Plant species of atoll forest include Pandanus tectorius, Lepturus repens, Cocos nucifera, Boerhavia repens, Pisonia grandis, Portulaca lutea, Triumfetta procumbens,[6] Tournefortia argentea and Scaevola sericea, as well as areas of atoll scrub and vines.

[10] Bikar's status as a major seabird nesting site was affected by a cyclone and the introduction of more aggressive rat species.

Migrant birds include small numbers of the ruddy turnstone, wandering tattler, bristle-thighed curlew, lesser golden plover, and Pacific reef heron.

[3] By 1993, a "population explosion" of non-Polynesian rats had been noted on the atoll, most likely introduced by Asian fishing trawlers operating illegally in the vicinity of Bikar.

The lack of water and the susceptibility of the atoll to cyclone and storm disturbance precluded traditional Micronesian stables, and indicate that it will probably remain uninhabited.

[15] The French corvette Danaide, Capt J. de Rosamel, visited the atoll in August 1840 during a hydrographical survey of islands in the Pacific.

[16][17] During the late 1800s, Bikar was the subject of a number of commercial transactions related to the increasing German presence in the Marshall Islands.

The German Empire annexed Bikar and the rest of the Marshall Islands in 1885,[18] and in December 1887 property rights were transferred to the Jaluit Gesellschaft.

[19] In 1900, the Manchester, a four-masted steel-hulled cargo ship of 2851 tons with a load of kerosene, went missing at sea between New York City and Yokohama.

Wreckage and signs of habitation were discovered on Bikar in 1901, suggesting that the ship had come to grief there and that the survivors had pushed off in lifeboats shortly before the discovery.

Like the Germans before them, the Japanese colonial administration (the South Seas Mandate) did not attempt to exploit the atoll, and the Northern Radak Marshallese continued to hunt and fish unmolested.

In 1951, the U.S. Geological Survey and the Army Corps of Engineers sponsored an expedition to Bikar and Taongi Atolls, to characterize their primeval environment.

[22] While en route from the US to Asia in April 1953, LST 1138, later commissioned as USS Steuben County, dropped anchor at Bikar to search for rumored Japanese stragglers.

This experience led to a pre-planned aerial survey of atolls adjacent to the subsequent March 27 Castle Romeo test, timed at one and four hours after the shot.