Response of six species of Hawaiian forest birds to a 1991-1992 El Nino drought
[No abstract available]
Geology topics
Publications and source records attributed to G.D. Lindsey.
[No abstract available]
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Fifteen juvenile Puerto Rican Parrots (Amazona vittata) from wild nests in 1985, 1986 and 1987 were radio monitored an average of 110 +- 15.9 (SE) d (range 4-209 d) post-fledgling. Minimum survival was 67% (n = 3) in 1985, 100% (n = 4) in 1986 and 43% (n = 7) in 1987. Most mortality (three of five deaths) occurred during the first 35 d following fledgling. A major cause of mortality was predation by raptors. This research shows that additional studies are needed to define mortality causes to juvenile and adult free-flying Puerto Rican Parrots and to develop management guidelines to increase survival.
Methods for identifying the sex and age of the Akiapolaau (Hemignathus munroi), an endangered honeycreeper found only on the island of Hawaii, were developed by examination and measurement of 73 museum specimens and 24 live birds captured in mist nests. Akiapolaau probably undergo a single annual molt, with most birds molting between February and July. The mottled juvenal plumage is replaced by a first basic plumage characterized by yellowish-gray or yellowish-green underparts and often by retained wingbars. Male Akiapolaau may not attain adult plumage until their third molt. In adult females, only the throat and upper breast become yellow, whereas in adult males the superciliaries, cheeks, and entire underparts are yellow. Adult males have greater exposed culmen, gonys, wing chord, tail, and tarsus lengths than do females. Akiapolaau in first prebasic molt or older can be identified as to sex by culmen length, that of males being >23.4 mm.
Methods to determine the sex and age of Apapane (Himatione sanguinea) and Iiwi (Vestiaria coccinea) were developed on the basis of 189 museum specimens and 91 live birds captured in mist nets on the Island of Hawaii (USA). Both species retain all juvenal primaries and some juvenal secondaries and body feathers after the first prebasic molt and attain full adult plumage after the second prebasic molt. Apapane in their first basic plumage retain some buff-edged juvenal secondaries (particularly secondaries five and six) and sometimes retain a few gray-brown feathers on the head. The first basic plumage of Iiwi is characterized by secondaries 6-9 being longer and darker than secondaries 1-4 and the presence of a few yellowish juvenal body feathers with black spots at the tips. Adult male Apapane and Iiwi have longer wing, tail, exposed culmen, culmen and tarso-metatarsus lengths than females. Linear discriminant functions are presented to sex adult Apapane and Iiwi from lengths of their wing chord and exposed culmen.
Methods to sex and age Palila (Loxioides bailleui), an endangered Hawaiian finch restricted to subalpine woodlands on Hawai'i, were identified on the basis of measurements and plumage characteristics of 17 museum specimens and 96 known-age, live Palila. Palila undergo a single annual molt during September-December following the breeding season. Presence of a complete or partial wingbar distinguishes hatch-year and second-year Palila from after-second-year birds. Adult male Palila are distinguished from females by a distinct napeline and lt 30% gray feathers intermixed with yellow feathers on the head. The black or gray feathers of the lores and chin of males are darker than those on the back, whereas the lores and chin of females are lighter or of the same shade as back feathers.
The effectiveness of 17 yr of nestguarding from observation blinds for increasing reproductive success of the endangered Puerto Rican Parrot (Amazona vittata) is described. As personnel and time allowed, active nests were guarded part-time during the nest site exploration and selection s stage of the breeding cycle, and part-time to full-time when a nest contained eggs or chicks. Biologists identified nine categories of threat to the success of parrot nests. Since 1973, a minimum of 20 nests, which otherwise would have failed, successfully produced fledglings as a direct result of nest guarding and intervention. Nest success averaged 66% with nest guarding compared to an estimated 38% without guarding. Nest guarding from blinds can help maintain a wild population of a critically endangered species while other management techniques are being developed to stimulate population growth.
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Explore the source record for details and available documents.