Question: Ostava and Birds of Tokyo are both what?

Context paragraphs:
Birds of Tokyo: Birds of Tokyo is a five-piece alternative rock band from Perth, Western Australia.  Their debut album "Day One", gained them domestic success, reaching number three on the AIR Independent Album charts and spending a total of 36 consecutive weeks in the top ten.

Wild at Heart (Birds of Tokyo song): "Wild at Heart" is the third single from Australian alternative rock band Birds of Tokyo's self-titled third album, "Birds of Tokyo".  The song peaked at #50 on the Australian Singles Chart in February 2011 and was certified gold.  It was voted #47 in Triple J's Hottest 100 countdown of 2010.

The Saddest Thing I Know: "The Saddest Thing I Know" is the first single from Australian alternative rock band Birds of Tokyo's self-titled third album, "Birds of Tokyo".  It was the first released under new label EMI Music Australia.  The song because their first ARIA Chart song, peaked at #66 in May 2010.  It was voted #87 in Triple J's Hottest 100 countdown of 2010.

Birds of Tokyo (album): Birds of Tokyo is the third album by Australian alternative rock band Birds of Tokyo, released on 23 July 2010 through EMI Records.  It was recorded in Sydney, Australia; New York City, United States; London, UK; and Gothenburg, Sweden, produced by Scott Horscroft, co-produced by Adam Spark and mixed by Michael Brauer.  This is the last album to feature Anthony Jackson on bass guitar before his departure in March 2011.  The album won the ARIA Award for Best Rock Album in 2010.

Plans (song): "Plans" is the second single from Australian alternative rock band Birds of Tokyo's self-titled third album, "Birds of Tokyo".  The song proved to be their most successful single to date, peaking at #11 on the Australian Singles Chart and becoming their first ever single to hit the top 50 in Australia.  "Plans" was performed by the group at the 2010 ARIA Awards, in which the song was nominated for "Single of the Year".  It was voted #4 in Triple J's Hottest 100 countdown of 2010.  As of September 2012, "Plans" has been certified triple platinum by ARIA with sales exceeding 210,000.

I'd Go with You Anywhere: "I'd Go with You Anywhere" is a song by Australian band, Birds of Tokyo.  It was written by the group and released on 25 September 2015 as the lead single from their compilation album, "Playlist".  "I'd Go with You Anywhere" debuted at No. 40 on the ARIA singles chart and peaked at No. 18 five weeks later, becoming Birds of Tokyo's third Top 20 hit after "Plans" (2010) and "Lanterns" (2013).

March Fires: March Fires is the fourth studio album by Western Australian alternative rock band Birds of Tokyo.  It was released on 1 March 2013 in Australia, North American and Europe through EMI.  It is the band's second major-label studio album release after 2010's "Birds of Tokyo" under EMI.  It is also the first album by the band not to feature founding member Anthony Jackson, after he had left the band in 2011.  His replacement, Ian Berney, makes his debut appearance on the album as the band's new bassist.

Running on Air: Running on Air is the fourth studio album by the Australian hip hop trio Bliss n Eso.  It was released on 30 July 2010.  The album debuted at No. 1 in Australia for the week commencing 9 August 2010.  It has since been certified Platinum by ARIA.  It was nominated by Australian radio station, Triple J for Album of the Year, along with Megan Washington's "I Believe You Liar", and Birds of Tokyo's "Birds of Tokyo".

Ostava: Ostava are an alternative rock band from Bulgaria.  They formed in 1991, but it was not until 2000 that they released a long-playing record (and subsequently received critical acclaim.

Tatsuo Utagawa: Tatsuo Utagawa (宇田川 竜男 , Utagawa Tatsuo , 1917 – 2006) is a Japanese ornithologist and retired professor from Azabu University.  A native of Tokyo, he graduated from Tokyo University in 1937 in veterinary medicine.  Worked at Ueno Zoo.  In 1958 he obtained his doctorate in science from Hokkaido University, on research in "A Comparative Study of chromosomes in birds".  Later he became the Section Chief for Birds and Wild Animals at the Experimental Forestry Station for the Japanese Ministry of Agriculture and Forestry.

Supporting paragraphs: Ostava Birds of Tokyo
Answer: alternative rock band