Nest Microclimate Research Articles

Burrow nests fall below critical temperatures of threatened seabirds but offer thermal refuge during extreme cold events

Climate change is altering the severity and intensity of extreme weather events. Occupying microhabitats that buffer extreme weather may help species avoid harsh environmental conditions. We describe the thermal microclimate of Atlantic Puffin ( Fratercula arctica) and Leach’s Storm-petrel ( Hydrobates leucorhous) burrows and quantify whether burrows are thermal refuges during extreme cold weather events. We further test for the effect of weather conditions and burrow characteristics on nest microclimate and buffering capacity during extreme cold weather. We find that both species actively breed in burrow microclimates that are below their lower critical temperatures, which may impose significant thermoregulatory costs. However, burrows do act as thermal refuges because nests are kept 7.4–8.0 °C warmer than ambient temperatures during extreme cold weather events. Overall, external temperature and wind speed were strong drivers of burrow temperature, but burrow and habitat characteristics did not explain the variability in burrow buffering capacity during extreme cold weather. Our results suggest that burrows may provide a direct line of defence for seabird chicks against cold events. Given the complex responses of burrow microclimates to extreme events, quantifying how changes in environmental conditions will impact burrow-nesting seabirds in the future is key.

Use of Nest Shelters by American Common Eiders (Somateria mollissima dresseri): Occupancy Rates and Effects of Shelter Type on Nest Microclimate

Use of Nest Shelters by American Common Eiders (Somateria mollissima dresseri): Occupancy Rates and Effects of Shelter Type on Nest Microclimate

Factors Affecting Nest Site Selection by Freshwater Turtles: A Systematic Review

Nest site selection is an important behavior, particularly in species that lack parental care, as nest microclimate can greatly impact embryos’ survival and offspring phenotype. Understanding which factors influence oviposition decisions is critical to identifying priority areas for conservation. This systematic review aimed to synthesize the factors that affect nest site selection by freshwater turtles. The search was conducted in the Web of Science database. In total, 35 publications met the eligibility criteria. The first study on the topic was published more than three decades ago, but only within the last ten years have studies started to be published annually. More than half of the studies were conducted in the United States and the most studied species was Chrysemys picta. Environmental factors, mainly vegetation characteristics, but also soil properties and beach morphology, are the most studied. Anthropogenic factors have been increasingly studied, especially residential areas and agricultural fields. Some studies suggest that human-altered habitats may act as ecological traps, emphasizing the need for further research on this topic. More studies are also needed on the influence of predation risk, co-species cues, female size, and offspring phenotype on nest site selection by freshwater turtles. We highlight that understanding the factors affecting nest site selection is important for identifying the habitat needs of nesting females, predicting possible ecological implications of nest site choice, assessing the adaptive potential of species to environmental change, and determining the vulnerability of populations to different threats.

Consequences of topography on nest microclimate and reproductive success in an open-cup nesting passerine

El microclima de los nidos puede ser influenciado por diferencias sutiles en la localización del nido como la topografía y el aspecto y puede diferir entre nidos localizados relativamente cerca uno del otro. Microclimas más favorables pueden influir en la selección de sitio de los nidos que hacen las aves y en su desenlace reproductivo. Sin embargo, muchos estudios de microclima de nido han considerado especies que anidan en cavidades y pocos han investigado especies paserinas de anidación de copa abierta. Comparamos microclimas de 87 nidos de la reinita Setophaga citrina contruidos en posiciones topográficas ligeramente distintas (cresta, ladera y valle) en Tar Hollow State Forest, al sudeste de Ohio. Examinamos luego la relación de la posición topográfica del nido con la edad parental y 3 medidas del resultado reproductivo. Nuestra predicción fue que las aves más viejas anidarían en sitios más favorables (más cálidos) y tendrían mayor éxito reproductivo en estos sitios. Encontramos diferencias significativas en microclimas de anidación entre sitios que diferían levemente en topografía y aspecto. Como era esperado, los sitios de anidación en el valle tenían temperaturas ambientales significativamente inferiores (temperatura promedio diaria, mínima y máxima) que las que estaban en la parte alta del risco. Sin embargo, el aspecto del nido tuvo pocos efectos en la temperatura ambiental de los sitios de anidación. Cuando se consideraron los sitios de anidación utilizados por las hembras de diferentes edades, encontramos algo de evidencia de que las hembras mayores (después del segundo año) tenían sitios de anidación más cálidos que las hembras menores (de segundo año), lo que apoyaba nuestra predicción. Sin embargo, no hay evidencia de que hembras mayores o nidos más cálidos necesariamente se asocien a un mayor éxito reproductivo, contrario a nuestras predicciones. Nuestros hallazgos sugieren que, aunque la topografía influye significativamente en el microclima del nido, factores distintos a las diferencias de temperatura son determinantes más importantes del éxito reproductivo y que otras consideraciones influyen en que las aves más viejas elijan sitios más cálidos de anidación en las crestas. Las relaciones entre el microclima del nido, la selección de sitio de anidación y éxito reproductivo son complejas y requieren estudios adicionales para las aves con nidos de copa abierta. Palabras clave: edad de la hembra, éxito reproductivo, microclima del nido, la reinita Setophaga citrina, topografía

Nest orientation and proximity to snow patches are important for nest site selection of a cavity breeder at high elevation

Timing and location of reproduction are central to reproductive success across taxa. Among birds, many species have evolved specific strategies to cope with environmental variability including shifts in timing of reproduction to track resource availability or selecting suitable nest location. In mountain ecosystems, complex topography and pronounced seasonality result in particularly high spatiotemporal variability of environmental conditions. Moreover, the risk of climate‐induced resource mismatches is particularly acute in mountain regions given that temperature is increasing more rapidly than in the lowlands. We investigated how a high‐elevation passerine, the white‐winged snowfinch Montifringilla nivalis, selects its nest site in relation to nest cavity characteristics, habitat composition and snow condition. We used a combination of field habitat mapping and satellite remote sensing to compare occupied nest sites with randomly selected pseudo‐absence sites. In the first half of the breeding season, snowfinches preferred nest cavities oriented towards the morning sun while they used cavities proportional to their availability later on. This preference might relate to the nest microclimate offering eco‐physiological advantages, namely thermoregulatory benefits for incubating adults and nestlings under the harsh conditions typically encountered in the alpine environment. Nest sites were consistently located in areas with greater‐than‐average snow cover at hatching date, likely mirroring the foraging preferences for tipulid larvae developing in meltwater along snowfields. Due to the particularly rapid climate shifts typical of mountain ecosystems, spatiotemporal mismatches between foraging grounds and nest sites are expected in the future. This may negatively influence demographic trajectories of the white‐winged snowfinch. The installation of well‐designed nest boxes in optimal habitat configurations could to some extent help mitigate this risk.

Egg shape variation across the distribution of the partially migratory fork‐tailed flycatcher Tyrannus savana

The evolution of egg shape across birds has been associated with breeding ecology, body shape constraints and nest microclimate, among other factors. We model the effects of migratory status, climate, clutch size and egg volume on egg shape variation over the distribution of fork‐tailed flycatchers Tyrannus savana. Although migratory status and climatic variables appear to be influencing intraspecific egg shape, these effects are not significant when accounting for nest identity as a random factor (i.e. eggs from the same clutch are more similar than to other clutches). Moreover, the differences that we observe in egg shape are not explained by variation in egg size. Finally, within a breeding population of migratory fork‐tailed flycatchers, egg shape does not vary with respect to egg‐laying order and/or female wing length (standardized by weight). Egg shape is highly variable within populations of fork‐tailed flycatchers but not within clutches, suggesting that female traits, apart from migratory status and wing morphology, constrain egg shape variation.

Experimental warming during incubation improves cold tolerance of blue tit (Cyanistes caeruleus) chicks.

ABSTRACTClimate change and increasing air temperature may alter environmental conditions for developing birds, with a range of phenotypic consequences for offspring. The thermal environment during incubation may affect the trade-off between growth and thermoregulation, but the effects of temperature on the ontogeny of endothermy are not fully understood. Therefore, we experimentally tested whether heating the nest cup of Eurasian blue tits (Cyanistes caeruleus) during incubation would influence cold tolerance of the chicks after hatching. Chicks from both heated and control nests showed a decrease in cooling rate with age as they became increasingly endothermic and homeothermic. However, chicks from previously heated nests cooled at a lower rate per unit surface area and from across the whole body. These chicks also had a greater body mass during the first 12 days of life compared with chicks from control nests. Lower cooling rates in heated chicks may reflect greater thermogenic capacity or a reduced surface area to volume ratio owing to a greater body mass. Future projections for climate change predict rising air temperature and increased likelihood of heatwaves, even in temperate regions. Our results indicate that nest microclimate can affect thermoregulation in offspring, and thus may be used to predict some of the future physiological responses of birds to climate change during breeding.

Effects of elevated nest box temperature on incubation behaviour and offspring fitness-related traits in the Collared Flycatcher Ficedula albicollis

Ambient temperature experienced by an animal during development or subsequently as an adult can affect many aspects of its behaviour and life-history traits. In birds, egg incubation is a vital component of reproduction and parental care. Several studies have suggested that environmental factors (such as nest microclimate) can influence the ability of incubating parents to maintain suitable conditions for embryo development. Here, we manipulated the developmental conditions of embryos through a modification of nest box thermal microclimate to investigate female incubation behaviour and its impact on offspring fitness-related traits in a wild population of the Collared Flycatcher (Ficedula albicollis). The temperature in experimental nests was increased using a heat-pack placed under the roof of a nest box, resulting in an average temperature increase of 2.5 ºC, which corresponds to projected climate change scenarios. We demonstrated that females from nests with elevated temperature spent less time in the nest box during egg incubation and had more off-bouts than females from control nests. Moreover, we found that offspring from the experimentally heated nests had larger body mass at fledging in comparison to the control ones. Our study indicates that nest microclimate during the incubation period affects female incubation behaviour and offspring quality, indicating that environmental variation in nest temperature early in ontogeny can have important and long-lasting fitness consequences.

Florida Grasshopper Sparrow (Ammodramus savannarum floridanus) nests are oriented northeast

Nest microclimate can be affected by wind and solar radiation, which can influence offspring survival. The endangered Florida Grasshopper Sparrow (Ammodramus savannarum floridanus) constructs a domed nest on the ground in dry prairie and pasture habitats of central Florida. We measured the nest opening orientation for 116 Florida Grasshopper Sparrow nests across 2 sites with different habitats (2014–2016). Nest openings were primarily oriented to the northeast and orientation did not differ by site. Nest opening orientation did not influence the probability that a nest would successfully fledge at least 1 nestling. It is possible that Florida Grasshopper Sparrows may orient nests to the northeast to avoid wind-blown rain from summer storms and solar radiation during the hottest part of the day, but high local rates of nest predation documented at both sites mask the selective advantage of nest orientation on nest survival.

Climate variability and parent nesting strategies influence gas exchange across avian eggshells.

Embryo survival in birds depends on a controlled transfer of water vapour and respiratory gases through the eggshell, and this exchange is critically sensitive to the surrounding physical environment. As birds breed in most terrestrial habitats worldwide, we proposed that variation in eggshell conductance has evolved to optimize embryonic development under different breeding conditions. This is the first study to take a broad-scale macro-ecological view of avian eggshell conductance, encompassing all key avian taxonomic groups, to assess how life history and climate influence the evolution of this trait. Using whole eggs spanning a wide phylogenetic diversity of birds, we determine that body mass, temperature seasonality and whether both parents attend the nest are the main determinants of eggshell conductance. Birds breeding at high latitudes, where seasonal temperature fluctuations are greatest, will benefit from lower eggshell conductance to combat temporary periods of suspended embryo growth and prevent dehydration during prolonged incubation. The nest microclimate is more consistent in species where parents take turns incubating their clutch, resulting in lower eggshell conductance. This study highlights the remarkable functional qualities of eggshells and their importance for embryo survival in extreme climates.

Comparative egg attendance patterns of incubating polar petrels

BackgroundThe internal environment of eggs in most birds is regulated by transferring heat energy through contact incubation, maintaining nest microclimate, and frequent egg turning by the incubating parent on its nest. However, we lack information about egg attendance patterns in birds that breed in polar environments where variations in life history are expected to influence incubation behavior. Moreover, crevice/burrow nesting petrels in high-latitude regions are known for periodically leaving their egg unattended (hereafter ‘egg neglect’), but there is little reporting on the internal condition of unattended eggs. At Dumont d’Urville Station, Antarctica, we studied the incubation behavior of 24 snow (Pagodroma nivea) and 15 Cape (Daption capense) petrel pairs using egg loggers that recorded egg turning rates, orientation changes, and temperatures at 1 Hz for durations of 3–6 days.ResultsEgg turning frequency (1.31 ± 0.33 vs. 1.38 ± 0.39 turns h−1), angle change per turn (43.1 ± 43.2 vs. 48.6 ± 43.7° turn−1), and egg temperature (34.1 ± 2.3 vs. 34.1 ± 2.0 °C) were nearly identical for snow and Cape petrels, respectively. However, egg neglect was only observed in snow petrel nests (based on egg temperature changes) where loggers recorded mean durations of 1.34 ± 1.15 days (maximum duration of 3.63 days). During periods of neglect, eggs cooled to 5.5 ± 1.8 °C over an average of 91 min, but were rewarmed by parents in only 76 min at a rate of 0.33 °C min−1.ConclusionsEgg temperatures of both species during regular incubation were within 1–2 °C of other high-latitude petrel species, but neglected snow petrel eggs remained several degrees above freezing, which was likely attributed to crevice nesting where neglected eggs are buffered by environmental conditions. Using egg rewarming rates, thermal capacity of eggs, and published metabolic rates, we estimate egg rewarming costs in snow petrels to be 1.5 to 1.9 × BMR. Excluding egg neglect periods, turning rates for both petrel species were lower than other seabirds studied using biologging devices, which may be associated with the prolonged incubation periods that are characteristic of procellariiform seabirds.

Nest microclimate and limits to egg viability explain avian life-history variation across latitudinal gradients.

Variation in life-history strategies is central to our understanding of population dynamics and how organisms adapt to their environments. Yet we lack consensus regarding the ecological processes that drive variation in traits related to reproduction and survival. For example, we still do not understand the cause of two widespread inter- and intraspecific patterns: (1) the ubiquitous positive association between avian clutch size and latitude; and (2) variation in the extent of asynchronous hatching of eggs within a single clutch. Well-known hypotheses to explain each pattern have largely focused on biotic processes related to food availability and predation risk. However, local adaptation to maintain egg viability could explain both patterns with a single abiotic mechanism. The egg viability hypothesis was initially proposed to explain the cause of asynchronous hatching and suggests that asynchronous hatching results from early incubation onset in response to unfavorable nest microclimatic conditions, which otherwise reduce egg viability. However, allocation of resources to early incubation, prior to clutch completion, may energetically constrain clutch size and help explain the positive association between clutch size and latitude. We measured intraspecific variation in five functionally linked life-history traits of burrowing owls at five study sites spanning a 1,400-km latitudinal transect in western North America: clutch size, the timing of incubation onset, the degree of hatching asynchrony, the probability of hatching failure, and nestling survival. We found that most traits varied clinally with latitude, but all the traits were more strongly associated with individual nest microclimates than with latitude, and all varied with nest microclimate in the directions predicted by the egg viability hypothesis. Furthermore, incubation began earlier, hatching asynchrony increased, and clutch size declined across the breeding season. These results suggest that nest microclimate drives an important life-history trade-off and that thermal gradients are often sufficient to account for observed biogeographic and seasonal patterns in life-history strategies. Furthermore, our results reveal a potentially important indirect mechanism by which reproductive success and recruitment could be affected by climate change.

Intraspecific variation in incubation behaviours along a latitudinal gradient is driven by nest microclimate and selection on neonate quality

Abstract The strategies by which animals allocate reproductive effort across their lifetimes vary, and the causes of variation in those strategies are actively debated. In birds, most research has focused heavily on variation in clutch size and fecundity, but incubation behaviour and other functionally related traits have received less attention. Variation in incubation period duration is notable because time‐dependent sources of clutch mortality should impose strong directional selection to minimize the incubation period. However, life‐history theory predicts multiple mechanisms by which inter‐ and intraspecific variation in incubation behaviours may be adaptive. We conducted one of the first studies of intraspecific latitudinal variation in avian incubation behaviours across a large portion of a single species’ range. We placed motion‐activated nest cameras inside burrowing owl nests at five study sites to quantify variation in daily nest attentiveness, cumulative nest attendance and incubation period duration. We tested predictions of two alterative hypotheses that have been proposed to explain variation in incubation periods: the parental risk tolerance hypothesis and the neonate quality hypothesis. Daily nest attentiveness, cumulative nest attendance and incubation period duration in burrowing owls were all positively correlated with latitude. Burrowing owls reduced their daily nest attentiveness at low latitudes and on days when the average nest temperature was within the range that is optimal for embryo development. Further, longer incubation periods were most strongly associated with greater cumulative nest attendance instead of reduced daily nest attentiveness. These results support predictions of the neonate quality hypothesis: longer incubation periods result from stronger selection on neonate quality rather than selection to reduce reproductive effort in response to low extrinsic mortality risk. However, some owls facultatively reduced their daily nest attentiveness, and this result supports the general hypothesis that incubation decisions reflect a trade‐off between reproduction and self‐maintenance, and that the optimal solution to that trade‐off varies systematically in response to latitudinal gradients in adult mortality. A free Plain Language Summary can be found within the Supporting Information of this article.

Climate as an Evolutionary Driver of Nest Morphology in Birds: A Review

Avian nests are critical for successful reproduction in birds. Nest microclimate can affect egg development, chick growth and fledgling success, suggesting that nest building behavior should be under strong selective pressure to nesting conditions. Given that the internal microclimate of the nest is critical for avian fitness, it is expected that nest morphology is shaped by the local environment. Here we review the relationship between nest morphology and climate across species’ distributions. We collate growing evidence that supports a link between environmental conditions and particular nest traits, within species and across species. We discuss the degree to which phenotypic plasticity in nesting behavior can contribute to observed variation in nest traits, the role of phylogenetic history in determining nest morphology, and which nest traits are likely to be influenced by climatic conditions. Finally, we identify gaps in our understanding of the evolution of nest morphology and suggest topics for future research. Overall, we argue that nests are part of the extended phenotype of a bird, they play a crucial role in their reproductive success, and may be an important factor in determining which species will be able to persist in the face of ongoing climate change.

Role of the thermal environment in scaled quail (Callipepla squamata) nest site selection and survival

Temperature is increasingly recognized as an important component of wildlife habitat. Temperature is particularly important for avian nest sites, where extreme temperatures can influence adult behavior, embryonic development, and survival. For species inhabiting arid and semiarid climates, such as the scaled quail (Callipepla squamata), frequent exposure to extreme temperatures may increase the importance of the nest microclimate. Limited data suggest that scaled quail respond to temperature when selecting nest sites, and they are also known to respond to the presence of surface water and shrub cover on the landscape, two resources which may mitigate thermal stress. To better understand the role of temperature in nest site selection and survival, and to evaluate how other landscape resources may benefit nesting quail, we investigated nest site characteristics of scaled quail in southeastern New Mexico, USA. During the breeding seasons of 2018 and 2019 we located nests, monitored nest fate, and recorded thermal and vegetation characteristics at three spatial scales: the nest bowl, the nest microsite (area within 10m of the nest bowl), and the landscape. We found that nest bowls moderated temperature relative to both the surrounding microsite and the broader landscape, remaining almost 5°C cooler on average than the surrounding microsite at mid-day. Nest bowls also had taller, greater cover of vegetation compared to both the surrounding microsites and the landscape. Despite apparent selection for cooler temperatures and taller vegetation, these characteristics demonstrated a weak relationship with nest survival. Rather, nest survival was positively influenced by proximity to surface water and honey mesquite (Prosopis glandulosa), with survival decreasing with increasing distance from these features. Although the mechanism for this relationship is unclear, our results support the importance of temperature for nest site selection of ground-nesting birds in semiarid landscapes, and suggest further exploration of landscape-level sources of thermal mitigation.

Contrasting sensitivity of nestling and fledgling Barn Swallow Hirundo rustica body mass to local weather conditions

Local weather can influence the growth and development of young birds either indirectly, by modifying prey availability, or directly, by affecting energetic trade‐offs. Such effects can have lasting implications for life history traits, but the nature of these effets may vary with the developmental stage of the birds, and over timescales from days to weeks. We examined the interactive effects of temperature, rainfall and wind speed on the mass of nestling and fledgling Barn Swallows Hirundo rustica both on the day of capture and averaging weather across the time since hatching. At the daily timescale, nestling mass was negatively correlated with temperature, but the strength of this association depended on the level of rainfall and wind speed; nestlings were typically heavier on dry or windy days, and the negative effect of temperature was strongest under calm or wet conditions. At the early lifetime timescale (i.e. from hatching to pre‐fledging), nestling mass was negatively correlated with temperature at low wind speed. Fledgling body mass was less sensitive to weather; the only weather effect evident was a negative correlation with temperature at the daily scale under high rainfall that became slightly positive under low rainfall. These changes are consistent with weather effects on the availability and distribution of insects within the landscape (e.g. causing high concentrations of flying insects) and with the effects of weather variation on nest microclimate. These results together demonstrate the impacts of weather on chick growth, over immediate (daily) and longer term (nestling/fledgling lifetime) timescales. This shows that sensitivity to local weather conditions varies across the early lifetime of young birds (nestling–fledgling stages) and illustrates the mechanisms by which larger scale (climate) variations influence the body condition of individuals.

Nest Orientation in Closed Nests of Passeriformes across a Latitudinal Gradient in the Southern Neotropic

Birds are expected to orient their nests non-randomly in order to avoid extreme thermal conditions that are known to affect their reproductive success. Considering the hypotheses that yearly mean temperature influences entrance orientation in birds, nests at higher latitudes are expected to face the equator in order to take advantage of warmer temperatures. Here we explore the relationship between latitude and nest entrance orientation in closed nests of Passeriformes in the southern Neotropics (Furnariidae, Rhinocryptidae, Troglodytidae, Tyrannidae), using both published and original data. We found a positive and significant correlation between mean entrance orientation and latitude, and report significantly non-random nest orientation at 62% of the locations with available samples. Overall, there is a trend for nests at lower latitudes to have north-northeasterly orientations, and for nests at higher latitudes to be oriented northwest. The reasons for the observed trends remain unclear, but likely involve the availability and intensity of solar radiation and its effect upon the nest microclimate.

Optimization of nest microclimate of bee families during winter period

In modern conditions, the improvement of technological methods in bee-farming significantly affects the production of bee-farming products. The concordance of technological operations of keeping bee families to climatic conditions of a particular region largely determines the production activity effectiveness of a beekeeper. Temperature differences in winter negatively affect the condition of bee families; humidity and excess condensate are accumulated in hives. The use of “zeolite” desiccant in winter allows improving microclimate inside the hive, contributing to more intensive development of bee families in spring and increasing marketable honey productivity due to its unique highly porous structure. Field studies were conducted during 2014-2016. Four groups of bee families were selected using the pair-analogue method in the course of the research: control group (without desiccant) and ex-perimental groups № 1, № 2, № 3 where in winter, the desiccant was placed at the hive bottom in the amount of 100, 150, 200 g, respectively.

Cavity type influences abundance of nest‐dwelling avian blow flies: an experiment with tree swallows

1. Diverse assemblages of blood‐feeding parasitic arthropods occupy the nests of birds, and nest temperature and humidity can strongly influence the population dynamics of these ectoparasites, with important implications for parasite–host relationships.2. This study used two types of nest box that differed in internal microclimates, one constructed of plywood and the other constructed of boles of aspen (Populus tremuloides Michx.), more closely replicating natural cavities, to examine how nest microclimate affects the prevalence and abundance of nest‐dwelling larval blow flies (Protocalliphora and Trypocalliphora spp.) in nests of tree swallows (Tachycineta bicolor Vieillot, 1808).3. Based on known microclimatic differences between the box types and responses of larval blow flies to different temperatures, it was predicted that the microclimate of plywood boxes would be more favourable for growth and development of larval blow flies, and therefore have higher abundance, and possibly higher prevalence, of larval blow flies.4. Plywood nest boxes had higher abundance, but not prevalence, of larval blow flies compared with aspen boxes at two different geographical locations in Canada. Nest composition also differed between box types, particularly at one site, where aspen boxes contained more nesting material (grass and feathers) than did plywood boxes.5. Although it seems probable that microclimate was driving the differences between box types in abundance of larval blow flies, several additional explanations are discussed. These findings may have implications for conservation efforts, particularly those where nest boxes are used to aid in the recovery of declining bird populations.

Nest characteristics determine nest microclimate and affect breeding output in an Antarctic seabird, the Wilson's storm-petrel.

The importance of nest characteristics for birds breeding in the extreme climate conditions of polar regions, has been greatly understudied. Nest parameters, like nest orientation, exposure and insulation, could strongly influence microclimate and protection against precipitation of the nest, thereby affecting breeding success. A burrow nesting seabird, the Wilson’s storm-petrel (Oceanites oceanicus) is an excellent model species to investigate the importance of nest characteristics, as it is the smallest endotherm breeding in the Antarctic. Here, we investigated the effects of nest parameters such as internal nest dimensions, nest micro-topography and thermal properties of the nest burrow and the influence of weather conditions on breeding output, measured as hatching success, chick survival, and chick growth. We collected data during the austral summers of 2017 and 2018, on King George Island, maritime Antarctica. Our results showed that the thermal microclimate of the nest burrow was significantly improved by a small entrance size, a low nest height, and insulation and tended to be enhanced by a low wind exposition index and an eastern nest site orientation. In addition, an eastern nest site orientation significantly reduced the chance of snow blocking. However, the relationships between nest characteristics and breeding output were complex and might be affected by other parameters like food availability and parental quality. The relation between chick growth and nest air temperature remained especially indistinct. Nevertheless, our results indicate that nest characteristics that enhance the thermal microclimate and reduce the risk of snow blocking favoured both hatching success and chick survival. Due to climate change in the Antarctic, snowfall is expected to increase in the future, which will likely enhance the importance of nest characteristics that determine snow blocking. Additionally, despite global warming, thermally favourable nest burrows will likely still be advantageous in the highly variable and challenging Antarctic climate.