No one who has encountered the fearless Laysan and Nihoa finches can remain uncharmed. Having evolved without terrestrial ground predators and with few avian predators, they readily approach other animals that they encounter, including humans, and are easily captured. In the absence of humans, their intense curiosity is adaptive for their omnivorous feeding habits, but in the presence of humans, this intense curiosity can be non-adaptive. The finches find human paraphernalia (such as tents or plastic containers) irresistible: more than one biologist has been horrified to discover an overheated finch dead inside a hot tent, caught under a tarp, stuck in a pit toilet, or drowned in a bucket of water. A nesting female on eggs, sometimes unwilling to flush, must be slowly pushed aside in order to examine the nest's contents. During biologist John Sincock's first visit to Nihoa in 1967, he gently picked up one healthy finch and photographed it in his hand (Sincock and Kridler 1977). In spite of field camp rules to keep the finches wild by not feeding them, one “camp follower” Laysan Finch regularly hopped onto socks (still being worn) and picked off and ate favorite seeds that had gotten stuck on the socks. The scurrying, inquisitive, and adaptable nature of the finches has earned them the dubious nickname of “flying mice”(MPM).
The Laysan and Nihoa finches are closely related members of the Hawaiian Honeycreeper Subfamily (Drepanidinae), and are two of the four remaining so-called “finch-billed” drepanidine species with functional populations. The other two species are the Palila (Loxioides bailleui) and the Maui Parrotbill (Pseudonestor xanthophyrys: see Simon et al. 1997), although evidence suggests that the Parrotbill is more closely allied with the sickle-billed dre-panidines. Another finch-billed species, the ‘Ö‘ü (Psittirostra psittacea) is recently extinct, four other extinct finch-billed species are historically known, and additional species were recently described from bones or are known from undescribed fossils (James and Olson 1991, Snetsinger et al. 1998, Olson 1999).
Laysan Finches are now naturally restricted to the remote refuge island of Laysan, and a small introduced population also occurs on Pearl and Hermes Atoll; Nihoa Finches are likewise now restricted to the refuge island of Nihoa. Introduced populations of Laysan Finches at Midway Atoll and Nihoa finches at French Frigate Shoals have been extirpated since about 1944 and the mid-to-late1970s, respectively (Fisher and Baldwin 1946, U.S. Fish and Wildlife Service 1984d). As is the case for many endemic Hawaiian species, fossils of Laysan and Nihoa Finches have also been found on one or more of the main Hawaiian Islands, which indicates a much wider distribution during the Holocene (Olson and James 1982b, James and Olson 1991). All four of the remaining finch-billed drepanidines are listed as endangered species, which is not surprising given the array of other finch-billed Hawaiian honeycreepers that are now known to have become extinct either during historical times or during the earlier centuries of Polynesian colonization (James and Olson 1991, Snetsinger et al. 1998, Olson 1999). No Hawaiian names are known for the Laysan and Nihoa finches.
The bright yellow head and breast of the adult male Laysan Finch are striking; although females and immatures have some yellow, they are generally drabber and more streaked. A few older females are almost as brightly yellow as the males. Nihoa Finches are slightly smaller than Laysan Finches, and the females and immatures more heavily streaked.
Laysan Finch song has been described as “canary-like” (Bryan 1917), explaining why the species has sometimes been called the “Laysan Canary” (Munro 1960). In the late 1800s and early 1900s, Laysan Finches were taken to Honolulu, O‘ahu I., and elsewhere to be kept as cage birds, but eventually all died, almost certainly owing to their vulnerability to avian diseases (Wilson 1890b, Warner 1968a, Ely and Clapp 1973, Van Riper III et al. 1986). The Laysan Finch was first described by Wilson (Wilson 1890b), based on a captive subadult bird he purchased in Honolulu that had been brought there by the schooner “Mary Bohm” (Berger 1981). The holotype currently resides in Leiden and looks just like the plate from Wilson's original description (Olson and James 1986).
There is no evidence that Polynesians ever lived on Laysan I. Laysan's interesting recent history is summarized by Ely and Clapp (Ely and Clapp 1973; see Conservation and management: effects of human activity, below).
Most information about the Laysan Finch has been obtained in the past 40 years. J. Sincock and E. Kridler did population studies in the 1960s. We studied finch breeding biology, ecology, morphometrics, and demography from 1980 to the present time. Some genetic studies have been published (Fleischer et al. 1991a, Tarr et al. 1998, Tarr et al. in press), and others are on-going (A. McClung pers. comm.).
That Nihoa Finches survived on tiny Nihoa I. is surprising, because Polynesians inhabited and then abandoned the island before Western contact occurred in the late 1700s. Extensive archaeological features on Nihoa include agricultural terraces, indicating humans had a significant impact on ecosystems there (Cleghorn 1988, Juvik and Juvik 1998). Although the Nihoa Finch was reportedly seen on Nihoa I. in 1885 by Sanford Dole (Munro Munro 1941a, Munro 1960) and again seen in 1915 (Bryan 1916), it was not collected and officially described until 1916 (Bryan 1917, Vanderbilt and Meyer De Schauensee 1941). It was given the specific name of “ ultima ” because Bryan (Bryan 1917) thought this would very likely be the last native Hawaiian passerine to be “discovered” by western biologists. The Nihoa Finch has not been well studied: other than periodic censuses done by U.S. Fish and Wildlife Service, most of the scant information has been obtained by Sincock and Kridler (Sincock and Kridler 1977), Conant (Conant 1983b, unpubl. data), and Conant et al. (Conant et al. 1981b). The holotype and three paratypes are in the Los Angeles County Museum, CA (Willett 1945).