A site I am working on had 404 errors which were on following URLs:
Do I really need these faviocons on my site? Are bots coming to these links or real people?
The two URLs you reference are most probably requested from iOS (iPhone, iPad) devices.
If you check the access logs on your server, you can (in the most part) find out who/what exactly is requesting these resources.
Do I really need these faviocons on my site?
If you want to give iPhone and iPad users the best experience then yes. Otherwise it's not a show stopper.
Are bots coming to these links or real people?
Real people (with probably a few bots thrown in for good measure).
Whether you really need them or not is determined by whether or not you want to cater to users on all devices. iOS uses different icons than Android which uses different icons than Windows.
I've found http://realfavicongenerator.net/ to be the simplest way to generate everything for me all at once. All you have to do is create one "favicon" image at least 260*260px and the site will generate all different icons for you in one go. It even gives you the HTML to include in your sites
<head> section to display them on all devices correctly.
Their FAQ has a breakdown of all the images generated.