Implanted Satellite Transmitters Research Articles

Disparate data streams together yield novel survival estimates of Alaska‐breeding Whimbrels

Survival estimates are critical components of avian ecology. In well‐intentioned efforts to maximize the utility of one's research, survival estimates often derive from data that were not originally collected for survival assessments, and such post hoc analyses may include unintentional biases. We estimated the survival of Whimbrels captured and marked at two breeding sites in Alaska using divergent data streams that in isolation were subject to methodological biases. Although both capture sites were chosen to study the migration ecology of Alaska‐breeding Whimbrels, maximizing the conservation value of the data we collected was obviously desirable. We used multi‐year telemetry information to infer survival from one site (Colville River) and mark–resight techniques to estimate survival from a second site (Kanuti River). At Colville River, we could not feasibly include a control group of birds to assess potential survival effects of externally mounted transmitters, and at Kanuti River we were unable to account accurately for potential emigration events because we used resightings alone. We integrated these datasets in a Bayesian hierarchical framework, an approach that permitted insights across sites that moderated methodological biases within sites. Using telemetry enabled us to detect permanent emigration events from breeding sites in two of 10 birds, results that informed estimates for birds without tracking devices. These datasets yielded point estimates of true survival of Whimbrels from Colville River equipped with solar‐powered satellite transmitters that were higher (0.83) than true survival estimates of Whimbrels from Kanuti River marked with leg flags alone (0.74) or equipped with surgically implanted satellite transmitters (0.50), but the 95% credible intervals on these estimates overlapped across groups. For species such as Whimbrels that are difficult and costly to study, combining information from disparate data streams allowed us to derive novel demographic estimates, an approach with clear application to other similar studies.

Surf Scoters use deeper offshore waters during nocturnal resting periods in the Salish Sea of Washington and British Columbia

Abstract Diurnally biased monitoring and research dominate our ecological understanding and guide conservation and management decisions regarding important indicator sea duck species, such as Surf Scoters (Melanitta perspicillata). Advances in telemetry technology are improving our ability to track wildlife across the entire 24-hr day. Using location data derived from birds with surgically implanted satellite transmitters and habitat layers within a GIS (geographic information system), we analyzed Surf Scoter location data to (1) estimate movement distances between diurnal and nocturnal sites, (2) assess differences in environmental conditions at diurnal and nocturnal use locations, (3) evaluate the environmental conditions influencing nocturnal habitat selection, and (4) develop a predictive model to estimate likely nocturnal resting areas across the Salish Sea, which is composed of the inland marine waters of British Columbia, Canada, and Washington State. Surf Scoters in the Salish Sea traveled an average of 4,287 m between diurnal and nocturnal habitats, but distances varied regionally. We found that distance to shore, water depth, tidal current, and vessel traffic influenced nocturnal habitat use. Surf Scoter nocturnal use sites were characterized by greater distances from shore and deeper water than diurnal locations, although scoters avoided areas with strong tidal currents and heavy shipping traffic at night. The Salish Sea is experiencing increased ship traffic from multiple U.S. and Canadian ports. Oil tanker and shipping container vessel traffic pose a potential threat to nocturnal scoter flocks aggregating in deeper water adjacent to and sometimes overlapping with shipping lanes in narrow, glacial-carved channels of the Salish Sea. Current oil spill response plans in Washington State waters utilize diurnal distribution data, lacking important nocturnal use data. Our findings provide critical nocturnal habitat use information that can improve oil spill response policy and highlight the importance of elucidating nocturnal ecology for marine vertebrate species.

Implanted satellite transmitters affect sea duck movement patterns at short and long timescales

AbstractStudies of the effects of transmitters on wildlife often focus on survival. However, sublethal behavioral changes resulting from radio-marking have the potential to affect inferences from telemetry data and may vary based on individual and environmental characteristics. We used a long-term, multi-species tracking study of sea ducks to assess behavioral patterns at multiple temporal scales following implantation of intracoelomic satellite transmitters. We applied state-space models to assess short-term behavioral patterns in 476 individuals with implanted satellite transmitters, as well as comparing breeding site attendance and migratory phenology across multiple years after capture. In the short term, our results suggest an increase in dispersive behavior immediately following capture and transmitter implantation; however, behavior returned to seasonally average patterns within ~5 days after release. Over multiple years, we found that breeding site attendance by both males and females was depressed during the first breeding season after radio-marking relative to subsequent years, with larger relative decreases in breeding site attendance among males than females. We also found that spring and breeding migrations occurred later in the first year after radio-marking than in subsequent years. Across all behavioral effects, the severity of behavioral change often varied by species, sex, age, and capture season. We conclude that, although individuals appear to adjust relatively quickly (i.e. within 1 week) to implanted satellite transmitters, changes in breeding phenology may occur over the longer term and should be considered when analyzing and reporting telemetry data.

Long Nights, Airplanes, and Avian Surgery: A Tale of Working With Volunteers to Study Long-tailed Ducks (Clangula hyemalis) Wintering on Lake Michigan

Evidence suggests that wintering populations of long-tailed ducks along the Atlantic and Pacific coasts are in decline, but little is known about wintering populations on Lake Michigan. Researchers seek answers to basic questions regarding habitat use and migration patterns (temporal and spatial) of long-tailed ducks that winter on Lake Michigan, by using surgically implanted satellite transmitters. The processes of locating the birds, capturing and implanting satellite transmitters, and interpreting the results were challenging, and efforts relied on dedicated researchers, veterinarians, resource managers, and many volunteers.

Annual cycle of White-winged Scoters (Melanitta fusca) in eastern North America: migratory phenology, population delineation, and connectivity

Understanding full annual cycle movements of long-distance migrants is essential for delineating populations, assessing connectivity, evaluating crossover effects between life stages, and informing management strategies for vulnerable or declining species. We used implanted satellite transmitters to track up to 2 years of annual cycle movements of 52 adult female White-winged Scoters (Melanitta fusca (Linnaeus, 1758)) captured in the eastern United States and Canada. We used these data to document annual cycle phenology; delineate migration routes; identify primary areas used during winter, stopover, breeding, and molt; and assess the strength of migratory connectivity and spatial population structure. Most White-winged Scoters wintered along the Atlantic coast from Nova Scotia to southern New England, with some on Lake Ontario. White-winged Scoters followed four migration routes to breeding areas from Quebec to the Northwest Territories. Principal postbreeding molting areas were in James Bay and the St. Lawrence River estuary. Migration phenology was synchronous regardless of winter or breeding origin. Cluster analyses delineated two primary breeding areas: one molting area and one wintering area. White-winged Scoters demonstrated overall weak to moderate connectivity among life stages, with molting to wintering connectivity the strongest. Thus, White-winged Scoters that winter in eastern North America appear to constitute a single continuous population.

Erratum: Biochemical and clinical responses of Common Eiders to implanted satellite transmitters

Erratum: Biochemical and clinical responses of Common Eiders to implanted satellite transmitters

Biochemical and clinical responses of Common Eiders to implanted satellite transmitters

ABSTRACT Some statistics in “Biochemical and clinical responses of Common Eiders to implanted satellite transmitters” were miscalculated due to missing data. We provide corrected values for the affected variables. Corrected data did not affect the conclusions of the paper.

Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds reduced nesting propensity and might also lead to fertility losses argues against the use of implanted transmitters for studies on breeding biology, and for a careful evaluation of the methodology in studies of migration.

Factors influencing immediate post-release survival of spectacled eiders following surgical implantation of transmitters with percutaneous antennae

Surgically implanted transmitters are a common method for tracking animal movements. Immediately following surgical implantation, animals pass through a critical recovery phase when behaviors may deviate from normal and the likelihood of individual survival may be reduced. Therefore, data collected during this period may be censored to minimize bias introduced by surgery-related behaviors or mortality. However, immediate post-release mortalities negate a sampling effort and reduce the amount of data potentially collected after the censoring period. Wildlife biologists should employ methods to support an animal's survival through this period, but factors contributing to immediate post-release survival have not been formally assessed. We evaluated factors that potentially influenced the immediate post-release survival of 56 spectacled eiders (Somateria fischeri) marked with coelomically implanted satellite transmitters with percutaneous antennae in northern Alaska in 2010 and 2011. We modeled survival through the first 14 days following release and assessed the relative importance and effect of 15 covariates hypothesized to influence survival during this immediate post-release period. Estimated daily survival rate increased over the duration of the immediate post-release period; the probability of mortality was greatest within the first 5 days following release. Our top-ranking model included the effect of 2 blood analytes, pH and hematocrit, measured prior to surgical implantation of a transmitter. We found a positive response to pH; eiders exhibiting acidemia (low pH) prior to surgery were less likely to survive the immediate post-release period. We found a curvilinear response to hematocrit; eiders exhibiting extremely low or high pre-surgery hematocrit were also less likely to survive the immediate post-release period. In the interest of maximizing the survival of marked birds following release, hematological data obtained prior to surgical implantation of telemetry equipment may be useful when screening for optimal surgical candidates or informing appropriate response to mitigate potentially deleterious disorders such as acidemia. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Effects of implanted satellite transmitters on behavior and survival of female common eiders

AbstractSurgically implanted satellite transmitters have been widely used in studies of avian ecology, yet little is known about their potential impacts on birds. We implanted satellite transmitters with percutaneous antennae (approx. 50 g) in 17 female common eiders (Somateria mollissima) at a breeding colony in Arctic Canada. Among females implanted during incubation, 11 of 12 nests were abandoned within 1 week of being radioed. We observed no differences in the proportion of time that implanted female eiders allocated to basic behaviors. Radioed birds were more likely to pick or preen their abdominal (site of surgical incision) and posterior–dorsal (site of antenna exit) regions than unmarked females, although these behaviors were rare (approx. 0.3% of total time budget). Three of 10 females re‐observed had a pronounced limp following surgery, but we observed no walking difficulties among these females in subsequent seasons, and we observed some implanted eiders nesting in subsequent years. Mark–resighting models suggest eiders with transmitters had lower apparent survival the year after implantation (67.0%; 85% CI: 47.8–81.9%) than did color‐banded eiders (87.5%, 85% CI: 82.5–91.2%), but there was no model support for a survival difference in subsequent years. We conclude that transmitter implantation in common eiders leads to short‐term changes in behavior and a decline in first year survival. We encourage researchers to collect similar data on their study subjects where possible and use it to determine the degree to which data are representative of the greater population. © 2011 The Wildlife Society.

Migration patterns, breeding and moulting locations of king eiders wintering in north-eastern Norway

The Norwegian coast is a very important winter area for king eiders (Somateria spectabilis), but their origin has been unknown. We determined spring and autumn migration routes, timing of migration and potential breeding areas of king eiders wintering in north-eastern Norway using implanted satellite transmitters. Five males and five females were equipped with transmitters in February 2008, and location data were received from six birds. All birds departed within 10 days in mid April and flew to the Pechora Sea and Kara Sea in western Russia where they staged until mid June. Subsequently, four of five birds with active transmitters (two females and two males) moved east to potential breeding locations on the Gydan and Taymyr Peninsulas. In early July, the males moved west to moult at Kolguyev Island and in the Pechora Sea. The two females departed in mid July, one probably moulting between the gulfs of the Ob and Yenisei Rivers, after which it moved to the Pechora Sea. The other female probably moulted in the eastern Taymyr, thereafter moving to Novaya Zemlya. This female returned to the north-eastern coast of Norway 1 December, while the other female returned 2 January. For the males, the transmitters stopped in December/January when they were still in the Pechora/Kolguyev area. King eiders wintering in north-eastern Norway thus originate from the western half of Arctic Russia, and the Taymyr Peninsula is probably the dividing point between the eastern and western flyways.

Post-Fledging Movements of Juvenile Common Mergansers(Mergus merganser)in Alaska as Inferred by Satellite Telemetry

Abstract We implanted satellite transmitters into eight juvenile Common Mergansers to investigate post-fledging movements from their natal river in southcentral Alaska. Subsequently, they moved widely throughout portions of western and southcentral Alaska up to 750 km from their natal areas during fall and winter months. Transmitters of two birds (one male and one female) continued to send location data into their second year and allowed us to determine the location and timing of the flightless molt period for each bird. Overall, our data suggest that juvenile Common Mergansers range widely immediately after fledging, that second year males and females may differ in their movement patterns, and that these movements have implications for population genetic structure of this species.

MOVEMENTS OF LONG-TAILED DUCKS WINTERING ON LAKE ONTARIO TO BREEDING AREAS IN NUNAVUT, CANADA

Abstract We used implanted satellite transmitters to track the northbound (spring) and southbound (fall) migration and possible breeding locations of three Long-tailed Ducks (Clangula hyemalis) wintering on western Lake Ontario in Ontario, Canada. The birds exhibited short, rapid migration movements punctuated by extended periods of up to 30 days at staging areas. For much of the nesting period (∼10 June to 10 July), the birds remained inland of western Hudson Bay in Nunavut. During fall migration, they circumnavigated Hudson Bay to its eastern coast, opposite the coast they had followed in spring, for a mean travel distance of 6,760 km. Identification of these previously unknown, key migration sites fills some important information gaps on Long-tailed Ducks in eastern Canada, and it augments what is known about important coastal marine habitats in the Arctic.

Seasonal Movements and Pelagic Habitat Use of Murres and Puffins Determined by Satellite Telemetry

AbstractWe tracked the movements of Common Murres (Uria aalge), Thick-billed Murres (U. lomvia), and Tufted Puffins (Fratercula cirrhata) using surgically implanted satellite transmitters. From 1994–1996, we tagged 53 birds from two colonies in the Gulf of Alaska (Middleton Island and Barren Islands) and two colonies in the Chukchi Sea (Cape Thompson and Cape Lisburne). Murres and puffins ranged 100 km or farther from all colonies in summer, but most instrumented birds had abandoned breeding attempts and their movements likely differed from those of actively breeding birds. However, murres whose movements in the breeding period suggested they still had chicks to feed foraged repeatedly at distances of 50–80 km from the Chukchi colonies in 1995. We detected no differences in the foraging patterns of males and females during the breeding season, nor between Thick-billed and Common Murres from mixed colonies. Upon chick departure from the northern colonies, male murres—some believed to be tending their flightless young—drifted with prevailing currents toward Siberia, whereas most females flew directly south toward the Bering Sea. Murres from Cape Thompson and Cape Lisburne shared a common wintering area in the southeastern Bering Sea in 1995, and birds from Cape Lisburne returned to the same area in the winter of 1996. We conclude that differences in foraging conditions during summer rather than differential mortality rates in winter account for contrasting population trends previously documented in those two colonies.

SEASONAL MOVEMENTS AND PELAGIC HABITAT USE OF MURRES AND PUFFINS DETERMINED BY SATELLITE TELEMETRY

We tracked the movements of Common Murres (Uria aalge), Thick-billed Murres (U. lomvia), and Tufted Puffins (Fratercula cirrhata) using surgically implanted satellite transmitters. From 1994–1996, we tagged 53 birds from two colonies in the Gulf of Alaska (Middleton Island and Barren Islands) and two colonies in the Chukchi Sea (Cape Thompson and Cape Lisburne). Murres and puffins ranged 100 km or farther from all colonies in summer, but most instrumented birds had abandoned breeding attempts and their movements likely differed from those of actively breeding birds. However, murres whose movements in the breeding period suggested they still had chicks to feed foraged repeatedly at distances of 50–80 km from the Chukchi colonies in 1995. We detected no differences in the foraging patterns of males and females during the breeding season, nor between Thick-billed and Common Murres from mixed colonies. Upon chick departure from the northern colonies, male murres—some believed to be tending their flightless young—drifted with prevailing currents toward Siberia, whereas most females flew directly south toward the Bering Sea. Murres from Cape Thompson and Cape Lisburne shared a common wintering area in the southeastern Bering Sea in 1995, and birds from Cape Lisburne returned to the same area in the winter of 1996. We conclude that differences in foraging conditions during summer rather than differential mortality rates in winter account for contrasting population trends previously documented in those two colonies.

At-Sea Distribution of Spectacled Eiders: A 120-Year-Old Mystery Resolved

The at-sea distribution of the threatened Spectacled Eider (Somateriafischeri) has remained largely undocumented. We identified migration corridors, staging and molting areas, and wintering areas of adult Spectacled Eiders using implanted satellite transmitters in birds from each of the three extant breeding grounds (North Slope and Yukon-Kuskokwim Delta in Alaska and arctic Russia). Based on transmitter locations, we conducted aerial sur- veys to provide visual confirmation of eider flocks and to estimate numbers of birds. We identified two principal molting and staging areas off coastal Alaska (Ledyard Bay and east- ern Norton Sound) and two off coastal Russia (Mechigmenskiy Bay on the eastern Chukotka Peninsula, and the area between the Indigirka and Kolyma deltas in the Republic of Sakha). We estimated that >10,000 birds molt and stage in monospecific flocks at Mechigmenskiy and Ledyard bays, and several thousand molt and stage in eastern Norton Sound. We further identified eastern Norton Sound as the principal molting and staging area for females nest- ing on the Yukon-Kuskokwim Delta, and Ledyard Bay and Mechigmenskiy Bay as the prin- cipal molting and staging areas for females nesting on the North Slope. Males marked at all three breeding grounds molt and stage in Mechigmenskiy Bay, Ledyard Bay, and the Indi- girka-Kolyma delta region. Males from the Yukon-Kuskokwim Delta molt and stage mainly at Mechigmenskiy Bay. Equal numbers of males from the North Slope molt and stage at all three areas, and most males from arctic Russia molt and stage at the Indigirka-Kolyma delta region. Postbreeding migration corridors were offshore in the Bering, Chukchi, and Beaufort seas. In winter, eiders were in the Bering Sea south of St. Lawrence Island. Our estimates from surveys in late winter and early spring suggest that at least 333,000 birds winter in

Effect of Implanted Satellite Transmitters on the Nesting Behavior of Murres

We implanted 6 Common Murres (Uria aalge) and 10 Thick-billed Murres (Uria lomvia) with satellite transmitters and compared subsequent presence at the colony, nesting status, and provisioning to a control group that underwent a simple surgical procedure. In the 10 days following implantation, we resighted 10 of 11 control birds at the colony and 6 of 16 implanted birds. Of the birds that returned, 7 of 10 control birds retained breeding status, whereas zero of six implanted birds retained breeding status. We conclude that abdominal implantations alter murre nesting behavior.

Use of Implanted Satellite Transmitters to Locate Spectacled Eiders at-Sea

Population estimates of Spectacled Eiders (Somateria fischeri) on the Yukon-Kuskokwim Delta (YKD), Alaska, suggest that by 1992 the number of birds nesting on this major nesting area had declined to 1,721 pairs, 4% of that estimated in the 1970s (Stehn et al. 1993). Consequently, Spectacled Eiders were listed as threatened under the Endangered Species Act. As nesting habitats for this species are believed to have changed little over the past 100 years, hypotheses concerning the cause of this decline include factors away from nesting areas. The non-nesting distribution of this eider is unknown, but birds are believed to molt and winter in the Bering and Chukchi seas (Dau and Kistchinski 1977). Systematic aerial surveys to locate areas where birds concentrate are expensive because of the vast area to be surveyed and dangerous because of restricted daylight and extreme weather conditions. Surveys from ships along the ice margin in the Bering Sea failed to locate concentrations of birds (Irving et al. 1968, Everett et al. 1989). We initiated a study to determine if at-sea areas used by Spectacled Eiders could be identified using satellite telemetry.