Tag Archives: frogs

Season’s Croakings

25 Dec

Hi blog.

Just a quick, mostly visual post this time.

This post involves a mistake I never got around to correcting.  You may possibly remember a post from several years back in which I mentioned obtaining a pair of tadpoles that metamorphosed into what I thought were kajika frogs.

The first one to morph died soon afterward, but the second is still with us.  However, I have consulted several books on the subject and come the the conclusion that it is not a kajika frog but in fact a Japanese brown frog (Rana japonica), or Nihon akagaeru (日本赤蛙) – literally “Japanese red frog” in the local language.

(There is a very slight chance that it the physically similar montane brown frog (Rana ornativentris), but this will require time to get a good look at it – the frog tends to spend a lot of its time hiding.)

You may be wondering why I’m writing about a frog in winter – it should be hibernating, right?

Normally, yes.  But frogs will become active even in mid-winter if the weather is warm enough.  And December 22nd and 23rd brought us that kind of weather.  The forecast for the 22nd – incidentally the last day of term 2 at school – was for temperatures topping out at about 17℃ before moist air brought rain.  The warm temperatures didn’t come although the rain did.  It rained heavily late in the night – trust me, I was walking through it – through to the early hours of the morning.  The 23rd, however, brought that warm change, and the frog became active in the warm (-ish) humid weather.

Hello!

 

“Get that camera out of my face!”

 

You can see some of the stripes on the legs and the yellow on the underbelly.

You can see some of the stripes on the legs and the yellow on the underbelly.

 

They have beautiful eyes, eh?

They have beautiful eyes, eh?

I might not see this little chap again until spring.

Until next time, stay safe.

 

What’s Newt?

12 Jun

June is upon us, daytime temperatures range from warm to hot, and the hydrangeas are in bloom.  Although we are still over a week away from the solstice, the longer days are making their influence felt – plants growing at an almost alarming rate, and me getting woken up by first light about 4:30 in the morning.  (Compare that to a 6:50 dawn in winter)

The weather is a bit abrupt – rain will suddenly fall in a small localised area for a few minutes and then stop with equal suddenness.

Late last month, the bureau of meteorology predicted the rainy season would start on June 6th.  A few days later we had a series of wet days and the date was brought forward.  Now we’ve passed June 6th, but didn’t have any significant rain for nearly two weeks.  Yesterday, that all changed.

I haven’t had many wild encounters lately (one morning seeing a grey heron, a kingfisher and a male pheasant being the exception, but that hardly counts without photographic evidence), so I’ll take this opportunity to introduce the newest arrivals at home.

First, let’s look at the pair of kajika frogs.

These are the survivors of three collected one afternoon as tadpoles in the Hanno River in late April.  The first one finished its metamorphosis toward the end of May, while the other still had the remnant of a tail a few days ago.

This one was still in the process of absorbing its tail when I took this photo on June 8th.

I am sure that they are kajika frogs (Buergeria buergeri), since almost no other frog spawns in upper streams – most prefer lakes, ponds or paddies.

The Japanese name kajikagaeru (河鹿蛙) – literally “river deer frog” – comes from the mating call of the males, which is said to sound much like the call of deer.  Just don’t ask me what a deer sounds like!

While males grow around 4 cm long and females up to 7 cm, mine are still very small, around 2 cm long.

The more mature one is also larger – female maybe?

As tadpoles they are omnivores, quite happy to eat algae, mosquito larvae, and will even cannibalize if food supply is short.  Tadpoles, as you may have guessed, are easy to keep.

Adult frogs, however, are a real challenge.  Suddenly, they transform into fussy carnivores which will eat only live worms, insects and spiders.  (It is possible to trick them into eating dead food, even strips of meat, by holding the food in a pair of tweezers and making movements that mimic insect flight)

It must also be remembered that they swallow food whole (frogs have no teeth – instead, they use their eyes to help push prey down their gullet), which makes the challenge of providing live food so much harder – catching something that is small enough for them to eat, like vinegar flies, is likely to incur my wife’s wrath!  I’m experimenting with tubifex worms, but ultimately I’m planning to donate the frogs to a school, where they’ll be given larger housing and a wider variety of food than I can provide.

They have beautiful eyes, don’t they?

The other arrivals – a pair of Japanese fire-bellied newts (Cynops pyrrhogaster) – were somewhat less unexpected.

You can see the reason for both the Japanese and English names on this pair.

A friend invited me to Tokyo Reptiles World, essentially a convention of exotic pet dealers.  Despite the name, there were a large number of stalls dedicated to birds of prey, mammals, spiders, insects, and more.

I was surprised by the sheer numbers of sugar gliders being traded.

I have mixed feelings about this kind of event – nominally wild animals (especially mammals) in cages bothers me, and I wonder what kind of home they will end up in.  On the other hand, conscientious owners can give these animals a high-quality life.

I took the kids too, along with the unspoken understanding that I was NOT to purchase any critters.  My friend breeds turtles, and he has no such restrictions at home.

It is hard to go to any kind of festival in Japan without encountering a variation of a goldfish scooping stall.  In this case we came across a newt scooping stall.  The rules were simple – you paid your ¥200, and could keep up to two newts.

My friend let his daughter have a go – she caught two newts – and then paid for my son to have a turn.  Now, I was sure he wouldn’t catch any.  But he caught two.  He wanted to take them home.  I said that his mother probably wouldn’t let him keep them.  (It should be noted here that I had wanted some newts for several years – the plot thickens, heh, heh, heh!)

However, when we got home, some well-timed comments from my friend and tears from my son (equally well-timed) convinced the wife to let me him keep them – even after the shock of discovering they can live for over 25 years in captivity!

Japanese fire-bellied (or fire belly) are known locally as akahara imori (赤腹井守, or less commonly赤腹蠑螈) “red belly newt” and are the most common and best-known of the newts found in Japan – so much so that they are often called Nihon imori (日本井守 or 日本蠑螈), literally “Japanese newt”.

Cute, aren’t they?  Newts need only a token amount of “land” in their cage, at least when they aren’t hibernating.

Newts, like salamanders, are tailed amphibians, but unlike salamanders they spend a large amount of their adult lives in or near water, some choosing to rarely leave it.  They like clear cool water, and breed in rivers, lakes, ponds and paddies, and were once a common site in rice growing areas.  However, chemical pollution and the digging of drains have severely damaged wild breeding populations in many localities.

Like most amphibians, females tend to grow larger than males, up to 13 cm compared to 10 cm for a male.  It is possible to sex adults by the shape of their tails, the male’s being deeper and having a sharper taper.

Newts are carnivorous, and in the wild will feed on worms, insects, small fish, tadpoles, and even frog and salamander eggs.

In captivity they are not particularly fussy, and have no problems with fish or turtle food.

Stop Press:

I was changing their water recently when I noticed a small round object attached to a piece of waterweed leaf.  A closer examination revealed several more.  I have no intention of counting my newts before they hatch, but it looks like we are going to have some more newts!

Newt eggs! This was completely unexpected – I was sure both newts were females! Here’s hoping for a good hatch rate!

Toad Time

23 Mar

Spring is finally here, the ume and peach blossoms are out, albeit late, and the last of the wintersweet blooms are hanging on weeks after they would normally have all gone.  The daily cherry blossom reports are on the evening news and soon every park with a cherry tree will be crowded with merry-makers.

Having lived on an orchard for more than a decade, I’m a little cynical about the fuss made over the cherry blossom.  Almond, peach, plum, apricot, plumcot, nectarine, peacherine, and especially prune, we grew them all, and the cherry does not stand out – in my opinion at least – from any of the others.  (Then again, millions of Japanese people haven’t asked my opinion…)

 

The end of the academic year is upon us, and the new school year starts in early April.  In my darker moments, I swear that graduation and entrance ceremonies are timed so close together – about only three weeks apart – to coincide with the appearance of the cherry blossom.

 

Another dark reminder of the arrival of spring is the number of Japanese toads I see splattered on the roads after spring rain.  As an aficionado of reptiles and amphibians, I wish they were more road-safety savvy, or that at least boy-band idol groups would get run over with equal disregard.

 

The Japanese toad (Bufo japonicus) is one of the most familiar frogs to Japanese people.  It is commonly known as Nihon hikigaeru (日本蟇蛙), but has other names such as hiki, hikki, ibogaeru, gotobiki, gorota, gama and gamagaeru.  These last two are retained in the name “gama no abura” (ガマの油), which is said to be essential oils extracted from the toad’s poison glands.  In the Edo era, these were pedalled in much the same way as snake oil in the American West.

 

The Japanese toad is the largest frog in Japan – 18cm is a widely quoted figure and some sources claim lengths of 20cm (with which I’m not inclined to disagree).  Adults don’t need to stay near water, getting the moisture they need from leaf litter or damp soil, coming out in the night rain.  They only need a sizable water source during the breeding season.  Ponds, lakes, wet rice paddies, irrigation channels and even swimming pools become breeding grounds.  I can personally attest to the last one – one school I worked at was surrounded by farmland, and the pool was literally swimming with toads by the beginning of summer.

 

The “warts” on the toads include the poison glands which are supposed to deter predators.  The tiger keelback (see “Union of the Snake” for more details), however, is not only capable of ingesting this poison, it also then uses it for its own defence.

 

Japanese toads feed mainly on worms, slaters, insects and spiders, but large individuals may prey on mice and smaller frogs.

 

One reason for their high mortality rate when crossing roads is that they tend to be sluggish in cooler weather (such as rain), and they don’t hop.  Japanese toads crawl.

 

I had never seen one of these animals alive up close until very recently.  We went on a drip to Ome in rural Tokyo, and were strolling along a path paralleling the Tama River.  I was explaining to my mum that later in the year we might have been able to see river crabs or salamanders, when we came across this individual.  I would estimate its size as around 20 cm.

 

Sense of proportion – that’s my foot in the photo, and my shoes are almost 30 cm long. I make that frog at 20 cm.

The patterns on this particular toad. Colouring and patterns vary significantly within the species.

Here you can see the “warts” on the toad. Always wash your hands after handling amphibians.

Many thanks to my daughter for taking the photos.

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