In the last few days, during the heavy rain in Beijing, two separate contacts have been in touch to ask about ‘ducks’ that have suddenly appeared around their residences.
“a group of ducks has been quacking for hours in a small lush and green, wooded area in front of our building in Chaoyang, near the park. Did they get stuck here perhaps? What do you make of it? Maybe they are geese. I can’t see them, they are loud!”
I was intrigued… but then the same contact sent me a short recording:
Ahah! The sound is certainly similar to ducks but actually the creatures responsible are not ducks or geese at all – they are Boreal Digging Frogs (Kaloula borealis 北⽅狭⼝蛙 Běi fāng xiá kǒu wā) and, if you are out and about in Beijing right now, especially near any ‘wild’ areas with standing water, you are likely to hear them.
The Boreal Digging Frog has an interesting life cycle and is an explosive breeder. It spends most of its time underground in burrows and emerges after the heavy summer monsoon rains to breed in temporary pools. They breed fast, as they need to complete the breeding cycle before the pools dry up, so time is of the essence! They will ‘sing’ persistently, even all through the night, when they first emerge and eggs will be laid within a few hours. After a few days, the tadpoles will hatch and they will need to mature quickly in order to fully develop and find refuge in burrows before the pools dry up later in the summer.
The eggs of the Boreal Digging Frogs (Kaloula borealis 北⽅狭⼝蛙 Běi fāng xiá kǒu wā).
The tadpoles of the Boreal Digging Frog (Kaloula borealis 北⽅狭⼝蛙 Běi fāng xiá kǒu wā).
Here is a recording I took just last week by the Wenyu River. It’s hard to miss them!
So the lesson is: not everything that ‘quacks’ is a duck!
For more about the amphibians of Beijing, see this dedicated page.
Header image: a Boreal Digging Frog (Kaloula borealis 北⽅狭⼝蛙 Běi fāng xiá kǒu wā) ‘singing’, 11 June 2016 (Xing Chao)