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Freed and Cann (2013) criticized our use of linear models to assess trends in the status of Hawaiian forest birds through time (Camp et al. 2009a, 2009b, 2010) by questioning our sampling scheme, whether we met model assumptions, and whether we ignored short-term changes in the population time series. In the present paper, we address these concerns and reiterate that our results do not support the position of Freed and Cann (2013) that the forest birds in the Hakalau Forest National Wildlife Refuge (NWR) are declining, or that the federally listed endangered birds are showing signs of imminent collapse. On the contrary, our data indicate that the 21-year long-term trends for native birds in Hakalau Forest NWR are stable to increasing, especially in areas that have received active management.

We developed an epidemiological model of avian malaria (Plasmodium relictum) across an altitudinal gradient on the island of Hawaii that includes the dynamics of the host, vector, and parasite. This introduced mosquito-borne disease is hypothesized to have contributed to extinctions and major shifts in the altitudinal distribution of highly susceptible native forest birds. Our goal was to better understand how biotic and abiotic factors influence the intensity of malaria transmission and impact on susceptible populations of native Hawaiian forest birds. Our model illustrates key patterns in the malaria-forest bird system: high malaria transmission in low-elevation forests with minor seasonal or annual variation in infection; episodic transmission in mid-elevation forests with site-to-site, seasonal, and annual variation depending on mosquito dynamics; and disease refugia in high-elevation forests with only slight risk of infection during summer. These infection patterns are driven by temperature and rainfall effects on parasite incubation period and mosquito dynamics across an elevational gradient and the availability of larval habitat, especially in mid-elevation forests. The results from our model suggest that disease is likely a key factor in causing population decline or restricting the distribution of many susceptible Hawaiian species and preventing the recovery of other vulnerable species. The model also provides a framework for the evaluation of factors influencing disease transmission and alternative disease control programs, and to evaluate the impact of climate change on disease cycles and bird populations.

Many universities require coursework in environmental studies or science, with the goal of developing environmental literacy among their graduates. Does enrollment in an environmental issues course have an effect on an undergraduate’s environmental worldview? We assess the role of a required, core curriculum environmental issues course on the environmental worldview formation of undergraduates not majoring in environmental studies or science, using data collected at the University of New England (UNE), Maine, USA. Using a pre- and postcourse design, we administered the New Ecological Paradigm (NEP) survey to all enrolled students over an eight-semester interval from 2006 to 2010 (N = 976 paired surveys). Precourse surveys demonstrated that UNE students began the course with a belief system that endorsed an ecological worldview, on average, and that was structured into five domains. Comparison of pre- and postcourse data revealed: (1) students’ level of environmental concern increased significantly in each of five worldview dimensions after taking the course, although effect size varied among the five areas; (2) endorsement of the NEP increased more among students with an initially low level of environmental concern than those with a high level; and (3) students who began the course unsure of their beliefs moved away from uncertainty, indicating worldview clarification through the course. Our results demonstrate that a required, introductory environmental studies course for nonmajors can effectively achieve affective learning goals and develop ecological awareness in a student body characterized by diverse professional objectives and belief systems.

We documented patterns of nectar availability and nectarivorous bird abundance over ∼3 years at nine study sites across an 1,800-m elevational gradient on Hawaii Island to investigate the relationship between resource variation and bird abundance. Flower density (flowers ha-1) 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...

The Hakalau Forest National Wildlife Refuge was established to protect native Hawaiian forest birds, particularly endangered species. Management for forest restoration on the refuge has consisted mainly of removing feral ungulates, controlling invasive alien plants, and reforesting former pastures. To assess effects of this habitat improvement for forest birds, we estimated density annually by distance sampling and examined population trends for native and alien passerines over the 21 years since the refuge was established. We examined long-term trends and recent short-term trajectories in three study areas: (1) reforested pastureland, (2) heavily grazed open forest that was recovering, and (3) lightly grazed closed forest that was relatively intact. Three species of native birds and two species of alien birds had colonized the reforested pasture and were increasing. In the open forest, densities of all eight native species were either stable or increasing. Long-term trends for alien birds were ...

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

We studied the effects of chronic avian malaria (Plasmodium relictum) infections on the reproductive success of a native Hawaiian honeycreeper, Hawaii Amakihi (Hemignathus virens). Chronic malaria infections in male and female parents did not significantly reduce reproductive success as measured by clutch size, hatching success, fledging mass, number of nestlings fledged, nesting success (daily survival rate), and minimum fledgling survival. In fact, nesting success of pairs with chronically infected males was significantly higher than those with uninfected males (76% vs. 38%), and offspring that had at least one parent that had survived the acute phase of malaria infection had a significantly greater chance of being resighted the following year (25% vs. 10%). The reproduction and survival of infected birds were sufficient for a per-capita population growth rate >1, which suggests that chronically infected Hawaii Amakihi could support a growing population. Efectos de las Infecciones Crónicas de Malaria Aviaria (Plasmodium relictum) en el Éxito Reproductivo de Hemignathus virens

The 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 km2 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.

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 year-round 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.

Within the last 30 years, five endemic bird species of the Alaka'i Swamp, Kaua'i, Hawaii, 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 K¯ oke'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 coc- cinea) 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 (

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±12.0 ha, range 0.4–31.9) or breeding home-ranges (mean area 1.2±0.34 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.

From 1995 to 1999, two species of endemic Hawaiian thrushes, `Oma`o (Myadestes obscurus) and Puaiohi (M. palmeri), were captive-reared and re-introduced into their historic range in Hawai`i by The Peregrine Fund, in collaboration with the U.S. Geological Survey–Biological Resources Division (BRD) and the Hawai`i State Department of Land and Natural Resources. This paper describes the management techniques that were developed (collection of wild eggs, artificial incubation, hand-rearing, captive propagation, and release) with the non-endangered surrogate species, the `Oma`o; techniques that are now being used for recovery of the endangered Puaiohi. In 1995 and 1996, 29 viable `Oma`o eggs were collected from the wild. Of 27 chicks hatched, 25 were hand-reared and released into Pu`u Wa`awa`a Wildlife Reserve. Using the techniques developed for the `Oma`o, a captive propagation and release program was initiated in 1996 to aid the recovery of the endangered Puaiohi. Fifteen viable Puaiohi eggs were collected from the wild (1996–1997) to establish a captive breeding flock to produce birds for re-introduction. These Puaiohi reproduced for the first time in captivity in 1998 (total Puaiohi chicks reared in captivity 1996–1998 = 41). In 1999, 14 captive-bred Puaiohi were re-introduced into the Alaka`i Swamp, Kaua`i. These captive-bred birds reproduced and fledged seven chicks in the wild after release. This is the first endangered passerine recovery program using this broad spectrum of management techniques (collection of wild eggs, artificial incubation, hand-rearing, captive-breeding, and release) in which re-introduced birds survived and bred in the wild. Long-term population monitoring will be published separately [BRD, in preparation]. Zoo Biol 19:263–277, 2000. © 2000 Wiley-Liss, Inc.

Nest predation and parasitism are the primary causes of reproductive failure in northern temperate passerine songbirds. I demonstrate the use of a two-step modeling approach to determine the implications of parasitism and nest predation for the population dynamics of songbird populations and to quantitatively evaluate alternative options for their management. I used a model to predict seasonal fecundity from parameters of nest success, productivity, and breeding season length ( Pease & Grzybowski 1995) and a stage-based matrix model to examine population dynamics. I used this approach to model the population dynamics of the Puerto Rican Vireo ( Vireo latimeri), a single-island endemic species that is exposed to high rates of parasitism by a nonnative brood parasite and to nest predation by introduced mammalian predators. The analysis showed that the introduction of the Shiny Cowbird ( Molothrus bonariensis), rather than the mammalian nest predators, caused this population to become a “sink” and is probably the cause of recent population declines. Moreover, the analysis explicitly shows that knowledge of the relationships among parasitism, predation, and population growth rate can aid in designing an effective conservation strategy. This modeling approach can be used to determine the reproductive health of a population over a range of parasitism and predation values, to test alternative hypotheses for the cause of an observed population decline, and to make a priori predictions about the outcomes of specific management actions. La depredacion de nidos y el parasitismo son las principales causas de la falla reproductiva de una cantidad de aves cantoras paserinas de zonas templadas del norte. En este trabajo muestro el uso de una aproximacion de modelado de dos pasos para determinar las implicaciones del parasitismo y la depredacion de nidos en las dinamicas poblacionales de aves cantoras y la evaluacion cuantitativa de opciones alternativas para su manejo. Utilice un modelo para predecir la fecundidad estacional a partir de los parametros de exito reproductivo, productividad y longitud de la temporada reproductiva (Pease y Grzybowski 1995) y un modelo de matriz basado en estadios para examinar las dinamicas poblacionales. Utilice esta aproximacion para modelar las dinamicas poblacionales del vireo de puerto Rico ( Vireo latimeri) una especie endemica a una sola isla y que se encuentra expuesta a tasas de parasitismo altas por un parasito de nidada no nativo, asi como a la depredacion de nidos por depredadores mamiferos introducidos. El analisis mostro que la introduccion de Molothrus bonariensis y no la probablemente sea la causa de recientes disminuciones poblacionales. Mas aun, el analisis muestra explicitamente que el conocimiento de las relaciones entre parasitismo, depredacion y tasa de crecimiento poblacional pueden ayudar a disenar una estrategia de conservacion efectiva. Esta aproximacion de modelado puede ser utilizada para determinar la salud reproductiva de una poblacion sobre un rango de valores de parasitismo y depredacion, para evaluar hipotesis alternativas sobre la causa de disminuciones observadas en poblaciones, asi como para hacer predicciones a priori sobre los posibles resultados de acciones especificas de manejo.

Summary We examined the eVects of protection from human activities and eVects of tourist hunting on densities of 21 large mammal species in Tanzania. Aerial censuses revealed that mammal biomass per km 2 was highest in National Parks. Densities of nine ungulate species were significantly higher in National Parks and Game Reserves than in areas that permitted settlement; these tended to be the larger species favoured by poachers. The presence of tourist hunters had little positive or negative impact on ungulate densities, even for sought-after trophy species; limited ground censuses confirmed these results. Our analyses suggest that prohibition of human activity, backed up by on-site enforcement, maintains ungulate populations at relatively high densities, and challenge the idea that enforcement is only eVective when spending is high.

An aerial photographic census of flamingos (Phoenicopterus minor and P. ruber) was conducted on 20 July 1994 on nine lakes in Tanzania: Lakes Natron, Manyara, Magadi (Ngorongoro), Burungi, Embagai, Eyasi, Lagarja, Masek, and Ambussel. This census, conducted concurrently with a survey in Kenya, documented the numbers and distribution of flamingos in the Rift Valley Lakes of East Africa. The total population size of flamingos in the Tanzanian lakes surveyed was |mF907,000. The largest concentrations in Tanzania were found in Lake Natron and Embagai Crater Lake. Although flamingos are known to breed in Lake Natron, no evidence of breeding was observed during the survey. The total estimate for the southern Kenya and northern Tanzania Rift Valley was |mF2·8 million. Trends in flamingo populations, survey methodology, and future monitoring needs are discussed.

The Puerto Rican Vireo (Vireo latimeri) is a single-island endemic resident on Puerto Rico. The Shiny Cowbird (Molothrus bonariensis), a generalist brood parasite native to South America, arrived on the island in 1955 and has established itself as a breeding resident. To determine the impact of the exotic cowbird on vireo reproductive success, I studied the demography of marked Puerto Rican Vireos in Guanica Forest, Puerto Rico, in 1990-1993. Vireo breeding season length varied among years (69-106 days), apparently influenced by rainfall. The primary causes of reproductive failure were nest parasitism and nest predation. Cowbirds parasitized 73-83% of vireo nests. Parasitism reduced the number of vireos fledged per successful nest by 82%, primarily through decreased hatching success and fledging success. Vireos did not abandon nests in response to cowbird egglaying, but frequently deserted if cowbirds removed host eggs. Native avian predators and exotic mammalian predators together caused the demise of about 70% of all nest attempts. As a result, daily nest survival rate was low (0.93 ± 0.01), and only 13-19% of nests fledged vireo or cowbird young. Pairs renested after failure and attempted to raise second broods. Females in this population attempted two to six nests per season and fledged an average of 1.33 vireos in 1991 and 0.24 vireos in 1993. The combination of restricted breeding season, high predation and parasitism rates, large impact of parasitism on reproductive output, and low seasonal fecundity of females suggests that, despite high survival rates, the Puerto Rican Vireo is in danger of extirpation from portions of its range.

Infectious diseases now threaten wildlife populations worldwide but population recovery following local extinction has rarely been observed. In such a case, do resistant individuals recolonize from a central remnant population, or do they spread from small, perhaps overlooked, populations of resistant individuals? Introduced avian malaria (Plasmodium relictum) has devastated low-elevation populations of native birds in Hawaii, but at least one species (Hawaii amakihi, Hemignathus virens) that was greatly reduced at elevations below about 1000 m tolerates malaria and has initiated a remarkable and rapid recovery. We assessed mitochondrial and nuclear DNA markers from amakihi and two other Hawaiian honeycreepers, apapane (Himatione sanguinea) and iiwi (Vestiaria coccinea), at nine primary study sites from 2001 to 2003 to determine the source of re-establishing birds. In addition, we obtained sequences from tissue from amakihi museum study skins (1898 and 1948–49) to assess temporal changes in allele distributions. We found that amakihi in lowland areas are, and have historically been, differentiated from birds at high elevations and had unique alleles retained through time; that is, their genetic signature was not a subset of the genetic variation at higher elevations. We suggest that high disease pressure rapidly selected for resistance to malaria at low elevation, leaving small pockets of resistant birds, and this resistance spread outward from the scattered remnant populations. Low-elevation amakihi are currently isolated from higher elevations (> 1000 m) where disease emergence and transmission rates appear to vary seasonally and annually. In contrast to results from amakihi, no genetic differentiation between elevations was found in apapane and iiwi, indicating that slight variation in genetic or life-history attributes can determine disease resistance and population recovery. Determining the conditions that allow for the development of resistance to disease is essential to understanding how species evolve resistance across a landscape of varying disease pressures.

Wildlife diseases can present significant threats to ecological systems and biological diversity, as well as domestic animal and human health. However, determining the dynamics of wildlife diseases and understanding the impact on host populations is a significant challenge. In Hawai‘i, there is ample circumstantial evidence that introduced avian malaria (Plasmodium relictum) has played an important role in the decline and extinction of many native forest birds. However, few studies have attempted to estimate disease transmission and mortality, survival, and individual species impacts in this distinctive ecosystem. We combined multi-state capture-recapture (longitudinal) models with cumulative age-prevalence (cross-sectional) models to evaluate these patterns in Apapane, Hawai‘i Amakihi, and Iiwi in low-, mid-, and high-elevation forests on the island of Hawai‘i based on four longitudinal studies of 3–7 years in length. We found species-specific patterns of malaria prevalence, transmission, and mortality r...

Background The Hawaiian honeycreepers (Drepanidinae) are one of the best-known examples of an adaptive radiation, but their persistence today is threatened by the introduction of exotic pathogens and their vector, the mosquito Culex quinquefasciatus. Historically, species such as the amakihi (Hemignathus virens), the apapane (Himatione sanguinea), and the iiwi (Vestiaria coccinea) were found from the coastal lowlands to the high elevation forests, but by the late 1800's they had become extremely rare in habitats below 900 m. Recently, however, populations of amakihi and apapane have been observed in low elevation habitats. We used twelve polymorphic microsatellite loci to investigate patterns of genetic structure, and to infer responses of these species to introduced avian malaria along an elevational gradient on the eastern flanks of Mauna Loa and Kilauea volcanoes on the island of Hawaii. Results Our results indicate that amakihi have genetically distinct, spatially structured populations that correspond with altitude. We detected very few apapane and no iiwi in low-elevation habitats, and genetic results reveal only minimal differentiation between populations at different altitudes in either of these species. Conclusion Our results suggest that amakihi populations in low elevation habitats have not been recolonized by individuals from mid or high elevation refuges. After generations of strong selection for pathogen resistance, these populations have rebounded and amakihi have become common in regions in which they were previously rare or absent.