Calcarius Lapponicus Research Articles

Effect of melatonin supplementation upon parental care and nestling growth in arctic-breeding songbirds.

Arctic-breeding birds exhibit around-the-clock activity, and these activity cycles are postulated to maximize reproductive success during the short breeding season characteristic of high-latitude regions. Two closely related species of arctic-breeding songbirds, Lapland longspurs (Calcarius lapponicus; ground-nesting) and snow buntings (Plectrophenax nivalis; cavity-nesting) exhibit extended activity cycles throughout the polar day (71° N) except for 4-5 h of daily quiescence. Ground-nesting Lapland longspurs experience higher levels of nest predation than cavity-nesting snow buntings, and this difference is reflected in elevated nest vigilance in male longspurs compared with snow buntings. In this study, we examined the effect of melatonin supplementation upon male parental care, corresponding measures of nestling growth, and ability to reduce activity (and increase sleep). A pharmacological dose of melatonin in captive snow buntings dampened the amplitude of activity rhythms over the polar day with no detectable phase-shifting compared with control-implanted birds. Melatonin treatment reduced nest visits and overall time spent on the nest by male snow buntings compared with controls. There was no significant increase in time spent by female snow buntings on the nest to compensate for this, and there was no significant effect on offspring growth rates. There were no effects of melatonin supplementation on longspur adults or offspring, suggesting behavioral insensitivity to exogenous melatonin treatment. These differences in sensitivity underscore the importance of nest defense in ground-nesting longspurs compared with cavity-nesting snow buntings, which participate minimally in nest defense.

Patterns in avian reproduction in the Prudhoe Bay Oilfield, Alaska, 2003–2019

The Arctic Coastal Plain is one of the most important avian breeding grounds in the world; however, many species are in decline. Arctic‐breeding birds contend with short breeding seasons, harsh climatic conditions, and now, rapidly changing, variable, and unpredictable environmental conditions caused by climate change. Additionally, those breeding in industrial areas may be impacted by human activities. It is difficult to separate the impacts of industrial development and climate change; however, long‐term datasets can help show patterns over time. We evaluated factors influencing reproductive parameters of breeding birds at Prudhoe Bay, Alaska, 2003–2019, by monitoring 1265 shorebird nests, 378 passerine nests, and 231 waterfowl nests. We found that nest survival decreased significantly nearer high‐use infrastructure for all guilds. Temporally, passerine nest survival declined across the 17 years of the study, while there was no significant evidence of change in their nest density. Shorebird nest survival did not vary significantly across years, nor did nest density. Waterfowl nest density increased over the course of the study, but we could not estimate nest survival in all years. Egg predator populations varied across time; numbers of gulls and ravens increased in the oilfields 2003–2019, while Arctic fox decreased, and jaeger numbers did not vary significantly. Long‐term datasets are rare in the Arctic, but they are crucial for understanding impacts to breeding birds from both climate change and increasing anthropogenic activities. We show that nest survival was lower for birds nesting closer to high‐use infrastructure in Arctic Alaska, which was not detected in earlier, shorter‐term studies. Additionally, we show that Lapland longspur nest survival decreased across time, in concert with continent‐wide declines in many passerine species. The urgency to understand these relationships cannot be expressed strongly enough, given change is continuing to happen and the potential impacts are large.

Selection of territorial habitat in a declining population of Lapland Longspurs (Calcarius lapponicus)

Cover photo: Male Lapland Longspur in its breeding habitat. Photo: Vegard B. Fjeldheim. The population of Lapland Longspur Calcarius lapponicus has declined drastically in the Scandinavian mountains over the last decades. One hypothesis is that the population decline has been caused by a change in vegetation composition, specifically an increase in lichen cover leading to a possible decrease in seed-producing plants. We tested the hypothesis by recording vegetation composition inside and outside Lapland Longspur territories in a 10 km2 study area at Hardangervidda, southern Norway, where longspurs previously bred in high numbers. Vegetation composition was recorded by percentage coverage in 295 1 x 1 m quadrats laid out evenly over the study area and compared to a similar treatment of 85 points inside 17 territories of Lapland Longspurs. No difference in lichen coverage or coverage by seed-producing plants was found inside versus outside territories. Instead, Lapland Longspurs were found to establish their territories in the upper part of the study area, where the snow melts earlier. Also, the occupied territories had an orientation towards the sun (sector S–W). Precipitation has increased strongly in the western parts of the Scandinavian Peninsula in recent decades. Falling as snow in the mountains, the increased precipitation leads to delays in spring thaw which could reduce the availability of breeding habitat for Lapland Longspurs during territorial establishment. We suggest that changes in spring conditions could be responsible for the species’ population decline in the western parts of the Scandinavian Peninsula.

Diet of three sympatric species of granivorous songbirds in a Norwegian high mountain area during the early breeding season

Cover photo: A male Lapland Longspur Calcarius lapponicus. Photo: Terje Lislevand. Stomach samples of Lapland Longspur Calcarius lapponicus, Snow Bunting Plectrophenax nivalis, and Horned Lark Eremophila alpestris were collected at Hardangervidda in an early phase of the breeding season (during egg-laying and onset of incubation) in 1974. Our analyses of diet composition found that plant material, mainly seeds, made up 90, 95 and 97% by number of items, and 49, 66 and 83% by dry mass, in the diets of Lapland Longspur, Horned Lark, and Snow Bunting, respectively. Seeds of Potentilla, Luzula, different Caryophyllaceae, and Omalotheca were important foods for all three species. Seeds of Empetrum were only found in longspurs and buntings, and fragments of Bryophyta were abundant only in the Horned Larks. Arthropoda were dominated by adult Coleoptera (in particular Patrobus spp., Helophorus glacialis, and Otiorrhynchus dubius) and Diptera larvae (notably Tipulidae), and were taken by all three species in small quantities by number of items but made up 51, 34 and 17% by dry mass in the diets of Lapland Longspur, Horned Lark, and Snow Bunting. Food overlap compared asymmetrically between the species ranged from 0.49 to 0.74 by number of items and from 0.43 to 0.74 by dry mass (scale from 0 to 1.0). Recent population declines in Lapland Longspur and Snow Bunting but increases in Horned Larks may have affected interspecific food competition among the three species early in the breeding season. The food overlap has presumably increased over the last decades due to a longer-lasting snow cover over the nesting habitats of longspurs and buntings which has been a result of increased precipitation due to climate change.

Historical avifaunal change and current effects of hiking and road use on avian occupancy in a high‐latitude tundra ecosystem

Tourism is increasing in tundra ecosystems across the world, yet its influence on bird communities and its interaction with other drivers of change is poorly known. To help fill this gap, we paired an interview‐based survey of 11 people with local knowledge of Denali National Park and Preserve, with an occupancy study of 15 bird species in relation to road proximity, traffic volume and hiking. Interviewees noted declines in American Golden PloverPluvialis dominica, Arctic TernSterna paradisaea, Long‐tailed JaegerStercorarius longicaudusand Northern WheatearOenanthe oenantheover the past five decades. Our occupancy study confirmed these reports as we detected no Arctic Terns, few Northern Wheatears, and found both plovers and jaegers to be sensitive to hiking. Occupancy of tundra and shrub habitats by American Golden Plover, American Tree SparrowSpizelloides arborea, Lapland LongspurCalcarius lapponicus, Long‐tailed Jaeger and Willow PtarmiganLagopus lagopusdeclined with increasing hiking intensity. We found that occupancy probability of tundra by Horned LarkEremophia alpestrisincreased, while that of the shrub‐tolerant Wilson’s WarblerCardellina pusilladecreased, with distance from the park road. Detection of species varied based on survey length, noise, start time, presence of a trail and date. The knowledge gained from this study reveals a loss in avian diversity over the past few decades that has the potential to cause a shifted baseline syndrome, and ongoing threats of hiking to sensitive tundra‐breeding birds. Park managers should seek to balance human recreation with the needs of sensitive tundra‐breeding birds to further protect species of conservation concern. This may be done by not building new trails in tundra, limiting access to tundra hiking areas during the early breeding season, reducing the spatial extent of hiking by improving maintained trails and designating a single, maintained path in areas with multiple unofficial hiking tracks, educating tourists about tundra‐nesting birds and closing especially important nesting areas to the public.

Life-history attributes of Arctic-breeding birds drive uneven responses to environmental variability across different phases of the reproductive cycle.

Animals exhibit varied life‐history traits that reflect adaptive responses to their environments. For Arctic‐breeding birds, traits related to diet, egg nutrient allocation, clutch size, and chick growth are predicted to be under increasing selection pressure due to rapid climate change and increasing environmental variability across high‐latitude regions. We compared four migratory birds (black brant [Branta bernicla nigricans], lesser snow geese [Chen caerulescens caerulescens], semipalmated sandpipers [Calidris pusilla], and Lapland longspurs [Calcarius lapponicus]) with varied life histories at an Arctic site in Alaska, USA, to understand how life‐history traits help moderate environmental variability across different phases of the reproductive cycle. We monitored aspects of reproductive performance related to the timing of breeding, reproductive investment, and chick growth from 2011 to 2018. In response to early snowmelt and warm temperatures, semipalmated sandpipers advanced their site arrival and bred in higher numbers, while brant and snow geese increased clutch sizes; all four species advanced their nest initiation dates. During chick rearing, longspur nestlings were relatively resilient to environmental variation, whereas warmer temperatures increased the growth rates of sandpiper chicks but reduced growth rates of snow goose goslings. These responses generally aligned with traits along the capital‐income spectrum of nutrient acquisition and altricial–precocial modes of chick growth. Under a warming climate, the ability to mobilize endogenous reserves likely provides geese with relative flexibility to adjust the timing of breeding and the size of clutches. Higher temperatures, however, may negatively affect the quality of herbaceous foods and slow gosling growth. Species may possess traits that are beneficial during one phase of the reproductive cycle and others that may be detrimental at another phase, uneven responses that may be amplified with future climate warming. These results underscore the need to consider multiple phases of the reproductive cycle when assessing the effects of environmental variability on Arctic‐breeding birds.

Book Review

Book Review

The Lapland Longspur (Calcarius lapponicus): some field observations in the Czechia

Abstract Historical data on birds are a cultural and scientific legacy of past generations of dedicated observers. This data cannot be deleted without obvious rebuttable evidence. An example of the Lapland Longspur (Calcarius lapponicus) is described.

An anti-narcolepsy drug reveals behavioral and fitness costs of extreme activity cycles in arctic-breeding songbirds.

Sleep loss impairs cognitive function, immunological responses and general well-being in humans. However, sleep requirements in mammals and birds vary dramatically. In circumpolar regions with continuous summer light, daily sleep duration is reduced, particularly in breeding birds. The effect of an anti-narcolepsy drug (modafinil) to putatively extend wakefulness was examined in two species of closely related arctic-breeding passerine birds: Lapland longspurs (Calcarius lapponicus) and snow buntings (Plectrophenax nivalis). Free-living adult males were implanted during the nestling phase on day 4 (D4; 4 days post-hatching) with osmotic pumps containing either vehicle or modafinil to extend the active period for 72 h. Nestlings were weighed on D2 and D7 to measure growth rates. Additionally, focal observations were conducted on D6. Male longspurs receiving modafinil made fewer feeding visits and spent less time at the nest but tended to spend more time near the nest than controls. We observed no change in longspur nestling growth rates, but fledging occurred significantly later when males received modafinil, suggesting a fitness cost. In contrast, modafinil had no measurable impact on male or female snow bunting behavior, nestling growth rates or time to fledging. We suggest male longspurs compromise and maintain vigilance at their nests in lieu of sleeping because of the increased predation risk that is characteristic of their tundra nesting habitat. Snow buntings are cavity nesters, and their nests do not require the same vigilance, allowing males to presumably rest following provisioning. These life-history differences between species highlight the role of predation risk in mediating behavioral modifications to prolonged wakefulness in arctic-breeding songbirds.

Ecological determinants of avian distribution and abundance at Rankin Inlet, Nunavut in the Canadian Arctic

Large areas of the Arctic remain poorly surveyed, creating biological knowledge gaps as scientists and managers grapple with issues of increasing resource extraction and climate change. We modelled spatiotemporal patterns in abundance for avian species in the low Arctic ecosystem near the community of Rankin Inlet, Nunavut, from 2015 to 2017. We employed six habitat covariates, including terrain ruggedness and freshwater cover, and contrasted the influence of elevation with distance from coast, as well as the normalized difference vegetation index (NDVI; a proxy for vegetative productivity) with the normalized difference water index (NDWI; a proxy for vegetation water content). Our results most clearly show the importance of low elevation, large amounts of freshwater and high vegetative productivity for Arctic birds at relatively local scales (<1 km2). Although NDVI more consistently appeared in competitive models of abundance, NDWI was particularly important in predicting abundance for shorebirds, ducks, Tundra Swans (Cygnus columbianus) and Lapland Longspurs (Calcarius lapponicus), demonstrating that it may be a more influential habitat covariate than NDVI for species that frequent habitats with wet vegetation. We also documented apparent shifts in habitat between early and late summer for geese, which were more strongly associated with freshwater later in the season, likely due to the presence of flightless juveniles and moulting adults at that time. Our study illustrates a relatively easy to implement survey methodology for avian species, provides baseline information for an Arctic study area that had not previously been surveyed intensively, and includes species that are underrepresented in previous literature.

Effect of sleep loss on executive function and plasma corticosterone levels in an arctic-breeding songbird, the Lapland longspur (Calcarius lapponicus)

Sleep is a fundamental component of vertebrate life, although its exact functions remain unclear. Animals deprived of sleep typically show reduced neurobiological performance, health, and in some cases, survival. However, a number of vertebrate taxa exhibit adaptations that permit normal activities even when sleep is reduced. Lapland longspurs (Calcarius lapponicus), arctic-breeding passerine birds, exhibit around-the-clock activity during their short breeding season, with an inactive period of ca. 4 h/day. Whether behavioral or physiological costs occur from sleep loss (SL) in this species is unknown. To assess the effects of SL, wild-caught male longspurs were placed in captivity (12L:12D) and trained for one month to successfully learn color association and spatial memory tasks. Birds were then placed in automated sleep fragmentation cages that utilize a moving wire to force movement every 1 min (60 arousals/h) during 12D (inactive period) or control conditions (during 12L; active period). After SL (or control) treatment, birds were presented with color association and spatial memory tasks a final time to assess executive function. Baseline plasma corticosterone concentration, body mass, and satiety were also measured. SL significantly elevated corticosterone levels and increased accuracy during color association recall but did not affect the overall time required to complete the task. SL had no effect upon spatial memory, body mass, or satiety. Taken together, these results suggest that Lapland longspurs exhibit a degree of behavioral, but not physiological, insensitivity to acute SL. Whether elevated plasma concentrations of corticosterone play a direct role in ameliorating cognitive deficits from SL require additional study.

Reindeer carcasses provide foraging habitat for insectivorous birds of the alpine tundra

On August of 2016, almost an entire herd (n = 323) of wild tundra reindeer (Rangifer tarandus) was killed by lightning on Hardangervidda in southern Norway. While conducting fieldwork for another study in 2017, we opportunistically registered the occurrence and behaviour of birds on carcasses from this mass die-off. Several passerine species other than corvids were observed actively foraging on arthropods, such as blowfly (Calliphoridae sp.) adults and larvae, which are typically associated with carcass decomposition. We quantified observations of those birds, and described their foraging behaviour at the carcass site. In decreasing order of abundance, five passerine species were observed taking arthropods at the site: Meadow Pipit (Anthus pratensis), Northern Wheatear (Oenanthe oenanthe), Common Reed Bunting (Emberiza schoeniclus), Bluethroat (Luscinia svecica,), and Lapland Bunting (Calcarius lapponicus). Systematic surveys of passerines utilizing carcass sites would further our understanding of how such resources may affect behaviour and life history of various bird species.

Unusual late July observation of a fledgling Lapland longspur in low Arctic Greenland following the cool spring of 2018

We report an observation of a flightless fledgling Lapland longspur (Calcarius lapponicus (Linnaeus, 1758)) at a long-term study site near Kangerlussuaq, Greenland, in late July 2018. Based on our observations of longspur nests at the site dating back to 1993, we estimate that the fledgling observed in 2018 may have originated from a nest initiated 12–37 d later than nesting in previous years. Onset of spring in 2018 was late, but comparable with other years in which longspur nests were observed a full calendar month earlier than in 2018. An analysis including multiple candidate predictor variables revealed a strong negative association between estimated longspur nest initiation dates and mean May temperature, as well as a weaker association with the length of the annual period of vegetation green up at the site. Given the limitations of our data, however, we are unable to assign causality to the 2018 observation, and cannot rule out other possibilities, such as that it may have resulted from a second clutch.

Reactions of shorebirds and passerines to human development in the Russian Arctic under the influence of strict conservation measures

Anthropogenic impact on nesting waders and passerine birds in the Arctic in surroundings of the industrial complex Sabetta, Yamal Peninsula, Russia was studied. A lot of factors associated with human development may affect nesting birds. The human-subsidized predation is considered to be the most significant. Anthropogenic food sources are usually present in human-transformed habitats, as well as additional dens and perch sites. This leads to a higher press of predation. In Sabetta, there are specific conditions causing artificially-limited predation and human-induced disturbance. Finding a large number of nests in close proximity to industrial infrastructure we have suggested that waders (order Charadriiformes) and passerine (order Passeriformes) birds may be tolerant to an urbanized landscape. In the studied industrial habitat, they probably do not reduce the nesting density, thanks to particular advantages of such habitats (drainability and variety of shelters). To test this hypothesis, we performed an analysis of the relationship between the nesting density of the 8 most abundant species of waders and passerines in relation to the degree of habitat transformation. Statistical analysis was carried out using the GLM module of Statsoft Statistica 10. We found a positive relation between nesting density of the Ringed Plover (Charadrius hiaticula) and Snow bunting (Plectrophenax nivalis) and the degree of transformation. Habitat transformation did not significantly affect the White wagtail (Motacilla alba) and Red-throated pipit (Anthus cervinus). The Lapland longspur (Calcarius lapponicus) showed a clear decrease of the nest density in transformed habitats. Last but not least, the Little stint (Calidris minuta), Temminck’s stint (C. temminckii) and Red-necked phalarope (Phalaropus lobatus) completely ignored only artificial habitats, whereas in partially transformed habitats, their mean nesting density was similar to undisturbed natural areas.

ORIBATID MITES IN NESTS OF THE LAPLAND BUNTING (CALCARIUS LAPPONICUS) ON THE ARCTIC ISLAND OF VAYGACH (WITH ANALYSIS OF THE ISLAND'S FAUNA)

In the seven nests of the Lapland Bunting ( Calcarius lapponicus ) collected from the Arctic island of Vaygach, 1348 oribatid mite specimens representing 25 species, 24 genera of 21 families were found. Nine species were found for the first time on this island: Atropacarus striculus (Koch, 1835), Phthiracarus ligneus Willmann, 1931, Eueremaeus oblongus oblongus (Koch, 1835), Gustavia microcephala (Nicolet, 1855), Carabodes areolatus Berlese, 1916, Banksinoma lanceolata (Michael, 1885), Scutovertex minutus (Koch, 1836), Scheloribates laevigatus (Koch, 1835), Trichoribates berlesei (Jacot, 1929). Representatives of seven of these genera: Atropacarus, Eueremaeus, Gustavia, Banksinoma, Scutovertex, Scheloribates, Trichoribates , as well as genera Nothrus and Achipteria , also six families, viz. Nothridae Berlese, 1896; Eremaeidae Sellnick, 1928; Gustaviidae Oudemans, 1900; Thyrisomidae Grandjean, 1953; Scutoverticidae Grandjean, 1954; Scheloribatidae Jacot, 1935, are reported for the island for the first time. The taxonomic list of oribatid mites of Vaygach Island, compiled based on both new data and the available literature, includes 43 species, 34 genera and 25 families. The fauna is mostly composed of Holarctic species (71.0 %), with a significant proportion of Circumpolar species (47.4 %) in it. Species with a polyzonal latitudinal distribution predominate in numbers. The share of Arcto-Boreal species is low; no Arctic species were found. The faunal composition of oribatid mites of Vaygach Island demonstrated a high degree of similarity with the insular fauna of the European sector of the Arctic, as well as with the fauna of continental tundra. The nests of the Lapland Bunting contained four so-called 'southern' species, whose core distribution range is situated at lower latitudes: Phthiracarus ligneus, Eueremaeus oblongus oblongus, Gustavia microcephala, Banksinoma lanceolata.

Effect of testosterone blockers on male aggression, song and parental care in an arctic passerine, the Lapland longspur (Calcarius lapponicus)

In many passerine birds, testosterone stimulates song and aggression but inhibits paternal care, but few studies have explored whether such effects can be reversed with testosterone blockers. We explored the effect of testosterone blockers on song, aggression and paternal care of Lapland longspurs (Calcarius lapponicus), an arctic passerine with a short breeding season. Twenty-one “blocker males” received implants containing an androgen receptor blocker and an aromatase inhibitor, compared to 27 control males with empty or no implants. Song, aggression and other behaviors were evaluated with simulated territorial intrusions (STI) during mate-guarding, and with focal observations (without STI) during mate-guarding and incubation. Nests were monitored and nestlings weighed as an indirect measure of paternal care. During STI, blocker males exhibited similar song rates, significantly lower aggression, and were significantly less likely to be found on territory than control males. Focal observations revealed no differences in spontaneous song, aggression, foraging, preening, or flight activity. Blocker males' nestlings had greater body mass on day 5 after hatching, but this difference disappeared by fledging, and both groups fledged similar numbers of young. Two blocker males exhibited unusual paternal care: incubation and brooding of young, or feeding of nestlings at another male's nest. In sum, testosterone blockers affected aggression but not song, contrasting with results from previously published testosterone implant studies. Effects on paternal care were concordant with testosterone implant studies. These patterns may be related to rapid behavioral changes characteristic of the short breeding season of the Arctic.

Late‐season snowfall is associated with decreased offspring survival in two migratory arctic‐breeding songbird species

While the effect of weather on reproduction has been studied for many years in avian taxa, the rapid pace of climate change in arctic regions has added urgency to this question by changing the weather conditions species experience during breeding. Given this, it is important to understand how factors such as temperature, rain, snowfall, and wind affect reproduction both directly and indirectly (e.g. through their effects on food availability). In this study, we ask how weather factors and food availability influence daily survival rates of clutches in two arctic‐breeding migratory songbirds: the Lapland longspur Calcarius lapponicus, a circumpolar breeder, and Gambel's white‐crowned sparrow Zonotrichia leucophrys gambelii, which breeds in shrubby habitats across tundra, boreal and continental climates. To do this, we monitored clutch survival in these two species from egg‐lay through fledge at field sites located near Toolik Field Station (North Slope, Alaska) across 5 yr (2012–2016). Our results indicate that snowfall and cold temperatures decreased offspring survival rates in both species; although Lapland longspurs were more susceptible to snowfall. Food availability, quantified by pitfall sampling and sweep‐net sampling methods, had minimal effects on offspring survival. Some climate models predict increased precipitation for the Arctic with global warming, and in the Toolik region, total snow accumulation may be increasing. Placed in this context, our results suggest that changes in snow storms with climate change could have substantial consequences for reproduction in migratory songbirds breeding in the North American Arctic.

Inventory of Lowland-Breeding Birds on the Alaska Peninsula

AbstractWe conducted the first systematic inventory of birds in the lowlands (areas ≤100 m above sea level) of the Alaska Peninsula during summers of 2004–2007 to determine their breeding distributions and habitat associations in this remote region. Using a stratified random survey design, we allocated sample plots by elevation and land cover with a preference for wetland cover types used by shorebirds, a group of particular interest to land managers. We surveyed birds during 10-min counts at 792 points across 52, 5 km × 5 km sample plots distributed from south of the Naknek River (58.70°N,157.00°W) to north of Port Moller (56.00°N,160.52°W). We detected 95 bird species including 19 species of shorebirds and 34 species (36% of total) considered at the time to be of conservation concern for the land managers in the region. The most numerous shorebirds on point counts were dunlin Calidris alpina, short-billed dowitcher Limnodromus griseus, and Wilson's snipe Gallinago delicata. We found the breeding-season endemic marbled godwit Limosa fedoa beringiae at 20 plots within a 3,000-km2 area from north of Ugashik Bay to just north of Port Heiden and east to the headwaters of the Dog Salmon and Ugashik rivers. The most abundant passerines on point counts were American tree sparrow Spizelloides arborea, Lapland longspur Calcarius lapponicus, and savannah sparrow Passerculus sandwichensis. Sandhill crane Antigone canadensis, glaucous-winged gull Larus glaucescens, and greater scaup Aythya marila were also relatively abundant. We categorized habitat associations for 30 common species and found that lowland herbaceous vegetation supported wetland-focused species including sandhill crane, marbled godwit, short-billed dowitcher, and dunlin; whereas, dwarf shrub-ericaceous vegetation supported tundra-associated species such as willow ptarmigan Lagopus lagopus, rock sandpiper Calidris ptilocnemis, and American pipit Anthus rubescens. Tall shrub vegetation was important to several species of warblers and sparrows, as well as one species of shorebird (greater yellowlegs Tringa melanoleuca). We found that point counts augmented with incidental observations provided an almost complete inventory of lowland-breeding species on the study area. These data form a baseline to monitor any future changes in bird distribution and abundance on the Alaska Peninsula.

Weathering the storm: Do arctic blizzards cause repeatable changes in stress physiology and body condition in breeding songbirds?

Severe weather events are increasing worldwide because of climate change. To cope with severe weather events, vertebrates rely on the stress response which is activated by the hypothalamic-pituitary adrenal (HPA) axis to adjust physiology and behavior. Previous studies have detailed changes in baseline concentrations of the stress hormone corticosterone during a single storm event, but little data exists on how stress physiology and body condition are adjusted as the storm progresses across multiple days. This represents a serious gap in our understanding of how birds respond physiologically over the duration of a storm. We documented arctic snowstorms that occurred over five consecutive years that were endured by Lapland longspurs (Calcarius lapponicus; 2012–2016) and in three consecutive years by white-crowned sparrows (Zonotrichia leucophrys gambelii; 2014–2016). Data were collected on storm-free days, during snowstorms ranging in length from 1 to 3 days, and the day immediately following a snowstorm. The specific aims were to understand how stress physiology, measured at baseline and in response to restraint handling, and body condition changed over multiple days of the storm, and if these responses were consistent across years. Snowstorms did not affect baseline corticosterone concentrations for either species except for female Lapland longspurs and male white-crowned sparrows in 2014. Lapland longspurs, regardless of sex, increased stress-induced (restraint handling) corticosterone in response to snowstorms in all years but 2013, which was characterized by unusually harsh conditions. Both sexes of White-crowned sparrows showed a significant increase in the stress-induced levels of corticosterone during snowstorms in one of the three years of the study. Stress-induced corticosterone concentrations were only different across each day of the storm in one year of the study for Lapland longspurs. Changes in fat and body mass were not uniform across years, but measurable increases in fat stores and body mass were detected in males of both species during the first day of a snowstorm with declines typically occurring by the second day. Our study showed that severe weather events often caused rapid increases in HPA axis activity and body condition, but these profiles are likely dependent upon ecological and environmental context within the breeding season.

Extreme spring conditions in the Arctic delay spring phenology of long-distance migratory songbirds

Arctic regions are warming rapidly, with extreme weather events increasing in frequency, duration, and intensity just as in other regions. Many studies have focused on how shifting seasonality in environmental conditions affects vegetation phenology, while far fewer have examined how the breeding phenology of arctic fauna responds. We studied two species of long-distance migratory songbirds, Lapland longspurs, Calcarius lapponicus, and white-crowned sparrows, Zonotrichia leucophrys gambelii, across five consecutive breeding seasons in northern Alaskan tundra. We aimed to understand how spring environmental conditions affected breeding cycle phenology, including the timing of arrival on breeding grounds, territory establishment, and clutch initiation. Spring temperatures, precipitation, and snow-free dates differed significantly among years, with 2013 characterized by unusually late snow cover. In response, we found a significant delay in breeding-cycle phenology for both study species in 2013 relative to other study years: the first bird observed was delayed by 6-10days, with mean arrival by 3-6days, territory establishment by 6-13days, and clutch initiation by 4-10days. Further, snow cover, temperature, and precipitation during the territory establishment period were important predictors of clutch initiation dates for both species. These findings suggest that Arctic-breeding passerine communities may have the flexibility required to adjust breeding phenology in response to the increasingly extreme and unpredictable environmental conditions-although future generations may encounter conditions that exceed their current range of phenological flexibility.