Introducing a New Series: History, Biology, and Conservation of Pacific Endemics
Edward Webb and Curtis C. Daehler, 411
A thorough review of Oxera pulchella Labill., also called the “royal creeper,” was carried out to better understand the amazing story of this almost forgotten New Caledonian ornamental species. The history of this plant is interestingly related to the history of New Caledonia. The literature record’s analysis shows that taxonomic placement of the genus Oxera Labill. has been widely discussed from its discovery until very recently. This review also offers the opportunity to understand and hypothetize how Oxera pulchella was exported and disseminated worldwide through botanical gardens and private nurseries at the end of the nineteenth century. Along with a review of Oxera pulchella’s etymology, vernacular names, iconography, and horticultural fame, this review considers its current taxonomy, horticultural importance, conservation, biology, and various economic issues with a perspective from our ongoing research on this genus of special ornamental potential.
Nectar Production by Invasive Lantana camara and Endemic L. peduncularis in the Galápagos Islands
J. Carrión-Tacuri, R. Berjano, G. Guerrero, M. E. Figueroa, A. Tye, and J. M. Castillo, 435–445
Measurements of nectar volume and sugar concentration along two elevational gradients, in flower exclusion experiments, and over a diurnal cycle of nectar production were compared for invasive Lantana camara and endemic Lantana peduncularis in the Galápagos Islands during the dry season. Both species show the same pollination syndrome and are pollinated by Lepidoptera. Lantana camara flowers had a higher nectar volume than L. peduncularis flowers at every elevation and higher total sugar content. However, nectar in L. peduncularis flowers was much more concentrated than in L. camara flowers at lower elevations. The differences in nectar production between Lantana species seemed to be intrinsic and related to contrasting strategies to cope with drought. Nectar volume of unbagged flowers of L. camara was lower than that of bagged flowers at sunrise, which was probably related to consumption of nectar by nocturnal Lepidoptera. Nectar removal by floral visitors had a pronounced effect on total amount of nectar secreted by L. camara flowers but sugar concentration did not vary significantly. Our results suggest that L. camara may compete with L. peduncularis for pollinators.
Interisland Range Expansion of Viola lanaiensis (Violaceae: Malpighiales), an Endangered Hawaiian Violet
J. Christopher Havran, Hank Oppenheimer, Jacob Keaton, and Krystal Piotrowski, 447–456
The monophyletic Hawaiian violet lineage includes five species that are endangered or threatened. A new population of Viola was recently discovered on Helu Peak, West Maui. Individuals in the Helu Peak population appeared morphologically similar to critically imperiled Viola lanaiensis, endemic to the nearby island of Lāna‘i. To identify the population on Maui, the Internal Transcribed Spacer sequence from the new population was compared with all other known Hawaiian violets using maximum parsimony. Leaf and floral traits were compared between the Helu Peak population, V. lanaiensis, and V. oahuensis. Maximum parsimony analysis placed the Helu Peak population in an unresolved polytomy with V. lanaiensis and V. oahuensis. Canonical Variates Analysis of leaf variables suggests that the Maui population is morphologically indistinguishable from V. lanaiensis. Floral organ lengths of the new population overlap with previously published values for V. lanaiensis. Due to similarities in morphology and close genetic relationships, we are classifying the Maui population as a new interisland population of V. lanaiensis. On Lāna‘i, V. lanaiensis is reduced to an extant population of six individuals. Over 140 individuals are currently distributed on Maui. Despite the increase in the wild population of V. lanaiensis, the species will likely remain listed as endangered. Conservation actions for the species on Lāna‘i and Maui will involve seed collection and storage, propagation and outplanting, and habitat protection.
Historical Land-Cover Classification for Conservation and Management in Hawaiian Subalpine Drylands
James R. Kellner, Gregory P. Asner, Susan Cordell, Jarrod M. Thaxton, Kealoha M. Kinney, Ty Kennedy-Bowdoin, David E. Knapp, Erin J. Questad, and Stephen Ambagis, 457–466
We used aerial photography from 1954 and airborne LiDAR and imaging spectroscopy from 2008 to infer changes in extent and location of tallstature woody vegetation in 127 km2 of subalpine dry forest on the island of Hawai‘i (Pōhakuloa Training Area), and to identify 25.8 km2 of intact woody vegetation for restoration and management. Total cover of woody vegetation was 54.7 km2 in 1954 and 58.6 km2 in 2008. Approximately 28.9 km2 underwent woody vegetation change (22.7%) between 1954 and 2008. Increases in woody vegetation cover occurred in 16.4 km2, and 12.5 km2 represented reduction of woody vegetation cover (12.9% and 9.8% of the 127 km2 study area, respectively). Our findings suggest that 3.9 km2 (3.0%) experienced a net increase in woody vegetation cover between 1954 and 2008. Spatial patterns suggest that fires may be the primary driver of reductions in woody vegetation cover. Increases could be due to regeneration of dry forest trees or measurement errors associated with historical imagery. Areas remaining in woody vegetation cover over the 53-yr study interval can be targeted for restoration and management. We discuss challenges to integrating historical photography with contemporary conservation and management in Hawai‘i and the Pacific and we outline additional studies that would help to improve estimates. The methods and analysis are general and could be applied to other dryland ecosystems with complex volcanic substrates in Hawai‘i and the Pacific.
Translocation of Tuamotu Kingfishers, Postrelease Exploratory Behavior, and Harvest Effects on the Donor Population
Dylan C. Kesler, Allison S. Cox, Guillaume Albar, Anne Gouni, James Mejeur, and Chelle Plassé, 467–480
Conservationists previously described the need for research into using translocation to rescue threatened populations. We conducted an experimental translocation of Tuamotu kingfishers (Todiramphus gambieri gertrudae) to provide foundational information about movement ecology and inform conservation planning for the critically endangered bird. We captured and radio-marked mated pairs of kingfishers on Niau Atoll, French Polynesia, where approximately 125 individuals compose the last remaining population of Tuamotu kingfishers. One bird from each pair was translocated to a reintroduction site on the opposite side of the island, and the other pair member was released back onto the home territory. Home-ranging pair members remained on territories and used habitats disproportional to availability, as determined by Brownian bridge analysis. Translocated individuals made multiple forays from the release site to explore the surrounding landscape, during which habitats were used in proportions similar to availability. The exploratory behavior resembled that of dispersing juvenile birds, which suggested that adults retain the ability to explore, and that dispersal theory may be a useful basis for planning translocations. Vacancies on donor territories were filled within 1–10 days. Our results indicated that translocation was not effective for range expansion on Niau because birds readily returned to donor areas; however, translocation to other islands remains a potential conservation strategy for Tuamotu kingfishers.
Patterns in Benthic Coral Reef Communities at Pearl and Hermes Atoll along a Wave-Exposure Gradient
Kimberly N. Page-Albins, Peter S. Vroom, Ronald Hoeke, Mark A. Albins, and Celia M. Smith, 481–496
This study compares percentage cover of benthic organisms at the species level at Pearl and Hermes Atoll (PHA), the largest atoll in the Northwestern Hawaiian Islands, to determine (1) the degree of difference among sites, (2) whether wave-exposure zones explain observed patterns in benthic community structure, and (3) whether species richness differs among wave-exposure zones. Thirty-four sites were surveyed representing four categorical-wave-exposure regimes: high, intermediate-high, intermediate-low, and low. A two-way nested analysis of similarity (ANOSIM) found significant differences among sites and that wave exposure explained some, but not all, of this variation. High and low wave-exposure zones were found to differ significantly from other zones. Low wave-exposure sites exhibited the highest similarity to each other and were dominated by the finger coral Porites compressa (38% cover). High wave-exposure sites were also similar to each other and were dominated by crustose coralline red algae (37% cover). Sites within the intermediate-high zone exhibited substantial variability; however, the presence of the green alga Microdictyon setchellianum was a unifying characteristic among many sites in this zone. Finally, intermediate-low wave-exposure sites exhibited the greatest degree of variability among sites and also exhibited the greatest level of benthic species diversity, including presence of rarer species. Wave exposure proved a useful tool in describing the diverse assemblages of benthic communities at PHA, especially for sites experiencing extreme high and low wave exposure.
Offshore Spawning for the Newly Discovered Anguillid Species Anguilla luzonensis (Teleostei: Anguillidae) in the Western North Pacific
Mari Kuroki, Michael J. Miller, Jun Aoyama, Shun Watanabe, Tatsuki Yoshinaga, and Katsumi Tsukamoto, 497–507
A new anguillid eel species, Anguilla luzonensis, was recently discovered on Luzon Island of the northern Philippines, but little is known about its life history. DNA identification was used to determine that five leptocephali of this species (29.2–51.2 mm) were collected offshore in the western North Pacific (13°–17.5° N, 125°–141° E) in April, June, and July between 2002 and 2009. One leptocephalus was caught west of Luzon and four were close to the spawning areas of Anguilla japonica and Anguilla marmorata. Otolith microstructure showed that the leptocephali were up to 103–138 days old. Glass eels from northern Luzon in previous studies that were thought to be Anguilla celebesensis now appear likely to have been A. luzonensis, and they were estimated by otolith analysis to have long larval durations similar to those of A. marmorata. Estimated hatching dates of these glass eels and the A. luzonensis leptocephali were both in the February to May season. Offshore presence of leptocephali of A. luzonensis and direction of ocean currents suggest that this species migrates offshore to spawn in the North Equatorial Current.
A preliminary survey of coconut crabs, Birgus latro (L.), on Sorol Atoll, Yap, during 3 weeks in June and July 2011 is only the second quantitative assessment of B. latro for any island or island group in the Federated States of Micronesia (FSM). A population density of at least 169 crabs/ha (based on 10 m and 2 m fixed-width transects combined) and as high as 354/ha (2 m fixed-width transects only) was estimated for Pigelmol Island in the atoll. The largest male measured 71.4 mm in thoracic length (TL) and weighed 2,750 g, and the largest female was 44.0 mm TL and weighed 720 g; 24 males (26% of the 91 crabs from Pigelmol) were larger than the largest female. The sex ratio did not differ significantly from 1:1. Crabs were active during the day as well as at night. Population density of B. latro on Pigelmol probably is among the highest of any island in the FSM, but a dearth of similar studies in the FSM precludes more-definitive interisland comparisons. Coconut crabs were not recorded on the two Sorol Atoll islands where suitable habitat was lacking, or marginal at best, and they were scarce on the three others. Overexploitation by residents of the former settlement; predation by rats, pigs, and monitor lizards; and competition from hermit crabs (Coenobita spp.) are suggested as possible reasons for the scarcity of crabs, at least on the main island. Government legislation regulating harvest of coconut crabs in the FSM is mainly at the state level and varies greatly across the FSM. Although the most effective conservation practice appears to be traditional leadership at the community level, poaching remains frequent, enforcement is difficult, and the few existing scientific management strategies are applied without baseline knowledge of stock populations.
The Lancelet Asymmetron lucayanum Complex in Cocos Island National Park, Pacific Costa Rica
Jeffrey A. Sibaja-Cordero, Jesús S. Troncoso, and Jorge Cortés, 523–528
The lancelet Asymmetron lucayanum complex was collected from subtidal (5–42 m) sandy bottom during a benthic survey designed to describe the biota of Cocos Island National Park (Parque Nacional Isla del Coco), Costa Rica, a World Heritage Site. Taxonomically significant characters of A. lucayanum (number of myotomes, gonads only on the right side of the body, shape of metapleural folds) are discussed. These lancelets were living in poorly sorted and slightly gravelly sand. Although this taxon has a circumtropical distribution, this is the first time it has been collected anywhere in the eastern Pacific.
Schimmelmannia (Rhodophyta: Acrosymphytales): First Report of the Genus in Hawai‘i
Alison R. Sherwood and Amy L. Carlile, 529–533
The marine red alga Schimmelmannia cf. elegans was identified from samples collected from an aquaculture facility on the island of Hawai‘i based on morphological and molecular data analyses. The genus has never before been reported from the Hawaiian Islands. Awareness of this species is raised given that it has been suspected as introduced in Cape Town, South Africa, and because Hawaiian coastal marine waters are already heavily impacted by introduced algae.
Index to Volume 66