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RESPONDENT
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Richard Lanctot
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SITE NAME
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Barrow, Alaska, USA
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| Contact details
(phone/fax//e-mail//address): |
| 907-786-3609/907-786-3641(f) // richard_lanctot@fws.gov // USFWS, 1011 E. Tudor Road, MS 201 Anchorage, AK 99503, USA
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PROJECT DETAILS |
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Project name:
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Barrow, Alaska, Shorebird Survey
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Start of survey:
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End
of survey: |
Team
size: |
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1.06
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7.09
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4
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WEATHER
CONDITIONS
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| Season phenology: |
average
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Weather conditions: |
| The spring and summer was unusually warm, especially compared to 2003, with no really cold spell. The snow melt was later than in 2003 however. No severe winter storm took place during the field season. Weather data available from NOAA weather station located near Barrow.
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| Date of 50%
snow-cover: |
9.06
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| Date of ice-break on
rivers: |
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| Date of final loss of
snow: |
16.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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The identity of species nesting on or near our plots was similar to that found in 2003, although the number of nests detected was higher in 2004 (total nests was 218 compared to 88). Nests located on our plots included Red Phalarope (REPH, N = 79), Dunlin (DUNL, N = 25), Pectoral Sandpiper (PESA, N = 18), Semipalmated Sandpiper (SESA, N = 10), Long-billed Dowitcher (LBDO, N = 3), Red-necked Phalarope (RNPH, N = 1), and American Golden Plover (AMGP, N = 5). Two additional species were found nesting on our plots in 2004, including White-rumped Sandpiper (WRSA, N = 2) and Western Sandpiper (WESA, N = 1). An additional 21 DUNL, 15 PESA, 1 LBDO, 25 REPH, 6 SESA, 2 WRSA and 4 AMGP nests were located on the periphery of our plots. We believe the increase in nests detected was due to an increase in the number of plots, more intense nest searching, and higher levels of renesting due to high nest predation.
The first shorebird clutch was initiated on 3 June and the last on the 3 July in 2004 (1 day earlier for both dates relative to 2003). Median and peak initiation dates were the 16 June (2 days later than 2003). Nests were initiated first by DUNL, RNPH, WRSA and SESA (median lay dates = 9, 12, 13, and 15 June, respectively), followed by REPH, PESA, WESA and AMGP (17, 18, 19, and 19 June, respectively), and finally LBDO (27 June). This pattern resembles that from 2003. Nest density, calculated as the number of nests found divided by the study area size (= six plots of 36 ha each) was 0.66/ha (compared to 0.51/ha in 2003). Nest density per plot varied from 0.47/ha to 1.0/ha. Predators destroyed 67.9% of the nests in 2004 compared to 42.7% of the nests in 2003. A comparison of nesting success across species indicated hatching success (# hatching at least one young/total number of nests) was highest in DUNL (21.7%, N = 46), followed by PESA (20%, N = 20 after eliminating nests manipulated), SESA (12.5%, N = 16), and REPH (10.6%, N = 104). A similar comparison across study plots indicated plots 1, 2, and 3 had extremely low hatching success (3.2, 4.2 and 11.1%, respectively) compared to that reported in 2003 (52.6, 46.2 and 38.8%, respectively). The three new plots established in 2004 had higher hatching success, ranging from 11.1 to 23.7%. All of these values of hatching success are considerably lower than that reported in 2003 and is likely due to predators switching to shorebirds in what appeared to be a very low lemming year.
Having completed two years of study at this location, we noted a few major differences between years. In 2004, the weather conditions appeared to more favourable for breeding shorebirds as the temperatures were much warmer, allowing a much larger production of insects. These favourable conditions, however, proved to be undone by the extremely low lemming numbers and a much higher predation rate on nests. Indeed, hatching success was considerably lower in 2004 relative to 2003. We also noticed a greater diversity of shorebird species nesting in or near our study plots in 2004 although nesting densities were similar. New species included buff-breasted sandpipers, white-rumped sandpipers and western sandpipers. The other noticeable difference was the increase in the number of renests, probably driven by the extremely high predation rates and the relatively warm summer.
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Rodent dynamics:
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| No capture data. Brown Lemmings were seen at least once on 20 days out of 97 day field season by 5-person crew. Denver Holt, who was studying Snowy Owls in the area, laid out traps to capture small mammals. He indicated this was one of lowest lemming years in 12 years of trapping. Greenland Collared Lemmings were observed on 5 days out of 97 day field season by 5-person crew. Other mammals seen included Polar Bear, Caribou, Arctic Fox, Ringed Seal (Phoca hispida), Short-tailed Weasel (Mustela erminea), Walrus, Beluga, Gray Whale.
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus trimucronatus | rare |
| Dicrostonyx groenlandicus | rare |
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Summary
of fauna studies: |
In 2004, we conducted the second year of a long-term shorebird study at Barrow, Alaska (71.29øN, 156.64øW). The objectives of this study are to (1) collect baseline data on arrival date, nest initiation and effort, clutch and egg size, and hatching success of arctic-breeding shorebirds, (2) to establish a marked population of as many shorebird species as possible that would allow us to obtain estimates of adult survival, mate and site fidelity, and natal philopatry, and (3) to relate weather, predator and prey abundances to shorebird productivity. Data on demographic parameters are vitally needed to understand why many shorebirds are declining.
To increase the sample size of nests found and the number of birds banded, we increased the number of plots sampled in 2004 from 4, 36-ha plots to 6, 36-ha plots. One of the plots sampled in 2003 was abandoned and three additional plots were staked out. As in 2003, two of the original plots were surveyed in the 1970s and 1990s. One of the new plots established in 2004 was located where a new landfill will be built this winter so that we can document how shorebirds respond to landfill construction and general disturbance. We also allowed nest searchers to share information in 2004 and increased the frequency with which they visited plots.
In 2004, we captured and color-marked 158 adults and 143 young. This represents a substantially greater number of marked adults but fewer young relative to 2003. Adults captured included 57 REPH, 60 DUNL, 19 PESA, 11 SESA, 1 LBDO, 1 RNPH, 1 BBSA, 1 WESA, 3 WRSA and 4 AMGP. Chicks banded at nests on our plots included 56 REPH, 40 DUNL, 18 PESA, 15 SESA, 3 WRSA and 2 AMGP. We documented several instances of renesting by marked AMGP, DUNL, SESA and PESA in 2004. We captured 10 DUNL, 2 SESA and 1 REPH that were initially marked in 2003. Other marked birds were resighted but the total number has not been quantified yet.
Three other studies were also occurring at this location. Their summaries follow:
(1) Behavioral Ecology of Pectoral Sandpipers
Investigators: Bart Kempenaers and Kim Teltscher, Max Planck Research Centre for Ornithology, and Richard Lanctot, U.S. Fish and Wildlife Service.
The mating system of the pectoral sandpiper has been described as polygynous, serially polygynous, or promiscuous (Holmes and Pitelka 1998). Males of this sexually dimorphic species defend territories, which range between 4 and 10 ha in size (Holmes and Pitelka 1998). Females visit these areas for mating and may or may not breed within a male's territory; males provide no parental care whatsoever (Pitelka, Holmes et al. 1974; Holmes and Pitelka 1998). Because females have been observed associating with a number of males in close succession (Pitelka, Holmes et al. 1974; Ehrlich 1988), the question arises whether multiple paternity might also occur in this species (i.e., multiple males father offspring in one nest). To date, the lack of marked individuals (especially males) and the absence of genetic analyses have precluded determining the paternity and thus mating system of this species.
In 2004, we began a study in Barrow, Alaska, to investigate the breeding system of the Pectoral Sandpiper. We captured 26 adult males opportunistically using mist nets, sampled blood, and marked them with unique color bands. The territory location of these males and their behavioural interactions with females were monitored. Forty nests were also found, and in most cases the females were captured and blood sampled. Because nest predation was extremely high, we replaced eggs with dummy eggs and artificially incubated the real eggs. Unfortunately, in most cases, predators took even the dummy eggs, requiring us to euthanize the growing embryos. In the end, we were able to gather DNA material from 125 chicks belonging to 35 broods. We recently developed microsatellite primers for this species, and hope to conduct genetic analyses this winter to investigate paternity. Depending on these results, additional studies into the species may be conducted in 2005.
(2) Behavioral Ecology of Semipalmated Sandpipers
Investigators: Bart Kempenaers and Kim Teltscher, Max Planck Research Centre for Ornithology, and Richard Lanctot, U.S. Fish and Wildlife Service
Matings between close relatives often have negative fitness consequences, probably because homozygosity leads to the expression of recessive deleterious alleles. Recent studies of birds and mammals have shown that reproductive success is negatively related to genetic similarity between parents, and that fitness-related traits correlate with individual levels of genetic diversity. These studies strongly suggest that selection favours avoidance of matings with genetically similar individuals. Yet, constraints on social mate choice, such as a lack of alternatives, may lead to pairing with genetically similar mates. It has been suggested that females might then seek extra-pair copulations with less related males, but evidence is weak or lacking. In a prior study (Blomqvist et al. 2002), we showed that extra-pair paternity and maternity (quasi-parasitism) in three wader species was strongly related to genetic similarity between social pair members. We suggested that extra-pair parentage in many non-passerine birds may represent adaptive behavioural strategies to avoid negative effects of pairing with a genetically similar mate. To further test this hypothesis, we continued studying the paternity of Semipalmated Sandpipers at Barrow in June and July 2004. This represents the second year of this study. A total of 93 nests (compared to 51 in 2003) were located and 108 adults and 17 chicks (plus 21 embryos) were sampled for genetic material. Despite finding nearly twice the number of nests in 2004, we were able to sample only a small proportion of the chicks due to extremely high rates of predation. We have tested a limited number of not so variable microsatellite primers and are continue to test new primers to determine the genetic similarity of adults within a pair and the likelihood of that pair having extra-pair offspring.
(3) Pre-migratory movements and physiology of shorebirds staging on Alaska's North Slope
Investigators: Audrey Taylor and Abby Powell, University of Alaska Fairbanks, and Richard Lanctot, U.S. Fish and Wildlife Service.
Preliminary work conducted in the 1970's in Barrow, Alaska, indicated that coastal areas along the Arctic Coastal Plain (ACP) were of critical importance for most arctic-breeding shorebirds prior to southbound migration. Little information exists to quantify the size and distribution of pre-migratory shorebird populations along the ACP, nor to assess use of ACP habitats during the staging period. This information is critical given proposed energy development across the ACP, and because several species of shorebirds that stage on the North Slope are declining and are on the U.S. Fish and Wildlife Service's Birds of Conservation Concern 2002 list. Our specific objectives are to: (1) assess the abundance, distribution, and species composition of shorebirds along the Arctic Coastal Plain prior to fall migration, (2) quantify movement patterns (both within the staging period and relative to breeding location) and tenure times of pre-migratory shorebirds at staging sites across the ACP, and (3) examine how physiological factors (fattening rates and stress levels) of shorebirds vary among staging sites across the ACP. Variation in these physiological parameters may be indicative of site quality and therefore provide another measure of the importance of staging sites in preparing birds for migration.
During the summer of 2004 we conducted a pilot investigation in Barrow to test methods and predictions proposed for the larger-scale study across the North Slope in 2005 and 2006. We investigated the location of staging sites within the Barrow vicinity, the phenology of staging among different shorebird species using the Barrow area prior to fall migration, and the residency time of individual birds captured during the staging period. We also collected data on shorebird density along historical transects last surveyed for staging shorebirds during the OCSEAP program in the late 1970's. We found that numbers of birds at prominent staging locations and on the historical transects varied widely throughout the staging period. Shorebird species present in the largest numbers around Barrow included red and red-necked phalaropes, semipalmated sandpipers, western sandpipers, dunlin, and long-billed dowitchers. Adult shorebirds were recorded in the study area through July and the first few days of August; thereafter all birds seen in Barrow were juveniles (with the exception of adult dunlin). Staging shorebirds generally used areas of saline tundra, the shores of small brackish ponds and lagoons, and the Barrow sewage lagoon as foraging habitats. We captured 204 birds during August 2004 and recorded 182 resightings of banded or painted birds within the study area, including several adult dunlin that had been previously banded on the adjacent tundra area during the breeding season by either USFWS (2003 or 2004) or by Japanese researchers (2001 or 2003). The longest interval between banding and subsequent resighting was 17 days (red phalarope). The longest residency time of a radioed bird was 13 days (dunlin) and the shortest residency times were <1 day (3 radio tagged red phalaropes were never heard after they were banded and the radios attached). Preliminary examination of shorebird movements in the Barrow vicinity indicates that marked or radio tagged birds moved widely around the study area on a daily basis. Additional analyses on site tenure and movements are underway. We also collected blood for stress hormone and fat metabolite analysis from individuals of four species: Red Phalaropes (n = 84), Semipalmated Sandpipers (n = 23), Western Sandpipers (n = 40), and Dunlin (n = 26). Lab work and analysis of the physiological data from these blood samples will be conducted during fall and early winter 2004.
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