How to query wikidata for the number of taxonomic entities that have a wikipedia page?

Question

I am trying to find out how many biological taxonomic entities have an article on wikipedia, across all languages.

I am able to get the number of entities in wikidata, but many of these don't have an article on wikipedia.

Below is the SPARQL query I used. How do I modify it so it only counts taxons with a wiki article?

SELECT (COUNT(*) AS ?count)
WHERE {
  ?item wdt:P31 wd:Q16521 .
}