Welcome to Bird Forum (BF) Cranefan. I'm not one of the experts who can help much with identifying your birds. However, I have been helped here a lot.
I notice you are posting png files for some reason. Most people use jpgs (which is what your camera should produce, and which show a greater range of colours, which can be important for identification)
Also, all of your photos seem to be small, barely bigger than the thumbnail itself. If your photos simply are that small, then I apologise for picking you up on it, but maybe you could change your technique and produce photos more helpful to those who want to identify them for you.
There are rules about photo size on BirdForum (to save on the server space). When I started, it wasn't obvious how to get the balance between quality and small file size that BF wants. So I experimented and here is how I do it now.
Open your photo in whatever software you use to edit photos. To make sure you don't save over the original, Save the photo somewhere (as a jpg if it isn't already) with a new name (I add BF to the photo name, or S for 'small').
Crop this newly saved photo so that the important bit for identification is in the photo. For printing, you may want an artistic photo with branches, flowers and sky, but for identification, you basically just want the bird. Adjust the levels to get as good a contrast and brightness in the photo as you can.
You want your photo to be 'not too big' and 'not too small'. On your software, check the photo size - I use Photoshop Elements, so I find the 'Resize' section under 'Image'. Check that the longest side is 1000 pixels or less (BF maximum is 1024x900, but this works for me). But at the same time try to get the long side as near to 1000 as you can, so the photo will be fairly large. Play around with cropping more or resizing to get the best quality you can.
(Depending on the subject, if the photo is really clear but small, it may even be worth magnifying the photo, by putting in a larger pixel number than the original. (Remember, most screens will have about 90 pixels per inch.))
Then save the photo again, making sure that the File Size is less than 300kb (the BF gallery size is 325kb, but again this rule works for me). To do this with Photoshop Elements, use the quality slider after you press 'Save' - this tells you what the file size is. Don't worry that the 'Quality' is getting lower because you have already made the photo as good as it can be in the first step of editing, just concentrate on the file size here.
You don't have to worry about the thumbnail size: BF will make a thumbnail for you. Try to get as good and large a picture as you can within the 1024x900 and 325kb limits for a single picture. (Valéry in this thread gives a much higher number, but unless it's changed recently, then I think I'm right.)
You post the photos using 'Manage Photos' on the BF site as you have obviously worked out how to do already.
I hope this helps in the future. And if it's just that your photos are really small, then I apologise again. But your photo basic quality seems fine, and so it seems odd that ALL of your photos on all of your threads are so small.