Impacts of roads associated with the Ekati Diamond MineTM, Northwest Territories, Canada, on reproductive success and breeding habitat of Lapland Longspurs

2005 ◽  
Vol 83 (10) ◽  
pp. 1286-1296 ◽  
Author(s):  
Sean K Male ◽  
Erica Nol

We examined the effects of roads associated with the Ekati Diamond MineTM, Nortwest Territories, Canada, on reproductive success and breeding habitat of Lapland Longspurs (Calcarius lapponicus (L., 1758)) by comparing these attributes on study sites located directly beside and at least 5 km away from roads. No significant differences between roads and reference sites were detected for first-egg dates, clutch size, mean nestling mass on the 7th day following hatch, or daily nest survival. We found no evidence that Lapland Longspurs were avoiding nest sites located near roads. Recorded frequencies of male song overlapped with the harmonics of heavy-truck noise. Snow-water equivalent and percent cover of mosses were significantly higher on reference sites, while soil moisture and dust deposition were higher on road sites. Dust suppressant applied midway through the breeding season significantly reduced dust deposition. Lapland Longspur nest sites had significantly higher percent cover of graminoids and of shrubs and forbs, and significantly lower percent cover of lichens than random sites, an effect that occurred both near and distant from roads. Currently, there appears to be no measurable effect of roads associated with the Ekati Diamond MineTM on current territorial choice and reproductive performance of Lapland Longspurs. Observed differences in habitat characteristics between reference plots and road plots suggest that long-term changes in the vegetation community may occur that could affect nest-site selection of Lapland Longspurs.

2006 ◽  
Vol 84 (11) ◽  
pp. 1533-1539 ◽  
Author(s):  
Rebecca Jo Safran

Despite hundreds of studies, we know very little about the causes and fitness-related consequences of nest-site selection. For example, it is not typically known whether the rarely reported fitness consequences of site selection are the result of nest, individual, or nest-site variables or combinations of these factors. Reuse of previously constructed nest sites is a prevalent behavior in many animals and offers the opportunity to experimentally tease apart whether seasonal reproductive success is a function of nest, individual, or nest-site characteristics. I used observational and experimental data to test three hypotheses related to these factors in association with barn swallow ( Hirundo rustica L., 1758) nest reuse. While both nest and individual characteristics explain variation in seasonal reproductive success, nest location per se is not an important factor defining the outcome of nest-site selection. Whereas traits related to habitat and individual characteristics are likely confounded in correlational studies, my experiments demonstrate a causal relationship between seasonal reproductive success and aspects of the nest and individual, the latter explaining more variation in the model than nest characteristics. Knowledge of the relative roles of individual, nest, and nest-site attributes are important for understanding the causes and consequences of habitat selection behavior.


2006 ◽  
Vol 27 (3) ◽  
pp. 359-364 ◽  
Author(s):  
David Scott ◽  
Dean Croshaw

AbstractNest site selection is an important part of adult reproductive behavior because growth and survival of young are often affected by the local environment. In terrestrially nesting marbled salamanders, nest elevation is likely important to reproductive success because it is directly related to the time of hatching. We tested the hypothesis that females choose nest sites based on elevation and its correlates by controlling the availability of nesting cover, a potentially important factor in nest site selection which often covaries with elevation. Breeding adults were confined to field enclosures in which natural nesting cover had been removed and replaced with equal proportions of artificial cover in each of three elevation zones. In four enclosures that spanned from lowest to highest areas of a wetland breeding site, females used artificial nesting cover most frequently at low elevations. These results contrast with other studies in which intermediate elevations had highest nest densities, but are consistent with a conceptual model in which opposing selective forces result in locally adapted nest site selection.


2009 ◽  
Vol 36 (6) ◽  
pp. 479 ◽  
Author(s):  
Rick J. Baxter ◽  
Jerran T. Flinders ◽  
David G. Whiting ◽  
Dean L. Mitchell

Translocations have been used for decades to restore or augment wildlife populations, yet more often than not, little to no data and/or arbitrary means are used for determining translocation success. The objectives of our study were to describe nesting habitat utilised by the greater sage grouse translocated into an extant population and to identify factors related to nest success, thereby demonstrating the adaptability of the birds to their new environment and producing one measure of long-term translocation success. We trapped female grouse individuals during the spring on and near leks of source populations, fitted them with radio-transmitters, and released them in the morning onto an active lek in an extant population in Strawberry Valley, Utah. We monitored translocated females for nesting activity and documented nesting attempts, nest success, clutch size and embryo viability. Data were recorded on habitat variables associated with nest sites and paired-random sites, including factors known to be important for resident females that nested successfully. We used logistic regression and an a priori information-theoretic approach for modelling nest v. paired-random sites and successful v. unsuccessful nest sites. Our analyses suggested that crown area of the nest shrub and percentage grass cover were the two variables that discriminated between nest and paired-random sites. Females that nested successfully selected sites with more total shrub canopy cover, intermediate size-shrub crown area, aspects other than NW and SE, and steeper slopes than for unsuccessful nests. After being translocated from distant sites with differing habitat characteristics, these birds were able to initiate a nest, nest successfully, and select micro-habitat features similar to those selected by resident sage grouse across the species range. Our results demonstrate the adaptability of the translocated female sage grouse individuals and produce one tangible measure of long-term translocation success.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9892
Author(s):  
Rocío Fernanda Jara ◽  
Ramiro Daniel Crego ◽  
Michael David Samuel ◽  
Ricardo Rozzi ◽  
Jaime Enrique Jiménez

Background Birds can maximize their reproductive success through careful selection of nest-sites. The ‘total-foliage’ hypothesis predicts that nests concealed in vegetation should have higher survival. We propose an additional hypothesis, the ‘predator proximity’ hypothesis, which states that nests placed farther from predators would have higher survival. We examined these hypotheses in the world’s southernmost forests of Navarino Island, in the Cape Horn Biosphere reserve, Chile (55°S). This island has been free of mammalian ground predators until recently, and forest passerines have been subject to depredation only by diurnal and nocturnal raptors. Methods During three breeding seasons (2014–2017), we monitored 104 nests for the five most abundant open-cup forest-dwelling passerines (Elaenia albiceps, Zonotrichia capensis, Phrygilus patagonicus, Turdus falcklandii, and Anairetes parulus). We identified nest predators using camera traps and assessed whether habitat characteristics affected nest-site selection and survival. Results Nest predation was the main cause of nest failure (71% of failed nests). Milvago chimango was the most common predator, depredating 13 (87%) of the 15 nests where we could identify a predator. By contrast, the recently introduced mammal Neovison vison, the only ground predator, depredated one nest (7%). Species selected nest-sites with more understory cover and taller understory, which according to the total-foliage hypothesis would provide more concealment against both avian and mammal predators. However, these variables negatively influenced nest survival. The apparent disconnect between selecting nest-sites to avoid predation and the actual risk of predation could be due to recent changes in the predator assemblage driven by an increased abundance of native M. chimango associated with urban development, and/or the introduction of exotic mammalian ground predators to this island. These predator assemblage changes could have resulted in an ecological trap. Further research will be needed to assess hypotheses that could explain this mismatch between nest-site selection and nest survival.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3182 ◽  
Author(s):  
Myriam Ramirez-Herranz ◽  
Rodrigo S. Rios ◽  
Renzo Vargas-Rodriguez ◽  
Jose-Enrique Novoa-Jerez ◽  
Francisco A. Squeo

In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic morphological characteristics followed by extrinsic variables associated to human disturbance. Likewise, within reproductive ravines, intrinsic characteristics are more strongly related to the number of nests. The probability of producing eggs, however, was related only to distance to roads and human settlements. Patterns suggest that C. patagonus mainly selects nesting sites based on intrinsic morphological characteristics of ravines. Scale differences in the importance of ravine characteristics could be a consequence of the particular orography of the breeding habitat. The arrangement of resources is associated to the location of the gullies rather than to individual ravines, determining the spatial availability and disposition of resources and disturbances. Thus, nest selection is influenced by intrinsic characteristics that maximize the fitness of individuals. Scaling in nest-selection is discussed under an optimality approach that partitions patch selection based on foraging theory.


2020 ◽  
Vol 13 (3) ◽  
pp. 63-69
Author(s):  
Bo Zhou ◽  
Changzhang Feng ◽  
Wei Liang

The quality of breeding habitat may directly affect the survival and development of progeny. Therefore, the selection of a suitable nest-site is an important factor affecting the reproductive success of birds. The most important reason for a bird’s reproductive failure is nest predation. Predation may cause birds to change their nest-sites and even nest morphology. Here we investigated the nest-site characteristics by long-tailed broadbills ( Psarisomus dalhousiae) in Nonggang, Guangxi, southwestern China. Our results showed that long-tailed broadbills in Nonggang mainly build their nests on power lines (88.5%) and nest-site selection was mainly affected by predation pressure and food resources. At the same time, nest-site concealment was trade-off against predator avoidance. This anti-predator strategy effectively utilizes human infrastructure.


The Condor ◽  
2007 ◽  
Vol 109 (1) ◽  
pp. 15-31 ◽  
Author(s):  
Paul Allen Smith ◽  
H Grant Gilchrist ◽  
James N.M Smith

Abstract Abstract In environments such as arctic tundra, where bird densities are low and habitats are comparatively homogeneous, suitable nest sites likely are not limited. Under these conditions, reproductive success of birds may be determined by factors other than the habitat characteristics of nest sites. We studied the relative influence of nest habitat, food, nest distribution, and parental behavior on the reproductive success of tundra-breeding shorebirds at East Bay, Southampton Island, Nunavut, Canada. From 2000 to 2002, we monitored the nests of five species: Black-bellied Plover (Pluvialis squatarola), Semipalmated Plover (Charadrius semipalmatus), Ruddy Turnstone (Arenaria interpres), White-rumped Sandpiper (Calidris fuscicollis), and Red Phalarope (Phalaropus fulicarius). For each species, habitat differed between nest sites and random sites. In contrast, habitat differed between successful and failed nest sites only for White-rumped Sandpipers. Shorebirds did not prefer to nest in habitats where food was most abundant. Although nest success varied among species in all years, artificial nest experiments suggested that interspecific variation in predation rate was not related to habitat type. Instead, the marked interspecific variation in nest success may have been related to incubation behavior. Species taking fewer incubation recesses had higher nest success, although these results should be viewed as preliminary. The factor with the greatest interannual influence on nest success was fluctuating predation pressure, apparently related to the abundance of predators and lemmings.


2012 ◽  
Vol 90 (10) ◽  
pp. 1215-1220 ◽  
Author(s):  
C.A. Peet-Paré ◽  
G. Blouin-Demers

Nest-site selection is an important behaviour in oviparous reptiles because incubation conditions affect offspring phenotype, with favourable conditions leading to higher offspring fitness. We aimed to identify the habitat characteristics involved in nest-site selection in Eastern Hog-nosed Snakes ( Heterodon platirhinos Latreille, 1801) and to determine whether females select nest sites that result in offspring with phenotypes likely to improve fitness. We compared the habitat characteristics and temperature profiles of 21 nests with 21 randomly selected sites. Eastern Hog-nosed Snakes selected open, grassy sites with less herbs and shrubs than random sites, and nests were significantly warmer than random sites during the 2 years of the study. In the second year of the study, we incubated 215 eggs from eight nests in a split-clutch design at mean nest (24 °C) and random site (22 °C) temperatures approximating those of the first year of the study. Eggs incubated at 24 °C resulted in neonates that hatched earlier, had fewer scale anomalies, were larger, and swam faster than neonates from eggs incubated at 22 °C. Our results indicate that Eastern Hog-nosed Snakes select nest sites that lead to offspring with phenotypes likely to improve fitness.


The Auk ◽  
2020 ◽  
Vol 137 (3) ◽  
Author(s):  
Kelly S Overduijn ◽  
Colleen M Handel ◽  
Abby N Powell

Abstract The vertical structure and composition of vegetation can influence the quantity and quality of potential nesting sites for birds. Interspecific competition for high-quality nesting habitat may force some individuals into suboptimal habitat and lead to reduced reproductive success, eventually leading to changes in distribution or abundance. Large climate-mediated shifts in vegetation, including the rapid expansion of shrubs onto tundra, are occurring in the Arctic across important breeding grounds of many shorebird species of conservation concern. We investigated effects of vegetation structure and composition on nest-site selection and nest success of sympatrically breeding American Golden-Plovers (Pluvialis dominica) and Pacific Golden-Plovers (P. fulva), which nest along an elevational gradient ranging from coastal tundra meadows to alpine tundra. Both species strongly selected nest sites with less cover of tall shrubs and other tall vegetation than available at random sites within their territories. American Golden-Plovers selected territories and nest sites that were higher in elevation and had more rocky substrates and less graminoid vegetation than those selected by Pacific Golden-Plovers. The daily nest survival rate was equivalent in the 2 species (0.966, 95% CI: 0.955, 0.975) and similar to that found in other Arctic-breeding shorebirds; however, contrary to predictions, nest survival was not associated with habitat features selected for nest sites for either species. Strong selection of open habitat for nest sites suggests that continued climate-related shrub expansion may reduce the amount of suitable breeding habitat for both species, but partitioning along the elevational gradient and differences in body size suggest that impacts may be more severe for Pacific Golden-Plovers. Additional research is needed to determine if differential selection of nesting habitat is related to survival of the adults or their young.


1997 ◽  
Vol 75 (11) ◽  
pp. 1835-1844 ◽  
Author(s):  
Stanislav Pribil ◽  
Jaroslav Picman

Nest-site preferences of birds have traditionally been inferred from correlations between reproductive success and various habitat attributes. Because there are several problems associated with this method, we examined preferences by comparing characteristics of actual nest sites with those of sites available to females at the time of their settlement. We examined these preferences on two spatial scales using the marsh-nesting Red-winged Blackbird (Agelaius phoeniceus). On the broad spatial scale, univariate analyses established that female settlement was nonrandom with respect to four of five habitat characteristics. However, a multivariate analysis revealed that females settled nonrandomly only with respect to water depth (they preferred areas located in deep water). The other characteristics, including cattail density, were not important. On the narrow spatial scale, females preferred sites located in dense cattail clumps that were surrounded by unusually sparse cattail vegetation. The preference of female redwings for deep-water areas was not detected in an earlier study conducted in the same marsh using the traditional method. In addition, if we were to have examined female preferences on the broad scale only, we would have failed to recognize the importance of cattail density in nest-site selection. The results of this study demonstrate the importance of examining nest-site selection using an appropriate method and multiple spatial scales.


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