frogs (one of which I watched catch a massive march fly…. at least he’s had his tea tonight!).

    Thanks for your help – just a little baffled as to where all these guys came from. But delighted to have them here!

    They seem to make the pond cleaner day by day!

    All the best from sunny Perth, WA.

    Dave

  • Dave Jones:

    01 Mar 2014 16:24:35

    FAO Jess Price.

    Hi Jess. Just read your post about frogspawn. Have a question: just moved to Western Australia and now have a lovely big garden with a large pond. I have recently added a pump so that there are various water features adding O2 to the water and there has been an explosion (literally) of tadpoles which is wonderful to see.

    The pond is in two parts with a shallow end and a deeper end which are separated by 3 tunnels connecting each end.

    When we arrived 4 months ago, there were some very large tadpoles (some 10cm long), but in much lesser numbers. Since literally draining the pond (to add some lights and waterfeatures), the tadpole population has exploded but I have seen no spawn whatsoever! I can’t understand this as like you, as a kid, my dad would get a load of frog spawn and we would marvel at how the tadpoles emerged and slowly changed to frogs.

    In my pond, the new small tadpoles seem to have just appeared! Could the frogspawn be in the darker areas under the tunnels? (I would doubt this as I was in these connecting up water pipes). It’s surely not possible to produce tadpoles without spawn so what’s happening?

    I’d be really grateful for your help and advice.

    Just spend a lovely hour watching the tadpoles feeding off the green/black algae around the pool while being watched by at least 3 cute frogs (one of which I watched catch a massive march fly…. at least he’s had his tea tonight!).

    Thanks for your help – just a little baffled as to where all these guys came from. But delighted to have them here!

    They seem to make the pond cleaner day by day!

    All the best from sunny Perth, WA.

    Dave

    PS. email is david.jones@talktalk.net if you can reply. Thanks.

  • Brian Banks:

    03 Mar 2014 23:52:37

    Dave,
    That is a tricky question to ask a Pom because we do not have anything like the diversity of Australian frogs and toads (check out this website). it could be that you simply missed the spawn. Some species in Europe spawn later in the spring and the spawn can be less conspicuous than our common frog spawn, and might also hatch rapidly. Other species may breed on land, transfering the tadpoles to the water when they hatch. In Europe the midwife toad does this, but I don’t know if any Australian frogs copy this. Check out this website: http://museum.wa.gov.au/explore/frogwatch/frogs

  • Brian Banks:

    04 Mar 2014 20:38:38

    I don’t think it is a good idea to move spawn between garden ponds and the countryside, or over long distances, because of the risk of transferring pathogens and non-native weed, but I don’t think it is a problem moving spawn between garden ponds if they are close together to stock a new pond.

    One point though. Frog tadpoles have an interesting way of regulating their density. They get attacked by micro-organisms in the gut that compete with the tadpoles for food, then get passed out in the droppings, which other tadpoles eat, so when tadpoles are present in large numbers they build up a heavy load. Smaller tadpoles are more adversely affected so what happens is that small numbers of the largest tadpoles grow to metamorphose, and once they move on a few others follow on. By the end of the autumn there can be large numbers of tadpoles left that have not developed, which die over winter. If you move lots of spawn you make things easier for the remaining tadpoles by cutting the competition so you might get more young frogs metamorphosing as a result, and the frog population increases despite removing spawn! This mechanism also results in competition between species. Early spawning frogs inhibit the growth of common toads, and both impact on natterjack toads adversely

  • 05 Mar 2014 09:46:08

    Hi Dave, Thank you for your interesting question, however with over 200 native species of frogs in Australia we are unable to help you answer it. This website http://www.learnaboutwildlife.com/wildlifeAustraliaFrogs.html looks useful and may be a good starting point.

  • Holly:

    24 Mar 2015 13:40:28

    Hello Jess
    Thanks for your post about frogs – it’s really helpful and has made me aware that I need some advice. I’ve just discovered a clump of frog spawn in a flower pot container in my back garden. It’s a tiny container and I realise I need to move the spawn to something bigger. Would you advise me to make a very small pond? (I don’t have room for anything more than about 18’‘ wide.) Or is it sufficient to get a bigger tray? I’d also like advice on whether I need to feed any tadpoles that emerge and, if so, when and how…. Many thanks for any help with these questions – and for any other advice you can give a complete frog novice! Holly

  • Liz:

    24 Mar 2015 15:57:41

    please advise.. To be minus 6 tonight. Will my frogspawn survive? Can I do anything to help them ? Please answer!!!

  • 24 Mar 2015 16:16:10

    Sometimes frogs will spawn in what seems like an unsuitable place such as a puddle in field or a bucket in a garden. Frogs see these locations as temporary ponds and spawning here is a tactic to try to give their offspring a better chance of survival. Basically Ďpondsí that dry out for some of the year will not have any fish in and will have far fewer predators, also fewer frogs will spawn there so there is less competition for food between tadpoles.

    This tiny container doesnít sound ideal, so if possible I would recommend you move the spawn into something slightly bigger. 18 inches square would probably be ok, as long as it will hold water for the next few months. Rather than hastily building a pond, I would recommend a temporary tub pond for now. An old washing up bowl or paddling pool would be fine. Instead of feeding the tadpoles it would be preferable to add some native pond plants into the tub pond as this will provide food and keep the oxygen level of the water up. If you need to plant them in something, childrenís play sand is good as it doesnít contain any nutrients that would pollute the water. You will also need to add a ramp so that wildlife can get in and out. Unfortunately when the tadpoles change into froglets the froglet will drown if they canít get out of the water. You also need to think about location as tadpoles develop best in warm, sunny ponds. Although some shade can be helpful to stop algae taking over.

    You can get more advice on tub ponds here: http://www.froglife.org/info-advice/bog-gardens-and-mini-ponds/. The Froglife website also has information on feeding tadpoles (if you think this becomes necessary), and on creating good wildlife ponds. A pond in your garden will be helpful to lots of wildlife, not just frogs. However if it is going to be quite small then you want to think about the best design and location, which is why I recommend you use a temporary pond for the spawn that needs help now.

  • 24 Mar 2015 16:20:27

    If you can insulate the pond, by covering the water with a plastic sheet for example (if this is practical to do). This will reduce the chance of the water freezing. However, even if the water around the frogspawn does freeze, then only the outer layer of eggs will be lost.

    The large number of eggs in frogspawn is part of the frogs survival strategy.

  • David Jones:

    29 Mar 2015 13:47:53

    Hi this year some of the frog spawn in my pond is with white dots and not black can you tel me why this is and is it ok thank you please reply David

  • Ian Hudd:

    05 Apr 2015 11:37:55

    For the last couple of weeks, whilst walking my dogs, I’ve been coming across a huge patch of frog spawn on the ground! The patch measures approx 2.5 × 2.5 feet. Each time I walk there I see fresh spawn and this morning I saw a frog spawning there. There is no water there but there are rushes growing nearby as the area floods in winter.
    Having read previous comments I can see why the frogs would be in the area but not why they would all keep spawning on this patch of dry land, the amount of spawn being laid there is unbelievable!

  • Judith Grace:

    06 Apr 2015 23:59:01

    read advise from web after making temp washing bowl home for spawn saw in plastic food tray lying on grass. Luckily used water from a butt after letting run clear from debris. Not much, just covered bottom. Positioned bowl at angle, as difficult to dig much, built up sides with bit of turf and soil with stones to hold in place under and round lip. Was near original site. Left over night, and Sunday carefully lifted tray placed at slight angle inside bowl.Was just above water with stones round it, but exposed to birds,cats and foxes. So today put 2 pots of plants beside so their leaves hung over. Sun still reached it and felt was not so exposed. Hope it was right thing to do. Will put thick stick in tomorrow to aid moving out of water. (am 75 so not easy to bend or dig).

  • rosie riddell:

    11 Apr 2015 12:25:32

    My 2 year old very small pond had 10 frogs this year , lots of frogspawn all seemed OK. 8 frogs then left the pond, 2 remaining appeared to carry on mating. All the frogspawn has now disappeared. Could these 2 frogs eat it all??

  • Frances Aldridge:

    20 Apr 2015 10:41:08

    We used to get many frogs spawning in our pond. About 60 mating and croaking some years ago,. However these last five years we have had none. This year we have seen two frogs, but not in the pond. Any idea what has gone wrong?

  • Bob:

    20 Mar 2016 06:04:33

    Hi Jess
    That really help thanks!

  • Lucy day:

    02 Apr 2018 18:03:07

    Hi we’ve got frog spawn in a clump on the floor/ pavement next to our pond will it survive out of the water? If not can it be transferred to the pond? How? Many thanks

  • Imogen:

    03 Apr 2018 14:56:02

    Hi I have some frogs spawn and the embryos inside are not perfect spheres they are blobbed shapes is there something wrong with them or are they ok?

  • 03 Apr 2018 15:32:30

    @Imogen: I don’t think you have anything to worry about, it is likely that the spawn is starting to develop, so they aren’t perfect spheres

  • 03 Apr 2018 15:35:56

    @Lucy Day: You should move the spawn into the pond as soon as you can. Frogs sometimes lay spawn elsewhere, especially in wet weather, but it needs to be in the pond to develop. I would put on rubber gloves and try and move the spawn by hand.

  • Liz:

    22 Feb 2019 09:35:00

    My frogspawn comes on the same date every year. Why?

  • Janice Huckle:

    01 Mar 2019 22:59:00

    There is a question from David 2015 about frogspawn with white dots but you didn’t reply. I have the same problem with the spawn in my pond. Last year there were more than 30 tightly clutching pairs of frogs and loads of spawn but mostly with white dots. I put lots in buckets as it always seems to disappear from the pond. Previous years this has been successful and I’ve had lots of tadpoles to return to the pond to develop but last year all the spawn died. This year the spawn again has black dots. Could all my frogs be carrying some infection or fungus. How can I help the colony survive?

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