Question: Boyd Matson is the former anchor of "National Geographic Explorer", an American documentary television series that originally premiered on what network on April 7, 1985?

Context paragraphs:
The Urban Gorilla: The Urban Gorilla is a 1991 documentary television film from National Geographic Explorer and ArgoFilms.  The film explores the lives of gorillas in an urban environment.  "The Urban Gorilla" was narrated by Glenn Close and shot by Robert Collins.  The film was directed, produced, and written by Allison Argo.  This was the first film that Argo produced.  The film was directly inspired by a gorilla named Ivan, who is featured in the documentary.

Robert H. Gardner: Robert H. Gardner (born, June 3, 1947 in Berkeley, California) is an American documentary filmmaker, Producer and Director of the Academy Award nominated The Courage to Care, Emmy Award winning Egypt: Quest for Immortality, Dupont Columbia Award recipient, Arab and Jew: Wounded Spirits in the Promised Land, National Geographic Explorer series; Search for the Lost Ark, Tiwanaku, and Desert Warriors; The History Channel series, Barbarians, Barbarians II, and .  In 2001 his groundbreaking series, aired on PBS, and Islamic Art: Mirror of the Invisible World in 2012.

Tierney Thys: Tierney Thys (born 1966) is an American marine biologist, science educator, and National Geographic explorer.  In 1988 she earned a degree in biology from Brown University, and in 1998 she earned a doctorate in biomechanics.  She was formerly the director of research at the Sea Studios Foundation.  She was also the science editor for "The Shape of Life" and director for "Strange Days on Planet Earth".  She has also written, narrated and produced short films.  Since 2000 she and her colleagues have been studying the giant ocean sunfish (mola).  In 2004 she was named a National Geographic "Emerging Explorer".  She has since joined National Geographic expeditions and developed a National Geographic children's television conservation series.

National Geographic Explorer: National Geographic Explorer (or simply Explorer) is an American documentary television series that originally premiered on Nickelodeon on April 7, 1985, after having been produced as a less costly and intensive alternative to PBS's "National Geographic Specials" by Pittsburgh station WQED.  The first episode ("Herculaneum: Voices from the Past") was produced by WQED and featured long-time "Explorer" camerman Mark Knobil, who is the few staff members with the franchise during all 24 seasons.  The program is the longest-running documentary television series on cable television.  Presented every Sunday from 5:00 pm to 8:00 pm, the original series was three hours in length, containing five to ten short films.  Although the National Geographic Society had been producing specials for television for 20 years prior to "Explorer", the premiere of the series required an increase in production from 4 hours of programming a year to 156 hours.  Tim Cowling and Tim Kelly were the executive producers for the series during this transition.

Richard Hammond's Engineering Connections: Richard Hammond's Engineering Connections is a documentary series originally broadcast on the National Geographic Channel, and later on BBC2.  It is presented by Richard Hammond, and looks at how engineers and designers use historic inventions and clues from the natural world in ingenious ways to develop new buildings and machines.  The show's format is very similar to that of James Burke's 1978 documentary series, "Connections".  The first series premièred on 8 September 2008, on National Geographic, and on 1 March 2010, on BBC2.  The first series contained four episodes.  The second series premièred on 7 September 2009, on National Geographic, and on 8 May 2010, on BBC2.  The second series contained six episodes.  The third series premièred on 8 May 2011, on BBC2 and contained six episodes.  The BBC2 broadcasts of the first two series have a slightly shorter running time and contain less information than the original National Geographic broadcasts, with on average one minute of footage cut from every episode.  None of the three series of the programme are available to purchase on DVD in the UK, however, all three can be watched on demand for subscribers of National Geographic on Sky, Virgin Media and BT Vision.  In Australia, all three series are available on DVD, either separately or as a box-set.

Great Migrations: Great Migrations is a seven-episode nature documentary television miniseries that airs on the National Geographic Channel, featuring the great migrations of animals around the globe.  The seven-part show is the largest programming event in the ten-year history of the channel and is part of the largest cross-platform initiative since the founding of the National Geographic Society.  It was filmed in HD, and premiered on November 7, 2010 with accompanying coverage in the "National Geographic" magazine and an official companion book.

Boyd Matson: Boyd Matson (b. April 26, 1947) is the former anchor of "National Geographic Explorer" and a former co-anchor of NBC's "Sunday Today" program.  He was also an NBC News correspondent in the 1980s, working mostly on news features and earlier as a sports reporter on KNBC in Los Angeles.  He now hosts the show "Wild Chronicles" on PBS and the nationwide radio program NG Weekend.  Matson also writes a monthly column for NG Traveler magazine.  He lives in Virginia with his wife Betty Hudson and his two children.

Trapped (2007 TV series): Trapped is a documentary television series that premiered on November 7, 2007 on the National Geographic Channel.  Produced in association with the National Geographic Channel and Cineflix (which produced "Mayday", also known as "Air Crash Investigation"), the program examines various actual incidents or disasters in which victims were trapped on the site.

Sandesh Kadur: National Geographic Explorer Sandesh Kadur is a Wildlife Film Maker and Conservation Photographer known for his contributions to Planet Earth II.  Sandesh's films have been shown on television networks including National Geographic Channel, BBC, Discovery Channel and Animal Planet.

Hiding in the Light: "Hiding in the Light" is the fifth episode of the American documentary television series "".  It premiered on April 6, 2014 on Fox and aired on April 7, 2014 on National Geographic Channel.  The episode explores properties of light, cameras, the scientific method, and the composition of the universe.  The episode includes a look at the contributions of the 10th century physicist Ibn al-Haytham, described as the "father of the modern scientific method".

Supporting paragraphs: Boyd Matson National Geographic Explorer
Answer: Nickelodeon