Haleakala Research Articles

RECOGNITION AND DESCRIPTION OF BLACKBURNIA KAVANAUGHI, NEW SPECIES (COLEOPTERA: CARABIDAE, PLATYNINI) FROM KAUAI, HAWAII

Blackburnia kavanaughi, new species, previously misidentified as Blackburnia asquithi Liebherr, is described from the western portion of the Alakai Plateau, Kauai, Hawaii. The species is placed phylogenetically based on cladistic analysis including all known Hawaiian Blackburnia, supporting membership in the subgenus Metromenus Sharp. The new species is hypothesized to be most closely related to B. debilis (Perkins) of Molokai and B. kuiki Liebherr of East Maui, sharing enhanced pubescence of the antennal pedicel, reduction in number of the dorsal elytral setae, and elongate ventrolateral setae of tarsomere 5. Individuals of all three species reside in deep arboreal moss mats associated with ohia lehua trees (Metrosideros polymorpha: Myrtaceae). Blackburnia debilis, previously known only from the single male holotype collected in 1902, was recollected in 2005 from Uapa summit, Molokai, in arboreal moss on the mesic leeward edge of ohia lehua forest. Discovery of B. kavanaughi on Kauai implies an additional colonization event from Kauai to newer islands during the diversification of Blackburnia, while corroborating the previous general biogeographic pattern of progressive colonization of the Hawaiian Islands by this clade. Phylogenetic placement of B. debilis B. kuiki as adelphotaxon to B. kavanaughi results in a hypothesized sister-group relationship between sympatric sister species—the epigean B. calathiformis (Sharp) and the troglobitic B. howarthi (Samuelson and Liebherr)—corroborating F. G. Howarth's general hypothesis for the evolution of Hawaiian troglobites.

Hyposmocoma molluscivora Description

In our brevia “Web-Spinning Caterpillar stalks snails” (22 July 2005, p. [575][1]), we reported a new species of cosmopterigid moth, Hyposmocoma molluscivor a. The species description was given in the Supporting Online Material; however, according to the International Code of Zoological Nomenclature, the formal description must appear in print to make the name officially available. The description follows. ![Figure][2] Hyposmocoma molluscivora . Type specimen. ![Figure][2] Male genitalia ventral aspect. Hyposmocoma molluscivora Rubinoff & Haines, new species Male. Length of forewing: 6 mm, ( n = 1). Head. Creamy dull white with scattered fuscous scales. Labial palpi prominent, recurved, mostly black. Antenna uniformly black, unscaled except for small white mark on dorsal side of elongated first basal segment; vertex same color as rest of head. Thorax. Dorsal scaling similar to that of head centrally but with more fuscous scales, abruptly becoming black at periphery where joining at base of costal margin of wing. Underside black toward head, abruptly becoming white with few fuscous scales toward abdomen. Legs. Prothoracic legs mostly black. Mesothoracic legs basally white abruptly becoming black, metathoracic legs same pattern. Tibial spurs prominent, off-white. Forewing: (see left panel of figure) very elongate, narrow, 6 times longer than broad. Ground color a lustrous white overlaid extensively with indistinct pattern of fuscous scales over upper (costal) ⅔ of wing, sometimes dense enough to appear as black spots, posterior ⅓ mostly white, fuscous scales becoming very sparse with distinct, undulating margin, except apical lower ⅓ remaining mostly fuscous like rest of forewing. Hindwing. More lanceolate than forewing, 7 times longer than broad. Subcostal brush (fig. S1) ([1][3]) prominent, dark brown, extending ⅔ the length of hindwing. Lustrous light gray with long concolorous fringe maximum length nearly half as long as hindwing. Abdomen uniformly dark gray. Genitalia as in the right panel of the figure and fig. S2 ([1][3]). Pseuduncus elongate, curved, attenuated distally into sharp point; aedeagus stout, prominent, blunt tipped; anellus lobes ⅓ length of uncus, broadened and setose distally, left lobe with distinctly broader tip; valva broadened distally, with four prominent, broad, uniformly spaced spurs, sequentially longer distally. Male. HOLOTYPE. HAWAII: Maui, Makawao Forest Reserve. Elevation 920 m. GPS coordinates (UTM, NAD83): 04Q 783924, 2305563. Adult emerged III-23-05. (W. Haines, C. King collectors). Deposited in the University of Hawaii Insect Museum, on indefinite loan to the Bishop Museum, Honolulu, Hawaii. Hyposmocoma molluscivora is most similar and may be sympatric with Hyposmocoma lebetella Walsingham in montane wet forest areas of East Maui. The taxa can be easily distinguished by differences in forewing pattern, and the presence of the subcostal brush in H. molluscivora , but absent in male H. lebetella . Hyposmocoma molluscivora larvae form elongate, almost cylindrical cases of silk, algae, and small snail shells. The larvae use silk to attach resting snails to leaves and then force their way out into the snail's shell to feed (fig. S3) ([1][3]). 1. 1.[↵][4]Supporting Online Material is available at [www.sciencemag.org/cgi/content/full/311/5766/1377a/DC1][5]. 2. 2.We thank M. Bryce, F. Starr, and K. Starr for bringing specimens to our attention; B. Holland and R. Cowie of the University of Hawaii for identifying snail specimens; and F. Duvall for access to the Makawao Forest Reserve. J. Powell of UC Berkeley provided very helpful comments. W. Haines was supported by a National Science Foundation GK-12 grant (#DGE-0232016) awarded to the University of Hawaii's Center for Conservation Research and Training, K. Y. Kaneshiro, principal investigator. [1]: /lookup/doi/10.1126/science.1110397 [2]: pending:yes [3]: #ref-1 [4]: #xref-ref-1-1 View reference 1. in text [5]: http://www.sciencemag.org/cgi/content/full/311/5766/1377a/DC1

ECOLOGICAL SPECIATION IN THE EAST MAUI–ENDEMIC DUBAUTIA (ASTERACEAE) SPECIES

Adaptive diversification can be viewed as a balance between the conservative force of interpopulation gene flow and selection for differential environments. In this paper, we examine ecological, morphological, and genetic differentiation in a small clade consisting of four East Maui–endemic species of Dubautia D. menziesii, D. platyphylla, D. reticulata, and D. waianapanapaensis, in the Hawaiian silversword alliance (Asteraceae). The East Maui clade is apparently recently derived (less than 1 million years ago) and is geographically restricted yet displays significant ecological and morphological differences. We used geographic data from historical herbarium specimens, measurements of plant architecture and leaf morphometrics, and measures of genetic differentiation in both microsatellite and nuclear coding loci to examine the correlation of different forms of divergence in this small species flock. We found overlap in large-scale geographic distributions, significant differentiation in most habitat factors, significant microsatellite differentiation, and many shared alleles at nuclear coding loci suggesting on-going lineage sorting. Despite the presence of apparent hybrids in some populations, microsatellite variation is consistent with isolation among species. Using Mantel tests, we compared the direction and extent of diversification among different datasets, to determine whether ecological/morphological divergence was correlated with genetic divergence. Correlations among different datasets showed that habitat was strongly correlated with plant architecture but not leaf morphology. Taken together, these results indicate that ecological and morphological diversification has driven genetic divergence at rapidly evolving microsatellite loci, whereas there is continuing lineage sorting at neutral sites in nuclear coding loci.

Conservation status of the Hawaiian endemic fern Diplazium molokaiense (Athyriaceae) in Honomanu, East Maui, Hawai’i

Diplazium molokaiense W. J. Rob is one of Hawai'i's rare and endangered endemic fern species. This paper summarizes its conservation status with information concerning its historical and current distribution and its morphology, habitat, and ecology within the Honomanu region of the Nature Conservancy's Waikamoi Preserve, East Maui. With 303 of Hawai'i's plant taxa federally listed as endangered there is an urgent need to conduct rapid biological assesments of remote insu- lar ecosystems and to make conservation collections of the endangered flora. Poorly known species such as D. molokaiense could easily become extinct without receiving special attention, while this biodiversity of many tropical areas is rapidly disappearing before having been adequately surveyed.

Depth of alkalic magma reservoirs below Kolekole cinder cone, Southwest rift zone, East Maui, Hawaii

The Kolekole cinder cone is located on the southwest rift near the summit area of East Maui, adjacent to the Haleakala Crater. The erupted lavas consist of ankaramitic picro-basalts and basanites. The ankaramites contain 26 to 33 modal percent olivine and clinopyroxene phenocrysts. Athough the cores of the clinopyroxene phenocrysts are not in equilibrium with the bulk rock compositions, recovered matrix compositions through image analysis indicate that the rims of the clinopyroxene phenocrysts and plagioclase microphenocrysts are in equilibrium with the matrix in many samples. Equilibrium pressures calculated from clinopyroxene rim–liquid equilibrium, and from equilibrium compositions of multiple phase-saturated liquids, yield values between 4.4 and 11.2 kb. In addition, barometry based on clinopyroxene composition indicates that the cores of the clinopyroxene phenocrysts crystallized at approximately 2.5 kb higher pressures than the rims. Therefore, the alkalic magmas of Kolekole resided in reservoirs that extended well below the crust–mantle boundary. The low Mg-content of the calculated matrix compositions indicates that extensive high pressure fractional crystallization of parental magmas occurred in the lower crust and upper mantle magma chambers.

Phenology and phylogenetic positioning of the Hawaiian endemic freshwater alga, Batrachospermum spermatiophorum (Rhodophyta, Batrachospermales)

SUMMARY The only known population of Batrachospermum spermatiophorum Vis et Sheath, located in a small stream on east Maui, Hawaii, was sampled from November 2001 to October 2002 to investigate its phenology. Additionally, the taxonomic status of the alga was examined. Phylogenetic analyses of the large subunit of the ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) gene for B. spermatiophorum confirm its placement within the Section Contorta of the genus Batrachospermum. Comparisons with rbcL gene sequences for all other available Batrachospermum species, including 10 other members of the Section Contorta, illustrate that B. spermatiophorum is distinct in its rbcL nucleotide sequence and should be maintained as a separate species. The phenology of B. spermatiophorum differed from most studies of Batrachospermum reproduction in that the gametophytes were present year round, and no macroscopic chantran-sia stages were identified at any point during the present study. Maximum plant length was highest in the late fall and early winter months, while gametangial production peaked in February and March. Carposporophyte abundance rose sharply in July and August, and the percentage of carposporophytes producing carpospores was highest in late summer and early fall months. Although significant correlations were determined among stream conditions and among phenological characteristics, only pH was associated with several of the reproductive characters, which is unusual for studies of Batrachospermum phenology. Timing of sexual reproduction for all macroalgal community members in the stream site was not coordinated, with some reproducing year round and others more sporadically. The year-round presence of Batrachospermum gametophytes may be a result of a combination of smaller seasonal changes in cues such as day length and water temperature in the tropical environment than occur in temperate locations, and lack of extreme conditions that might inhibit the persistence of the gametophyte.

150 Phylogenetic Systematics and Phenology of the Hawaiian Endemic Freshwater Red Alga, Batrachospermum Spermatiophorum

The only known population of Batrachospermum spermatiophorum Vis et Sheath, located in a small stream on east Maui, Hawaii, was sampled from November 2001 to October 2002 to investigate its phenology and taxonomy. Phylogenetic analyses of the rbcL gene for B. spermatiophorum confirm its placement within the Section Contorta. Comparison with rbcL gene sequences for all other available Batrachospermum species illustrates that B. spermatiophorum is distinct in its rbcL nucleotide sequence and should be maintained as a separate species. The phenology of B. spermatiophorum differed from similar studies on temperate Batrachospermum species in that gametophytes were present year round, and no “chantransia” stages were identified at any point during the study. Maximum plant length was highest in late fall and early winter months, while gametangial production peaked in February and March. Carposporophyte abundance rose sharply in July and August, and the percent of carposporophytes producing carpospores was highest in late summer and early fall months. The year‐round presence of gametophytes may be a result of fewer seasonal cues in the tropical environment than occur in temperate locations.

Influence of substrate on the distribution of the Hawaiian Silversword ( Argyroxiphium sandwicense DC.) in Haleakala (Maui, HI)

The spatial patterns of the Hawaiian silversword ( Argyroxiphium sandwicense DC.) were studied in Haleakala (Maui, HI). The silversword is a “giant” rosette plant nearly brought to extinction by human impact and goat browsing during the 1920s, but stern protection has resulted in the resurgence of plant populations. Silversword regeneration is occurring vigorously in soils with surficial layers of volcaniclastic fragments. Ten sites with sizable silversword populations and the associated substrates were examined in Haleakala's crater between 2175 and 2755 m. At each site, the population structure of 100 plants was determined along wandering-quarter transects, which limit sampling bias. Substrates where rosettes were rooted and the size of the biggest stone fragments upslope and downslope from the plant's base were determined. Volcaniclastic substrates were examined with photographs along 12-m-long transverse transects. Fine-debris samples (gravel and pebbles) were analyzed by mechanical sifting of surficial fragments gathered from 15×15 cm miniplots. Volcaniclastic fragments in silversword areas have different sources. (i) Most were ejected during eruptions yielding pyroclastic materials (ash to blocks) that built cinder cones on Haleakala's crater. (ii) On steep slopes, weathering of (olivine alkali) basalt outcrops and subsequent mass wasting of rock fragments contributed a mantle of clasts to slopes below. (iii) On some cinder cones, welded spatter was produced during late eruptive stages; this coalesced into ruff-like agglutinate layers around crater rims, called Pohaku-o-Hanalei (“wreath of stones”). Agglutinate deposits weather gradually, supplying clasts that roll downhill and accumulate on cone flanks. (iv) On weathered aa lava flows, stone fragments and rocky crags abound along eroding lava-flow ridges, associated with vegetation; but the intervening troughs, covered with fine ash and cinder, remain bare. Silversword population structures indicate healthy regeneration. All populations display a typical pattern of decreasing silversword numbers with increasing size (=age). Nearly 65% of the rosettes are rooted near cobbles (5–10 cm long) or pebbles (2.5–5 cm), and ∼23% grow at the base of blocks (>10 cm) or outcrops; 9% of the plants are on gravel (<2.5 cm), but only 1% have germinated on sandy soil without granules or stones; 2% of the silverswords grow on organic litter of dead rosettes. Plants on six sites showed noticeable differences in clast size between their upslope and downslope sides; particles are significantly larger upslope from rosettes. This suggests that successful seedlings germinate below clasts, which deflect finer downslope-moving sediment, thus protecting young plants from burial by descending debris. Statistical tests indicate a few blocks above plants may have been stopped by adult rosettes. Such a relationship underscores the dynamic nature of steep cinder and rubble (talus) slopes, regularly affected by dry debris slides, frost creep, and other mass-wasting processes. Slope instability is also evinced by (i) common bending and deformation of silversword roots—particularly in seedlings—which trail upslope; (ii) pronounced downhill tilting and asymmetry of tall rosettes on steep gradients; (iii) presence of accumulated fine-debris steps (9.9–13.8 cm thick) upslope from plants and blocks; (iv) ubiquitous fine-earth flags exposed below embedded blocks, which intercept descending debris and deflect it laterally; (v) widespread miniature sorted stripes.

New K-Ar ages and the geologic evidence against rejuvenated-stage volcanism at Haleakalā, East Maui, a postshield-stage volcano of the Hawaiian island chain

The postshield and previously inferred rejuvenated-stage history of Haleakalā volcano is reevaluated on the basis of 52 new K-Ar ages, 42 from the postshield Kula Volcanics and 10 from the overlying Hāna Volcanics. Postshield extrusion was robust from 0.93 to 0.76 Ma. A period of low extrusion rate or volcanic quiescence occurred between 0.76 and 0.65 Ma, well within Kula time. A chemical change to increasingly alkalic lava occurred at this time as the volcano changed from broadly hawaiitic to basanitic in its eruptive products and robust extrusion resumed. A slightly longer period of low extrusion rate or quiescence occurred after ca. 0.4 Ma, but only trifling change in geochemical character is observed. Geochemically, the Hāna Volcanics unit, chiefly basanitic, overlaps greatly with the upper part of the Kula Volcanics; there is a weak tendency to slightly more alkaline character among the Hāna Volcanics. The age of the Kula/Hāna boundary is ca. 0.15–0.12 Ma; thus, volcanic quiescence of only ∼0.03 m.y. separates the two formations, much shorter than the previously known limit of 0.25–0.30 m.y. The brevity of this hiatus, coupled with coincident vent loci and broadly similar geochemical characteristics for the Hāna and the upper part of the Kula Volcanics, indicates that the Hāna Volcanics unit comprises deposits of postshield-stage volcanism that has waned substantially since ca. 0.4–0.3 Ma. Haleakalā has not yet begun a classically defined rejuvenated stage. Our findings support recent numerical modeling of plume-lithosphere interactions that predict that Haleakalā is near the end of its postshield growth.

The influence of microclimates and fog on stable isotope signatures used in interpretation of regional hydrology: East Maui, Hawaii

Stable isotopes of precipitation, ground water and surface water measured on the windward side of East Maui from 0 to 3055 m altitude were used to determine recharge sources for stream flow and ground water. Correct interpretation of the hydrology using rainfall δ 18O gradients with altitude required consideration of the influence of fog, as fog samples had isotopic signatures enriched by as much as 3‰ in δ 18O and 21‰ in δD compared to volume-weighted average precipitation at the same altitude. The isotopic analyses suggested that fog drip was a major component of stream flow and shallow ground water at higher altitudes in the watershed. 18O/altitude gradients in rainfall were comparable for similar microclimates on Maui (this study) and Hawaii Island (1990–1995 study), however, East Maui δ 18O values for rain in trade-wind and high-altitude microclimates were enriched compared to those from Hawaii Island. Isotopes were used to interpret regional hydrology in this volcanic island aquifer system. In part of the study area, stable isotopes indicate discharge of ground water recharged at least 1000 m above the sample site. This deep-flowpath ground water was found in springs from sea level up to 240 m altitude, indicating saturation to altitudes much higher than a typical freshwater lens. These findings help in predicting the effects of ground water development on stream flow in the area.

Introduction and Distributional Expansion of Trechus obtusus (Coleoptera: Carabidae) in Maui, Hawai'i

Trechus obtusus Erichson (tribe Trechini), native to Europe and North Africa and introduced to the Pacific coast of North America, is recorded for the first time from East Maui Island, Hawai'i, based on collections made at Haleakala National Park in September 1998. The species subsequently expanded its distribution to include Polipoli Springs State Recreation Area, East Maui. Range expansion has averaged 3 km per year, based on documented absence of T. obtusus from the Polipoli Springs area in 1998. All Hawaiian individuals are macropterous, even though European and North American populations of T. obtusus are dimorphic for wing configuration, with the brachypterous form most common in long-established populations. The source area for the Hawaiian invasion is hypothesized to be Oregon or the San Francisco Bay area, based on the closest match in the frequency of macroptery between specimens from Hawai'i and those from those mainland areas. Monomorphic macroptery of the Hawaiian populations suggests that the founder population was small, with estimates ranging from as few as 6 individuals to as many as 25, assuming the founding propagule was drawn at random from populations in the western United States. Baseline abundance data are presented for Polipoli Springs State Recreation Area, where T. obtusus co-occurs with seven native Mecyclothorax species (tribe Psydrini), establishing the opportunity for long-term assessment of the impact of the introduced species on the sympatric native fauna. Means to identify T. obtusus in the context of the Hawaiian carabid beetle fauna are presented.

TEMPORAL VARIATION IN BIRD COUNTS WITHIN A HAWAIIAN RAINFOREST

We studied monthly and annual variation in density estimates of nine forest bird species along an elevational gradient in an east Maui rainforest. We conducted monthly variable circular-plot counts for 36 consecutive months along transects running downhill from timberline. Density estimates were compared by month, year, and station for all resident bird species with sizeable populations, including four native nectarivores, two native insectivores, a non-native insectivore, and two non-native generalists. We compared densities among three elevational strata and between breeding and nonbreeding seasons. All species showed significant differences in density estimates among months and years. Three native nectarivores had higher density estimates within their breeding season (December–May) and showed decreases during periods of low nectar production following the breeding season. All insectivore and generalist species except one had higher density estimates within their March–August breeding season. Density estimates also varied with elevation for all species, and for four species a seasonal shift in population was indicated. Our data show that the best time to conduct counts for native forest birds on Maui is January–February, when birds are breeding or preparing to breed, counts are typically high, variability in density estimates is low, and the likelihood for fair weather is best. Temporal variations in density estimates documented in our study site emphasize the need for consistent, well-researched survey regimens and for caution when drawing conclusions from, or basing management decisions on, survey data. Variación Temporal en Conteos de Aves en una Selva Lluviosa de Hawai Resumen. Estudiamos la variación mensual y anual en estimaciones de la densidad de nueve especies de aves a lo largo de un gradiente altitudinal en una selva lluviosa del este de Maui. Realizamos conteos mensuales en parcelas circulares por un período de 36 meses consecutivos a lo largo de transectas ubicadas desde la línea del bosque hacia abajo. Las estimaciones de densidad fueron comparadas entre meses, años y estaciones considerando todas las especies de aves residentes con poblaciones considerables, incluyendo cuatro nectarívoros nativos, dos insectívoros nativos, un insectívoro no nativo y dos generalistas no nativos. Comparamos densidades entre tres estratos altitudinales y entre las estaciones reproductivas y no reproductivas. Todas las especies mostraron diferencias significativas en las estimaciones de densidad entre meses y años. Tres nectarívoros nativos presentaron estimaciones de densidad mayores durante sus épocas reproductivas (diciembre–mayo) y mostraron disminuciones durante períodos de baja producción de néctar luego de la estación de cría. Excepto una, todas las especies insectívoras y generalistas presentaron mayores estimaciones de densidad durante sus épocas reproductivas (marzo–agosto). Las estimaciones de densidad de todas las especies también variaron con la altitud, y se encontraron cambios estacionales en las poblaciones de cuatro especies. Nuestros datos muestran que el mejor momento para realizar conteos de aves nativas de selva en Maui es enero–febrero, cuando las aves están criando o preparándose para criar, los conteos son típicamente altos, la variabilidad en las estimaciones de densidad es baja y la probabilidad de buen tiempo es más alta. La variación temporal en las estimaciones de densidad documentadas en nuestro sitio de estudio enfatizan la necesidad de regímenes de muestreo consistentes y bien establecidos, y sugiere cautela a la hora de sacar conclusiones para conservación o tomar decisiones de manejo a partir de datos de muestreos.

Geoecological alteration of surface soils by the Hawaiiansilversword (Argyroxiphium sandwicense DC.) inHaleakala's crater, Maui

The geoecological effects of organic matter addition to soil byHawaiian silverswords (Argyroxiphium sandwicense DC.,Asteraceae) in Haleakala's crater (Maui) are examined. Sets of 12 surfacesoil samples were gathered in three positions: bare soils; under the crowncanopy of adjacent live plants; and below dead, withered rosettes. Silverswordstanding litter and live foliage were also collected. Several physical andchemical properties were investigated. Bare soils were coarse and exceptionallylow in chemical nutrients and water-holding capacity. Litter addition belowsilverswords altered all properties except particle-size distribution; soilsunder dead rosettes became modified more strongly than those below live plants.While rosettes grow, standing litter is tightly preserved, thus only smallamounts of organic matter are added to soil. When plants die, a substantialinflux of litter is released in a short period (7 to 9 years average); thisraises the C and N content, C/N ratios, exchangeable nutrient levels (Ca, Mg,K, P) and cation exchange capacity of soil. Physical properties, such as color,bulk density and porosity are also greatly affected; as a result, soilwater-retention at field capacity nearly doubles under withering plants. Soiltemperatures (5 cm depth) at noon were ∼18.1 °C lower beneath silversword canopies(18.5 °C mean) than in contiguous bare soils(36.6 °C). This cooling may result in lower evaporationand further conservation of soil moisture, thus increased seedgermination. Nutrient-retention strategies may have evolved in the semelparousArgyroxiphium to help it cope with the harsh,drought-prone soils and unpredictable climate of Haleakala. Silverswordflowering results in a tremendous seed output, but the plant needs to ensurethat some seeds – which have limited dispersal capability – willgerminate, and thus provides a nutrient-rich, water-retaining substrate moresuitable for seedling establishment than bare soils. Through itsself-regulating influence on underlying soils,Argyroxiphium affects both soil formation and its ownregeneration in Haleakala.

Blackburnia gastrellariformis sp. n. (Coleoptera: Carabidae), from Molokai: successful prediction of a new taxon by reconciled tree analysis

AbstractBlackburnia gastrellariformis sp. n., is described from East Molokai, Hawaii. Based on cladistic parsimony analysis of adult characters, the species is hypothesized to be most closely related to B. komohana Liebherr &amp; Zimmerman of West Maui, with these two species comprising the adelphotaxon to the East Maui species pair, B. haleakala Liebherr &amp; Zimmerman + B. putealis (Blackburn). Previous reconciled tree analysis for the Hawaiian Blackburnia radiation conducted before discovery of B. gastrellariformis found a general pattern in which Molokai and West Maui were hypothesized as sister-areas to the exclusion of the East Maui volcano, Haleakala, though the less common, incongruent area relationship of (Molokai (West Maui + East Maui) was also represented in the taxon-area cladogram. In the present reconciled tree analysis, the closest hypothesized relationship of B. gastrellariformis and a West Maui species corroborates the more common pattern by replacing items of error in the previous analysis with the newly discovered species. Elevational habitat shifts are invoked to explain the occurrence of numerous sister-species pairs in Molokai and West Maui, currently separated by the Pailolo Channel, relative to species occupying Haleakala.

AGE AND SEX DETERMINATION OF THE MAUI PARROTBILL

Abstract We determined the best plumage and morphometric variables for ageing and sexing the Maui Parrotbill (Pseudonestor xanthophrys), an endangered Hawaiian honeycreeper found only on east Maui, Hawaii, by examining and measuring 30 museum specimens and 71 live birds captured in mist nets. Juvenal plumage was identified by the presence of pale-tipped wing bars on the middle and greater coverts, grayish olive dorsal plumage, and dingy white underparts and superciliaries. Birds undergoing first prebasic molt retained the juvenal remiges, rectrices, and wing coverts. Birds in first basic plumage possessed juvenal wing bars and a dull juvenal-like plumage. Subsequent molts were complete, and adults lacked wing bars. Adult males had bright yellow plumage on the cheeks, throat, and superciliaries, as did 27% of adult females. All other adult females had less yellow in the underparts. The dorsal plumage of adult females was more variable than adult males and was either yellow-olive like the males or grayish o...

Reproductive Ecology and Demography of the ‘ĀKohekohe

The ‘Ākohekohe (Palmeria dolei) is an endangered Hawaiian honeycreeper endemic to the montane rain forests of east Maui in the Hawaiian Islands. We investigated ‘Ākohekohe nesting ecology using color-banded birds for the first time as a background to understanding the species' conservation. From 1994–1997, we color-banded 78 individuals, located and monitored 46 active nests, and took behavioral data during 534 hr of nest observation at Hanawī Natural Area Reserve, near the center of the species' range. ‘Ākohekohe nesting behavior and life history closely resembled that of ‘Apapane (Himatione sanguinea) and related honeycreepers. The birds were monogamous within and among years, and we found no evidence of polyandry, polygyny, or helpers at the nest. The nesting season extended from November to early June. Females performed all incubation and brooding. Males provisioned females and nestlings, and they were more active than females in feeding fledglings during the two-week period of parental dependency. Modal clutch size, as determined from egg counts at three nests and by counting begging chicks at other nests, was two eggs, and parents frequently fledged two chicks. We found an overall nest success rate of 68% by the Mayfield method, a high rate compared with other Hawaiian honeycreepers and continental passerines. An average of 1.1 chicks fledged per active nest, and at least 42% of nesting pairs made two or more nesting attempts per season. Rats (Rattus spp.) were abundant at the study site, and we confirmed their depredating some ‘Ākohekohe nests, so we did not expect to find such a high rate of nest success. The estimated annual probability of adult survival was also high, at 0.95 ± 0.10 (SE). Ecología Reproductiva y Demografía de Palmeria dolei Resumen. Palmeria dolei es una especie de mielero amenazada endémica de las selvas nubladas de montaña del Este de Maui en las Islas de Hawai. Investigamos la ecología de nidificación de esta especie usando aves marcadas con anillos de colores como antecedente para entender la conservación de la especie. Entre 1994–1997 marcamos 78 individuos, localizamos y monitoreamos 46 nidos activos, y recolectamos datos de comportamiento durante 534 hr de observación de nidos en la Reserva Natural Hanawī, cercana al centro del rango de distribución de la especie. El comportamiento de nidificación y la historia de vida de P. dolei son marcadamente similares a los de Himatione sanguinea y otros mieleros relacionados. Las aves fueron monógamas dentro y entre años, y no hallamos evidencias de poliandría, poliginia, o ayudantes en los nidos. La estación de nidificación se extendió desde noviembre hasta principios de junio. Las hembras realizaron toda la incubación y cuidado de la nidada. Los machos aprovisionaron a las hembras y pichones, y fueron más activos que las hembras en alimentar a los volantones durante las dos semanas que dependen de los padres. La moda del tamaño de la nidada, determinada a partir del conteo de huevos en tres nidos y del recuento de gritos de llamada de pichones, fue de dos huevos, y los padres generalmente lograron criar dos pichones. Encontramos una tasa de éxito global de los nidos del 68% estimada con el método Mayfield, lo que representa una alta tasa comparada con la de otros mieleros hawaianos y paseriformes continentales. Un promedio de 1.1 pichones por nido activo llegaron a la etapa de dejar el nido, y al menos 42% de las parejas nidificantes realizaron dos o más intentos de nidificación por estación. Ratas (Rattus spp.) fueron abundantes en el sitio de estudio, y confirmamos que depredan nidos de P. dolei, por lo que no esperabamos obtener una tasa de éxito de nidificación tan alta. La probabilidad estimada de supervivencia de los adultos fue también alta, 0.95 ± 0.10 (ES).

Rejuvenated volcanism along the southwest rift zone, East Maui, Hawai'i

East Maui Volcano is the younger and larger of two volcanoes that form the island of Maui, Hawai‘i. Rejuvenated stage (Hāna volcanics) lava flows along the southwest rift zone form a veneer lying disconformably on top of the postshield Kula Volcanics (0.93–~0.36 Ma). Most of the 59 documented Hāna eruptions produced ‘a‘ā flows from large cinder cones. Fourteen new 14C ages and stratigraphic relationships suggest that the onset of rejuvenated volcanism on the southwest rift zone began at least 50 ka, showing that the quiescent period between the postshield and rejuvenated stage on East Maui was ~300,000 years long, the shortest yet documented on any Hawaiian volcano. Eruption frequency on the southwest rift zone steadily increased during the past ~4800 years; there have been at least six eruptions within the past ~960 years. Hāna volcanic activity on the southwest rift zone during the past ~4800 years may have occurred in three episodes, each lasting as long as 1000 years separated by quiescent periods ~500–800 years long. Geochemical data, ages, and geologic relations provide evidence for five multi-flow sequences that were erupted during single events, helping to define the eruptive character or style of rejuvenation stage volcanic activity on the southwest rift zone. Areas covered by the products of individual eruptions vary from 0.14 to ~40 km2, and volumes from 0.0003 to 0.40 km3. Geochemical evidence shows that the Hāna lavas are derived from a small range of parental melts that undergo varying degrees of fractional crystallization. MELTS crystallization simulations suggest that Hāna magmatic evolution occurs at a pressure of ~3 kbar (~10–11 km depth), just above the interface between the volcanic edifice and the oceanic plate. The Hāna volcanics are unique among Hawaiian rejuvenation suites in having been erupted along rift zones with a relatively high eruption frequency from a quasi-steady-state, deep crustal magma reservoir.

Eight Decades of Astronomical Seeing Measurements at Mount Wilson Observatory

ABSTRACTThe astronomical seeing has been recorded at the Mount Wilson Observatory for more than 80 years. Over this period of time, seeing measurements have been made in a consistent fashion using the largest telescopes at the site. This provides an excellent record of the historical observing conditions over the life of the observatory. While the literature clearly shows that the intrinsic seeing on Mount Wilson is the best in the continental United States and comparable to that on Mount Haleakala, Hawaii, the historical record shows that, with the exception of a brief upswing during the period of the Second World War, the number of subarcsecond seeing nights measured at the 60 and 100 inch domes has been on the decline. We compare this record against known events detailed in observatory reports and show that several of the low points in the seeing measurements correspond to periods of large‐scale construction and development activity in the vicinity of the domes. Despite the presence of weather‐related variance in the year‐to‐year seeing, we find no evidence for changes over a time period approaching 100 years.

Transpiration and forest structure in relation to soil waterlogging in a Hawaiian montane cloud forest.

Transpiration, leaf characteristics and forest structure in Metrosideros polymorpha Gaud. stands growing in East Maui, Hawaii were investigated to assess physiological limitations associated with flooding as a mechanism of reduced canopy leaf area in waterlogged sites. Whole-tree sap flow, stomatal conductance, microclimate, soil oxidation-reduction potential, stand basal area and leaf area index (LAI) were measured on moderately sloped, drained sites with closed canopies (90%) and on level, waterlogged sites with open canopies (50-60%). The LAI was measured with a new technique based on enlarged photographs of individual tree crowns and allometric relationships. Sap flow was scaled to the stand level by multiplying basal area-normalized sap flow by stand basal area. Level sites had lower soil redox potentials, lower mean stand basal area, lower LAI, and a higher degree of soil avoidance by roots than sloped sites. Foliar nutrients and leaf mass per area (LMA) in M. polymorpha were similar between level and sloped sites. Stomatal conductance was similar for M. polymorpha saplings on both sites, but decreased with increasing tree height (r(2) = 0.72; P < 0.001). Stand transpiration estimates ranged from 79 to 89% of potential evapotranspiration (PET) for sloped sites and from 28 to 51% of PET for level sites. Stand transpiration estimates were strongly correlated with LAI (r(2) = 0.96; P < 0.001). Whole-tree transpiration was lower at level sites with waterlogged soils, but was similar or higher for trees on level sites when normalized by leaf area. Trees on level sites had a smaller leaf area per stem diameter than trees on sloped sites, suggesting that soil oxygen deficiency may reduce leaf area. However, transpiration per unit leaf area did not vary substantially, so leaf-level physiological behavior was conserved, regardless of differences in tree leaf area.

ARE HIGH ELEVATIONS IN TROPICAL MOUNTAINS ARID ENVIRONMENTS FOR PLANTS?

Plants growing at high elevations in tropical mountains show a scleromorphic habit at the leaf and plant level, despite the fact that alpine landscapes are generally considered to be cool and humid environments. This paper tests the hypotheses (1) that aridity (potential transpiration Ep/rainfall P) in tropical alpine environments can be high despite low temperatures, and (2) that aridity in tropical alpine environments may be correlated with scleromorphic habit. A leaf energy balance model was developed that calculates the change in Ep for a standard leaf along elevational transects in equatorial and middle-latitude mountains by accounting for pressure (elevation) and temperature effects on transpiration. Modeled leaf-level transpiration in tropical alpine environments can be substantial and may even exceed transpiration at low elevations in middle latitudes. At 5000 m elevation, a high diffusion coefficient for water vapor under low air pressure and a high radiation load result in Ep rates 50–90% higher in tropical mountains than in middle-latitude ones. High Ep rates at high elevations are expected (1) in mountains of the dry tropics with low cloudiness and low rainfall but high radiation and, (2) in small oceanic mountain ranges with a strong advection of moist air and, thus, a reduced temperature lapse rate on the slope. Data from tropical Mount Haleakala (Maui, Hawaii) and from the middle-latitude Tyrolian Alps (Austria) were used to test the predicted Ep rates. The two mountains sharply contrast with respect to vertical distribution of Ep and rainfall. At high elevation on Maui, the calculated Ep was high (and was consistent with measured atmometer evaporation rates Em), whereas rainfall was moderate to low. At high elevation in the Alps, both Ep and Em were low compared to similar elevations on Maui, but rainfall was high. Worldwide mountain climate data sets show that rainfall tends to decrease upslope in many tropical mountains, while it increases with elevation in most middle-latitude mountains. I conclude that (1) high-elevation environments in tropical mountains are more arid than similar elevations in middle-latitude mountains as a result of both higher evaporative demand and lower rainfall, and (2) that aridity can significantly contribute to the scleromorphy of tropical alpine plants which had previously been attributed to low temperature or high radiation effects alone.