Vanessa cardui migrations take place at high altitude, which explains why these migrations are seldom witnessed. "V. cardui" is known for its distinct migratory behavior. In California, they are usually seen flying from north to northwest. These migrations appear to be partially initiated by heavy winter rains in the desert where rainfall controls the growth of larval food plants. Painted lady migration patterns are highly erratic and they do not migrate every year. Some evidence suggests that global climatic events, such as el Niño, may affect the migratory behavior of the painted lady butterflies, causing large-scale migrations. Based on experimental data, the
Pokémon Black and White "Yellow", and all subsequent main series games; however, Pikachu will not be obtainable in "Black" and "White" from the start of the game. It was later confirmed that "Black" and "White" are region locked on the Nintendo DSi and 3DS. Game director and composer Junichi Masuda stated that to keep the games fresh, he looks at every previous element to decide what to adapt to the new game, stating "people may not like what they like in the past, trend wise". He explained the new battle styles, stating that while triple battles take more strategy, rotation battles take more luck