Patterns Of Nest-site Selection Research Articles

Wood hardness drives nest-site selection in woodpeckers of the humid Chaco

Abstract Avian excavators (woodpeckers and other species) select nest sites based on characteristics of the nest patch, nest tree, and substrate. These characteristics could increase foraging opportunities or reduce the risk of predation, but there is also a potentially important role for wood hardness in restricting nest-site selection, a role that has been little explored and is expected to vary among species according to their ability to excavate. We examined patterns of nest-site selection in 8 woodpecker species in the humid Chaco of South America, where the dominant trees have extremely hard wood. We hypothesized that (1) wood hardness is the main factor driving selection of excavation sites, and (2) interspecific variation in body size and foraging behavior (traits frequently related to excavation ability) explain interspecific variation in the wood hardness of excavated nest substrates. From 2016 to 2019 in well-preserved forests of the Argentine Chaco, we compared nesting cavities excavated in wood (cases; n = 42) vs. potential wood substrates without cavities (matched controls) and made 187 focal observations of foraging woodpeckers. Woodpeckers selected nesting substrates with softer heartwood than potential substrates, regardless of any other characteristics of the tree or nest patch. Wood hardness around nest cavities increased with body size and the prevalence of chiseling during foraging, traits that were positively correlated. Woodpeckers often excavated in Prosopis spp. (Algarrobos) but rarely in Schinopsis balansae (Quebracho), a tree with exceptionally hard internal wood, in which cavity adopters frequently nest in non-excavated cavities. Wood hardness is critical to assessing the role of woodpeckers as cavity facilitators, understanding the costs and benefits of excavation, and interpreting excavation patterns across species and forests globally.

Patterns of nest-site selection by Colletes thoracicus within a forested watershed

Patterns of nest-site selection by Colletes thoracicus within a forested watershed

Personality-dependent nest site selection and nest success during incubation in wild chestnut thrushes

In birds, little is known about how individuals choose nest sites based on their personality traits. Here, we investigate whether a female's personality (activity and breathing rate) can affect patterns of nest site selection at different spatial scales in a wild population of chestnut thrush (Turdus rubrocanus) and determine whether nest site characteristics and female personality traits affect clutch size and nest success during incubation. We found that neither activity nor breathing rate were associated with large-scale nesting habitat variables. At the fine-scale level, more active females chose nest sites with greater nest lateral concealment. Females with higher breathing rates laid smaller clutch sizes than individuals with lower breathing rates. Nests of females with lower breathing rate had higher nest success during incubation. This work highlights the relationships between personality and nest site selection in birds, and the important role of female personality traits in reproductive success.

Factors affecting spatiotemporal patterns of nest site selection and abundance in diamondback terrapins.

Determining what factors influence the distribution and abundance of wildlife populations is crucial for implementing effective conservation and management actions. Yet, for species with dynamic seasonal, sex-, and age-specific spatial ecology, like the diamondback terrapin (Malaclemys terrapin; DBT), doing so can be challenging. Moreover, environmental factors that influence the distribution and abundance of DBT in their northernmost range have not been quantitatively characterized. We investigated proximity to nesting habitat as one potential driver of spatiotemporal variation in abundance in a three-step analytical approach. First, we used a scale selection resource selection function (RSF) approach based on landcover data from the National Landcover Database (NLCD) to identify the scale at which DBT are selecting for (or avoiding) landcover types to nest. Next, we used RSF to predict areas of suitable nesting habitat and created an index of nest suitability (NSI). Finally, analyzing visual count data using a generalized linear mixed model (GLMM), we investigate spatiotemporal drivers of relative abundance, with a specific focus on whether similar factors affect offshore abundance and onshore nest site selection. We found the scale of selection for developed and saltmarsh land use classes to be 550 and 600 m and open water land use classes to be 100. Selection was positive for nesting areas proximal to saltmarsh habitat and negative for developed and open water. Expected relative abundance was best explained by the interaction between NSI and day of season, where expected relative abundance was greater within high NSI areas during the nesting season (2.20 individuals, CI: 1.19-3.93) compared to areas of low NSI (1.84 individuals, CI: 1.10-3.10). Our results provide evidence that inferred spatial patterns of suitable nesting habitats explain spatiotemporal patterns of terrapin movement and abundance.

Flexible nest site selection of the endangered Oriental Storks (Ciconia boyciana): Trade-off from adaptive strategies

Nest site selection is a vital component of bird reproduction success, and an adaptive behavior conducted to decrease nest predation risk with avoiding external disturbances. Understanding patterns of nest site selection can provide insights into how species adapt to changes in their habitat and has important conservation implications. In this study, we used microhabitat variables and multi-scale data with a field survey of nest occurrence to determine nest site selection patterns and adaptive strategies of the breeding Oriental Storks (Ciconia boyciana) in different nest areas. Results demonstrate that the nest site microhabitat characteristics of the breeding Oriental Storks significantly differed among the three nesting areas, and nest height was higher in the middle and lower Yangtze River floodplain than in the Northeast China and Bohai Bay nest areas. The food resources and intensity of human disturbance had the greatest effects on the nest site selection of the breeding Oriental Storks. The intensity of human disturbance was positively correlated with the nest height of the breeding Oriental Storks in Bohai Bay and the middle and lower Yangtze River floodplain; however, nest height decreased with the abundance of food resources in the Northeast China nest area. Our findings indicate that the nest site selection patterns of Oriental Storks showed flexible adaptive strategies. In safer environments, nests were lower and closer to food resources, which allows parent storks to invest more in the nestlings. However, in areas where human activity was intense, nests were higher to ensure the safety of their offspring. Some measures that could be taken to improve the breeding habitat of Oriental Storks include increasing the percentage of wetland areas in nesting areas to enhance food resources availability and setting artificial nests at suitable heights in potential nesting grounds to encourage nesting. Finally, the establishment of soft barriers around the nesting areas could increase the safety of nests.

Strategic nest site selection in one of the world's largest loggerhead turtle nesting colonies, on Maio Island, Cabo Verde

AbstractFor species without parental care, such as sea turtles, nest site selection is particularly important for embryo development, hatchling survival and, ultimately, reproductive success. We conducted an 8-year (2012–2019) capture–mark–recapture study of the re-nesting behaviour of loggerhead turtles Caretta caretta to identify both inter- and intra-beach patterns of nest site selection. Our study site, Maio Island in the archipelago of Cabo Verde, hosts one of the largest loggerhead turtle nesting colonies globally. Of 1,060 females analysed, 77% laid repeated clutches within 15 km of their previous nesting sites both between and within nesting seasons. This site fidelity was particularly high (64–71%) for turtles nesting on the east coast of Maio Island. In two areas of the island (north-west and south-east) individual nesting zone consistency was extremely low (10–25%). In all cases extra-zone re-nesting events mainly occurred on the east coast. We also found that females avoided re-nesting near the shoreline, which is particularly relevant in the context of rising sea levels. Overall, loggerhead turtles nesting in Maio Island are philopatric but are using a bet-edging strategy to distribute nests amongst several beaches, choosing the safest area within each beach to maximize their reproductive success. This study highlights the priority sites for protection on Maio Island and could help to optimize capture–mark–recapture programmes. The data reveal the potential for adaptive responses to projected sea level rises.

Wood density and tree size used as cues to locate and excavate cavities in two Colaptes woodpeckers inhabiting a threatened southern temperate forest of Argentina

Nest-site selection is crucial for birds' breeding success and, therefore, studies on this topic are critical in order to understand what features species need. This is particularly important in areas with conservation issues, where habitats and/or trees with the required features may be scarce. However, little information is available on the nest-site selection patterns of woodpeckers breeding in southern temperate forests, where tree logging considerably reduced forest cover and, hence, availability of trees suitable for cavity excavation. In addition, previous studies did not include assessments at different spatial scales nor including quantitative wood density data. Therefore, the main objective of this study is to assess nest-site selection patterns (at the habitat and cavity-tree scales) of the Campo Flicker Colaptes campestris and the Green-barred Woodpecker C. melanochloros breeding in a threatened southern temperate forest of central-east Argentina. Moreover, we report the first wood density data of the trees used by these two woodpeckers when excavating cavities and assess niche partitioning by comparing their cavities and cavity-trees to one another. To assess selection at a habitat scale (recording forest cover and edge of stands and trees), we compared selected breeding habitats to randomly found habitats. At a tree-scale (recording tree height, diameter, wood density and wood decay status), we compared cavity-trees to randomly found trees. Most cavities were excavated in medium (DBH = 20–35 cm) or large (>35 cm) size trees with wood density < 0.5 g/cm3. Generalized linear models indicated that woodpeckers’ propensity to excavate a new cavity was negatively correlated with tree wood density (which was negatively correlated to wood decay status) and positively to tree size. Both woodpecker species focused more importantly on tree features compared to habitat features when excavating cavities. Because forest patches containing mid- and large-sized trees with main stems and/or branches with wood softened by decay processes have become less abundant in these forests due to uncontrolled logging actions, we emphasize the need to conserve trees with these characteristics to ensure the availability of the preferred features of these woodpeckers.

There goes the neighborhood: White-crowned Sparrow nest site selection and reproductive success as local density declines

ABSTRACT Changes in climate, vegetation, and land use are recognized as important drivers of changes in the distribution and abundance of wildlife. However, the behavioral and demographic mechanisms through which these changes affect populations have received less attention. Identifying these mechanisms is an important component of predicting the impacts of increasing environmental change. We used 30 yr of nest monitoring data at a study site where White-crowned Sparrow (Zonotrichia leucophrys) breeding density declined 85% to evaluate factors influencing habitat selection and reproductive success. Rapid secondary plant succession occurred at our study site, but the rate of change was faster in some areas than others. White-crowned Sparrows exhibited strong patterns of nest site selection, preferring open shrub vegetation and avoiding forest. As a result, many parts of the study area that were used for nesting early in the study period were no longer occupied by the end of the study period. Over the cours...

Nest-Site Selection Patterns of Coexisting Sandhill and Whooping Cranes in Wisconsin

Abstract Breeding sandhill cranes Antigone canadensis and released captive-reared whooping cranes Grus americana have coexisted in central Wisconsin since 2001. Despite 15 y of reintroduction efforts, the reproductive success of these whooping cranes has been near zero. Preliminary data suggest sandhill cranes nesting in central Wisconsin have apparent nest success rates that are similar to those reported from other populations in the region (∼50%). One hypothesized cause of the whooping crane population's low reproductive success is nest abandonment induced by blood-feeding ornithophilic black flies Diptera: Simuliidae. Species-specific differences in selection of nest sites could influence the abundance of black flies at nests and affect reproductive success rates. We measured multiple vegetative and hydrologic characteristics at 35 sandhill crane nests, 20 whooping crane nests, and 164 randomly selected locations at 5- and 200-m scales. We were unable to detect a species-specific difference in vegetation characteristics within 5 m of nest sites. At the 200-m scale, sandhill cranes built nests at sites with slightly greater coverage of woody vegetation than whooping cranes. Differences observed between nest sites of sandhill and whooping cranes appeared to be slight and likely insufficient to explain the dramatic differences in reproductive success in central Wisconsin.

Nest site selection patterns of a local Egyptian VultureNeophron percnopteruspopulation in Turkey

SummaryWe report the size and density of an Egyptian Vulture population in Turkey and provide insight into its nest site selection patterns. The study was carried out at Beypazarı (Turkey), holding one of the densest Egyptian Vulture populations (six pairs per 100 km2) in the Western Palearctic. Random Forests analysis revealed that human impact was a potential factor governing the distribution of nest sites, as the pairs clearly preferred to breed away from nearby villages, towns or roads. Utilisation of elevation gradient and aspect was similar to other studied populations, with the probability of nesting increasing at lower altitudes and for south-facing cliffs. Nearest-neighbour distance between nests was about 1.5 km, indicating territorial behaviour when choosing nest sites at the local scale. Our findings provide guidance for nature conservation NGOs and related government bodies for their various actions including designation of Important Bird Areas, regulation of mining practices and preparation of environmental impact assessments.

Territory and nest site selection patterns by Grasshopper Sparrows in southeastern Arizona

ABSTRACT Grassland bird populations are showing some of the greatest rates of decline of any North American birds, prompting measures to protect and improve important habitat. We assessed how vegetation structure and composition, habitat features often targeted for management, affected territory and nest site selection by Grasshopper Sparrows (Ammodramus savannarum ammolegus) in southeastern Arizona. To identify features important to males establishing territories, we compared vegetation characteristics of known territories and random samples on 2 sites over 5 years. We examined habitat selection patterns of females by comparing characteristics of nest sites with territories over 3 years. Males selected territories in areas of sparser vegetation structure and more tall shrubs (>2 m) than random plots on the site with low shrub densities. Males did not select territories based on the proportion of exotic grasses. Females generally located nest sites in areas with lower small shrub (1–2 m tall) densities th...

Nest Sites of Middle Spotted WoodpeckersLeiopicus mediusin a Primeval Forest

Forest management usually reduces the diversity and amount of substrates in which woodpeckers can excavate holes. In such conditions the recorded patterns of nest site selection could reflect a more reduced array of substrates than the species' nest site preferences. We analysed new data on nest sites of Middle Spotted Woodpeckers Leiopicus medius collected during 27 breeding seasons (1987–2013) in the strictly protected fragments of the Bialowieza National Park in Poland. The birds could use diverse excavation substrates, of various statures, that varied in condition from living and healthy to dead and completely rotten. Middle Spotted Woodpeckers used a wide array of tree species, with little overlap in the species used in the riverine habitat (mostly Alnus glutinosa, and Fraxinus excelsior) and oak—hornbeam habitats (Carpinus betulus and Quercus robur). The birds preferred to excavate in Q. robur but avoided Tilia cordata and Picea abies. They placed holes in large trees (median girth at breast height:...

The role of nest‐site selection and cereal production in differential nest predation in Common Quail Coturnix coturnix and hybrid quail C. coturnix × C. japonica

In Europe, farm‐reared quail used for restocking purposes are often hybrids between the Common Quail Coturnix coturnix and the Japanese Quail Coturnix japonica. These hybrids interbreed with wild Common Quail populations and suffer higher rates of nest predation, which would suggest that the two quail types have different nest‐site selection patterns. We monitored 103 radiotagged nesting females (77 wild Common Quail over 18 breeding seasons and 26 hybrid quail over six breeding seasons) and analysed their nest placement behaviour. Our results did not provide any evidence that the quail types showed different nest‐site selection trends, as they all preferred to nest near cereal field margins. The higher nest predation rate experienced by hybrids might therefore be explained by less effective anti‐predator behaviour among hybrid females during incubation. As no edge effect on nest predation was observed, the preference for nesting close to cereal margins could be due to the greater food resources of field margins. Moreover, Common Quail nest predation decreased with a rise in barley straw production, supporting evidence that nest cover plays an important role in the prevention of nest predation in this species. No such relationship was found for hybrid quail, but this result is not conclusive, as the data on barley straw production for hybrid quail covered a much smaller range of interannual variability. Barley straw production in Catalonia decreased significantly between 1992 and 2012, possibly as a result of a change in the barley varieties used. This practice could entail a conservation threat for ground‐nesting bird species.

Seasonal sex ratios and the evolution of temperature-dependent sex determination in oviparous lizards

Although the adaptive significance of temperature-dependent sex determination (TSD) remains a puzzle, recent models implicate a seasonal bias in offspring sex production that translates into sex-specific fitness benefits later in life. Sex-specific emergence has been linked to fitness gains in some fish, birds and reptiles, but field data supporting the occurrence of a seasonal pattern of sex ratios in oviparous lizards are lacking. We tested the hypothesis that patterns of nest site selection and seasonal temperature changes combine to inhibit the materialization of sex-biased hatching times in a population of water dragons (Intellagama lesueurii). As predicted, a seasonal increase in air and nest temperatures resulted in a sex bias by nesting date; male-producing clutches were laid 17.8 days sooner than female-producing clutches, on average. However, the seasonal ramping of nest temperatures also caused shorter relative incubation periods in the later, all-female clutches. As a consequence of this developmental ‘catch-up’, the mean hatching date for male-producing nests preceded the mean hatching date for female-producing nests by only 7.2 days. We suggest that a contracted distribution of hatching dates compared to the distribution of oviposition dates represents a general pattern for oviparous reptiles in seasonal climates, which in TSD species may largely offset the temporal disparity in nesting dates between the sexes. Although data are needed for other TSD species, such minor age differences between male and female hatchlings may not translate into fitness differences later in life, an assumption of some models for the evolution and maintenance of TSD.

Conflicting natural and anthropogenic threats reduce nest success in centrarchid fishes

As anthropogenic presence in riverine systems increases, it is essential to understand the associated impacts on ecologically important species such as centrarchid fishes. We tested the hypothesis that the conflicting pressures of natural factors (e.g., predation threat), the perceived threat of human traffic, and the impacts of habitat degradation would negatively influence centrarchid nest success. We surveyed centrarchid nesting areas in the Cacapon River, West Virginia, USA and collected a suite of biotic and habitat variables for each nest found. From these data, we analyzed site selection and nest success in three centrarchid species and male flight response to perceived harm in the most common (longear sunfish, Lepomis megalotis). We detected patterns of nest site selection in all species surveyed, with a large degree of overlap in influential variables. Males did not select for nest sites near in-stream cover, which appeared to reduce nest success by acting as refugia for benthic brood predators. However, the protection provided by cover dampened the magnitude of response to perceived harm. Therefore, the pressures of human and natural threats were contradictory, likely reducing fitness and fecundity. Future restoration procedures should seek to conserve nesting habitat by limiting the impacts of human presence.

Red-breasted nuthatches (Sitta canadensis) increase cavity excavation in response to a mountain pine beetle (Dendroctonus ponderosae) outbreak

In cavity-nesting vertebrate species, reproduction is limited by the production and availability of tree cavities. Excavating species may create new cavities to exploit food resource pulses in novel habitats, but availability of nesting resources may be constrained with increases in population densities. Over a 15-y period, we monitored the reproduction of cavity nesters and a large-scale mountain pine beetle (Dendroctonus ponderosae) outbreak that killed all mature lodgepole pine (Pinus contorta var. latifolia), at 30 mixed coniferous—deciduous stands in interior British Columbia, Canada. We examined how the probability of excavation of a bark insectivorous, facultative cavity excavator, the red-breasted nuthatch (Sitta canadensis), was influenced by mountain pine beetle abundance and changes in population densities of conspecific individuals and a nest predator, red squirrel (Tamiasciurus hudsonicus). Nuthatches always chose trembling aspen (Populus tremuloides) for nesting regardless of densities of nuthatch nests and availability of beetle-decayed pine as alternate nest trees. The number of nuthatch nests increased in years of increasing densities of beetle-infected pine, and the proportion of freshly excavated nests varied annually, increasing with the beetle outbreak from 26% of all cavities used in 2001 to 70% in 2002 and then declining after the outbreak to 17% in 2009. For each unit increase in densities per hectare of both nuthatches and beetle-infected pine trees, the odds that individuals would excavate a new cavity rather than use an existing cavity increased by 147 times. With each 10 m farther into the coniferous forest interior, the odds of excavation increased by 10 times. These results suggest that facultative excavators are able to exploit novel habitats during insect outbreaks by adjusting their nest-site selection patterns and increasing excavation, but that resource pulses may lead to limitation of nesting resources.

Nest-site selection pattern of Grus japonensis in Zhalong Nature Reserve of northeast China

Nest-site selection patterns of Red-crowned cranes (Grus japonensis) and the effects of environmental variables were studied during the years of 2002–2008 in Zhalong Nature Reserve, Qiqihar city, northeast China. The nest-site selection pattern of Red-crowned cranes included two orders and three choices: the choice of nest-site habitat type within the macro-habitat order, nest zone selection and nest-site microhabitat selection within the micro-habitat order. Various habitats (such as Carex swamps and reed fire districts) can be selected as the nest sites for Red-crowned cranes, of which reed swamps (93.15%) are given a preference. Factor Analysis reveals that the micro-habitat selection are affected by four main factors: fire, security (concealment / disturbance), incubation (conditions, nest-material), and food. Further analysis reveals that Red-crowned cranes have certain adaptability to the changes of nesting habitat quality in the Zhalong wetlands. In conclusion, fire, reeds, and water were the most important variables for nest-site habitat selection of Red-crowned Cranes in Zhalong Nature Reserve.

Do Orientation-Based Differences in Nestbox Temperature Cause Differential Ectoparasite Load and Explain Patterns of Nest-Site Selection and Offspring Condition in Great Tits?

Nest ectoparasites have been linked previously to patterns of nest-site choice and breeding success in birds. Recent research has shown nestboxes facing south-southwest are occupied less frequently by great tits (Parus major) than identical boxes facing other directions, and are associated with reduced offspring condition. Here, we investigate the hypothesis that these findings are due to ectoparasite load being directionally nonuniform, possibly because of nonuniformity in nestbox internal temperature. Nests contained, in order of prevalence, hen fleas (Ceratophyllus gallinae), haematophagous blowflies (Protocalliphoraspp.), biting lice (Ischnocera), and ticks/mites (Acari). Although southwest-facing nestboxes were significantly warmer than other boxes, there was no directional difference in total ectoparasite load or abundance of particular species. Similarly, there was no relationship between abundance of any ectoparasite species (either per-nest or per-chick) and avian offspring condition determined using wing length or relative mass. We discuss several possible, nonmutually exclusive, explanations for this, including compensatory responses, costs of parasitism being transferred to parents, and condition-dependent effects.

RESPONSES OF CAVITY-NESTING BIRDS TO CHANGES IN AVAILABLE HABITAT REVEAL UNDERLYING DETERMINANTS OF NEST SELECTION

Despite an abundance of studies describing nest selection in cavity-nesting birds, few account for the variation in habitat availability across the geographic range of a species and through time. Changes in the frequency of disturbances such as fires, timber harvests, and insect outbreaks can dramatically alter habitat. Responses by cavity-nesting birds to these changes provide an opportunity to evaluate underlying determinants of nest selection. We compared nest site attributes to available resources for 3 species of cavity-nesting birds: the Pileated Woodpecker (Dryocopus pileatus), Williamson's Sapsucker (Sphyrapicus thyroideus), and Black-backed Woodpecker (Picoides arcticus). Data collected in 2003–2004 were compared to data collected in the 1970s in the same study area to identify changes in patterns of selection. Due to severe insect outbreaks, available resources differed greatly between the 2 time periods. In studies separated by 30 y, Pileated Woodpeckers and Black-backed Woodpeckers exhibited remarkable consistency in patterns of nest site selection. Both species still selected Ponderosa Pine (Pinus ponderosa) snags preferentially for nesting despite their decline in availability. Williamson's Sapsuckers were less selective and nested in the most abundant snag species during both time periods. Selection for factors such as tree size and degree of decay remained consistent regardless of differences in habitat availability for the 3 species. By identifying these general patterns of nest site selection, our conclusions are applicable to a wider variety of habitat conditions.

Comparative habitat use by syntopic Kelp Gulls (Larus dominicanus) and Olrog's Gulls (L. atlanticus) in coastal Patagonia

We studied comparative microhabitat use by breeding Kelp Gull (Larus dominicanus) and the threatened Olrog's Gull (Larus atlanticus) at six colonies through the distributional range of Olrog's Gull in coastal Patagonia, Argentina. The ranges of values for most of the 13 microhabitat variables measured (related to vegetation, soil and topography) were broader for the Kelp Gull than Olrog's Gull, with those of that latter within the range of Kelp Gull, indicating potential spatial conflict between the two species. There was particular overlap in nest-site characteristics, but differences were observed between the two species. Multivariate analyses showed that the most important differences in habitat between the two species related to vegetation cover and distance to the high-tide line. Compared with Kelp Gulls, Olrog's Gulls placed their nests in sites with lower proportion of vegetation cover, lower percentages of silt-clay in the substrate, and closer to the high-tide line. For both species the patterns of nest-site selection did not vary among colonies, although the extent of differences between the two species varied with availability of habitat at each colony. Although Olrog's Gulls started laying 12–14 days earlier than the larger Kelp Gulls, the latter occupied breeding colonies earlier and may, therefore, interfere with settlement of Olrog's Gulls. Considering the increase in the numbers, colony area and nesting density of Kelp Gulls currently observed in coastal Patagonia, there is an urgent need to implement monitoring programs for both species and conduct studies to better predict the results of their interactions.