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Jeffrey M Black – 1st expert on this subject based on the ideXlab platform

  • black brant Branta bernicla nigricans forage at both tides on humboldt bay california usa
    Wildfowl, 2013
    Co-Authors: Elizabeth Elkinton, Long Lo, Jeffrey M Black

    Abstract:

    Black Brant Branta bernicla nigricans arrive at their breeding grounds in arctic and subarctic North America and eastern Russia in spring, a time when food resources are limited. They rely largely on energy stores, acquired at staging sites, for migration and to support egg laying and incubation. In California, Humboldt Bay is the most important staging site for Black Brant due to the abundance of Common Eelgrass  Zostera marina along its shores. Access to Common Eelgrass has been assumed to be limited to low tides, when the plants are reachable, and that little feeding occurs at higher tides. We tested this assumption by quantifying Black Brant foraging behaviour throughout the tidal cycle, including in relation to factors that contribute to the occurrence of detached Common Eelgrass leaves, which float to the surface and thus become available to the birds at higher tides. Throughout the winter and spring periods (January–April 2011) Black Brant at Humboldt Bay foraged directly on Common Eelgrass beds during low tides and continued to feed on drifting leaves during higher tides. They switched from bed-feeding to drift-feeding at a mean tide height of 0.9 m. On average, 48% of flock members typically fed when Common Eelgrass beds were reachable during low tides, with 24% of birds feeding on drifting eelgrass during higher tides. The prevalence of drift-feeding declined as the tide level increased in the bay, ranging from 35% of birds at 1 m tides to 10% at 2.5 m tides. The amount of drifting Common Eelgrass available to Black Brant increased with higher maximum wind speeds and greater tidal range in the previous 24 h, and with greater numbers of Black Brant on the bay. By providing current information about foraging strategies and the use of high-tide feeding opportunities, this study can inform future projections of the carrying capacity of Humboldt Bay for staging Brant. This is particularly important in light of projected future impacts of sea level rises on food availability at staging habitats along the Pacific Flyway.

  • Exuberant youth: the example of triumph ceremonies in Barnacle geese (Branta leucopsis)
    Ethology Ecology & Evolution, 1995
    Co-Authors: E. Bigot, Martine Hausberger, Jeffrey M Black

    Abstract:

    A study of a semi-captive Barnacle geese (Branta leucopsis) flock showed clearly that triumph ceremony frequency is related to the age of birds and is highest in young pairs. Females had an active role in that they could encourage or inhibit the male display. Younger females showed more encouraging behaviour than older ones. We argue that triumph ceremonies play a significant part during pair formation and maintenance. Older pairs may need less investment in such displays.

James S Sedinger – 2nd expert on this subject based on the ideXlab platform

  • carryover effects associated with winter location affect fitness social status and population dynamics in a long distance migrant
    The American Naturalist, 2011
    Co-Authors: James S Sedinger, Jason L Schamber, David H Ward, Christopher A Nicolai, Bruce Conant

    Abstract:

    AbstractWe used observations of individually marked female black brant geese (Branta bernicla nigricans; brant) at three wintering lagoons on the Pacific coast of Baja California—Laguna San Ignacio (LSI), Laguna Ojo de Liebre (LOL), and Bahia San Quintin (BSQ)—and the Tutakoke River breeding colony in Alaska to assess hypotheses about carryover effects on breeding and distribution of individuals among wintering areas. We estimated transition probabilities from wintering locations to breeding and nonbreeding by using multistratum robust-design capture-mark-recapture models. We also examined the effect of breeding on migration to wintering areas to assess the hypothesis that individuals in family groups occupied higher-quality wintering locations. We used 4,538 unique female brant in our analysis of the relationship between winter location and breeding probability. All competitive models of breeding probability contained additive effects of wintering location and the 1997–1998 El Nino–Southern Oscillation (…

  • survival and breeding advantages of larger black brant Branta bernicla nigricans goslings within and among cohort variation
    The Auk, 2007
    Co-Authors: James S Sedinger, Nathan D Chelgren

    Abstract:

    Abstract We examined the relationship between mass late in the first summer and survival and return to the natal breeding colony for 12 cohorts (1986-1997) of female Black Brant (Branta bernicla nigricans). We used Cormack-Jolly-Seber methods and the program MARK to analyze capture-recapture data. Models included two kinds of residuals from regressions of mass on days after peak of hatch when goslings were measured; one based on the entire sample (12 cohorts) and the other based only on individuals in the same cohort. Some models contained date of peak of hatch (a group covariate related to lateness of nesting in that year) and mean cohort residual mass. Finally, models allowed survival to vary among cohorts. The best model of encounter probability included an effect of residual mass on encounter probability and allowed encounter probability to vary among age classes and across years. All competitive models contained an effect of one of the estimates of residual mass; relatively larger goslings survived t…

  • early environment and recruitment of black brant Branta bernicla nigricans into the breeding population
    The Auk, 2004
    Co-Authors: James S Sedinger, Mark P Herzog, David H Ward

    Abstract:

    Abstract In geese, growth regulates survival in the first year. We examined whether early growth, which is primarily governed by environmental conditions, also affects the probability that individuals that survive their first year enter the breeding population. We used logistic regression on a sample of Black Brant (Branta bernicla nigricans) that were weighed at a known age in their first summer and observed during winter (indicating that they had survived the principal mortality period in their first year) to study whether early growth influenced the probability that those individuals would be recruited into the breeding population. We also examined the effects of cohort (1986–1996), sex, age when measured, and area where individuals were reared. The model with the lowest Akaike’s Information Criterion score contained body mass, age (days) at measurement, cohort, sex, and brood-rearing area. Models that included variable mass had 85% of the cumulative model weight of the models we considered, indicating…

Lily Montarcih Limantara – 3rd expert on this subject based on the ideXlab platform

  • Optimization of Improvement and Management on Sumber Brantas Watershed, East Java, Indonesia
    , 2020
    Co-Authors: Lily Montarcih Limantara

    Abstract:

    This paper studied the optimization of improvement and management watershed. Location of study was at Sumber Brantas watershed, Malang-East Java Province Indonesia, with area number was 43,529.25 ha. The methodology consisted of erosion analysis and its conservation, and then to analyze run off and optimized erosion due to optimization of land using. Result was used as consideration to improve and manage Sumber Brantas watershed.

  • Evaluation of synthetic rainfall application with respect to the flow volume at upstream Brantas watershed, East Java Province of Indonesia
    Journal of Water and Land Development, 2017
    Co-Authors: Lily Montarcih Limantara, Donny Harisuseno, Rana Karinta Hapsari

    Abstract:

    Indonesian Technical Implementation Unit (UPT) of Synthetic Rainfall has modified climate by generating synthetic rainfall from 9ᵗʰ May until 4ᵗʰ June 2013. This unit has cooperated with the Department of Technological Study and Application (BPPT) of Indonesia and Perum Jasa Tirta I and TNI AU Lanud Abdulrachman Saleh. This study intended to increase reservoirs water level in upstream Brantas watershed, one of them is Sutami reservoir. Successive grade evaluation of synthetic rainfall used the method of Double Ratio and Flow Discharge. The target area is upstream Brantas watershed that is represented by 12 rainfall stations and the control area is in the distance of ±30 km from the boundary of upstream Brantas watershed and is represented by 5 rainfall stations. Results show rainfall increasing by 152.05% according to the Double Ratio method and the increase of flow discharge from Sutami reservoir by 74.19% according to the Flow Discharge method.

  • Conformity evaluation of synthetic unit hydrograph (case study at upstream Brantas sub watershed, East Java Province of Indonesia)
    Journal of Water and Land Development, 2017
    Co-Authors: Dwi Priyantoro, Lily Montarcih Limantara

    Abstract:

    AbstractThis study intends to analyse the suitable hydrograph in upstream Brantas sub watershed. The methodology consists of comparing the result of hydrograph due to the methods of Nakayasu synthetic unit hydrograph (SUH), Limantara synthetic unit hydrograph, and the observed unit hydrograph. In detail, this study intends to know the difference of hydrograph parameters: α and Tg as recommended by Nakayasu and in the study location; to know the influence of main river length which is used in the methods of Nakayasu and Limantara to the time of concentration; to know the hydrograph ordinate deviation between Nakayasu and Limantara due to the observed hydrograph. Result is hoped for recommending the suitable hydrograph in upstream Brantas subwatershed so that it can be used accurately for the further design of water resources structure.