That is definitely a paint defect and nothing to do with birds.
Get in touch with Renault UK head office.
I agree that you should escalate your claim especially as the car is only 2 years new. Bird-muck damage can more or less be identified by its shape anyway [splattered?].
The only other [car oriented] thing that I am aware can damage paintwork is hydraulic fluid and it is not unknown for mechmanics to throw their hand-rag on top of the car if called away from their job for some reason. Have you had any maintenance done to your brakes? A rag that is moist with fluid can cause damage to cellulose paint within minutes; I am not too sure how the modern environment-friendly water-based paints react though but I expect they will react in the same way; usually what happens is that the surface kinda wrinkles and the painted loses its key and you can get your nail under it and peel it off without resistance. Naturally, as a new car, this will only have been into the Renault dealers' for servicing so they can't really say it was done by somebody else.
Do you have any photos that we could look at perhaps? Most people will have seen bird damage at some time and might give you an opinion. You should also have photos for your own records. A professional opinion from an independent paint maker or recognised bodywork shop would be helpful but may cost money. An experienced
friendly paintshop supervisor may also be able to give you an off-the-cuff opinion for your immediate guidance.
I'm not surprised that the dealers are trying to weasel out of it but that doesn't mean it is the official opinion of Renault. Try emailing and don't waste your time phoning because all you'll get on the phone are rehearsed replies... totally bereft of any knowledge and initiative at that level and they are paid to say "no"... at least that's my opinion formed after dealing with them. Mr Moore has helped some of our members in the past and I perceive him to be a man of integrity who will act with honour.
Don't leave the problem indefinitely though because they will say that you have caused more damage by not dealing with it immediately.
How long since you became aware of this problem and is there any chance that your car was vandalised at any time? The shape of the damage should give you a clue.
Read the conditions of the paintwork and rust guarantee and see if they have any disclaimers or conditions that may have a bearing.
Good luck and for the sake of others who may experience something similar, please keep us informed.