Bird in our venilation

There’s a bird trapped in our heating system ventilation. I saw him but he got away. I might let one of our cats loose in the duct work to get him.

And yet another pain in the *ss thing I get to spend time working on. Freakin bird, how the heck did he get from the ventilation pipe on the roof all the way to the vent pipe leading out of the furnace. And why can’t the stupid bird just fly UP and away, like birds are supposed to do.