scrublands exist in association with Scaevola taccada, Cordia subcordata, and Pisonia grandis. Grassland species include Dactyloctenium aegyptium and Tribulus cistoides. Wetlands are dominated by Sesuvium portulacastrum, and Pemphis acidula is found near intertidal lagoons. The atoll is home to multiple species of land crabs, with Coenobita perlatus being especially abundant. The atoll, with its surrounding marine waters, has been recognized as an Important Bird Area (IBA) by BirdLife International for its sooty tern colony, with some 200,000 individual birds estimated in 1999. 56 bird species have been sighted on the atoll. Due to human use, several invasive species have become established on the atoll. Feral cats were introduced in the 1960s as pets and for pest control. Eradication efforts began in earnest in 1996, and were deemed successful in 2008. Two species of rat, Rattus exulans and Rattus tanezumi, have colonized the island. R. tanezumi populations were successfully eradicated by 2014, however, R. exulans persists. Casuarina equisetifolia was planted on Wake Island by boy scouts in the 1960s for use as a windbreak. It formed large mono-cultural forests that choked out native vegetation. Concerted efforts to kill the populations began in 2017. Other introduced plant species include Cynodon dactylon and Leucaena leucocephala. Non-native species of ants are also found on the atoll. History Prehistory The presence of the Polynesian rat on the island suggests that Wake was likely visited by Polynesian or Micronesian voyagers at an early date. Early European contact The first recorded discovery of Wake Island was on October 2, 1568, by Spanish explorer and navigator Álvaro de Mendaña de Neyra. In 1567, Mendaña and his crew had set off on two ships, Los Reyes and Todos los Santos, from Callao, Peru, on an expedition to search for a gold-rich land in the South Pacific as mentioned in Inca tradition. After visiting Tuvalu and the Solomon Islands, the expedition headed north and came upon Wake Island, "a low barren island, judged to be eight leagues in circumference". Since the date – October 2, 1568 – was the eve of the feast of Saint Francis of Assisi, the captain named it St Francis Island (; ). The ships were in need of water and the crew was suffering from scurvy, but after circling the island it was determined that Wake was waterless and had "not a cocoanut nor a pandanus" and, in fact, "there was nothing on it but