Scholarly sources are written by academics and other experts and contribute to knowledge in a particular field by sharing new research findings, theories, analyses, insights, news, or summaries of current knowledge.

Scholarly sources can be either primary or secondary research. They can also come in many different formats.  Books, articles, and websites can all be scholarly sources. 

"What Counts As a Scholarly Source?" University of Toronto Libraries |, 18 May 2018, onesearch.library.utoronto.ca/faq/what-counts-scholarly-source.

Example:  Here is a popular news article which contains a scholarly source within the article: How Many Ants Are on the Earth?