The images below are the result of editing in Corel-Photo-PAINT 2020 and PaintShop Pro 2021.  The image on the left is of the first edits, cropped in Photo-PAINT, a digital noise reduction was done, then a mask was brushed around the highlight area on the birds head, back and side.  The colors were adjusted, cloned or painted in to remove the blown out areas in the image and then the mask was removed.

Then a mask was brushed around the entire bird excepting the leaf which is in front of the bird. Areas of the tree around the beak were cloned to accent the beak, color satuation and vibrancy was adjusted, the mask was removed and the file was saved as a 16 BIT TIF file. 

Photo-PAINT 2020 has several noise reduction filters however I had already used the one that had the best result on the original TIF file and the image was still not where I was willing to accept its quality. I opened the TIF file in PaintShop Pro 2021 because this application has 3 very distinctly different noise filters to try and I used the the digital noise filter  under the adjust menu as it had the most pleasing affect. I applied the filter settings of my choice and saved the file.

As Photo-PAINT has the absolute sharpest display of any imaging application I've ever used I opened the file there and made a slight unsharp mask adjustment and a minimal tone curve to enhance the contrast.

In this shot it's easy to see the short comings of the APS-C sensor and the Nikkor 70 to 300 lens in this camera, a shot of a bird this small with a 300mm lens at 35 feet produces an image that can be placed on the web however any desirable print would be under 4" without the help of a quality up sampling software.

So now the questions that begs are, do I move to a full frame camera or a medium format camera?