Heart strings for stray dog

I took the dogs out this evening after work, and right after I let them out of the car they got in a momentary confrontation with a scruffy black dog, and they ran onward. The dog hunkered down and crawled back into its hiding place. I backed the car up and saw where it had curled up, and talked to it ~ and it looked back at me, so scared and kinda scary, too. I made sure I got the dogs back in the car before we passed back by that spot and then I went home and got a bowl of food and went back and left it out for him. I am wondering if I should just let it be to its own fate or call someone. I am afraid getting it picked up will result in its ultimate demise... I will go back that way in the morning and just see... hmm???