The past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations. We examined host persistence in the face of introduced vector-borne diseases in Hawaii, where introduced avian malaria and introduced vectors have had a negative impact on most populations of Hawaiian forest birds for nearly a century. We studied birds, parasites, and vectors in nine study areas from 0 to 1,800 m on Mauna Loa Volcano, Hawaii from January to October, 2002. Contrary to predictions of prior work, we found that Hawaii amakihi (Hemignathus virens), a native species susceptible to malaria, comprised from 24.5% to 51.9% of the avian community at three low-elevation forests (55-270 m). Amakihi were more abundant at low elevations than at disease-free high elevations, and were resident and breeding there. Infection rates were 24 -40% by microscopy and 55-83% by serology, with most infected individuals experiencing low-intensity, chronic infections. Mosquito trapping and diagnostics provided strong evidence for yearround local transmission. Moreover, we present evidence that Hawaii amakihi have increased in low elevation habitats on southeastern Hawaii Island over the past decade. The recent emergent phenomenon of recovering amakihi populations at low elevations, despite extremely high prevalence of avian malaria, suggests that ecological or evolutionary processes acting on hosts or parasites have allowed this species to recolonize low-elevation habitats. A better understanding of the mechanisms allowing coexistence of hosts and parasites may ultimately lead to tools for mitigating disease impacts on wildlife and human populations.Hemignathus virens ͉ host-parasite coevolution ͉ Plasmodium relictum ͉ Culex quinquefasciatus T he past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations (1). This rise in the emergence of new infectious diseases is attributed to many factors, among them human alteration of habitats, transportation of vectors and pathogens, and climate and weather patterns, including anthropogenic climate change (2, 3). Vector-borne diseases in particular may undergo geographic range shifts and large changes in abundance with climate change because rising temperatures will affect vector distribution, parasite development, and transmission rates (4).Identifying the factors that allow for coexistence of hosts and parasites has been a topic of intensive study in the ecological literature for decades (5, 6). Modeling and empirical studies have identified host and vector abundance, vector competence and behavior, host community, spatial and metapopulation dynamics, host demography, seasonality, parasite virulence, and host resistance, among others, as being of importance (7,8). A better understanding of the mechanisms of host-parasite coexistence may ultimately lead to t...

Resumen.-Documentamos los patrones de disponibilidad de néctar y la abundancia de aves nectarívoras por cerca de tres años en nueve sitios de estudio a lo largo de un gradiente altitudinal de  m en la isla de Hawai para investigar la relación entre la variación en los recursos y la abundancia de aves. La densidad de flores (flores ha-) y el contenido energético del néctar de la planta monodominante llamada Metrosideros polymorpha fueron medidos a lo largo del gradiente. Cuatro especies nectarívoras fueron capturadas mensualmente con redes de niebla y censadas cada tres meses mediante muestreos de distancia con puntos en transectos en cada sitio para examinar los patrones de densidad y abundancia relativa. Los picos de floración se asociaron con la temporada, pero no con la precipitación ni con la elevación. Las densidades de aves presentaron un pico en el invierno y la primavera de cada año en las elevaciones altas, pero los patrones fueron -113 -The Auk 128(1):113 126,Abstract.-We documented patterns of nectar availability and nectarivorous bird abundance over ~ years at nine study sites across an ,-m elevational gradient on Hawaii Island to investigate the relationship between resource variation and bird abundance. Flower density (flowers ha − ) and nectar energy content were measured across the gradient for the monodominant `Ōhi`a (Metrosideros polymorpha). Four nectarivorous bird species were captured monthly in mist nets and surveyed quarterly with point-transect distance sampling at each site to examine patterns of density and relative abundance. Flowering peaks were associated with season but not rainfall or elevation. Bird densities peaked in the winter and spring of each year at high elevations, but patterns were less clear at middle and low elevations. Variability in bird abundance was generally best modeled as a function of elevation, season, and flower density, but the strength of the latter effect varied with species. The low elevations had the greatest density of flowers but contained far fewer individuals of the two most strongly nectarivorous species. There is little evidence of large-scale altitudinal movement of birds in response to `Ōhi`a flowering peaks. The loose relationship between nectar and bird abundance may be explained by a number of potential mechanisms, including () demographic constraints to movement; () nonlimiting nectar resources; and () the presence of an "ecological trap," whereby birds are attracted by the high resource abundance of, but suffer increased mortality at, middle and low elevations as a result of disease. Received  February , accepted  October .

We monitored the survival, dispersal, and home-range establishment of captive-bred, reintroduced puaiohi Myadestes palmeri, a critically endangered thrush endemic to the island of Kauai. Fourteen captive-bred, juvenile birds were released from hacktowers in January-February 1999 and monitored for 8-10 weeks using radiotelemetry. All 14 birds (100%) survived to 56 days post-release. Two birds (14.3%) dispersed greater than 3 km from release site within 1 day of release. The remaining birds settled within 1 week and established either temporary home-ranges (mean area=7.9 AE 12.0 ha, range 0.4-31.9) or breeding home-ranges (mean area 1.2 AE0.34 ha, range 0.8-1.6). Temporary home ranges were abandonded by the beginning of the breeding season, and ultimately 6 of the 14 birds (43%) established breeding home ranges in the release area. The high survival rate bodes well for establishing additional populations through captive breeding and release; however, the 57% dispersal rate out of the target area means that several releases of birds may be necessary in order to repopulate a given drainage. Furthermore, observed dispersal and gene flow between the reintroduced and wild populations have important implications for management of the captive flock. Published by Elsevier Science Ltd.

Within the last 30 years, five endemic bird species of the Alaka'i Swamp, Kaua'i, Hawai'i, have likely gone extinct. We documented population trends of the remaining avifauna in this time period to identify a common pattern in the Hawaiian Islands: decline of native species and expansion of introduced species. We conducted bird surveys over 100 km 2 of the Alaka'i and Kōke'e regions of Kaua'i in March-April 2000 to estimate population size, distribution, and range limits of seven native and six introduced forest birds. We compared the results with four previous surveys conducted over the last 30 years. Five of the seven native species we studied have fared well, maintaining sizeable populations (>20,000 individuals) and unchanged or increasing numbers. The endemic ' Akikiki (Oreomystis bairdi), however, declined from 6296 (SE ± 1374) to 1472 (SE ± 680) individuals and exhibited range contraction from 88 to 36 km 2 . The 'I'iwi (Vestiaria coccinea) also experienced a decline and contraction, though not as severe. Populations of several introduced forest birds are increasing, but all species, excluding the Japanese White-eye (Zosterops japonicus), were at low numbers (<5,500 individuals in survey area). One introduced species, the Japanese Bush-Warbler (Cettia diphone) recently invaded, whereas another, the Red-billed Leiothrix (Leiothrix lutea), has been extirpated. Two hurricanes in the past 20 years appear to have most strongly affected nectarivores and may have contributed to the decline or extinction of several other species. Overall, native bird populations on Kaua'i have exhibited species-specific responses to limiting factors. Although most native populations appear stable, the extant native avifauna is vulnerable as a result of limited distributions and the potential for widespread habitat degradation. Cambios Poblacionales a Largo Plazo de Aves Nativas e Introducidas en el Pantano Alaka'i, Kaua'i Resumen: Es probable que se hayan extinguido cinco especies endémicas del Pantano Alaka'i, Kaua'i en loś ultimos 30 años. Documentamos las tendencias poblacionales de la avifauna remanente en este período para evaluar un patrón común en las Islas Hawaianas: declinación de especies nativas y expansión de especies introducidas. Realizamos muestreos de aves en las regiones Alaka'i y Kōke'e de Kaua'i en marzo-abril 2000para estimar el tamaño, la distribución y los límites poblacionales de siete especies nativas y seis especies introducidas de aves de bosque. Comparamos los resultados con datos de cuatro muestreos previos llevados a cabo en losúltimos 30 años. Cinco de las siete especies nativas estudiadas han estado bien, manteniendo poblaciones de >20,000 individuos y números sin cambio o en incremento. Sin embargo, el ' Akikiki (Oreomystis bairdi) endémico declinó de 6,296 (ES ± 1,374) a 1,472 (ES ± 680) individuos y exhibió una contracción en su rango de 88 a 36 km 2 . El' I'iwi (Vestiaria coccinea) también sufrió una declinación y contracción, aunque no tan severa. Las poblaciones de varias especies de aves de bo...

Respiratory function and immunological status were studied in 40 cocoa and 53 flour processing workers employed as packers in a confectionry industry and in 65 unexposed control workers in the same industry. A high prevalence of chronic respiratory symptoms was recorded in exposed workers, varying from 5.0% to 30.0% in cocoa workers and from 5.7% to 28.3% in flour workers. Occupational asthma was diagnosed in 2 (5%) of the cocoa workers and in 3 (5.7%) of the flour workers. None of the control workers suffered from occupational asthma. The prevalence of almost all chronic respiratory symptoms was significantly greater in cocoa and flour workers than in control workers. There was also a high prevalence of acute symptoms that developed during the work shift, being highest for cough (cocoa: 57.5%; flour: 50.9%) and eye irritation (cocoa: 50.0%; flour: 54.7%). Significant across‐shift reductions of ventilatory capacity were recorded in exposed workers, being largest for flow rates at 50% and the last 25% of the vital capacity on maximum expiratory flow‐volume (MEFV) curves (FEF50, FEF75). The prevalence of positive skin tests for cocoa (60.2%) was significantly higher than the prevalence of positive skin tests for flour (25.8%) among the 93 exposed workers (p < 0.05). Control workers had significantly lower prevalences of positive skin tests to cocoa (4.6%) and flour (12.3%) than exposed workers (p < 0.01). Increased total serum IgE levels were found in 17.5% of cocoa and in 18.7% of flour workers; none of the control workers had increased IgE levels. Bronchoprovocation testing demonstrated significant decreases in lung function following inhalation of cocoa dust extract and flour dust in workers with respiratory symptoms and large across‐shift reductions in lung function. Dust concentrations in the working environment were higher than those recommended by Croatian standards. These data suggest that workers employed in the processing of cocoa and flour may be at a high risk for the development of allergic sensitization and respiratory impairment. Am. J. Ind. Med. 33:24–32, 1998 © 1998 Wiley‐Liss, Inc.

Summary Summary Summary Summary SummaryThe Hawaiian honeycreepers are thought to be limited primarily to middle-and high-altitude wet forests due to anthropogenic factors at lower altitudes, especially introduced mosquitotransmitted avian malaria. However, recent research has demonstrated that at least one native species, the Hawai'i 'Amakihi (Hemignathus virens virens), is common in areas of active malaria transmission. We examined the current distribution and abundance of native and exotic forest birds within approximately 640 km 2 of low-altitude (0-326 m) habitat on south-eastern Hawai'i Island, using roadside variable circular plot (VCP) at 174 stations along eight survey transects. We also re-surveyed 90 stations near sea level that were last surveyed in 1994-1995. Overall, introduced species were more abundant than natives; 11 exotic species made up 87% of the total individuals detected. The most common exotic passerines were Japanese White-eye (Zosterops japonicus), House Finch (Carpodacus mexicanus) and Northern Cardinal (Cardinalis cardinalis). Two native species, Hawai'i 'Amakihi and 'Apapane (Himatione sanguina), comprised 13% of the bird community at low altitudes. Hawai'i 'Amakihi were the most common and widespread native species, being found at 47% of stations at a density of 4.98 birds/ha (95% CI 3.52-7.03). 'Amakihi were significantly associated with 'ohi'a (Metrosideros polymorpha)-dominated forest. 'Apapane were more locally distributed, being found at only 10% of stations. Re-surveys of 1994-1995 transects demonstrated a significant increase in 'Amakihi abundance over the past decade. This work demonstrates a widespread recovery of Hawai'i 'Amakihi at low altitude in southeastern Hawai'i. The changing composition of the forest bird community at low-altitudes in Hawai'i has important implications for the dynamics of avian malaria in low-altitude Hawai'i, and for conservation of Hawai'i's lowland forests.

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The ultimate success of reintroduction programs for endangered species depends on the ability of reintroduced animals to breed in the wild. We studied the nesting success and breeding biology of a reintroduced population of Puaiohi (Myadestes palmeri) on the island of Kaua'i, Hawaii. Thirty-four captive-bred Puaiohi were released into the Alaka'i Swamp in 1999-2001 and monitored using radiotelemetry. Ten females and two males paired with wild and other released birds, including one polygynous trio. From March to September, 31 nests were built. Mean clutch size was 2.0 eggs, daily nest survival was 0.97 ± 0.01 (mean ± SE) and overall nest success was 0.40 ± 0.02. We confirmed predation, most probably by rats (Rattus spp.), as the greatest cause of nest failure, occurring at 38% of active nests with known fates, and causing the death of two nesting adult females. Ground-based rodent control proved ineffective at protecting nest attempts. Successful nests fledged an average of 1.4 young each (n = 10), and 85% of fledglings survived at least two weeks. Importantly, breeding behavior and success were comparable to those of wild Puaiohi. This is the first record of breeding in the wild from captive-bred endangered Hawaiian passerines. The ability of captive-bred Puaiohi to survive and breed successfully in the wild bodes well for future releases of this and other endangered passerines, but high predation rates on nests and nesting females highlights the importance of maintaining and restoring safe habitat for recovery. Biología y Éxito Reproductivo de una Población Reintroducida de Myadestes palmeri, una Especie en Peligro Crítico