CLARIFICATION: 8/18/14, 11:25 p.m. EDT. Additional information regarding Christian Taylor’s departure from Kirkland has been added to the sixth paragraph of this story.

Four months after becoming the latest Am Law 100 firm to open in Houston, Kirkland & Ellis continued this week to hire in the city and grab another role on a notable energy deal for a top private equity client.

The firm has brought on former Baker Botts associate David Castro Jr. as a corporate partner in Houston, where he joins former Baker Botts colleague Anthony Speier III, who left his former firm to join Kirkland’s energy transactional practice earlier this summer.

Speier was part of a team led by M&A partner Andrew Calder—Kirkland’s ballyhooed $5 million hire from Simpson Thacher & Bartlett in April—that is advising The Blackstone Group on its $2.1 billion buy of a 50 percent stake in a Louisiana shale play from Royal Dutch Shell.

But Kirkland’s prowess making splashy hires—Calder wasn’t the firm’s first $5 million rainmaker—and notable transactions have masked something else going on at the 1,550-lawyer firm, where gross revenue surpassed $2 billion and profits per equity partner hit nearly $3.3 million in 2013. Kirkland, profiled by The American Lawyer last year for its “all business” mindset as the firm strives to build a top-shelf M&A practice, has watched more than 50 partners head for the door since the beginning of this year.

Roughly half of those departures have come from Kirkland’s IP litigation group, with most of the losses coming in Chicago. In conversations with a half-dozen lawyers who have worked at the firm in recent years, the reasons for the exodus varied. Some cite an emphasis by Kirkland to invest in higher-margin practice areas like M&A, while others point to a gradual transition in the IP practice to focus on client work from the coasts following the departure of IP rainmaker John Desmarais in 2010 to start his own patent licensing company in New York.

For a long time Kirkland’s IP group was led by Robert Krupka in Los Angeles and William Streff in Chicago. But Krupka retired in early 2012, and Streff, who turned 65 this week, is transitioning his practice. Christian Taylor, another former equity partner in the IP group who founded Kirkland’s Palo Alto office and helped start its San Francisco office, took early retirement last year and started a film production company in addition to his role as president of a repertory theater, shortly before equity IP partner Paul Steadman left the firm’s Chicago office for DLA Piper.

This year, Kirkland has seen several equity IP partners depart. Eric Lamison, a founder of its San Francisco office, left the firm last month to become vice president of IP litigation at longtime firm client Cisco Systems. Also heading in-house was Linda DeBruin, another equity IP partner in Chicago who took early retirement earlier this year and headed to Deerfield, Ill.-based technology solutions company Textura as its chief IP counsel.

In April, equity IP litigation partner David Callahan left Kirkland after more than 22 years at the firm to join Latham & Watkins, taking with him two months later Ann Marie Wahls, who was promoted to partner at Kirkland in 2007. Barry Irwin, another equity IP partner in Kirkland’s Chicago office, left the firm in February to start his own IP boutique in suburban Burr Ridge, Ill. (Irwin now works with his wife, as does Krupka, whose better half serves as managing partner of their two-lawyer shop in Los Angeles.)

Kirkland’s robust nonequity partnership ranks have also seen their fair share of departures, as IP litigator Matthew Meltzer, just promoted to partner at the firm last October, left the firm at the start of the year to start his own student study abroad program. Also leaving in January were IP litigators Aaron Charfoos and Tiffany Cunningham in Chicago, who headed to Dykema Gossett and Perkins Coie, respectively.

February saw nonequity IP litigators Ryan Camasiquela join Arnold & Porter in San Francisco; Matthew Topic head to Chicago’s Loevy & Loevy; and Lee Stevenson decamp for Zuckerman Spaeder in New York. Elizabeth Locke and Thomas Clare formed their own Beltway-based shop, Clare Locke, in Apri.l and Tom Monagan III joined Chicago’s Norvell IP the following month. June saw Holland & Knight hire IP litigation partner Howard Suh in New York, while Proskauer Rose picked up general practice litigation partner Peter Duffy Doyle.

The growing Kirkland diaspora, once again overly represented by those coming from the firm’s IP ranks, has spread to in-house positions at companies around the country, some of which are firm clients. The most recent IP litigator to leave is Seth Gastwirth in Chicago, who was promoted to partner in October 2009 but left the firm earlier this month to become senior legal counsel for commercial and contracts at Akzo Nobel, the world’s largest paint manufacturer.

Julie Posteraro, another nonequity IP litigator in Washington, D.C., also left Kirkland this month. The Am Law Daily was unable to determine her new role by the time of this story, but Posteraro’s departure comes a month after her husband, fellow Kirkland IP litigator Chris Posteraro, left the firm’s Beltway base to become principal counsel with The Walt Disney Company in Orlando.

Other nonequity IP litigators leaving Kirkland in recent months include Christopher Freeman, who made partner in October 2013 and is now the cofounder, vice president and head of litigation at Blackbird Technologies in Glenview, Ill.; Josh Reed in Chicago, now vice president and chief IP counsel at Allscripts Healthcare Solutions; and Sean Christofferson, an IP litigator with Kirkland in Palo Alto who made partner in October 2013 but left the firm in May to become corporate counsel at Arista Networks.

At Arista, Christofferson joins former Kirkland colleague Candace Wilhelm, who became a partner in the firm’s San Francisco corporate practice in October 2010 before leaving in January to become assistant general counsel at the computer networking company in Palo Alto. Arista isn’t the only company acquiring former Kirkland partners.

Chicago-based jumbo jet-making giant Boeing, a longtime Kirkland client, picked up nonequity restructuring partner Sarah Seewer in June as senior counsel, the same month that IP litigation partner Joseph Cascio in Washington, D.C., also joined the company in an in-house role.

Other Kirkland clients that have tapped the firm for their in-house needs this year include hospitality giant Wyndham Worldwide, which hired general practice litigator Ryan Morettini in New York earlier this year to become its vice president of legal in Orlando, and private equity firms TPG Growth and Golden Gate Capital, which brought on corporate partners Yaman Shukairy in Chicago and Rachel Masory in San Francisco as counsel and deputy general counsel, respectively.

Asked to make sense of the volume of partner-level churn at Kirkland this year, Jay Lefkowitz, a litigation partner in New York who serves on the firm’s executive management committee, says that it comes with the territory of growing into a global legal giant.

“It’s a testament to the quality of the folks we bring in here,” says Lefkowitz, an adjunct professor at Columbia Law School. “You have some folks that end up leaving for different reasons, whether it’s because they want to become more entrepreneurial or to experience the business side of things.”

Lefkowitz declined to comment on the situations of specific partners, but scoffed at the notion that some of the departures were part of some Machiavellian plan by the firm to embed partners at potential clients or prune certain practice areas in order to invest resources in others.

Kirkland has continued making prominent hires, poaching Skadden, Arps, Slate, Meagher & Flom tax partner Dean Shulman in New York last month, shortly after adding Cravath, Swaine & Moore practice area attorney Michael Krasnovsky as a corporate partner in the same city. In May, Kirkland made waves in London by snagging Stephen Lucas, the local head of the banking practice at Weil, Gotshal & Manges.

Unlike many Am Law 100 firms, Kirkland itself does not have official practice leaders. The top leadership roles traditionally fall to the partner in each practice who sits on the firm’s management committee. In the IP group, that is New York partner Gregory Arovas, who joined Kirkland 15 years ago from Fish & Neave, a prominent IP firm that was subsequently absorbed into Ropes & Gray.

Kirkland, historically known for its robust litigation practice, has sought to bolster its IP group in recent years by hiring Steven Cherny from Latham in New York back in 2008, nabbing O’Melveny & Myers partner Dale Cendali in New York the following year and adding Jones Day’s Kenneth Adamo in Chicago in 2011. Whether or not Kirkland will continue recruiting in IP as it has in other areas like M&A and private equity, only time will tell.