Do not talk to them during your working hours. Tell them you prefer to communicate via email. If you think they have something to offer, then you can arrange time off from work, and talk to them.
If the recruiter really thinks you are a likely candidate he will work with you, if isn't. If they aren't willing to work withadjust to you, he'sthey're just covering the bases in case he getsthey get lucky.
