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At least 55 records · Page 3Linked to original sources
USGS2003

A genetic study to aid in restoration of murres, guillemots and murrelets to the Gulf of Alaska

Genetic data are needed to aid in restoring several species of seabirds to the Gulf of Alaska. We analyzed sequence variation in mitochondrial DNA, microsatellite DNA and nuclear introns in samples of commom murres ( Uria aalge ), pigeon guillemots ( Cepphus columba ) and marbled murrelets ( Brachyramphus marmoratus ) from throughout the North Pacific. Data were analyzed using traditional approaches, nested clade analyses and assignment tests. No cryptic species were found, and there was no strong evidence for inbreeding, low genetic variation, or souce or sink regions in any them. Pacific common murres constitute a single genetic management unit (MU), but hybridization occurs between common and thick-billed murres ( U. lomvia ). In contrast, gene flow in pigeon guillemots is very restricted and population genetic structure is very strong; guillemots from the spill area are part of a MU that extends from the Alaska Peninsula to somewhere between Prince William Sound and Vancouver Island. Marbled murrelets in the spill area are part of a MU that extends from the Alaska Peninsula to at least British Columbia; tree- and ground-nesting murrelets are not genetically differentiated. Little if any hybridization occurs between marbled and Kittlitz's murrelets.

Alaska↗
USGS2005

Population genetic structure and conservation of marbled murrelets ( Brachyramphus marmoratus )

Marbled murrelets ( Brachyramphus marmoratus ) are coastal seabirds that nest from California to the Aleutian Islands. They are declining and considered threatened in several regions. We compared variation in the mitochondrial control region, four nuclear introns and three microsatellite loci among 194 murrelets from throughout their range except Washington and Oregon. Significant population genetic structure was found: nine private control region haplotypes and three private intron alleles occurred at high frequency in the Aleutians and California; global estimates of FST or ??ST and most pairwise estimates involving the Aleutians and/or California were significant; and marked isolation-by-distance was found. Given the available samples, murrelets appear to comprise five genetic management units: (1) western Aleutian Islands, (2) central Aleutian Islands, (3) mainland Alaska and British Columbia, (4) northern California, and (5) central California.

Conservation Genetics↗
USGS2005

Characteristics of diving in radio-marked Xantus's Murrelets

We monitored diving activity of radio-marked Xantus's Murrelets Synthliboramphus hypoleucus near Anacapa Island, California, during the breeding season. Thirteen radio-marked murrelets were remotely monitored from Anacapa Island with a handheld antenna and radio receiver for 29 hours in three sample periods in April and May 2003. Mean dive durations in the sample periods were 18 s ?? 2 s, 28 s ?? 2 s, and 24 s ?? 4 s, suggesting that dives were less than 21 m from the surface. Dive duration and subsequent time on the surface differed between the sample periods. Dive duration and subsequent time on the surface were not correlated in observations stratified by individual bird or by sample period. Further, dive duration and subsequent time on the surface were not correlated within foraging bouts. Dive characteristics measured near Anacapa Island suggested that Xantus's Murrelets have the ability to capture prey found at varying depths, but will feed on prey that is most available near the surface of the water.

Marine Ornithology: Journal of Seabird Research an↗
USGS2000

Activity patterns of marbled murrelets in Douglas-fir old-growth forests of the Oregon Coast Range

We monitored activity patterns of Marbled Murrelets ( Brachyramphus marmoratus ) on a near-daily basis using audio-visual surveys during three breeding seasons at five forest stands in the Oregon Coast Range. Three measures of activity were recorded: number of daily detections, number of daily vocalizations, and duration of daily activity. Each measure was highly variable within and among stands and years, and we recorded greater variability than has been previously reported for this species. The three measures of activity were strongly correlated within a day at each survey station, but correlative relationships at temporal and spatial scales greater than this were inconsistent. Activity varied greatly from one day to the next during all portions of the breeding season, and we did not identify any month when variability in activity was consistently higher or lower than any other month. Multivariate analyses revealed that weather and date variates explained little of the variability in daily activity. Given the extreme levels of variability in Marbled Murrelet activity and our lack of understanding as to which factors drive that variability, it is critical that conclusions about activity or behavior not be drawn from data sets not specifically designed to answer the questions of interest.

Oregon↗
USGS1999

Diving and foraging patterns of Marbled Murrelets (Brachyramphus marmoratus): Testing predictions from optimal-breathing models

The diving behavior of Marbled Murrelets (Brachyramphus marmoratus) was studied using telemetry along the Oregon coast during the 1995 and 1996 breeding seasons and examined in relation to predictions from optimal-breathing models. Duration of dives, pauses, dive bouts, time spent under water during dive bouts, and nondiving intervals between successive dive bouts were recorded. Most diving metrics differed between years but not with oceanographic conditions or shore type. There was no effect of water depth on mean dive time or percent time spent under water even though dive bouts occurred in depths from 3 to 36 m. There was a significant, positive relationship between mean dive time and mean pause time at the dive-bout scale each year. At the dive-cycle scale, there was a significant positive relationship between dive time and preceding pause time in each year and a significant positive relationship between dive time and ensuing pause time in 1996. Although it appears that aerobic diving was the norm, there appeared to be an increase in anaerobic diving in 1996. The diving performance of Marbled Murrelets in this study appeared to be affected by annual changes in environmental conditions and prey resources but did not consistently fit predictions from optimal-breathing models.

Canadian Journal of Zoology↗
USGS2014

Fatal paralytic shellfish poisoning in Kittlitz's Murrelet ( Brachyramphus brevirostris ) nestlings, Alaska, USA

Paralytic shellfish poisoning (PSP) is an acute toxic illness in humans resulting from ingestion of shellfish contaminated with a suite of neurotoxins (saxitoxins) produced by marine dinoflagellates, most commonly in the genus Alexandrium . Poisoning also has been sporadically suspected and, less often, documented in marine wildlife, often in association with an outbreak in humans. Kittlitz's Murrelet ( Brachyramphus brevirostris ) is a small, rare seabird of the Northern Pacific with a declining population. From 2008 to 2012, as part of a breeding ecology study, multiple Kittlitz's Murrelet nests on Kodiak Island, Alaska, were monitored by remote cameras. During the 2011 and 2012 breeding seasons, nestlings from several sites died during mild weather conditions. Remote camera observations revealed that the nestlings died shortly after consuming sand lance ( Ammodytes hexapterus ), a fish species known to biomagnify saxitoxin. High levels of saxitoxin were subsequently documented in crop content in 87% of nestling carcasses. Marine bird deaths from PSP may be underreported.

Alaska↗
USGS1991

A comparison of aerial and boat-based surveys for marbled murrelets in southeast Alaska, July 23-28, 1991

Aerial and boat-based surveys for Marbled Murrelets ( Brachyramphus marmoratus ) were conducted simultaneously over short transect distances (ca. 2 km) in three different areas of the Alexander Archipelago to assess the accuracy and variability of aerial counts compared to boat-based counts. Additional aerial surveys were conducted over a wider geographic area to assess temporal and spatial variability of murrelet aggregations.

Alaska↗
USGS1995

Ecology and conservation of the Marbled Murrelet in North America: An overview

Over the past decade, the Marbled Murrelet has become a focus of much controversy. It was listed as threatened in Washington, Oregon, and California by the U.S. Fish and Wildlife Service in February 1993. In order to aid the various agencies with management, the Marbled Murrelet Conservation Assessment was formed to bring together scientists, managers, and others to gather all the available data on this small seabird. This volume of research is the culmination of that effort. In this chapter, we integrate the results of the investigations and summaries on the past history, present status, and possible future of the species, based on the data presented in this volume and other published research. We also propose what we consider the most important research needs. Then, based on the findings of this volume, we suggest actions for management to help ensure the survival of the species.

Book chapter↗
USGS1987

Winter diets of common murres and marbled murrelets in Kachemak Bay, Alaska

Knowledge of the winter diets of seabirds in high latitudes like Alaskan waters has been an elusive aspect of their biology. Scanty information on winter diets of Common Murres ( Uria aalge ) are available from the Pribilof Islands (Preble and McAtee 1923), California (Baltz and Morejohn 1977), Kodiak Island (Kraznow and Sanger 1986), Newfoundland (Tuck 1960), and the North Sea (Blake 1984), and for Marbled Murrelets ( Brachyramphus marmoratus ) from British Columbia (Munro and Clemens 1931, Carter 1984) and Kodiak (Krasnow and sanger 1986). This paper summarizes the diets of these two species, as observed during the winter season of 1977-1978 in Kachemak Bay, Alaska, as a part fo the Alaskan Outer Continental Shelf Environmental Assessment Program, OCSEAP (Sanger and Jones 1982; Krasnow and Sanger 1986; Fukuyama, Sanger, and Hironaka, unpubl.) and provides further interpretation of the data.

Alaska↗
USGS1999

Discovery of a new Kittlitz's murrelet nest: Clues to habitat selection and nest-site fidelity

On 13 June 1993, a new Kittlitz's murrelet ( Brachyramphus brevirostris ) nest was discovered near Red Mountain on the Kenai Peninsula, Alaska. The nest was on a 22° slope at about 900 m elevation with a northeast aspect, and contained a 60.2 × 40.6 mm egg that weighed 49.0 g. Downy feathers and weathered fecal material found at the nest indicated re-use from a previous year, suggesting possible nest site fidelity. The nest was located in an area scoured by winds and free of snow during early spring, suggesting that this may be an important mesoscale factor influencing selection of nesting habitat. Proximity to suitable foraging habitat, particularly sheltered bays and glacial river outflows, may affect breeding habitat choice over larger spatial scales.

Alaska↗
USGS2018

Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data

Habitat models using lidar-derived variables that quantify fine-scale variation in vegetation structure can improve the accuracy of occupancy estimates for canopy-dwelling species over models that use variables derived from other remote sensing techniques. However, the ability of models developed at such a fine spatial scale to maintain accuracy at regional or larger spatial scales has not been tested. We tested the transferability of a lidar-based habitat model for the threatened Marbled Murrelet ( Brachyramphus marmoratus ) between two management districts within a larger regional conservation zone in coastal western Oregon. We compared the performance of the transferred model against models developed with data from the application location. The transferred model had good discrimination (AUC = 0.73) at the application location, and model performance was further improved by fitting the original model with coefficients from the application location dataset (AUC = 0.79). However, the model selection procedure indicated that neither of these transferred models were considered competitive with a model trained on local data. The new model trained on data from the application location resulted in the selection of a slightly different set of lidar metrics from the original model, but both transferred and locally trained models consistently indicated positive relationships between the probability of occupancy and lidar measures of canopy structural complexity. We conclude that while the locally trained model had superior performance for local application, the transferred model could reasonably be applied to the entire conservation zone.

Oregon↗
USGS2025

Laying sequence and oceanographic factors affect egg size in Scripps's Murrelets Synthliboramphus scrippsi at Santa Barbara Island

Egg size is an important avian life history parameter, with larger eggs indicating greater investment of resources in the chick. Prey availability can affect such investment. We investigated the effects of oceanographic conditions and laying sequence on Scripps's Murrelet Synthliboramphus scrippsi egg size at Santa Barbara Island, California during 2009-2017. We evaluated oceanographic covariates characterizing marine productivity for their effect on egg size, including large-scale oceanographic indices such as the Pacific Decadal Oscillation (PDO) index, Oceanic Niño Index (ONI), and North Pacific Gyre Oscillation (NPGO) index. We also evaluated a larval anchovy catch-per-unit-effort (ANCHL) index and the Biologically Effective Upwelling Transport Index (BEUTI) as region-wide indices, and sea surface temperature (SST) as a local index. We evaluated oceanographic conditions over the entire year and during the breeding season only. We also considered the contribution of lagged effects to oceanographic conditions. Our results generally ran counter to our hypothesis that increased ocean productivity should increase egg size. Based on Akaike's Information Criterion, the four top-ranked models provided support for an association between larger eggs and conditions indicative of lower oceanographic productivity, including lower values of BEUTI and NPGO, and higher values of ONI, PDO, and SST. The only result that supported our hypothesis was a positive relationship between ANCHL and egg size, although the 95% confidence interval for the effect included 0. The strongest relationship detected was between laying sequence and egg size, as second eggs were considerably larger than first eggs. Our results indicate substantial complexity in the relationship between ocean productivity and seabird demography. A better understanding of how ocean productivity affects seabird breeding outcomes through multiple mechanisms will help improve predictions of how seabirds will respond to changing ocean conditions.

California↗
USGS2013

Energy cost of vessel disturbance to Kittlitz's Murrelets Brachyramphus brevirostris

We evaluated the energy cost of vessel disturbance for individual Kittlitz’s Murrelets Brachyramphus brevirostris in Glacier Bay National Park and Preserve in Alaska, USA. We used Monte Carlo simulations to model the daily energy expense associated with flight from vessels by both breeding and non-breeding birds and evaluated risk based on both the magnitude of costs incurred and the degree to which the costs may be chronic. We used two scenarios of vessel disturbance for average- and peak-vessel traffic. Because they are more likely to fly away from vessels, non-breeding birds had a greater increase in energy expenditure when disturbed (up to 30% increase under the average scenario and >50% increase under the peak scenario) than breeders (up to 10% and 30% increases under the average and peak scenarios, respectively). Likewise, non-breeding birds were more likely to experience chronic increases in energy expense (i.e. a greater percentage of days with an increase in energy expenditure) than breeding birds. Our modeling results indicated that breeding and non-breeding birds were both susceptible to fitness consequences (e.g. reduced reproductive success and survival) resulting from the energy cost.

Alaska↗
USGS2004

Small boats disturb fish-holding marbled murrelets

Disturbance of seabirds by people at nesting colonies can reduce reproductive success and alter population demographics (Vermeer and Rankin 1984). In response to disturbance, adult seabirds may increase the incidence of alarm postures and alarm calling (Burger and Gochfeld 1993), increase heart and breathing rates (Culik and others 1990; Wilson and others 1991), reduce attendance of nest sites (Olsson and Gabrielsen 1990; Wilson and others 1991), and completely abandon nests and chicks (Boellstorff and others 1988; Evans and Kampp 1991). Daily or frequent handling of chicks can reduce their growth rates and survival (Harris and Wanless 1984; Pierce and Simons 1986; Piatt and others 1990).

Northwestern Naturalist↗
USGS2017

Disturbance of a rare seabird by ship-based tourism in a marine protected area

Managers of marine protected areas (MPAs) must often seek ways to allow for visitation while minimizing impacts to the resources they are intended to protect. Using shipboard observers, we quantified the “zone of disturbance” for Kittlitz’s and marbled murrelets ( Brachyramphus brevirostris and B . marmoratus ) exposed to large cruise ships traveling through Glacier Bay National Park, one of the largest MPAs in North America. In the upper reaches of Glacier Bay, where Kittlitz’s murrelets predominated, binary logistic regression models predicted that 61% of all murrelets within 850 m perpendicular distance of a cruise ship were disturbed (defined as flushing or diving), whereas in the lower reaches, where marbled murrelets predominated, this percentage increased to 72%. Using survival analysis, murrelets in both reaches were found to react at greater distances when ships approached indirectly, presumably because of the ship’s larger profile, suggesting murrelets responded to visual rather than audio cues. No management-relevant covariates (e.g., ship velocity, route distance from shore) were found to be important predictors of disturbance, as distance from ship to murrelet accounted for > 90% of the explained variation in murrelet response. Utilizing previously published murrelet density estimates from Glacier Bay, and applying an average empirical disturbance probability (68%) out to 850 m from a cruise ship’s typical route, we estimated that a minimum of 9.8–19.6% of all murrelets in Glacier Bay are disturbed per ship entry. Whether these disturbance levels are inconsistent with Park management objectives, which include conserving wildlife as well as providing opportunities for visitation, depends in large part on whether disturbance events caused by cruise ships have impacts on murrelet fitness, which remains uncertain.

Alaska↗