Beautiful bird!!
For your pictures. I have a couple of pieces of advice, since you asked.
First is the focus. The camera is focusing on the background rather than Merlin. Using the auto-focus the camera has to guess where the focus should be and it does that by using a focal point inside the camera sensor. When shooting the picture look at the the lcd screen on the back and make sure your target is in focus. Generally you do this by holding down the button halfway to force the camera to focus. Repeat that until you get the focus you want.
The lighting. The camera taking in the whole picture then running the image it sees through an algorithm then sets the shutter speed and the aperture (opening) of the lens. Since there is an open window behind you subject the camera is getting the exposure all messed up so Merlin is too dark. To fix is easy, don't let the window be the background. Move the side and let the light be on the side or in front of the window so the light is behind. (There are other ways, but just moving is the easiest).
Finally, just get a little closer. The subject is Merlin, so he should be the dominant item in the frame. We see a lot of window, chair, wall, air filter... all of that distracts from Merlin. Zoom in using the zoom feature of the camera, or just walk closer.
Hope this helps.
Thanks for sharing Merlin.
Mike