Your proposed lens types are sensible. For macro, a dedicated true macro lens around 100–180mm is a strong choice; the Sigma 180mm macro mentioned by users is regarded as a solid, well-built option.

For bird photography, the Canon 100-400mm is repeatedly praised in the answers as an excellent wildlife/bird lens: flexible zoom range, good image stabilization, and useful both handheld and on a tripod. One user also notes a 300mm f/4 plus 1.4× teleconverter can work well.

A crop-sensor body is often an advantage for birds because it gives a narrower field of view, helping distant subjects fill the frame.

Between Canon and Nikon, the answers don’t establish a clear winner; both systems are broadly capable. The strongest practical advice in the thread is to also consider staying with Sony if your existing lenses are still useful, since switching systems is expensive and newer Sony bodies may solve the limitations of your current camera while letting you keep your lenses.

So: macro lens around 100–180mm, long stabilized telephoto for birds, and consider total system cost before changing brands.