Spring is springing, and love is in the air!
Having just got home from a week in southern Europe, we were amazed to find the temperature here to be pretty much the same. The change from the cold snap to these spring like balmy days seems to have kick started everything into a mating frenzy. The collared doves are getting amorous all around the garden, cooing in wheedling tones and strutting their stuff. I watched two sparrows fluttering in the willow tree and wasn’t sure whether they were locked in combat or copulation. They fell out of the tree onto the ground, and lay motionless, still locked together, for three or four minutes. This surprised me, as surely if this were normal behaviour it would leave them very vulnerable to predators. I was just considering approaching for a closer look when they suddenly righted themselves and flew off.
But the main event so far has been the frogs. Have a look at my video of our excited amphibians here on YouTube.
We’ve counted seventeen of them in our garden pond, and as you can see in the video, they’ve only got one thing on their little amphibian minds. This is the third spring we (and our pond) have been here. The first year we had no spawn, but lots of very juvenile frogs, since we had brought tadpoles and froglets from our former pond, knowing that it was to be immediately filled in after we left. Last year we heard lots of croaking at night during March, and had three clumps of spawn. This year, I’ve not heard any nocturnal croaking, but the pond is full of very excited and noisy frogs during the middle of day. This is brilliant, as of course we can observe their behaviour during the day in a way that you can’t at night. Although to start with they would all disappear as you approached, now they don’t seem to mind at all and you can sit on the oak beams that form one edge of the pond, and watch their antics. The frogs who are camped out on the surface of the pond are males, and they are hoping to attract females by croaking – puffing out their throats (the vocal sac) to act as an acoustic chamber, amplifying the sound produced by forcing air across their vocal chords. The frogs respond very strongly to movement. So they all sit there in their assumed positions, croaking like crazy, waiting for something to happen. When one of them moves, or a new frog surfaces, they all pile on top of it jostling for position and grabbing the frog around the waist; this position is called amplexus, where the male will cling to the female so that he can fertilise her eggs as she lays them. I’ve observed that when the frogs pile onto another one who’s just moved or surfaced, the embrace only lasts until the embraced frog croaks, then the other one releases him, and they move apart. This is due to the male in question emitting a ‘release call’ – the amphibian equivalent of “Oi, gerroff – I’m not what you’re after”.
As far as I can tell, I’ve only seen two females, and they both happened to be very unusually coloured. One is brick red all over, and I’ve observed her in the pond occasionally since we created it. The other appeared only briefly yesterday, and was really striking; pale creamy yellow with reddish markings. I’ve got a past photo of the red frog (see right), but didn’t manage to snap the pale one. The reason I think they’re female is that when they appeared, they were absolutely swamped by very excited males, and rapidly tried to escape, wriggling away and disappearing into the depths again. I then saw the red female again today, once she appeared under the surface of the water. with another frog firmly grasped in amplexus, and the other she was alone, but hiding behind an area of grass that droops into the water, shielded from view.
Edited to add: I’ve seen the brick red female again, lurking under thick cover, and got some photographs of her. She’s really unusually coloured, and I knew I’d seen her before. I went through my old photos, and found some of her taken in September 2009. It’s nice to know that she’s breeding in the pond three years after she first visited us. She must have been two or three years old in 2009, as she was fully adult sized; apparently frogs can live eight or so years, so hopefully she’s got a few years left in her yet.
I wonder how many other beleaguered females are lurking in the depths, waiting until the moment is right to brave the amorous attentions of the males?