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Cover : A blue whale (Balaenoptera musculus) raises its fluke before making a deep dive on its winter feeding grounds, Sea of Cortez, Baja California, Mexico. Although blue whales are the largest animals on Earth, they are rare, and their abundance is difficult to estimate. On pages 526‐535, Williams et al. demonstrate an application of spatial modeling to estimate abundance of blue whales off the coast of Chile. Their comparison of these estimates of abundance with those for Antarctic blue whales allowed them to infer that Chilean and Antarctic blue whales are separate populations. Additionally, the methods allowed assessment of current abundance of Chilean blue whales relative to abundance before intensive hunting in the 1900s. Photographer : Tui De Roy ( http://www.tuideroy.com ) is a founding fellow of the International League of Conservation Photographers. Her work has been published in over 30 countries. She has published 7 large‐format books on the Galápagos Islands and other books on the Andes, Antarctica, New Zealand, and the world's albatrosses. Tui founded Th e Roving Tortoise Nature Photography ( http://www.rovingtortoise.co.nz ) in partnership with Mark Jones. She has spent most of her life in the Galápagos Islands, is a former member of the board of directors of the Charles Darwin Foundation, and works in close association with Galápagos National Park to document the islands and their rare species. Tui currently lives in New Zealand.     

Reef coral reproduction in the equatorial eastern Pacific: Costa Rica, Panamá, and the Galápagos Islands (Ecuador). VII. Siderastreidae, Psammocora stellata and Psammocora profundacella

Two zooxanthellate, scleractinian species present in the equatorial eastern Pacific, Psammocora stellata and Psammocora profundacella, were examined in terms of their reproductive biology and ecology at four study sites, non-upwelling (Ca?o Island, Costa Rica, and Uva Island, Panamá), upwelling (Gulf of Panamá, Panamá), and seasonally varying thermal environments (Galápagos Islands). Both species were gonochoric broadcast spawners lacking zooxanthellae in mature ova. Mature gametes and spawned gonads are present around full moon; however, no spawning was observed naturally or in outdoor aquaria. Mature gametes occurred in P. stellata at Ca?o Island for nearly 6?months, and year round at Uva Island, both non-upwelling sites. Reproductively active colonies occurred mostly in the warmer months in the Gulf of Panamá and Galápagos Islands. In the Galápagos Islands, where collecting effort was greatest for P. profundacella, mature gametes were also most prevalent during the warm season. Annual fecundity was high in both species, 1.3–1.8?×?10⁴?ova?cm^?2?year^?1 in P. stellata and 1.2–2.0?×?10⁴?ova?cm^?2?year^?1 in P. profundacella. Compared to other eastern Pacific corals, P. stellata was relatively resistant to ENSO-related bleaching and mortality, especially populations inhabiting deep (12–20?m) coral communities. Rapid recovery and persistence of Psammocora spp. can be attributed to several factors: (a) relative resistance to bleaching, (b) deep refuge populations, (c) broadcast spawning, (d) protracted seasonal reproduction, (e) high fecundity, and (f) asexual propagation.     

Reef coral reproduction in the eastern Pacific: Costa Rica, Panamá and Galápagos Islands (Ecuador). IV. Agariciidae, recruitment and recovery of Pavona varians and Pavona sp.a

The reproductive ecology of two eastern Pacific zooxanthellate coral species was examined as part of a continuing series of studies relating bleaching/mortality events caused by the El Niño–Southern Oscillation disturbance, and is described for study sites in Costa Rica, Panamá, and the Galápagos Islands (Ecuador). This study deals with the sibling agariciid species Pavona varians and Pavona sp.a over a 13?yr period (1985 to 1997). Both Pavona species are broadcast-spawners with some gonochoric, but mostly sequential hermaphroditic colonies. Minimum colony sizes (and ages) at first reproduction were 5?cm (5?yr) and 3?cm (2 to 3?yr), respectively, in P. varians and Pavona sp.a. In the Panamá and Galápagos populations, gonochoric colonies spawn eggs or sperm at least monthly. Six fecundity attributes were not significantly different in the two species, but the eggs of P. varians are white to beige and positively buoyant, and those of Pavona sp.a are dark green and neutrally to negatively buoyant. Eggs of both species lack zooxanthellae. Both species are reproductively active year-round, with maximum activity in the dry season in the nonupwelling Gulf of Chiriquí, and in the wet season in the upwelling Gulf of Panamá. Spawning is predominantly during full moon, and possibly also at new moon at most study sites. Spawning in P. varians and Pavona sp.a is 12?h out of phase, with the former species spawning ～1?h before sunrise and the latter about 1?h after sunset. The fecundity of Pavona spp. at Caño and the Galápagos Islands was much greater (19?900 to 27?900 eggs cm^?2?yr^?1) than at all Panamá sites (14?800 to 19?800 eggs cm^?2?yr^?1). Intraspecific crosses in both species resulted in swimming planula larvae after 25 to 36?h. Recruitment of P. varians was highest in Panamá, moderate in Costa Rica, and nil in the Galápagos Islands, matching, respectively, the contributions of P. varians to the pre-1982/1983 El Niño coral-population abundances in these areas. Recruitment success of P. varians at Uva Island was significantly related to maximum monthly positive sea surface-temperature (SST) anomalies that occurred in the year preceding recruitment over the period 1982 to 1996; recruitment failed when SST anomalies exceeded 1.6 to 1.9?C° during the severe ENSO events of 1982/1983 and 1997/1998.     

Reproductive ecology of the azooxanthellate coral <Emphasis Type="Italic">Tubastraea coccinea</Emphasis> in the Equatorial Eastern Pacific: Part V. Dendrophylliidae

The reproductive ecology of Tubastraea coccinea Lesson, an azooxanthellate tropical scleractinian coral, was studied over various periods from 1985 to 2006 at four principal eastern Pacific locations in Costa Rica, Panamá, and the Galápagos Islands (Ecuador). This small (polyp diameter 0.8–1.0 cm), relatively cryptic species produced ova and planulae year round, including colonies with as few as 2–10 polyps. Of 424 colonies examined histologically, 13.7% contained both ova and sperm. Mature ova varied in diameter from ∼300 to 800 μm and the time from spawning and fertilization of oocytes to release of brooded planulae was about 6 weeks. Planulae were 0.5–1.5 mm long and they settled and metamorphosed on a variety of substrates after 1–3 days. Spermaries, though more difficult to distinguish in histological sections, were present throughout the year. Spent spermaries were never observed in sections, but several colonies in Panamá and the Galápagos Islands released sperm from night one to night five after full moon, indicating the potential for cross-fertilization among colonies. Planula release was observed at Uva Island (Panamá) in March, May, June, and July, and in general planula presence was higher at warm ocean temperatures at all sites, whether or not the sites were influenced by seasonal upwelling. Annual fecundity estimates for T. coccinea are comparable with other high fecundity brooding species, including the zooxanthellate Porites panamensis, with which it co-occurs in Panamá. Tubastraea coccinea is widely distributed in the tropical Indo-Pacific and has colonized substrates in the western Atlantic. In addition to the reproductive characteristics described in the present study, other features of the biology of T. coccinea, such as an ability to withstand conditions that produce bleaching and mortality in zooxanthellate species, may account for its widespread, low-latitude distribution in multiple oceans. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. An erratum to this article can be found at     

Reef coral reproduction in the eastern Pacific: Costa Rica,Panamá, and the Galápagos Islands (Ecuador). VI. Agariciidae, <Emphasis Type="Italic">Pavona clavus</Emphasis>

The reproductive ecology of the zooxanthellate reef coral Pavona clavus was investigated at several sites in Costa Rica, Panamá, and the Galápagos Islands (Ecuador) over the period 1985–2009. Pavona clavus displayed stable gonochorism as only five hermaphrodites were found in 590 samples. At four of five locations, sex ratios were skewed toward female dominance; however, at Saboga Island (Panamá) male colonies predominated. In Panamá, sexual maturity was observed in an estimated eight-year-old female colony, and several colonies of 10–20 years of age demonstrated gametogenesis. Sexual activity was observed at all study sites, but gamete development occurred in only 14–31% of colonies sampled sporadically. Seasonality of gametogenic activity occurred predominantly during the warm/wet season, June to August, at mainland sites (Caño Island, Costa Rica, and Gulfs of Chiriquí and Panamá, Panamá). This pattern was repeated in the Galápagos Islands, but mainly from March to May when seasonally high sea temperatures and rainfall prevailed there. Histological sampling and field observations indicated that spawning was centered around the full moon, most frequently on lunar day 17, and near sunset (1,800 h). Mean fecundity (mature ova cm^?2 live tissue) estimates were significantly different for two sites and ranged from ~1,780 (Saboga Island, Gulf of Panamá, seasonally upwelling) to ~4,280 (Uva Is, Gulf of Chiriquí, non-upwelling). Assuming three annual spawning events colony^?1 (August, September, October), extrapolation of minimum and maximum fecundities yield 5,340 and 12,840 ova cm^?2 year^?1. Seasonal, lunar, and diel spawning patterns in nine zooxanthellate species at Uva Island indicate asynchronous coral community spawning.     

Cover Caption

Cover : The Takahe (Porphyrio hochstetteri), once widespread throughout New Zealand, was thought to be extinct by the end of the 1800s. In 1948 a remnant population was rediscovered in a remote region of the country's South Island. As of 2007, 72 birds descended from 18 founders were distributed across 4 islands off the coast of New Zealand. Grueber et al. (pages 1617‐1625) evaluated the effect of inbreeding depression across all life‐history stages of the Takahe. Although levels at each stage were low, accumulated inbreeding depression ultimately reduced long‐term fitness. These results suggest that even species with high historical levels of inbreeding can lose fitness as a result of recent inbreeding.     

Equivalency of Galápagos Giant Tortoises Used as Ecological Replacement Species to Restore Ecosystem Functions

Loss of key plant–animal interactions (e.g., disturbance, seed dispersal, and herbivory) due to extinctions of large herbivores has diminished ecosystem functioning nearly worldwide. Mitigating for the ecological consequences of large herbivore losses through the use of ecological replacements to fill extinct species’ niches and thereby replicate missing ecological functions has been proposed. It is unknown how different morphologically and ecologically a replacement can be from the extinct species and still provide similar functions. We studied niche equivalency between 2 phenotypes of Galápagos giant tortoises (domed and saddlebacked) that were translocated to Pinta Island in the Galápagos Archipelago as ecological replacements for the extinct saddlebacked giant tortoise (Chelonoidis abingdonii). Thirty‐nine adult, nonreproductive tortoises were introduced to Pinta Island in May 2010, and we observed tortoise resource use in relation to phenotype during the first year following release. Domed tortoises settled in higher, moister elevations than saddlebacked tortoises, which favored lower elevation arid zones. The areas where the tortoises settled are consistent with the ecological conditions each phenotype occupies in its native range. Saddlebacked tortoises selected areas with high densities of the arboreal prickly pear cactus (Opuntia galapageia) and mostly foraged on the cactus, which likely relied on the extinct saddlebacked Pinta tortoise for seed dispersal. In contrast, domed tortoises did not select areas with cactus and therefore would not provide the same seed‐dispersal functions for the cactus as the introduced or the original, now extinct, saddlebacked tortoises. Interchangeability of extant megaherbivores as replacements for extinct forms therefore should be scrutinized given the lack of equivalency we observed in closely related forms of giant tortoises. Our results also demonstrate the value of trial introductions of sterilized individuals to test niche equivalency among candidate analog species. Equivalencia de Tortugas Gigantes de las Galápagos Utilizadas como Especie de Reemplazo Ecológico para Restaurar las Funciones de los Ecosistemas     

Effects of vulture declines on facultative scavengers and potential implications for mammalian disease transmission

Vultures (Accipitridae and Cathartidae) are the only known obligate scavengers. They feed on rotting carcasses and are the most threatened avian functional group in the world. Possible effects of vulture declines include longer persistence of carcasses and increasing abundance of and contact between facultative scavengers at these carcasses. These changes could increase rates of transmission of infectious diseases, with carcasses serving as hubs of infection. To evaluate these possibilities, we conducted a series of observations and experimental tests of the effects of vulture extirpation on decomposition rates of livestock carcasses and mammalian scavengers in Kenya. We examined whether the absence of vultures changed carcass decomposition time, number of mammalian scavengers visiting carcasses, time spent by mammals at carcasses, and potential for disease transmission at carcasses (measured by changes in intraspecific contact rates). In the absence of vultures, mean carcass decomposition rates nearly tripled. Furthermore, the mean number of mammals at carcasses increased 3-fold (from 1.5 to 4.4 individuals/carcass), and the average time spent by mammals at carcasses increased almost 3-fold (from 55 min to 143 min). There was a nearly 3-fold increase in the mean number of contacts between mammalian scavengers at carcasses without vultures. These results highlight the role of vultures in carcass decomposition and level of contact among mammalian scavengers. In combination, our findings lead us to hypothesize that changes in vulture abundance may affect patterns of disease transmission among mammalian carnivores.     

Love thy neighbour? Social nesting pattern,host mass and nest size affect ectoparasite intensity in Darwin’s tree finches

Social nesting behaviour is commonly associated with high prevalence and intensity of parasites in intraspecific comparisons. Little is known about the effects of interspecific host breeding density for parasite intensity in generalist host–parasite systems. Darwin’s small tree finch (Camarhynchus parvulus) on Santa Cruz Island, Galápagos Islands, nests in both heterospecific aggregations and at solitary sites. All Darwin finch species on Santa Cruz Island are infested with larvae of the invasive blood-sucking fly Philornis downsi. In this study, we test the prediction that total P. downsi intensity (the number of parasites per nest) is higher for nests in heterospecific aggregations than at solitary nests. We also examine variation in P. downsi intensity in relation to three predictor variables: (1) nest size, (2) nest bottom thickness and (3) host adult body mass, both within and across finch species. The results show that (1) total P. downsi intensity was significantly higher for small tree finch nests with many close neighbours; (2) finches with increased adult body mass built larger nests (inter- and intraspecific comparison); (3) parasite intensity increased significantly with nest size across species and in the small tree finch alone; and (4) nest bottom thickness did not vary with nest size or parasite intensity. These results provide evidence for an interaction between social nesting behaviour, nest characteristics and host mass that influences the distribution and potential impact of mobile ectoparasites in birds.     

Phylogeography of California and Galápagos sea lions and population structure within the California sea lion

We investigate the phylogeography of California (Zalophus californianus) and Galápagos (Z. wollebaeki) sea lions and describe within-population structure for the California sea lion based on mitochondrial DNA. Fifty control-region haplotypes were found, 41 from Z. californianus and 9 from Z. wollebaeki, with three fixed differences between the two species. Ranked population boundaries along the range of Z. californianus were defined based on the Monmonier Maximum Difference Algorithm, resulting in five genetically distinct populations, two in the Pacific Ocean and three inside the Gulf of California. A Minimum Spanning Network showed a strong phylogeographic signal with two well-defined clusters, Z. californianus and Z. wollebaeki, separated by six base-pair differences, supporting the existence of two genetically distinct species with an estimated divergence time of ~0.8 Ma. Results are discussed in the context of the historical geologic and paleoceanographic events of the last 1 Ma in the eastern Pacific.     

Reproductive biology and population structure of the sea cucumber <Emphasis Type="Italic">Isostichopus fuscus</Emphasis> (Ludwig, 1875) (Holothuroidea) in Caamaño,Galápagos Islands,Ecuador

Pre-spawning reproductive biology and population structure of the sea cucumber Isostichopus fuscus were analysed at the Caamaño Island, Galápagos Islands, Ecuador on a monthly basis between January 1995 and June 1996. An average of 25 individuals of all sizes were collected each month. Using microscopic characteristics of the gonads three gonadal stages were described: (1) immature; (2) mature, and (3) spent. Mature individuals showed statistically different morphometric characteristics. I. fuscus was continuously sexually mature throughout the year independent of changes in sea water temperature. Mean oocyte diameter indicated planktotrophic larval development. Mean fecundity for this species was 567,884 (±95,528 SE) eggs per gonad. Size at first maturity was between 161.0 and 170.9 g drained weight and the smallest individual found with mature gonads had a drained weight between 121.0 and 130.9 g. The population sampled ranged between 13 and 31 cm (81.0–400.0 g) with less than 10% of the population of individuals ≥25 cm (≥300.0 g). No juveniles were recorded.     

Parent–offspring and sibling conflict in Galápagos fur seals and sea lions

Parent–offspring conflict theory is well supported by theoretical arguments. However, empirical observations are often difficult to interpret and have contradicted one of its most appealing predictions that parent and offspring should disagree over killing of nest or littermates. We present the first examples of deadly conflict between siblings of different cohorts. In Galápagos fur seals (Arctocephalus galapagoensis) and sea lions (Zalophus wollebaeki), mothers often wean their single offspring at 2 years. This leads to a situation where up to 23% of all pups are born while the older sibling is still being nursed. Younger siblings are disadvantaged by being born lighter than neonates without older still dependent siblings. Pups born while an older sib is still dependent grow less in early life (fur seal) and suffer increased early mortality (both species) through direct aggression or scramble competition with the older sibling. This effect is much stronger in years of high sea surface temperature (El Niño) indicating low marine productivity and if the older offspring is a male. In both species, mothers interfere aggressively in this conflict by defending the younger offspring. In years of El Niño, intense resistance to maternal aggression by the older offspring happens frequently in the fur seal. Such resistance against weaning can induce maternal neglect of the newborn. Given substantial year to year variation in offspring growth, maternal aggression forces weaning in the older sibling only if it has reached sufficient size to support itself by foraging. In Galápagos fur seals, pups with older siblings can either represent insurance against loss of older offspring or extra reproductive value.     

Applying science to pressing conservation needs for penguins

More than half of the world's 18 penguin species are declining. We, the Steering Committee of the International Union for Conservation of Nature Species Survival Commission Penguin Specialist Group, determined that the penguin species in most critical need of conservation action are African penguin (Spheniscus demersus), Galápagos penguin (Spheniscus mendiculus), and Yellow-eyed penguin (Megadyptes antipodes). Due to small or rapidly declining populations, these species require immediate scientific collaboration and policy intervention. We also used a pairwise-ranking approach to prioritize research and conservation needs for all penguins. Among the 12 cross-taxa research areas we identified, we ranked quantifying population trends, estimating demographic rates, forecasting environmental patterns of change, and improving the knowledge of fisheries interactions as the highest priorities. The highest ranked conservation needs were to enhance marine spatial planning, improve stakeholder engagement, and develop disaster-management and species-specific action plans. We concurred that, to improve the translation of science into effective conservation for penguins, the scientific community and funding bodies must recognize the importance of and support long-term research; research on and conservation of penguins must expand its focus to include the nonbreeding season and juvenile stage; marine reserves must be designed at ecologically appropriate spatial and temporal scales; and communication between scientists and decision makers must be improved with the help of individual scientists and interdisciplinary working groups.     

Cover Caption

Cover : Tuatara (Sphenodon punctatus) at Victoria University of Wellington, New Zealand. On pages 199‐207, Moir et al. examine potential methods to prevent extinction of species dependent on hosts of divergent taxa, including the tuatara, when translocating threatened animals or plants. A tick (Amblyomma sphenodonti) that is specific to tuatara did not establish after two translocations of tuatara. Moir et al. suggest determining viable sizes of founder host populations for dependent species and managing populations of dependent species to maximize the probability of sustainable rates of transmission between hosts. Cover image © 2012 Piotr Naskrecki. Photographer : Piotr Naskrecki is an entomologist and conservation biologist at the Museum of Comparative Zoology, Harvard University, where he works on conservation, biogeography, and evolution of sound‐producing insects. As a photographer, Piotr has mastered the art of creating portraits of some of the smallest and most beautiful organisms. Between 2002 and 2009 he served as director of the Invertebrate Diversity Initiative at the Center for Applied Biodiversity Science of Conservation International. His work on the distribution of numerous groups of invertebrates informed decisions such as designations of regions with high concentrations of species richness. Piotr's publications, both technical and popular, strive to promote appreciation and conservation of invertebrates. His book The Smaller Majority (2005, Harvard University Press) illustrates many threats to the persistence of invertebrates. Relics: Travels in Nature's Time Machine (2011, Chicago University Press) discusses ecology and conservation of some of the world's most ancient organisms and ecosystems.     

Reef coral reproduction in the eastern Pacific: Costa Rica,Panamá, and Galápagos Islands (Ecuador). III. Agariciidae (Pavona gigantea and Gardineroseris planulata)

The reproductive ecology of Pavona gigantea Verrill and Gardineroseris planulata (Dana) was investigated in the equatorial eastern Pacific region from 1985 to 1994. These zooxanthellate scleractinian corals were adversely affected in this region during the 1982–1983 El Niño warming event. Both species were hermaphroditic, with individual colonies showing sequential cosexual development, thus resulting in dominantly outbreeding reproduction. Sexuality was mixed, with high percentages of gonochoric and hermaphroditic colonies in both species. Approximately 1:1 male-to-female gonad ratios were found in gonochoric and hermaphroditic colonies combined. Broadcast spawning was observed in P. gigantea in the Galápagos Islands, and the sudden disappearance of mature gametes and the presence of spent gonads suggest that G. planulata is also a broadcast spawner. Colonies of both species with 200 cm² (10 cm diam) live tissue were nonreproductive. Estimated ages of the youngest reproductive colonies were 11 yr for P. gigantea and 20 yr for G. planulata. The percentage of all colonies of P. gigantea with gonads at nonupwelling sites (Caño Istand, Costa Rica and Uva Island, Panamá) ranged from 37 to 47%, respectively; colonies with gonads from upwelling environments (Saboga and Taboga Islands, Panamá) ranged from 31 to 39%, respectively, and reproductively active colonies from the thermally variable Galápagos islands comprised 40% of the collections. Compared with P. gigantea, the numbers of sexually active G. planulata colonies were roughly onehalf at nonupwelling Caño Island (20%) and Uva Island (25%) sites, or less (10%) at the upwelling Saboga Island site. Peak reproductive activity in P. gigantea occurred during the rainy season at all study sites. In the nonupwelling Costa Rican (Caño Island) and Panamainan (Uva Island) sites, mean monthly sea-surface temperatures (SSTs) were high (28 to 29°C), but slightly lower than in the dry season (29°C). In the upwelling Gulf of Panamá (Saboga and Taboga Islands), reproduction occurred after mean monthly SSTs increased from 24 to 28–29°C. In the Galápagos Islands, reproductive activity peaked during sea warming, when mean monthly SSTs reached 25°C. Sexually active colonies of G. planulata, present only at the main collection sites of Caño and Uva Islands, were also observed during the wet season. The presence of mature or spawned gonalds in both species mostly around new and full lunar phases suggests that spawning is at least weakly synchronized with moon phase. Fecundity estimates disclosed the following nonsignificant differences between sites for P. gigantea, expressed as egg production cm^-2 colony surface surface yr^-1: Galápagos (10 300 to 30 800), Uva Island (4900 to 9800), Caño Island (1800 to 7400), Saboga Island (600 to 1300) Taboga Island (1200 to 2400). Fecundity estimates for G. planulata were considerably lower: Uva Island (700 to 1400), Caño Island (500 to 1000). The sexual recruitment of P. gigantea into El Niño-Southern Oscillation (ENSO) 1982–1983-disturbed, equatorial eastern Pacific coral communities has been low, with only moderate recovery evident since 1983. G. planulata has revealed no sexual recruitment where seed populations are absent or rare (Caño Island, Galápagos Islands), and only low recruitment (Panamá) in areas with colonies that survived the ENSO disturbance.     

Suspected flunixin poisoning of a wild Eurasian Griffon Vulture from Spain

Exposure to residues of the nonsteroidal anti‐inflammatory drug (NSAID) diclofenac present in livestock carcasses has caused extensive declines in 3 Gyps vulture species across Asia. The carcass of a wild Eurasian Griffon Vulture (Gyps fulvus) was found in 2012 on an Andalucian (Spain) game hunting reserve and examined forensically. The bird had severe visceral gout, a finding consistent with Gyps vultures from Asia that have been poisoned by diclofenac. Liver and kidney samples from this Eurasian Griffon Vulture contained elevated flunixin (an NSAID) levels (median = 2.70 and 6.50 mg/kg, respectively). This is the first reported case of a wild vulture being exposed to and apparently killed by an NSAID outside Asia. It is also the first reported instance of mortality in the wild resulting from environmental exposure to an NSAID other than diclofenac. Caso de Sospecha de Envenenamiento por Flunixin de un Buitre Leonado en España     

Stable isotope ratios of a tropical marine predator: confounding effects of nutritional status during growth

Stable isotope analysis of carbon and nitrogen is frequently used to study the diets and foraging ecology of marine predators. However, isotopic values may also be affected by an individual’s nutritional status and associated physiological processes. Here, we use C and N stable isotopes in blood and feathers of blue-footed booby chicks at the Galápagos Islands to examine how isotopic values are related to body condition and growth rate, and to assess the consistency in the isotope ratios of individuals during growth. Size dimorphism in blue-footed boobies provided an additional opportunity to examine how isotope ratios differ between sexes in relation to body size and growth rate. There was no significant difference between sexes but both C and N stable isotopes were significantly negatively related to the body condition of chicks. These data were consistent with individual variation in physiological processes affecting fractionation, although we cannot rule out the possibility that they were also influenced to some extent by population-level variation in the stable isotope ratios of prey fed to chicks, for instance related to prey size, depth or lipid content. Our results highlight the need for methods that take proper account of confounding physiological factors in isotopic studies of foraging ecology and diet.     

Heavy metals in the Sea-Skater Halobates robustus from the Galápagos Islands: Concentrations in nature and uptake experiments,with special reference to cadmium

Samples of Halobates robustus Barber (Heteroptera: Gerridae) from the Galápagos Islands were analysed by optical emission spectrometry. The levels (in g g^-1 dry weight) of Zn (134), Cu (155), Pb (< 1), Cd (7), and Cr (3) were not significantly different among insects of different sexes or developmental stages. The low natural levels of Cd in H. robustus from the relatively unpolluted environment of the Galápagos Islands are compared to the high concentrations of Cd in Halobates spp. from relatively polluted regions. Since the measured levels of Cd in their natural zooplankton food rarely exceed 10 g g^-1, and very little of the Cd is found in the soft tissues, the high Cd concentrations (100 to 200 g g^–1) in some seaskater species have evidently been derived by drinking from the surface microlayer of the seawater.     

Allozymes and morphometric characters of three species ofMytilus in the Northern and Southern Hemispheres

Many authors have considered the common mussels in temperate waters of the Northern and Southern Hemispheres to be a single cosmopolitan species,Mytilus edulis Linnaeus, 1758. Others have divided these mussels into several subspecies or species. Samples of mussels were collected from 36 locations in the Northern Hemisphere and nine locations in the Southern Hemisphere. Electrophoretic evidence from eight loci indicates that the Northern Hemisphere samples consist of three electrophoretically distinguishable species:M. edulis from eastern North America and western Europe;M. galloprovincialis Lamarck, 1819 from the Mediterranean Sea, western Europe, California, and eastern Asia; andM. trossulus Gould, 1850 from the Baltic Sea, eastern Canada, western North America and the Pacific coast of Siberia. Mussels from Chile, Argentina, the Falkland Islands and the Kerguelen Islands contain alleles characteristic of all three Northern Hemisphere species, but because they are most similar toM. edulis from the Northern Hemisphere, we suggest that they tentatively be included inM. edulis. These South American samples are morphologically intermediate between Northern HemisphereM. edulis andM. trossulus. Mussels from Australia and New Zealand are similar in allele frequency and morphometric characters toM. galloprovincialis from the Northern Hemisphere. FossilMytilus sp. are present in Australia, New Zealand and South America, which suggests that the Southern Hemisphere populations may be native, rather than introduced by humans. Morphometric characters were measured on samples which the allozyme data indicated contained a single species. Canonical variates analysis of the morphometric characters yields functions which distinguish among our samples of the species in the Northern Hemisphere.     

Multiple Lineages of Avian Malaria Parasites (Plasmodium) in the Galapagos Islands and Evidence for Arrival via Migratory Birds

Haemosporidian parasites in the genus Plasmodium were recently detected through molecular screening in the Galapagos Penguin (Spheniscus mendiculus). We summarized results of an archipelago‐wide screen of 3726 endemic birds representing 22 species for Plasmodium spp. through a combination of molecular and microscopy techniques. Three additional Plasmodium lineages were present in Galapagos. Lineage A–infected penguins, Yellow Warblers (Setophaga petechia aureola), and one Medium Ground Finch (Geospiza fortis) was detected at multiple sites in multiple years. The other 3 lineages were each detected at one site and at one time; apparently, they were transient infections of parasites not established on the archipelago. No gametocytes were found in blood smears of infected individuals; thus, endemic Galapagos birds may be dead‐end hosts for these Plasmodium lineages. Determining when and how parasites and pathogens arrive in Galapagos is key to developing conservation strategies to prevent and mitigate the effects of introduced diseases. To assess the potential for Plasmodium parasites to arrive via migratory birds, we analyzed blood samples from 438 North American breeding Bobolinks (Dolichonyx oryzivorus), the only songbird that regularly migrates through Galapagos. Two of the ephemeral Plasmodium lineages (B and C) found in Galapagos birds matched parasite sequences from Bobolinks. Although this is not confirmation that Bobolinks are responsible for introducing these lineages, evidence points to higher potential arrival rates of avian pathogens than previously thought. Linajes Múltiples de Parásitos de Malaria Aviar (Plasmodium) en las Islas Galápagos y Evidencia de su Arribo por Medio de Aves Migratorias