STAFF at the Devon Wildlife Trust have been left scratching their heads, after finding frogspawn up a tree.

The trust's Working Wetlands project recently made the surprise discovery when working on land near Roadford Lake. They were quickly able to identify the jelly-like substance as frog spawn but weren't able to fathom how it had come to be on a tree trunk.

Project manager Mark Elliott said: 'Finding frogspawn at this time in winter is not that unusual, especially the mild weather of the past week.

'But finding it up in a tree was — it's not something I'd come across before. Common frogs lay their spawn in water and it's there that tadpoles develop, not in trees!'

Mark took a photo of the frogspawn and sent it to Devon Biodiversity Records Centre for identification.

Ellie Knot of DBRC had seen similar cases before and was able to offer an explanation.

She said: 'This kind of finding is commonly known as a 'star slime' — a lot of animals and birds eat frogs, but they don't eat their ovaries because the eggs or spawn contained in them expand massively when they come in to contact with water. This expansion would be enough to give anyone stomach-ache. 

'Freshly laid spawn is fairly small — the eggs in their jelly cases are less than five millimetres across, but once it has been around for a few hours the eggs expand to more than one centimetre across. 

'The clump of frogspawn usually ends up much larger than the frog that laid it.

'So, when birds eat a frog they leave the ovaries behind, which then expand and burst when they get wet, leaving a clump of spawn.

'In fact, it is not that uncommon to find frogspawn in trees — buzzards and crows will often take frogs, retreat to a nearby perch and then eat their prey there, leaving the ovaries and the spawn behind after their meal.'