Feral Cat gave birth on our balcony

Hi I live in a semi detached housing neighborhood, so the street cat's in our area navigate through the roofs and balconies with ease. For about 3 weeks a feral queen has given birth to four healthy looking kittens. They're about 3-4ish weeks old now, and I was wondering if it would be a good idea to try to move them to bring them to our local SPCA, however whenever I go on to the balcony, the mother cat hisses at me. 

What should I do? 

First you must be sure the SPCA will adopt them, ie if they do have a fostering homes lined up and waiting. Otherwise, the risk is verry big, they will be put to sleep immediately. At best be give a meal before, and off they go.

That is very common, especielly if the mom is semiferal and protective...

Otherwise, it is best YOU try to foster them as well you can.  And if you cant, let them be and live as semiferales... With an experienced mom they may make it.

Tx for caring!

Good luck!

ps.  Try and talk with the SPCA anyway. They may perhaps accept YOU as the fostering home, and help you with vet costs.  Spaying, deworming, vaccing, some check ups...

Hi thanks for the reply.

I have talked to the SPCA and they said that younger kittens are always taken in. The one problem with them being semi feral cats, is that i'm a bit concerned for their safety because there are a lot of stray dogs in this area as well.