Recent Submissions

  • Gizzard contents of the Smooth-billed Ani Crotophaga ani in Santa Cruz, Galapagos Islands, Ecuador

    Connett, Lillian; Guézou, Anne; Herrera, Henri W.; Carrión, Victor; Parker, Patricia G.; Deem, Sharon L. (2016-10)
    The Smooth-billed Ani Crotophaga ani was introduced to the Galapagos archipelago in the 1960s, since when its population has grown significantly. We studied the dietary items in the gizzards of 56 anis sampled on the island of Santa Cruz. We confirmed that the diet of C. ani consists primarily of invertebrates and plant material, including native species and non-native invasives. The second most abundant seed in the anis’ diet was that of the highly invasive plant, Rubus niveus. Our findings suggest that C. ani poses a threat to the Galapagos ecosystem by dispersing seeds of non-native plants and by competing with other insectivorous species on the islands. Furthermore, the discovery of a Darwin’s Finch nestling in the gizzard of one C. ani establishes direct predation by this species on native birds.
  • Back page of no. 68, 2016

    Fundacion Charles Darwin Foundation (2016-10)
    Instructions for Authors. Back cover with map.
  • The history of Prothonotary Warbler in the Galapagos Islands

    Jiménez-Uzcátegui, Gustavo (2016-10)
    The first and second records of Prothonotary Warbler Protonotaria citrea in Galapagos are clarified.
  • The biology of an isolated population of the American Flamingo Phoenicopterus ruber in the Galapagos Islands

    Tindle, Robert W.; Tupiza, Arnaldo; Blomberg, Simon P.; Tindle, L. Elizabeth (2016-10)
    A genetically and morphologically divergent population of c. 500 American Flamingos, isolated from the parental Caribbean stock of Phoenicopterus ruber, occurs in the Galapagos archipelago. Based primarily on data from a 3-year study, we provide the first description of the feeding and breeding biology of this population. Galapagos provides a suitable habitat comprising lagoons on a number of islands, among which the flamingos travel in response to food and nest site availability. We identify putative food items. The occurrence and quantity of some food species was associated with the chlorosity of lagoon water, as was the distribution of flamingos. The flamingos bred opportunistically at five lagoons on four islands, sometimes simultaneously on more than one island. Group display usually involved = 20 birds, and colonies contained as few as three nests. Laying occurred during nine months of the year, mainly August–January, coinciding with the coastal drier season and low lagoon water levels. On average c.30% of all adults incubated clutches each year, producing 0.37 fledglings per clutch. Recruitment is probably sufficient to sustain the population, which has been stable over at least c. 45 years, and is probably limited by suitable habitat. Moult to flightlessness was recorded among adults. We review potential dangers to this unique population and suggest conservation measures.
  • Alf Wollebæk and the Galapagos archipelago’s first biological station

    Grant, K. Thalia; Estes, Gregory B. (2016-10)
    Much has been written on the human history of Floreana Island, but the story of its oldest standing building, a lava house in Post Office Bay, has remained untold. We determined, and demonstrate with photographs, that the structure, now 90 years old, was once a biological station: the archipelago’s first. It was built by the 1925 Norwegian Zoological Expedition to the Galapagos Islands, led by Alf Wollebæk, then director of the Natural History Museum of the University of Oslo. The Galapagos portion of the expedition, which was preceded by short explorations of the West Indies and Colombia, spanned five months and five islands, and resulted in the collection of more than 500 biological specimens, the publication of over 20 articles and books, and the discovery or reclassification of several species, most notably the Galapagos Sealion Zalophus wollebaeki. Wollebæk’s accounts of the expedition were written in Norwegian, and are not well known outside Scandinavia. We provide a brief account of the expedition, a summary of Wollebæk’s observations in the Galapagos, and a history of the biological station that Wollebæk and his assistant, Erling Hansen, built.
  • Some off-shore marine species coming to light in Galapagos, Ecuador

    Manning, Cynthia M. (2016-10)
    With the recent deployment of a Phantom XTL remotely operated submarine vehicle (ROV) with video camera it has been possible to investigate the Galapagos inshore marine environment below SCUBA-diving limits, between 40 and 150 m depth. Video recordings are rare of species at these depths and are shedding light on the presence, abundance and behavior of various species. The side-gilled opisthobranch mollusk Berthella californica and a nudibranch Flabellina sp. were recorded at depths where they had not previously been seen in Galapagos. Other species fi lmed by the ROV may be new records for the archipelago such as a squat lobster Munida sp. and an octocorallian of the family Aquaumbridae. Several other octocorallians, including Virgularia cf. galapagensis, Cavernulina cf. darwini and Ptilosarcus cf. undulatus, rarely seen since 1984, were recorded. The Sideblotch Bass Serranus stilbostigma has now been identified in seven new sites throughout the archipelago.
  • Status of two species of tilefish, Caulolatilus princeps (jenyns) and C. hubbsi dooley, originally described from the Galapagos Islands

    Lea, Robert N.; Feeney, Richard F. (2016-10)
    We re-examine the characters and character states used to differentiate Caulolatilus hubbsi from C. princeps and find that they are continuously variable, subjective, arbitrary and non-informative. We conclude that C. hubbsi is a junior synonym of C. princeps.
  • The spider Theridion melanostictum (Araneae,Aheridiidae), a recent introduction to Galapagos?

    Baert, Léon; Van Keer, Johan; Wauters, Nina (2016-10)
    The theridiid spider Theridion melanostictum O. Pickard-Cambridge 1876 is reported as a possible recent introduction to Galapagos, having been found only in samples from Santa Cruz Island collected from 2010 onwards.
  • Rapid seafloor mapping of the northern Galapagos Islands, Darwin and Wolf

    Peñaherrera-Palma, César; Harpp, Karen; Banks, Stuart (2016-10)
    Darwin and Wolf are the most remote of the Galapagos islands and are famous for their remarkable pelagic and benthic marine species abundance and diversity. However, little is known about their surrounding bathymetry. Rapid surveys were carried out in 2008 and 2009 to collect geo-referenced depth soundings down to 100 m around both islands, as a step towards a better understanding of their habitat and species distribution. Five spatial interpolation methods were tested on the data, to find the most accurate. The Triangular Irregular Network (TIN) was the best interpolator for these data sets with the fewest interpolation errors, and was then used to create contour and three dimensional maps of the seafloor topography of both islands. Darwin has a bigger insular platform with gentle submarine slopes whereas Wolf has very steep slopes with a smaller platform.
  • Front pages with contents of no. 68, 2016

    Fundacion Charles Darwin Foundation (2016-10)
  • Back pages of No. 66, 2009.

    Fundación Charles Darwin Foundation (2009-06)
  • Forty years of paleoecology in the Galapagos

    Bush, M.B.; Colinvaux, P.A.; Steinitz-Kannan, M.; Overpeck, J.T.; Sachs, J.; Cole, J.; Collins, A.; Conroy, J.; Restrepo, A.; Zhang, Z. (2010-10)
    The Galapagos Islands provided one of the first lowland paleoecological records from the Neotropics. Since the first cores were raised from the islands in 1966, there has been a substantial increase in knowledge of past systems, and development of the science of paleoclimatology. The study of fossil pollen, diatoms, corals and compound-specific isotopes on the Galapagos has contributed to the maturation of this discipline. As research has moved from questions about ice-age conditions and mean states of the Holocene to past frequency of El Niño Southern Oscillation, the resolution of fossil records has shifted from millennial to sub-decadal. Understanding the vulnerability of the Galapagos to climate change will be enhanced by knowledge of past climate change and responses in the islands.
  • Unnatural selection in Galapagos : the role of disease in Darwin’s Finches (Geospizinae)

    Deem, Sharon L.; Blake, Stephen; Miller, R. Eric; Parker, Patricia G. (2010-10)
    Micro-evolutionary studies, such as those of Darwin’s finches (Geospizinae), have been used as indicators of rates of evolution under natural selection. Today however, such studies may be compromised by unnatural selection. Recently introduced infectious and parasitic agents in Galapagos may hamper our ability to monitor natural evolutionary change in endemic birds, by modifying such change. The opportunity to study natural selection in its iconic site may thus be lost, due to these and other forms of human environmental alteration, which may be replacing non-anthropogenic factors as the principal driver of evolution. To ensure that natural selection continues to shape the biota of Galapagos, anthropogenic impacts including introduced diseases must be managed effectively.
  • Climate and oceanography of the Galapagos in the 21st century : expected changes and research needs

    Sachs, Julian P.; Ladd, S. Nemiah (2010-10)
    With the likelihood that carbon dioxide and other greenhouse-gas levels in the atmosphere will continue to increase for the next decades, and that the planet as a whole will likely warm as a result, we expect the oceanography and climate of the Galapagos to change. Based on an analysis of observational studies and climate models, the main changes are likely to include higher sea-surface temperatures, continued El Niño and La Niña events, some of which will be intense, a rise in sea level of several cm, increased precipitation, lower surface ocean pH, and a reduction in upwelling. These changes will likely alter the marine and terrestrial ecosystems of the Galapagos in ways that are difficult to predict. Major uncertainties exist concerning the relationship between the expected regional changes in ocean temperatures, precipitation, upwelling and seawater pH that most climate models consider, and the local changes in the Galapagos Islands.
  • Characterizing the Galapagos terrestrial climate in the face of global climate change

    Trueman, Mandy; d’Ozouville, Noémi (2010-10)
    The position of Galapagos in the Eastern Pacific gives it a unique seasonal climate that is atypical of other equatorial oceanic islands. Conditions are influenced by the interaction of ocean currents and winds, governed by the movement of the Inter-Tropical Convergence Zone, and by the periodic Pacific-wide El Niño Southern Oscillation. Weather data from 1959 to 2009 on Santa Cruz Island show that the hot season prevails from January to May, characterized by elevated sea and air temperatures and highly variable rainfall. During the cool season, from June to December, cooler temperatures and a stratus cloud layer persist, resulting in relatively consistent precipitation in the humid highlands and almost none in the dry lowlands. Hot season rainfall totals are strongly correlated with sea surface temperature, whereas cool season rainfall totals are consistent from year to year, and not so closely correlated with sea surface temperature. Seasonal rainfall totals from ten locations on six islands show correlations among the majority of sites for the hot season but fewer for the cool season, one exception being the correlation between sites on Santa Cruz Island, all of which receive at least some cool-season precipitation. Biological productivity in the dry lowlands is primarily influenced by the variable hot-season rainfall. The humid highlands are maintained by more consistent precipitation every year in the cool season, but are also affected by conditions during the hot season. We suggest that the dry zone is vulnerable to a warmer, wetter climate which would favour invasive species and thereby doubly threaten aridadapted endemic species. Potential climate change impacts on the already-invaded and more species-rich humid highlands are harder to predict due to our lack of understanding of cool-season precipitation patterns. In order to understand spatial climate variability in Galapagos better, there remains a need for meteorological data with a greater spatial spread throughout the islands, especially at higher altitudes.
  • Galapagos does not show recent warming but increased seasonality

    Wolff, Matthias (2010-10)
    Recent literature postulates that Galapagos follows global warming, with an increase in sea surface temperature (SST) and frequency and amplitude of El Niño events. However, pronounced La Niña conditions over the last decade gave rise to the question of whether the “ocean thermostat model”, according to which heating of the tropics may lead to an increase in the temperature gradient across the equatorial Pacific, enhancing upwelling and surface cooling, may better describe what has recently occurred in the Eastern Tropical Pacific (ETP). A 44-year time series of measurements of SST, air temperature and rainfall taken on the Galapagos island of Santa Cruz revealed that Galapagos monthly mean SSTs have shown no pronounced trend, while annual rainfall has increased. Mean warm and cool season temperatures have slightly increased and decreased respectively, thereby increasing seasonality. Galapagos SST data did not correlate linearly with annual rainfall, which suggests that the latter is not a reliable proxy for reconstructing past SST trajectories. When compared with those of several ETP sites, the Galapagos SST series best correlates with those of Puerto Chicama (coastal Peru, 8°S) and Cocos Island (5°N). The Puerto Chicama time series, the longest available (1925–2006), showed a negative SST trend. Annual deviations in Galapagos SST from the trend line lie between the Chicama and Cocos Island curves, and follow the El Niño signals of the Chicama series in 1983, 1987, 1992 and 1997 more closely than the Cocos series. The Humboldt Current system coupled with the El Niño Southern Oscillation may be the main driver of interannual and interdecadal changes in the Galapagos climate. Since upwelling within the Humboldt Current has increased during the last decade of extended La Niña conditions, it is no surprise that the Galapagos climate has shown the same signal.
  • Possible effects of climate change on the populations of Galapagos pinnipeds

    Salazar, Sandie; Denkinger, Judith (2010-10)
    The future of Galapagos Sea Lion Zalophus wollebaeki and Galapagos Fur Seal Arctocephalus galapagoensis populations was evaluated with reference to a conservative model of predicted climate change. Populations of both species will decrease during strong El Niño events and disease outbreaks will likely increase. Fur Seals may be exposed to a high risk of extinction if thermocline depth increases during extended warming events, since they can feed only near the surface and depend on upwelling. While predictions of the oceanographic conditions around Galapagos for the next 50 years remain uncertain, the combination of climate change and other human-induced threats (disease, disturbance, massacres and pollution) increases the need for conservation measures to protect these animals and their ecosystem.
  • Morphological variation of Galapagos island populations of the Yellow Warbler Dendroica petechia aureola

    Browne, Robert A.; Collins, Elizabeth I.; Anderson, David J. (2010-10)
    Culmen (beak) length and width, wing length and body mass varied significantly among six Galapagos island populations of the Yellow Warbler Dendroica petechia aureola. Culmen length and body mass were also significantly different between Galapagos and North American populations of D. petechia. Morphological differences among island populations of D. p. aureola may be related to resource variability and the presence of different bird species on different islands.
  • A pilot survey of the central colony of the Waved Albatross Phoebastria irrorata on Española Island

    Gibbs, James P.; Woltz, Hara W. (2010-10)
    Española Island is the main breeding site of the Waved Albatross Phoebastria irrorata but little is known of the nesting populations other than those at Punta Cevallos and Punta Suárez. In May 2008 we located nesting albatrosses from nearly the top of the island to the south coast (the “Central Colony”), including in areas not previously reported. We found evidence of a strong interaction between the distribution of woody vegetation and nesting albatrosses. Many albatrosses nest in areas too overgrown to fly into, and walk long distances to and from more open take-off and landing points. Tortoises facilitate albatross movement and nesting by creating trails that albatrosses use. The need remains for a comprehensive estimate of albatross population size and distribution that includes both coastal and inland populations.
  • First inventory of ants (Hymenoptera: Formicidae) on Baltra Island, Galapagos

    Herrera, Henri W.; Causton, Charlotte E. (2010-10)
    Baltra Island is vulnerable to ant invasions because it is one of the principal ports of entry to the Galapagos archipelago. In spite of this, little was known about its ant fauna. We present 13 new records of ants for Baltra collected during 2005 and 2006: Tapinoma melanocephalum, Camponotus planus, Paratrechina longicornis, Paratrechina sp., Monomorium destructor, M. floricola, Pheidole sp., Solenopsis geminata, S. globularia pacifica, Tetramorium bicarinatum, T. lanuginosum and T. simillimum. In addition to this, we report a new species for Galapagos: Monomorium sp. nr. pharaonis. S. geminata and M. destructor are considered threats to native fauna

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