Factors determining nest-site selection of surface-nesting seabirds: a case study on the world's largest pelagic bird,the Wandering Albatross (Diomedea exulans)

Several factors may drive bird nest-site selection, including predation risk, resource availability, weather conditions and interaction with other individuals. Understanding the drivers affecting where birds nest is important for conservation planning, especially where environmental change may alter the distribution of suitable nest-sites. This study investigates which environmental variables affect nest-site selection by the Wandering Albatross Diomedea exulans, the world's largest pelagic bird. Here, wind characteristics are quantitatively investigated as a driver of nest-site selection in surface-nesting birds, in addition to several topographical variables, vegetation and geological characteristics. Nest locations from three different breeding seasons on sub-Antarctic Marion Island were modelled to assess which environmental factors affect nest-site selection. Elevation was the most important determinant of nest-site selection, with Wandering Albatrosses only nesting at low elevations. Distance from the coast and terrain roughness were also important predictors, with nests more generally found close to the coast and in flatter terrain, followed by wind velocity, which showed a hump-shaped relationship with the probability of nest occurrence. Nests occurred more frequently on coastal vegetation types, and were absent from polar desert vegetation (generally above c. 500 m elevation). Of the variables that influence Wandering Albatross nest location, both vegetation type and wind characteristics are likely to be influenced by climate change, and have already changed over the last 50 years. As a result, the availability of suitable nest-sites needs to be considered in light of future climate change, in addition to the impacts that these changes will have on foraging patterns and prey distribution. More broadly, these results provide insights into how a wide range of environmental variables, including wind, can affect nest-site selection of surface-nesting seabirds.     

Experimental Study of Nest-site Selection in the Biscutate Swift (Streptoprocne biscutata, Aves: Apodidae) in Southern Brazil

Biscutate swift Streptoprocne biscutata nests are usually built on protected rocky cliff walls. Birds often renest at the same location. Remains of previous nests may offer information about potential nests and quality of nest-sites. Here, we experimentally study nest-site selection to test the hypothesis that information from previous nests is used in current nest-site selection. We placed old nest material at artificial nest-sites to test whether new nest-sites are chosen based on the presence of nesting material. We also tested whether the use of natural nest-sites is influenced by nesting material by creating two types of natural sites: previously used natural nest-sites with vestiges of old nests removed and never used natural nest-sites to which vestiges of old nests were added. In the first experiment, in 139 nest-use opportunities, 16 artificial nest-sites were used, all of which included vestiges. In the second experiment, in 91 nest-use opportunities, four nests were in previously unused but natural locations to which vestiges had been added, 22 nests were in previously used sites without vestiges, and the remaining 65 nests remained unused. Two processes are apparently in action: first, prior experience and memory; second, vestiges indicate where nesting has occurred, possibly useful for first breeding, or for imperfect memory. Previous nesting information may explain why swifts use nesting locations for many years and why new nesting colonies seldom form. This transmission of information suggests that swifts tend to be conservative and nest where previous nesting has occurred.     

Testing the importance of individual nest-site selection for a social and group-living vulture

Nest-site selection by species is expected to be adaptive and lead to improved breeding productivity, but in some settings, there exist mismatches between preferred nesting habitat and breeding productivity. We tested the expectation that nest-site selection is adaptive in a sample of 63 nests of a long-lived social species that breeds and forages in groups: the critically endangered white-backed vulture (Gyps africanus). By studying breeding groups in the same area, we controlled for landscape-level effects on habitat selection and investigated how fine-scale nest-site characteristics affect breeding productivity. We developed models to assess how nine characteristics of nest sites selected by breeding vultures compared with 70 random trees and tested associations between these characteristics and breeding productivity. White-backed vultures selected nest sites in taller trees (>7 m), but neither tree height nor any other nest-site characteristics had a clear effect on breeding productivity. Vultures selected nest trees closer to each other than random trees, and the associations between nest density, nearest neighbour distance and breeding success were all positive. These positive associations and the absence of an observable effect between nest-site characteristics and breeding productivity suggest that for this semi-colonial breeder, the social imperative of proximity to conspecifics (i.e., nesting near other vultures and group foraging) may be more important than individual nest-site selection.     

利用天然树洞繁殖的五种鸟的巢位特征及繁殖成功率

对吉林省左家自然保护区次生阔叶林中的大山雀 ( Parusmajor)、沼泽山雀 ( Paruspalustris)、普通跓( Sitta europacea)、白眉姬? ( Ficedula zanthopygia)和灰椋鸟 ( Sturnus cineraceus) 5种利用天然树洞繁殖的次级洞巢鸟进行了巢位选择和繁殖成功率研究。本研究中共发现 1 41巢。五种鸟对树洞类型的选择存在种间差异 ,普通跓不利用裂洞 ,沼泽山雀不利用啄洞 ,其它 3种鸟对 3种洞均有利用 ,但有一定的倾向性。对 5种鸟 9个巢位变量的比较中 ,只有洞口方向差异不显著 ( p >0 .0 5 ) ,其它 8个变量均差异显著 ( p<0 .0 5 ) ,该结果说明 5种次级洞巢鸟对巢位的选择具有其各自的需求。洞口横径、洞口纵径、洞处树直径、洞内径、巢距地高是巢位选择重要变量 ,它们决定不同种类对树洞的利用。巢损失多数出现在产卵之前和孵化阶段 ,44个繁殖失败的巢中有 35个在这两个阶段损失。大山雀的巢成功率最低 ,灰椋鸟的巢成功率最高。 5种鸟的孵化率都超过 90 %。人为破坏和动物捕食是繁殖失败的主要原因 ,占总数的 61 .4%。洞巢鸟巢位选择中的重要变量影响繁殖成功。普通跓繁殖是否成功受洞口横径和巢高影响 ,沼泽山雀受洞口纵径、树胸径和洞内径影响 ,大山雀受洞口横径、巢高和洞内径影响 ,灰椋鸟受洞内径和洞深影     

Breeding success and nest-site characteristics of Red-breasted Flycatchers Ficedula parva in a primeval forest

Capsule Predation is a major factor influencing the breeding success of Red-breasted Flycatchers under natural conditions.

Aims To examine the breeding success of Red-breasted Flycatchers in relation to nest-site characteristics and time of breeding.

Methods Data were collected during seven breeding seasons under natural conditions in Bia?owie?a National Park. We used survival time analysis to estimate changes in survival probability over time and breeding success in relation to first-egg date and nest-site characteristics.

Results Offspring fledged successfully from 51% of clutches, but the Kaplan–Meier estimate of survival was lower at 0.43. Of the unsuccessful clutches, 82% were lost to predators. The highest probability of loss was during egg-laying and in the second half of incubation. Breeding success was influenced by the height of the nest above the ground, but no relation to other nest-site characteristics was found.

Conclusion To avoid predation Red-breasted Flycatchers build nests in various sites that are more open than most cavity-nesting species. The position of the nest-sites allows the sitting female to observe her surroundings and to escape rapidly from the nest, giving the chance for a replacement clutch.     

四川南充市区珠颈斑鸠的繁殖生态学和巢址选择

2002年11月~2004年4月在四川省南充市区内对珠颈斑鸠(Streptopelia chinensis)繁殖生态和巢址选择进行了研究。结果表明:珠颈斑鸠3月初开始求偶交配,求偶行为复杂,有“婚飞”行为;雌雄参与筑巢,营巢期7~8 d。影响巢址选择的主要因素有6种:栖位与巢周隐蔽因子、巢下隐蔽因子、光照因子、人为活动因子、食物因子和营巢树因子;窝卵数2枚,雌雄轮流孵卵,孵卵期17~18 d,孵化率86.67%;雌雄均参与育雏,育雏期18~20 d,雏离巢率73.08%,繁殖生产力1.82,种群育雏高峰期为7月和8月中上旬。     

Nest-site selection and predation in Savi's Warblers Locustella luscinioides

Capsule Savi's Warblers preferred sites dominated by high and dense Juncus and Rubus with thick litter, and avoided pure reeds; predation was higher in sites with less litter.

Aim To describe nest-site selection and identify which habitat and nest features influence predation risk.

Methods Comparisons were made between habitat characteristics measured at nest-sites and random points, and between predated and successful nests.

Results Total vegetation cover, litter thickness, habitat type, undergrowth height and undergrowth cover, which were higher or denser at nest-sites, were the most important variables influencing the distribution of Savi's Warbler nests. Nests were most often predated in sites with low litter thickness.

Conclusion Savi's Warblers are dependent on the presence of dense low vegetation and litter for nesting, which should be maintained close to or within reed-beds for their benefit.     

The influence of nest-site characteristics on the nesting success of the Karoo Prinia (Prinia maculosa)

Choice of nest site has important consequences for nest survival. We examined nest-site characteristics relative to nest success in Karoo Prinias breeding in coastal dwarf shrubland, where high nest predation is the main cause of nest failure. Initially, we compared nests that failed during the building, laying, incubation and nestling stages and those from which young were successfully raised, to test whether nests that survived to progressive stages in the nesting cycle differed in their nest-site characteristics. Subsequently, we compared the characteristics of successful nests with those of unsuccessful nests. The nest-site characteristics considered included nest height, nest-plant height, nest-plant species, distance from lateral foliage edge, nest concealment, nest-patch heterogeneity and vegetation cover at four different heights. We were unable to distinguish between the nest-site characteristics of nests that failed during the various stages of the nesting cycle. Concealment was the main nest-site characteristic that differentiated successful nests from unsuccessful nests, with successful nests being located in more concealed sites. The other variables that contributed to the discrimination between successful and unsuccessful nests by discriminant function analysis included nest-plant type and distance from edge, which are also directly related to concealment. This suggests that nest concealment is the most important variable influencing nesting success at this site, which has a preponderance of visually-oriented predators.     

Nest location, clutch size and nest success in the Scarlet Ibis Eudocimus ruber

Breeding success and nest-site characteristics were studied during the 1996–1997 breeding season in a colony of Scarlet Ibises Eudocimus ruber in south-eastern Brazil to test the hypothesis that nest-site characteristics and clutch size affect nest success. Two nesting pulses produced young, the earlier being more successful. Predation accounted for most failures during the first pulse, wind destruction during the second. A third pulse with few nests produced no young. Adult Ibises abandoned nests when they lost sight of other incubating birds. Logistic regression analysis indicated that nest success during the first pulse was positively related to clutch size, number of nests in the nest tree and in the nearest tree, and negatively to the distance to the nearest neighbour. During the second pulse there were significant negative associations between success, nest height and distance to the fourth nearest nest, and a positive association between success and nest cover. The results agree with the 'selfish herd' hypothesis, indicating that nest aggregation may increase breeding success, but the nest-site characteristics affecting success can differ over the course of one breeding season.     

东北地区北红尾鸲巢址选择及繁殖成效

北红尾鸲(Phoenicurus auroreus)是一种分布广泛的小型雀形目鸟类,主要分布于南亚东北部,东南亚北部、东亚及俄罗斯等地区,我国东北、华北、华中至西南等地也均有分布,是重要的食虫益鸟。为探究北红尾鸲巢址选择的影响因素,找到影响北红尾鸲繁殖成功率的主要巢址因子,于2017年4—7月,在辽宁仙人洞国家级自然保护区开展系统研究。共发现北红尾鸲自然巢44个,其中29巢繁殖成功,15巢繁殖失败。北红尾鸲主要筑巢于石墙缝、空心砖墙缝及废旧电表箱中。巢址参数的主成分分析结果表明:巢口因子(27.738%)、巢位因子(14.195%)、光照因子(12.145%)、人为干扰因子(10.440%)、安全因子(9.266%)和隐蔽因子(7.187%)是影响北红尾鸲巢址选择的重要因子。采用二元逻辑斯蒂回归分析繁殖成功巢与失败巢参数发现,成功巢的巢口最大高度显著小于失败巢(P=0.047),且其距顶的距离更近(P=0.043)。多元线性回归分析表明,巢上方盖度对繁殖成功率有极显著影响(t=2.883,P=0.009)。总的来说,北红尾鸲虽偏爱筑巢于人为干扰较大的村庄房屋附近,但较小的巢口能有效避免巢捕食者的捕食,更近的距顶距离和更大的巢上方盖度能有效降低巢上方的可视程度和降水等不利因素的影响,从而提高繁殖成功率。     

新疆阜康地区家麻雀的巢址选择

2013年7月和2014年5~7月,在新疆阜康地区对家麻雀(Passer domesticus)的巢址选择进行调查,以分析影响家麻雀巢址选择的生态因子。在研究区内共找到75个家麻雀的自然巢,筑巢生境为农田和防护林带,均在白杨(Populus adenopoda)林和胡杨(P.euphratica)林中的树上筑巢。其中,繁殖成功巢40个,繁殖失败巢20个,15个巢未记录到繁殖结果。在研究区内的居民房屋、墙洞等没有发现家麻雀的巢。采用逻辑斯蒂回归和主成分分析方法对筑巢地海拔(m)、筑巢树种、筑巢树高(m)、巢距路距离(m)、巢距地面高度(m)、巢上方盖度(%)、筑巢树胸径(m)、最近邻巢的距离(m)这些家麻雀的主要巢址参数进行分析,结果表明,影响新疆阜康地区家麻雀巢址利用的主要因素为巢距地面高度(m)、巢上方盖度(%)和巢距路距离(m)。对家麻雀繁殖成功巢(n=40)和繁殖失败巢(n=20)的巢址参数进行比较,两者差异不显著,因而推测,在研究区域的尺度内,家麻雀的巢址选择并不是影响其繁殖成效的主要因素。     

郑州郊区崖沙燕(Riparia riparia)的巢址选择

2014年3—8月,采用样方法对分布于河南省郑州市郊区的4处崖沙燕(Riparia riparia Linnaeus 1758)营巢地的13个生境因子进行了调查,测定了巢址样方和对照样方各160组数据,并利用Mann-Whitney U检验对这些数据的显著水平进行了检验;最后采用逐步判别分析(stepwise discriminate analysis)方法确定影响崖沙燕巢址选择的主要生态因子,并建立了标准化的典则判别函数。结果表明,1)崖沙燕洞巢的洞口横径(8.46±0.79)cm,纵径(8.30±0.79)cm,巢洞深(87.80±11.97)cm,巢室长径(11.25±1.33)cm,短径(10.43±1.33)cm,巢室高(9.99±1.33)cm;2)巢址样方与对照样方在植被均高、植被密度、坡位、坡度、崖高、崖长、崖龄及干扰度等8个方面差异达到显著水平,崖沙燕偏好选择的洞巢周围植被较高(97.24±8.42)cm,植被密度较大(64.34±7.15)株/m~2,坡度较大(83.78±0.35)°、上坡位(1.41±0.04)、崖较高处(7.54±0.13)m、崖壁较长(51.18±3.54)m、崖龄较短(2.41±0.05)月及人类干扰较低(1.94±0.06);3)逐步判别分析结果表明,影响崖沙燕营巢地选择的主要生境因子是坡位、崖龄和干扰度,标准化的典则判别函数为y=0.753×坡位+0.681×崖龄+0.288×干扰度。建议在城市化建设过程中针对崖沙燕的巢址选择特性建立合理的保护措施。     

Interactive effects of time and vegetation on reproduction of redshanks (Tringa totanus) breeding in Wadden Sea salt marshes

As shown for various species, nesting waders are non-randomly distributed on wetlands and preferentially select riparian nest-sites adjacent to limnic or marine waterbodies. Studying the redshank Tringa totanus, we tested the hypotheses that, in a coastal wader species which conceals its clutch in vegetation, predation and hatching success are affected by vegetation zonation, and that breeding in lower salt marsh areas has negative consequences for reproduction. We further predicted effects of timing of breeding and breeding experience/age of adults potentially reflected by egg biometrics both on nest-site selection and reproduction. Effects of vegetation, space, time and individual quality on hatching success of redshanks were studied in the German part of the Wadden Sea. Dominant plant species, vertical vegetation structure and nest concealment varied significantly between nests. Variation in nest concealment was relatively low: about 90% of clutches were classified as being well concealed. This variation was explainable by vegetation structure but not by vegetation composition at the nest-site, distance to shoreline, and time of clutch initiation. Vertical vegetation structure varied by dominant plant species but not by distance to shoreline and time of clutch initiation. Hatching success of clutches was low (10.6%) due to high predation (daily predation rate: 7.4%). Hatching success and duration of clutch survival were negatively and predation positively related to the date of clutch initiation. Furthermore, negative relationships were found between egg size and predation and duration of survival, respectively. We assume that concealed nests, early breeding and breeding experience diminish predation in salt marsh breeding redshanks. Thus, redshank reproduction appears to be affected by interactive effects of timing of breeding and vegetation facilitating early breeding. In contrast to open-nesting species, breeding in riparian habitats next to waterbodies may be disadvantageous for species breeding concealed in vegetation if these are covered by less structured vegetation.     

原鸡海南亚种的巢址特征

选择适宜的巢址对降低巢捕食风险,提高繁殖成效有重要意义。2008年3—7月,在海南省大田国家级自然保护区,采用随机样线法结合访问法在各种生境类型中系统地寻找原鸡海南亚种(Gallus gallus jabouillei)的巢,并在野外追踪观察基础上用样方法对原鸡的巢址选择进行研究。共记录到原鸡的巢16个,以巢为中心选取样方并测量反映巢址的13个特征生境参数,同时分析16个对照样方以进行比较,并通过主成分分析探讨影响巢址选择的主导因子。结果表明：（1) 原鸡的巢位于密集的丛生草本下或低矮的灌木丛基部。营巢背景多样,其中位于草本植物下10个(62.5%);灌草丛5个(31.3%);灌木下1个(6.25%)。（2) Mann–Whitney U检验的结果显示,原鸡偏好于比较开阔、地面落叶稀少而靠近的小道和林缘的位置营巢。（3) 主成分分析表明,植被盖度因子和空间位置因子贡献率最大,在降低巢捕食风险中有重要价值,是影响原鸡巢址选择的主要因素。     

Influence of nest-site and individual quality on breeding performance in Merlins Falco columbarius

We examined the effects of nest-site quality and bird quality on breeding performance in male and female Merlins Falco columbarius from a long-term study in Saskatoon, Saskatchewan. In addition, we tested whether nest-site quality was associated with survival, as well as lifetime reproductive success (LRS). For females, nest-site quality had little influence on any of the measures of breeding performance or survival. Even so, when females switched nest-sites, they tended to move to better ones. Hatch date was repeatable for the same females occupying different nest-sites but not for the same sites occupied by different females. Among males, birds surviving past each age category tended to occupy nest-sites of higher quality, and LRS was positively correlated with nest-site quality. The relationship between nest-site quality and LRS was heavily influenced by the poorest nest-sites. When males switched nest-sites, they too tended to move to ones of higher quality. In addition, chick hatch date was repeatable neither for the same males occupying different sites nor for the same sites occupied by different males. As with most other raptors, male Merlins provide most of the food for the pair and their young during the breeding season, and differences in nest-site quality may have affected the effort needed by males to secure food. Female Merlins, however, appear still to have considerable control over the timing of breeding.     

Nestbox provisioning in a rural population of Eurasian Kestrels: breeding performance,nest predation and parasitism

The breeding biology of the Eurasian Kestrel Falco tinnunculusin nestboxes in farmland was studied to test for differences between artificial and natural sites. We report on the direct effect of nestbox provisioning on some life-history traits and how nestbox use affects nest predation and parasitism. Five types of nest-sites were available: nestboxes on poles and trees (artificial sites), stick nests on trees, stick nests on pylons and holes in buildings (‘natural’ sites). The Kestrel population increased from 23 pairs in 1993 (prior to nestbox installation) to 55 in 1998 as nestboxes were provided. In general, pairs breeding in trees started to lay later than those nesting in nestboxes on poles or in building holes, but this difference was probably associated with habitat quality rather than nest type. Differences in clutch size were found between nest-sites in some years, and were associated with laying date and, probably, with variation in territory quality. Using only data from successful nests, pairs breeding in nestboxes produce more fledglings than those in building holes or pylons. The frequency of nest predation was higher in natural sites than in nestboxes. The number of fledglings from pairs breeding in nestboxes was higher than from those breeding in old stick nests in trees when all nests were considered. Nestbox provisioning had no effect on the occurrence of the ectoparasite Carnus hemapterus, but chicks from nestboxes showed higher intensity of infection. Our results suggest that nestbox provisioning increases reproductive success and the frequency of nest predation or intensity of parasite infestation in Kestrels.     

Landscape and anti-predation determinants of nest-site selection, nest distribution and productivity in a Mediterranean population of Long-eared Owls Asio otus

Nest predation is an important determinant of owl breeding success. We studied Long-eared Owl Asio otus productivity and attributes of nest-sites at the microhabitat and landscape scales in a Mediterranean locality over an 8-year period. We examined the effect on nest location and productivity of protective cover in concealing the nest from aerial and terrestrial predators. A dense cover of ivy and tree-foliage at canopy level favoured nest location but not productivity. By contrast, high shrub cover beneath the nest was selected by Owls and was positively related to both the site reoccupancy rate and the overall number of young fledged. Pre-fledging Owls use the ground, where they are exposed to terrestrial predators, which are much more abundant in the study area than are aerial predators. Our results therefore support the hypothesis that Owls adapt nest-site choice to local sources of predation risk. As reported elsewhere, Long-eared Owls in our study area showed restricted territoriality and nested in clusters. As active nest-sites during the same breeding season were more than 1 km apart on average, and their productivity was never greater for clustered nests than for more isolated nests, nest aggregation could not be interpreted as a case of facultative colonial breeding, which has been reported for this species in other areas. Neither landscape variables indicative of the availability of foraging areas nor structural attributes that protect young from predators explained the remarkable scarcity of nests in half of the study area. Unmeasured factors such as human disturbance could explain the pattern of distribution of Long-eared Owl nests.     

内蒙古达赉湖西岸地区大鵟巢穴特征和巢址选择

2010年和2011年3月-6月,对内蒙古达赉湖国家级保护区达赉湖西岸地区大鵟(Buteo hemilasius)的巢穴结构和巢址选择因子进行了调查研究.采用野外观察和样方法定位了13个大鵟巢址,并对巢址样方的20个生态因子进行测量,运用主成分分析法对影响大鵟巢址选择的主要因子进行了分析.测量显示,大鵟巢穴的基本结构特征为:外径(94.7+4.2) cm;巢高度(46.1±2.7) cm;内径(24.8±1.5)cm;巢深(14.0±+0.9)cm.生境因子分析结果表明,达赉湖西岸地区大鵟的巢集中分布在湖岸或水塘附近的悬崖,营巢点坡度为15°-45°之间的阳坡或半阳坡;隐蔽度高于20％;草本密度大于5株/m2;植被均高大于30cm;巢距悬崖上部距离2-5m;距水源l00m以内;距居民点距离大于lkm;距草原道路的距离大于0.5km;而对于物种丰富度没有特殊要求.主成分分析显示,影响大鵟巢址选择的主要因子有3个,依次为:隐蔽性因子(主要包括巢址区域的植物特征和地形特征)、干扰因子和食物因子.各主成分中,相对系数绝对值最高的变量依次是:植被盖度、距居民点距离、巢的高度和距草原道路距离.     

Nest-site selection by Common Black-Hawks in southwestern New Mexico

ABSTRACT.   Despite the interest of resource managers and conservationists in the status of Common Black-Hawk ( Buteogallus anthracinus ) populations in the southwestern United States, little is known about their nesting success and habitat requirements. Because such information is essential for effective population and habitat management, I examined the nesting success and nest-site selection of Common Black-Hawks in southwestern New Mexico during 2000 and 2001. Of the 37 nesting attempts in 21 territories, ≥1 young fledged from 25 nests (68%). Comparison of nest-sites and nonused sites suggested that breeding Common Black-Hawks selected nest-sites in areas with a sparser and shorter subcanopy tree layer and in trees with a smaller trunk diameter and a greater minimum crown diameter. These differences appear to be related to variation in forest ages within territories, with nonused sites having fewer, but older, canopy trees than nest-sites. Sites with younger, smaller subcanopy trees may provide forest structure for more effective foraging, whereas the characteristics of younger nest tree canopies may reduce the risk of nest predation or offer more protection from inclement weather. Due to the limited range of this species in the southwestern United States, efforts to encourage the establishment and maturation of riparian forests in Common Black-Hawk breeding areas could be important in sustaining available nesting habitat and, in turn, maintaining or expanding current population levels.