Reasons for a sharp decline in pages crawled

[Symmetri]

Hello!

I have a site I've been tracking using Moz since July. The site is mainly stagnant with some on page content updates. Starting the first week of December, Moz crawler diagnostics showed that the number of pages crawled decreased from 300 to 100 in a week.

So did the number of errors through. So crawler issues went from 275 to 50 and total pages crawled went from 190 to 125 in a week and this number has stayed the same for the last 5 weeks.

Are the drops a red flag? Or is it ok since errors decreased also? Has anyone else experienced this and found an issue?

FYI: sitemap exists and is submitted via webmaster tools. GWT shows no crawler errors nor blocked URLs.

[MickEdwards]

How many URLs are indexed in Google if you use site:yourdomain.com  Has that figure dropped too?

Have you got anything in your robots.txt that could be blocking?

[KeriMorgret]

If you fixed a problem, such as duplicate content, that would mean that we're showing fewer errors and crawling fewer pages, since that problem is fixed. Might that be the case?

[Symmetri]

Google is indexing just over 80 URLs, although about 40% of them are developer test URLs (they lead to live pages of the site though). Nothing in robots.txt. No errors.

The Google bot is still crawling, but it's crawling half the pages. What would make it decrease in page crawls? I'm working if there is a broken link or something on the home page that's pointing away from the site... although it's unlikely, I'll check....