Jon Stryker, the grandson of Homer Stryker and one of the top shareholders of the company that bears his name, has pared his ownership in the company by about 4 million shares in the past 10 months, according to regulatory filings.

Meanwhile, Capitol World Investors has increased its piece of Stryker Corp. (NYSE:SYK) by nearly 3 million shares. The Los Angeles-based investment firm is now one of the top five shareholders in the Kalamazoo, Mich.-based medical device company, controlling some 22.9 million shares and bumping Jon Stryker out of the top five.

Capitol World now owns 5.8 percent of Stryker, worth about $13.5 billion using the Feb. 11s closing price of $60.22. Last year, Capital World had just more than 20 million shares of Stryker stock, good for a 5.1 percent piece of the company.

Jon Stryker, a political activist who founded the Arcus Foundation with the dual mission of advancing gay rights and conserving and protecting the great apes, now controls some 18.5 million shares (about 4.7 percent of the company), valued at about $10.8 billion.

Last year, Jon Stryker owned 22.2 million shares of the company, amounting to a 5.6 percent stake, according to a 2010 proxy statement.