Tadpoles in Hong Kong?

  • strict warning: Non-static method view::load() should not be called statically in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/views/views.module on line 879.
  • strict warning: Declaration of content_handler_field::options() should be compatible with views_object::options() in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/cck/includes/views/handlers/content_handler_field.inc on line 208.
  • strict warning: Declaration of date_handler_field_multiple::pre_render() should be compatible with content_handler_field_multiple::pre_render($values) in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/date/date/date_handler_field_multiple.inc on line 185.
  • strict warning: Declaration of views_handler_argument::init() should be compatible with views_handler::init(&$view, $options) in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/views/handlers/views_handler_argument.inc on line 745.
  • strict warning: Declaration of views_handler_filter::options_validate() should be compatible with views_handler::options_validate($form, &$form_state) in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/views/handlers/views_handler_filter.inc on line 589.
  • strict warning: Declaration of views_handler_filter::options_submit() should be compatible with views_handler::options_submit($form, &$form_state) in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/views/handlers/views_handler_filter.inc on line 589.
  • strict warning: Declaration of views_plugin_row::options_validate() should be compatible with views_plugin::options_validate(&$form, &$form_state) in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/views/plugins/views_plugin_row.inc on line 135.
  • strict warning: Declaration of views_plugin_row::options_submit() should be compatible with views_plugin::options_submit(&$form, &$form_state) in /nfs/c03/h02/mnt/51424/domains/batgung.com/html/drupaldir/sites/all/modules/views/plugins/views_plugin_row.inc on line 135.

Does anyone know where to find tadpoles in Hong Kong? Or even frogspawn / toadspawn?

At home when I was growing up we had a little pond in the garden. Each spring we'd go out to find tadpoles, bring them back and watch them grow into frogs. (Ok, some years the eggs all went gray and died, but most years there were little hopping frogs to see by late spring).

We had a parent-teacher meeting at our daughter's kindergarten this morning, and it seems tadpoles aren't high on their list of priorities. So I'd be interested to get some here in our flat for our girls to see. We'll have to work out some way to get the resulting little frogs from the 20th floor safely to somewhere more frog-friendly, but that shouldn't be a problem.

Any ideas?

MrB

Tadpoles

Tadpoles can be found in natural or near-natural environment where there is submerged and emergent (grown above water) vegetations for their protection and food. The water should be shallow - no more than a few inches and preferable stationary, and has access to sunlight to raise its temperture. Their life-span as tadpoles is a week or two and only in the spring when the water temperature is sufficiently warm for development and growth. In Hong Kong, this could mean finding them in the country side or farmland.
I built a backyard fish pond in a new housing development in eastern Canada on land that once was natural environment. Each summer, a dozen or so frogs would sit around the edge of, and facing the pond. They would jump high into the air to catch flying insects that come for water and next dive into the pond. My kids would suspend big and scary spiders by their silk using a stick to feed them. They start to accept your close-up company. After a few years, they never return and I suspect that their natural environment has been sadly permanently lost, plus the use of pesticides (I don't) that I think have serious impacts on their hatching and development.

tadpoles

MrB,
You might want to try the gold fish market in TST. They may have some frogs for there.

http://www.mytravelguide.com/attractions/profile-77926805-Hong_Kong_Hong...

I have also seen some small 'bio-spheres' being sold in HK where you have water, plants & small 'shrimp' like animals in a sealed glass tanks. Quite good for showing the kids the relationships each have within the sealed environment.
Vince.

MrB, I don't suggest to find

MrB,

I don't suggest to find tadpoles from nature and bring homes or buy them from Gold Fish market or elsewhere. It's not sure those tadpoles sold in Gold Fish market are foreign species; in case they're grown up and you'll lose interest, and bring back them to nature, the foreign species will influence the local wildlife. Why not take the kids to nature and revisit the wild creatures from time to time, this will be a much better nature education than raising them at home...

Where & when

I stepped out this morning with a jam-jar and fishing net in my bag - I was a man on a mission.

First question, where to find the little devils? As OldTimer writes, a pool of stationary water should do the trick. So first stop was the 'Lily pond' at Hong Kong University. But it all looked rather muddy and uninviting when I got there, certainly no tadpoles.

That raised another question - just when do tadpoles appear in Hong Kong?Was I looking at the wrong place, or the right place but at the wrong time?

Next idea was the pond in the Hong Kong Botanical Gardens. I think I noticed tadpoles there last year, on one of our visits to see the monkeys. I heard the answer to my second question while I was still some distance from the pond:

Usually we fail to spot any frogs in the pond, but today I counted up to 30 then gave up. Unfortunately the full answer to the 'when?' question was probably 'come back tomorrow', as apparently I was witnessing a massed display of frog foreplay. Lots of little male frogs clutching lovingly to their chosen, but not an egg to be seen, let alone a tadpole.

Even if there had been tadpoles, there was the tricky question of how to get at them without being pounced on by a security guard. So, hopping on a bus I went in search of somewhere the frogs and I could be alone. Pok Fu Lam reservoir.

I know, tadpole in a reservoir, needle in a haystack. But at the top of the reservoir where the river flows in, there are concrete barriers with likely-looking pools behind. Still no tadpoles though, so I set off up the riverbed, to see if any of the smaller pools would have any. Not a tadpole to be seen, but a lovely spot for a walk. What with the jam-jar and net, I felt about nine again. The pools all looked empty to start with, but there were pond skaters, water boatmen, whirligig beetles, pond snails, butterflies, and tiny, almost transparent freshwater shrimps. It was beautiful, and all the better for the lack of mozzies, probably as a result of the long cold spell this year.

Thanks to Vince, and to the suggestions by email and sms of where to find tadpoles. I agree with SF that it's better to stick to native tadpoles, so I won't try the shops. But I don't think removing a few tadpoles from the wild will do too much harm. It looks like the best chance will be to head back to the Botanical Gardens in week or two with our four year-old, and have her make a wide-eyed request for a few tadpoles from their pond.

But, if you know of any ponds that are easily accessible, and have lots of tadpoles, I'd still love to hear from you.

MrB

came to me in a dream

Sorry MrB, this isn't the answer you're looking for, but thought I should tell you that after reading about your search for tadpoles the other day, I happened to dream about them last night...  and surprisingly after reading your post today, I remember watching their mating ritual... go figure? LOL

I think just stationary

I think just stationary water is not enough. The water must be shallow, say, no more than two inches deep, and warms up easily under sunlight. They seem to like keeping themselves warm, and will rapidly escape to deeper and cooler water when intruder like myself shows up. Lily pond's water is too deep and cool; the lily pads block the sun, and goldfish are their predators. You have better luck when the bottom is muddy and yuky and "looks" dirty, as compared to crystal-clear water which has no nutrients or food to sustain tadpole/frog life. Bring along a pair of rubber boots and a long-handle net.
Not living in HK now, I wonder it you have enough solar energy input in early March to raise the water temperature. Would April be a better timing?

tadpoles

OldTimer, I wonder if the shallow water requirement is specific to colder areas? When I used to go tadpole hunting as a boy, we'd end up at a couple of ponds, both several feet deep. That was in Wales in the UK. In fact there was a different problem there - the frogs would often lay eggs in the large puddles that were left after heavy rain. When the puddle dried up, the eggs died.

Willis, Mr Tall already delights in pointing out the freudian overtones of my interest in tunnels and obelisks. Probably best to keep those dreams about tadpoles to yourself! ;-)

MrB

tunnels and obelisks

LOL!!!  why I have an interest in them too...  yeah tadpoles, I debated whether I should tell ya, but what the heck?

tunnels, spawn, etc.

Uh, MrB, I really don't want to see the list of Google search referrals for our site this month, okay?

tadpoles

I saw some tadpoles at the Kadoorie farm in some of the shallow ornamental ponds they had.  I was tempted at the time to take some for my son  but didn't have a suitable container.  I'm not sure if they're seasonal or not!  It was at the residential / retreat / educational part of the farm, not the main part, if that's of any help!

Too early

I think you're too early, or at least out here in Clearwater Bay, it's too early. We haven't heard the annual chorus begin yet. But we're pretty cool up here, and our temps probably aren't warm enough yet. We have lots of frogs and toads out here--there was a boy who lived here when I first moved here and he had several huge tubs full of water with hanging mossy stuff in them and they were filled with tadpoles--I believe he found the eggs and took them before they hatched. I don't know how many hundreds of little frogs and toads he had over that summer, but it was pretty amazing.

But I still think you're somewhat early. April is a better bet, but I seem to recall them even in the hot months (but I've never paid that close of attention to timing--my seasonal clock gets crazy living in the tropics--same thing when I lived in Hawaii).

M

Tadpoles in Hong Kong?

(Trasferred from another subject page) ...
The original tadpoles page cannot be opened. My apology for opening up this page to answer Mr.B's week-old question whether the requirement for warm water to find tadpoles is confined to only cold region.
I think one has better luck, generally, to find tadpoles in warmer,sunny and shallow water. In my previous neighbourhood, the winter air temeratures can get down to -30C. When spring comes,much of the ground and deep part of the wetland remain cold even under the hot sun and warm air temperatures. Only in the shallow area, which is a very small portion of the marshland, I could find tadpoles.
Having left HK almost 50 years ago, I am not knowledgeable to comment on it, but tend to think that the tadpoles there also have the same preference.
Cheers.

Tadpole gold

Okay, MrB, you're going to hate me for this, but I've pretty much had the answers you're seeking all along -- I've got a book titled The Ecology and Biodiversity of Hong Kong, lent to me by a colleague, which has a couple sections on amphibians. To wit:

Many of the 22 species of local frogs and toads breed in April or slightly later during the wet season, but several species have a lengthy breeding period [lucky dogs -- ed.]. The Asian Common Toad, Hong Kong's most abundant and widespread amphibian, starts earlier -- in February -- and continues until May [with, I assume, breaks for tiny cigarettes]. Interestingly, the Brown Wood Frog . . . is at the southern limit of its range in Hong Kong, begins breeding in winter. Tadpoles of a few species of frogs (e.g. the Lesser Spiny Frog) can be seen in all months, but this could reflect slow larval growth during the cooler months rather than year-round breeding.

Most local frogs and toads become inactive at temperatures below 13C, but begin calling and mating activity as temperatures and humidity rise; typically, male Bufo melanostictus are the first to be heard. The reproductive succes of frogs that breed in ponds and marshlands is certainly enhanced by rainfall and rising water levels, and may actually stimulate breeding [sic]. For those species that inhabit streams, however, population size will reflect the interaction of rising temperatures and humidity (that stimulate reproduction) and mortality of tadpoles caused by wet-season spates. In Hong Kong (as elsewhere in Asia where there is a pronounced dry season) rainfall appears to regulate reporductive patterns of most amphibians, but Hong Kong's location on the northern margin of the tropics means that temperature also has some effect on the timing of frog breeding.

and

The Giant Spiny Frog, which can reach over 14 cm body length, is confined to boulder-strewn streams at altitudes exceeding 600 m. Thus far, it has been found only on Tai Mo Shan . . . . The Lesser Spiny Frog, which reaches a length of 8 cm, is also found in rocky forested streams, especially headwater tributaries, and is the most frequently encountered stream frog. Larger forest streams are home to the Hong Kong Cascade Frog. It has a rather flat body and well-developed adhesive discs on the digits that it uses to cling on to rocks in waterfalls and cascades. The tadpoles have a sucker-like mouth, and live in fast flowing water where they graze algae. The Green Cascade Frog has less specialised habits and is more widespread . . . . The uncommon Brown Wood Frog and the rare Big-headed Frog occur only in small slow-flowing forest streams. In lowland and more open conditions, the frogs associated with streams tend to be generalist species that also occur in standing water. . . . The Paddy Frog and especially Gunther's Frog are examples of these habitat generalists. The Three-striped Grass Frog is occasionally encountered along stream margins but is more frequent in marshlands.

I suspect this might help.

Mr Tall

tadpoles

Mr Tall, you've hit the tadpole jackpot! Looks like oldtimer and mom2boys are right that I'm a bit early. Not sure why the party has already started at the botanical gardens?

The point on rainfall triggering breeding makes a lot of sense. A couple of older local residents pointed me towards the Peak garden park as a guaranteed source of tadpoles. I went to take a look and there's hardly any water, let alone tadpoles!

I'm surprised to read how many of the local tadpoles live in streams, where I expected them to be in ponds. Anyway, it looks like I should wait until April and then go out for another look.

MrB

PS Gweipo, thanks for the kadoorie farm sighting. I'll keep trying to find tadpoles on HK island first, but may have to head up there if I still don't have any luck.

few cents...

MrB

But I don't think removing a few tadpoles from the wild will do too much harm.

I was suprised to read this. I can't imagine when traveller visiting Tibet using this as an excuse to hunt down Tibetan antelope.
Though this is an exaggerated sample, but the logic is same.

In the good old days, people used same statement on animals like whales, wolves, dingo, sharks e.t.c.

Mathew

Tadpoles

I would not align Tibetan antelopes and tadpoles in the same logic. Hunting down Tibetan antelope is for hunter's trophy which he will proudly, not necessarily wisely, display on his wall. There is indeed a risk of wiping out this species. On the other hand, bringing home some tadpoles will not do too much harm. Note (some)harm is already recognized by the speaker; but sometimes it is necessary to remove some from their habitat to educate and amuse the younger generations with the hope that they too when grown up will appreciate and protect the environment. There is no tadpole-rush from the HK population.
One time, I brought home a dozen or so tadpoles from the wild. My children and I placed them in the best place in our backyard pond away from fish and other dangers. We would watch them grow into frogs. Some stayed in the pond, others left likely going back into the wild.
Ex-farmer and now urbanite

Tadpoled

Yesterday we completed the tadpole mission, and now share our home with around 10-20 new wriggly friends.

Last week I walked along the course of a stream on Hong Kong island, and noticed a frog in one of the little rock pools. I can't remember having seen one before, and a little further along I heard another frog calling, so I took that as a good sign.

On yesterday's walk I found this happy couple in one of the pools. At first I couldn't see any eggs, so I thought I was too early again. But looking closely there were these two strings of eggs trailing behind. (The start of the video is slowed down so you can see the eggs more clearly).

They were smaller than I remembered, and I didn't expect them to have the mottled pattern (turns out the eggs are black on top, light brown underneath, giving this effect). Since the eggs are in strings like this, we must be looking at a couple of toads, not frogs. (Frogspawn is a mass of individual eggs).

I was also surprised to find several brown, striped fish in the pool. Once I noticed them in one pool, I could see them in several other pools too. They would be useful later on.

It was good to see the spawn, but again it seemed I was too early, and would need to come back later to see tadpoles. But in a pool further down the stream I caught a sudden movement, and bent down for a closer look. It was one of those stripey fish darting at a tadpole - lunch, I guess. We joined in the feast, and netted a few tadpoles to bring home.

MrB

Tadpoled

Mr. B. You are about a month ahead of the conditions here, just outside Toronto, Canada. I have removed the cover of my backyard fishpond and all the fantail goldfish survived the winter (at one time down to -20C). But the frogs are still hibernating at the bottom. The night time temperatures still generate a thin layer of ice which melts under the morning sun. When the frogs get to know you better, they let you tap their nose with your finger tip.

Tadpoled

On Saturday afternoon we all took a walk up to where I'd seen the toad in the video above. No sign of the toads, but the small pool was criss-crossed with these strings of spawn - there must be several thousand eggs in all.

Toadspawn

As with many things, once you know what to look for, they seem to pop up everywhere. Yesterday we took the girls up to the Wong Nai Chung Reservoir Boating Park to paddle around in one of the boats. In the shallows were more strings of toadspawn, and some tadpoles too.

MrB

PS Oldtimer, the hillsides here have that lovely bright green colour from the fresh growth, and I can see the first traces of mould on our bathroom ceiling. Spring is definitely here!

Tadpoled

MrB:
You made me envy now. Here outside Toronto, I still have about one foot of snow on the ground but it is melting slowly and partly escaping into the air (process called sublimation).
Two days ago although the temperature was near 0C, the bright warm sunlight brought up one big frog from the pond. He rested by the pond absorbing all the solar radiation he could get before returning to the pond later in the afternoon. This, MrB., is a sign of spring here.

tadpoles

On Monday I walked up to the stream where we'd found the spawn and tadpoles. I was wondering if the heavy rain over the weekend would have washed them all away, but there are still plenty to be seen. None have started growing legs yet. No signs of adults or spawn either, so I guess we've passed the mating time of year.

Back home I've been hard-pressed to tell you if any tadpoles had survived, as our tank's contents had turned into thick green soup. A quick google of the problem shows the solution is to "replace 20% of the water with fresh water each day until the water is clear, then replace 20% every week or two to keep it clear".

We've been doing that for several days, and I'm happy to report the soup has thinned and the tadpoles are still there. The snails have gone forth and multiplied (several have been rounded up and passed on to a friend with a turtle. Mmm, crunchy!), and the freshwater shrimps have had babies, so the tank is teeming with life at the moment.

The tadpoles are now part of the family, and have to be wished good night by our 2- and 4-year old daughters each night. In fact it's like living with the Waltons, "Goodnight tadpoles, goodnight snails, goodnight baby snails, goodnight shrimps, ..."

And after a request for volunteers, several of the bravest tadpoles were relocated to elder MissB's kindergarten. That was last week, so I hope to hear this week if the children have found them interesting.

MrB

tadpoles

I walked through the Botanical Gardens today, and had a look at the pond you see in the video above. Same deal as the mountain stream - lots of tadpoles, but no adults in sight.

MrB

Tadpoles

MrB: The adults probably have moved to where the food is, bugs and insects that don't like the cool water of the pond and stream at this time of the season.
Two frogs, who hibernated in my pond, emerged from about a month ago. One has left likely to find his romance. But the other one prefers the good old home and sun-bathes every time the sun shines, with only his head slightly above the water level.
Today, my kids fed him a spider hanging from the tip of the stick. The frog remembered the routine from last year very well. So I guess a frog's memory is longer than that of a goldfish.

Frogs' legs

The proud father reports that the first of our tadpoles have sprouted their hind legs. They'll be all grown up and leaving home before we know it...

MrB

Frogs

The change from having one front leg to losing the tail and turning into a little frog is very quick. I wonder if it's confusing for them? One moment you're swimming around under water with a tail, then a day or so later you've got legs and want to spend all your time climbing around in the open air.

Three have changed into frogs so far (their body is less than 1cm long):

Baby frogs

Their single goal is to climb out of the tank:

Baby frogs

So we've instituted a high-tech security barrier to keep them safe - an old pair of MrsB's tights are now stretched across the top of the tank! But it's clearly time to take them back to their stream in the next few days.

MrB

tadpoles

Almost two weeks ago we took the toads back to the stream we'd collected the toadspawn from. There were still a few large tadpoles in the ponds that hadn't changed into toads yet. But there were also many more tiny tadpoles, that must have hatched out in the previous few days. I wonder if they are another batch from the same toads, or from a different type of toad altogether?

Then last Friday night we had very heavy rain. When I checked the observatory's website on Saturday morning it showed the Central and Western areas of Hong Kong Island had been among the worst hit, with over 100mm of rain in the previous hour, and over 400mm in the previous 24 hours!

In the afternoon I walked up to the stream again. Although it had been several hours since the heavy rain stopped, the stream was still unrecognisable. The gentle stream with sleepy pools was now all rushing torrent and white water.

Slideshow image


Since your web browser does not support JavaScript, here is a non-JavaScript version of the image slideshow:

slideshow image


slideshow image


The batch of baby tadpoles I'd seen the previous week must all have been washed away, but hopefully some of the young toads had found a sheltered patch on the hillside and survived. Looking at the speed of the water it's hard to imagine how any of the shrimps, fish, and other water creatures manage to live out the whole year in these hillside streams.

MrB

Tadpoles 2009

The stream is full of tadpoles again, so late March / early April seems to be primetime for tadpoles in western Hong Kong.

Baby toads

We've just been back to the stream to release our first batch of baby toads. I was surprised to see the pools are full of toadspawn again (no sign of frogs), and a couple of pairs of amorous toads were in residence.

As I stepped close to the pond, it looked as though a tremor passed through the ground. I'd just disturbed the young toads who were heading out from the pools - there must have been twenty or thirty of them.

Also the fish in the pools were looking fatter than when we'd been to collect the spawn a couple of months back. No doubt they'd been well fed on a diet of tadpoles.