Originally posted by Paul the Sunman the focus is not quite right for many of them. If you are using Auto Area focus, the camera won't necessarily make the choice you would have. I would recommend spot or very restricted AF, centred on the eye if you can. You may like to experiment with AF.C instead of AF.S, which I would certainly use for birds in flight, but it may not make much difference for a bird on a perch.
This is the main problem. By default the K-70 uses Auto 11 point AF. The trouble is that the camera doesn't focus on the eye - it might focus with any one of the 11 points. For birds you generally need to use a single point, whether centre point or select AF point, and focus on the eye, as Paul says. Change the default to one of these.
With a centre point only, you will need to learn to focus and recompose: that is, half-press the shutter to focus on the eye, hold it half-pressed to keep the focus and reposition to compose the shot. Alternatively, if you set the camera to focus only with the back button, take you thumb off the button when you have focus, then re-compose and shoot.
The only situation where auto selection of AF points can work effectively for birding is with birds in flight. Like Paul I would use AF.C for this, and shutter priority with a speed like 1/1250th or 1/1600th. I save my birds in flight settings as a user mode for quick access.
If you focus with the rear screen (LiveView), there is an option for EyeAF. But I don't think it works on birds in the K-70. (Maybe in the K-3iii.)
As for the settings, ideally you want bright conditions where you can use a fast shutter speed, low ISO and f8. But don't give up or wait for mid-summer when you might get those conditions. Make the best of what's available. You often need to shoot wide open (the 55-300 PLM is fine at this). Sometimes you need to drop the shutter to 1/125th or even less. Sometimes you need to raise the ISO to 6400. Sometimes you have to do all three. The odds get worse with each compromise but if you have good technique you can still get a usable shot, This is with the PLM at 210mm, f5.6 (ie wide open), 1/100th sec, 6400 ISO
But as Paul said, to use a high ISO like this, shoot RAW and use good post-processing (PP) software. (I use DxO PhotoLab, which uses AI for its NR and is excellent.)
In fact shooting RAW is essential to get the best from your birding photos. Here is a before and after as an illustration. (First shot is a straight conversion of the RAW file, the second after processing.)
When shooting with a slower-than-ideal shutter speed, focus as best you can and try shooting a burst (put the drive mode into Continuous shooting high) of 5 or 6 shots, maybe more. Often one will stand out - just delete the rest.
A couple of people have mentioned using flash. This can help to bring out colour and detail and even up the light (e.g. bird in shadow against a bright sky). The key is to use it only as fill, not as the main light, and keep the contribution to 1 or 2EV. Ideally, the only indication of using the flash should be a nice little catchlight in the eye.
Use an external flash, not the popup in the camera, unless you have no other choice. If you get redeye or steel eye, it's usually fixable in PP if you shoot RAW.
My other key tip for a newby is to work on your technique for handheld shots. This really helps. Great article here:
Making the Most of Long Exposure Handhelds - Introduction - In-Depth Articles