Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) prefer shells for nesting:A field experiment

Shorebird populations are declining worldwide,mainly due to human disturbances and loss of coastal wetlands.However,supratidal habitats as saltpans could play a role in buffering human impact.Saltpans have shown to be important as feeding or breeding sites of some shorebird species.A potential conservation strategy to increase shorebird populations in saltpans is to manipulate the cues that birds use to select optimal breeding habitat.Here it is hypothesized that shorebirds are attracted to bivalve shells due to the advantages they offer.Following this hypothesis,we supplemented a restored saltpan in 2019 and 2021 with bivalve shells,expecting an increase in the number of breeding birds’ nests.More than 75% of Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) nests were found in patches with shells in both years.The best model for both species indicates that the presence of shells is the factor that most correlates with the location of nests.The probability of choosing one place over another to settle their nest increases in areas with an abundance of shells,double in the case of the Kentish Plover and triple in the case of the Little Tern.The result of this study may constitute a valuable tool for attracting birds to restored saltpans and could contribute to the success of expensive restoration projects where time is usually a constraint.

Modelling the nesting-habitat of threatened vulture species in the caucasus:An ecosystem approach to formalising environmental factors in species distribution models

Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formalised the biotic predictors of nesting sites for four threatened Caucasian vultures by including species distribution models(wild ungulates,nesting tree species)as biotic layers in the vulture Maxent models.Maxent was applied in the R dismo package and the best set of the model parameters were defined in the R ENMeval package.Performance metrics were continuous Boyce index,Akaike's information criterion,the area under receiver operating curve and true skill statistics.We also calculated and evaluated the null models.Kernel density estimation method was applied to assess the overlap of vulture ecological niches in the environmental space.The accessibility of anthropogenic food resources was estimated using the Path Distance measure that considers elevation gradient.The availability of pine forests(Scots Pine)and wild ungulates(Alpine Chamois and Caucasian Goat)contributed the most(29.6%and 34.3%)to Cinereous Vulture(Aegypius monachus)nesting site model.Wild ungulate distribution also contributed significantly(about 46%)to the Bearded Vulture(Gypaetus barbatus)model.This scavenger nests in the highlands of the Caucasus at a minimum distance of 5–10 km from anthropogenic facilities.In contrast,livestock as a food source was most important in colony distribution of Griffon Vulture(Gyps fulvus).The contribution of distances to settlements and agricultural facilities to the model was 45%.The optimal distance from Egyptian Vulture(Neophron percnopterus)nesting sites to settlements was only 3–10 km,to livestock facilities no more than 15 km with the factor contribution of about 57%.Excluding the wild ungulate availability,the ecological niches of studied vultures overlapped significantly.Despite similar foraging and nesting requirements,Caucasian vultures are not pronounced nesting and trophic competitors due to the abundance of nesting sites,anthropogenic food sources and successful niche sharing.

Nesting Biology and Site Selection of Olive Ridley—A Coherence of Nature

Nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. In the present study, characteristics of the breeding turtle, Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of North Andaman Islands were investigated, for the nesting periods 2016-2017. Olive Ridley is the dominant sea turtles, with more than 300 individuals nesting every season with at least a 75% hatching success rate. It is one of the conducive, highly protective and undisturbed nesting sites for Olive Ridley on North Andaman coast. In the present study an initiative is made, to identify nature’s cues and the biological characteristics of Olive Ridley, which leads it to nest at Ramnagar beach, with a high hatchling success rate.

The Probable Cause for Nesting Pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar Beach, North East Coast of Andaman Island, India

The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with the nesting behaviour of the Olive Ridley turtles. In the present study, characteristics of the breeding beach and nesting pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of Andaman Islands were investigated, during the nesting periods 2016-2017. The study area hosts Olive Ridley, the dominant sea turtles with more than 300 individuals nesting each year. For this study, the number of sea turtles visited, nested, the sediment characters, salinity, and temperature were taken. The exposed sandy nesting beach characteristics are prone to varying degrees of morphological changes every day. The results depict that even though similar grain size (Coarse Sand to Fine Sand and Very well sorted to Poorly Sorted), with an ambient incubating temperature, pH and salinity with wide nesting area, the selective nesting in the particular location of the beach identified because of comfortable energy conditions in the waters (1.5 m/s) favours the female turtles to reach the beach at the preferable site of Ramnagar and nest.

The effects of climate and land use change on the potential distribution and nesting habitat of the Lesser Adjutant in Nepal

Climate change and land use change pose a threat to the world’s biodiversity and have significant impacts on the geographic distribution and composition of many bird species,but little is known about how they affect threatened large-sized waterbird species that rely on agricultural landscapes.To address this gap,we investigated how climate and land use changes influence the distribution and nesting habitats of the globally vulnerable Lesser Adjutant(Leptoptilos javanicus) in Nepal.Between 2012 and 2023,we collected distribution data from 24 districts and nesting site information from 18 districts.In a nation-wide breeding survey conducted in 2020,we documented a total of 581 fledglings from 346 nests in 109 colonies.The ensemble model predicted a current potential distribution of 15%(21,637 km2) and a potential nesting habitat of 13%(19,651 km2) for the species in Nepal.The highest predicted current suitable distribution and nesting habitat was in Madhesh Province,while none was predicted in Karnali Province.The majority of this predicted distributional and nesting habitat falls on agricultural landscapes(>70%).Our model showed a likely range expansion of up to 15%(21,573 km2) for the distribution and up to 12%(17,482 km2) for the nesting habitat under SSP5-8.5 scenarios for the 2070s.The range expansion is expected to occur mainly within the current distribution and breeding range(Tarai and some regions of Siwalk),particularly in Lumbini and Sudurpashchim provinces,and extend to the northern portions(Siwalik and Mid-hill regions) in other provinces.However,the current Protected Areas and Important Bird and Biodiversity Areas are inadequate for providing optimal habitats for the species.Although the model suggests range expansion,the use of such novel habitats is primarily contingent on the availability and protection of large-sized trees(particularly Bombax ceiba,observed in 65% of colonies) in agricultural regions where nesting occurs.Therefore,our research suggests that agricultural landscapes should be prioritized in management plans for the conservation of the Lesser Adjutant in Nepal.

一种基于NeSTiNg的TSN强实时流量调度和自动配置方法

流量调度是时间敏感网络(Time Sensitive Networking, TSN)技术的核心.在大型工业嵌入式系统应用中,TSN流量调度的设计和仿真阶段需要对链路、流、门控等调度信息进行复杂且苛刻的配置.现有的基于仿真框架的配置方法多采用手动配置,这阻碍了这些框架对大型TSN网络的适用性.基于TSN强实时流量传输机制和NeSTiNg(Network Simulator for Time-Sensitive Networking)框架,提出一种适用于大型网络的强实时流量调度和自动配置方法.首先,该方法区别于传统的手动配置输入方式,实现了对流偏移、门状态和路由表等信息的自动配置;其次,该方法提取了流的端到端时延,验证了大型网络中TSN传输的强实时性;最后,通过计算拓扑变化后选择新路径的运算时间,评估了该方法对动态拓扑的适用性.结果表明:该方法保证了大型网络中大量流传输的强实时性,且当拓扑改变时,相比于静态路由有更低的运算时间.

眼针对脑缺血再灌注损伤大鼠Nesting、GAP43蛋白表达影响

目的：通过观察眼针治疗对脑缺血再灌注损伤大鼠大脑皮层巢蛋白（Nesting）、生长相关蛋白43（Growth associated protein 43,GAP43）蛋白表达的影响,探讨眼针治疗对脑缺血后神经再生作用。方法：SD大鼠随机分为空白组、假手术组、模型组（3 h、24 h、72 h）、眼针组（3 h、24 h、72 h）,每组6只。采用改良线栓法制备大脑中动脉缺血2 h再灌注损伤模型,眼针组给予眼针治疗方法,每12 h 1次,每次20 min。各组大鼠在治疗点结束后,对大鼠神经功能缺损进行评分,用Westblot法检测缺血侧大脑皮层Nesting、GAP43蛋白含量。结果：（1）眼针组24 h、72 h神经功能评分低于同时间点的模型组（P〈0.05）。（2）脑缺血后模型组Nesting蛋白表达升高并随着缺血时间延长持续升高,与空白组比较,P〈0.05;眼针组Nesting蛋白表达趋势与模型组相似,与模型组同时间点比较,眼针组Nesting蛋白表达升高更明显（P〈0.05）。（3）脑缺血后模型组GAP43蛋白表达升高并随着缺血时间延长持续升高,与空白组比差异明显（P〈0.05）;眼针组GAP43蛋白表达趋势与模型组相似,与模型组同时间点比较,眼针组GAP43蛋白表达升高更明显（P〈0.05）。结论：眼针治疗可以促进脑缺血后Nesting、GAP43蛋白的表达,从而具有促进脑缺血后神经发生的作用。

HABITAT SUITABILITY INDEX MODELS: GREY HERON NESTING IN ZHALONG NATIONAL NATURE RESERVE

Grey heron (Ardea cimerca) is one kind of the great birds which are often seen in the northeast marsh area of P.R.China, and there are many grey herons to reproduce in Zhalong Nature Reserve from March to August annually. In this paper, through the inveingation of the grey herons nesting habitat and according to the water depth, vegetation type, cover density and plan heigh of the nesting place, the grey heron’s nesting habitat suitability index medes are established. The main model is s=(s1xs2xs3xs4)1/4,where s1 is the water depth suitability index, s2 is the vegetation type suitability index, s3 is the cover density index, sa is the plant height suitability index. These models provide a kind of reliable method for evaluating the habitat quality of the grey heron’s nesting.

Green Turtle, <i>Chelonia mydas</i>, Nesting and Temperature Profile of the Nesting Beach at Huyong Island, the Similan Islands in Andaman Sea

Global change in temperature is regarded as a serious natural disaster that may cause extinction of organisms. Green turtle, Chelonia mydas, is not only an endangered species but also a species with temperature dependent sex determination that could be affected by the global warming. In this study, nesting and temperature profile of C. mydas nesting beach at HuyongIsland, the most important nesting site of C. mydas in Andaman Sea of Thailand, were studied in order to monitor a potential effect of regional climate change on the green turtle nesting activity and habitat. Nesting activities were surveyed during May-August 2011 and temperature profiles of the nesting beach were monitored for 58 days during the normal incubation period of this species. The total of 25 nests with clutch size of 105 ± 25 eggs was found during this study period suggesting normal nesting activity of the green turtle. Temperature profile of the nesting beach showed similar trend among nests with no clear influence of the vegetation cover. Mean nest temperature at the middle-third period, corresponding to the temperature-sensitive period of C. mydas, ranged from 28.3°C to 28.9°C, suggesting a slightly male-biased sex ratio of the offspring. Overall, temperature profile of the nesting beach showed little or no indication of adverse effects of regional increase in temperature on nesting activity and egg incubation of the green turtle at this period.

Monitoring hawksbill turtle nesting sites in some protected areas from the Persian Gulf

Iranian nesting populations of the critically endangered hawksbill turtle(Eretmochelys imbricate) are some of the most important in the Indian Ocean. In this study, four of the most important hawksbill nesting grounds in the Persian Gulf, situated within three Iranian marine protected areas, were surveyed during nesting season,including Nakhiloo, Ommolgorm and Kharko Islands and the mainland beaches of the Naiband Marine-Coastal National Park(NMCNP). We present GIS maps of these key nesting grounds and describe sand texture of key nesting zones, along with conservation recommendations. About 9.2(28.3%) out of 32.5 km of all shores surveyed in this study were used by nesting hawksbill turtles follows: Nakhiloo: 1.4 km(52% of potential nesting area);Ommolgorm: 1.94 km(40%);Kharko: 3.4 km(28%), and NMCNP: 2.46 km(18.9%). The average nesting density was calculated as 131 nests/km at Nakhiloo, 76 nests/km at Ommolgorm, 7 nests/km at Kharko, and 15 nests per km at NMCNP. Highest nesting density was observed in Nakhiloo and Ommolgorm. It is thought that high hawksbill nesting density in these islands seems likely a result of limiting adequate nesting shores rather than the size of population, and also low density in Kharko and NMCNP more related to past and current pressures and low population density. With the exception of Ommolgorm Island, sands at the nesting grounds were well sorted.Grain size indicated that female hawksbill turtles in the Iranian Persian Gulf nest in sands that are generally mixed, with mean grain size ranging from coarse sands(0.4Φ;~0.5–1 mm) to fine sands(2Φ;~0.25 mm). We provide and discuss conservation recommendations and suggestions for future.

Is nesting in closed nestboxes advantageous for the European Robin(Erithacus rubecula)?

Background:The European Robin(Erithacus rubecula)is eurytopic in its choice of nest site,which can be either half-open or closed,and situated either on the ground or at a height of several meters.On occasion,robins also nest in closed nestboxes,though generally only solitary such cases are documented,albeit that dozens of such events can be recorded during the course of some long-term studies.However,until now,nobody has summarised the peculiarities of robins nesting in closed nestboxes.Methods:In the period 1978-2020,wooden tit and starling nestboxes were inspected regularly at five study sites in Lithuania,this totaling more than 18,000 nestbox-seasons.During these inspections,90 cases of robins nesting in the nestboxes were recorded.Publications on this topic from the entire robin distribution range were reviewed.Results:Robins prefer to nest in old large-sized fairly shallow nestboxes with wide entrance holes,for example starling nestboxes or tit nestboxes with enlarged entrance holes.Increased numbers of nestboxes being occupied by robins were recorded for 3-8 years in row.In Lithuania,nesting success in nestboxes is not higher than compared with nesting on the ground.Tree climbing mammals,Pine Martens(Martes martes),Hazel Dormice(Muscardinus avellanarius),Edible Dormice(Glis glis)and Forest Dormice(Dryomys nitedula),are the main predators of robin nests in nestboxes.Conclusions:Some geographic variation was found in the occurrence of robins nesting in nestboxes with more such cases recorded in central and southern parts of the range.Possibly robins are more philopatric in these parts of the range,with the same females or their offspring nesting in nestboxes for several years in row.In areas inhabited by dormice,nesting in closed nestboxes is not advantageous for robins.

A high incidence of non-cavity nesting in an introduced population of House Sparrows suggests that the species should not be constrained by cavity-nest site availability

Background: The House Sparrow(Passer domesticus) has undergone dramatic population declines in many parts of Europe.It has been widely hypothesised that a lack of cavity nest sites has contributed to this decline.However the idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the species.Methods: The nest-site selection in a population of non-native House Sparrows introduced to Australia from Europe just over 150 years ago was characterised.The prevalence of non-cavity nesting was quantified,and nest-site selection in terms of landscape and nesting structure were described.Results: Flexible nesting behaviors were reported over a range of different landscapes and a surprisingly high rate of nesting in vegetation(43%) was documented.Most nests found in vegetation were not in cavities,but were woven into the foliage and supported by branches and stems.Conclusion: The high rate of vegetation nesting indicates that in this introduced population,the House Sparrow is unlikely to be constrained by cavity-nest site availability.The high degree of nest site plasticity in the Australian population may suggest that European House Sparrows have the potential to shift away from their proclivity for cavity nests.Future work in Europe should examine the incidence of non-cavity nesting in House Sparrows more closely,and perhaps reconsider the idea that House Sparrows are nest-site constrained.

Sea Turtle Nesting: What Is Known and What Are the Challenges under a Changing Climate Scenario

The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival;especially temperature increase, which is particularly fast, impacts life history characteristics, such as temperature-dependent sex determination (TSD), late maturity and sea turtles highly migratory nature. This review aims to identify and summarize the information that has been collected from 2009-2020 in order to aid future empirical studies that seek to fill these and other knowledge gaps, and subsequently assist conservationists in making multilevel decisions to protect sea turtle populations and species. In a summarized way the general knowledge acquired so far on the influence of environmental abiotic and biotic factors on nesting behaviour and hatching, emergence and survival successes of sea turtle hatchlings, was gathered. To accomplish this work, a search on Web of Science, Science Direct, NCBI/PubMed, and Google Scholar was carried out using the terms “sea turtles + climate change”. Published articles in the period 2009-2020 were selected, related to the nesting ecology of 5 species of sea turtles: Caretta caretta, Eretmochelys imbricata, Dermochelys coriacea, Chelonia mydas, Lepidochelys olivacea. Emphasis was also placed on geographical information and on population location (e.g. climatic conditions during the nesting season). These articles (N = 126) were analysed giving relevance to researcher’s data interpretations, comparisons with other researches, and the reached conclusions. An attempt was made to represent all 5 species of sea turtles when selecting articles on each of the environmental factors that influence sea turtle nesting: temperature, humidity, nesting substrate, gases, depth of the nest, sea surface temperature (SST), nest location on the beach, nesting phenology and geographic distribution of nesting habitats. The interaction between these parameters and their consequences on the terrestrial phase of reproduction are presented and discussed.

Diversity, Habitat Utilization and Nesting Characteristics of Waterbirds in and around Maduru Oya Reservoir in Maduru Oya National Park, Sri Lanka

Maduru Oya National Park (MONP) including its largest reservoir, Maduru Oya Reservoir (MOR), has been identified with a high waterbird density. However, a limited number of researches have been conducted on waterbirds in MONP. In this study, diversity, habitat use of waterbirds at MOR and their nesting characteristics were analyzed. Bird survey was carried out using the point count method and block count method. A common ethogram was constructed to identify the behavior categories. Percentage cover of habitat types was estimated by quadrat method. A total of 30 species belonging to 15 families were recorded, including two globally threatened species and three winter visitors. Year around Shannon-Weiner index for MOR was 1.491. Little Cormorant had the highest relative abundance. Percentage coverage of grass had increased gradually from March to September with the highest in September (69.27%) while open water had the highest coverage in the other months. Significantly high number of individuals used areas of grass, open water and mud for feeding and exposed rocks, dead trees/logs for resting (One-way ANOVA, p ≤ 0.05). Four waterbird species were observed building nests. Occupied nesting tree species were Senna spectabilis (Kaha Kona), Dymorphocalyx glabellus (Weliwanna) and Alstonia scholaris (RukAththana). The number of nests observed in three layers of canopy was significantly different (p ≤ 0.05). The highest average number of nests was observed in middle layer (8.90 ± 2.67). Black-headed Ibises had high preference to nest in Dymorphocalyx glabellus (p ≤ 0.05, 3.30 ± 1.32) while Great Cormorants (p ≤ 0.05, 2.38 ± 0.74) and Grey Herons (p ≤ 0.05, 4.27 ± 2.12) in Alstonia scholaris. Little Cormorants had no significant difference in their preference for nesting trees. As a preliminary study, this can be used for future research on waterbirds and to compose management and conservation plans.

Nesting and Berth Allocation by an Expert System Using Heuristic Search

Nesting is a common problem in industries such as shipbuilding, auto-maker, clothing, shoe-making, and furniture, in which various parts are cut off from a stock or stocks while minimizing the wastes or maximizing the utilization of the stock. Berth allocation at seaside is also considered one form of two dimensional nesting problems, in which a ship is assigned a location for service during a certain time slot. This paper presents an expert system using a heuristic search method for nesting problems. The parts and stocks are represented by pixels with which utility function is used to evaluate current state in search tree. The system is developed in CLIPS, an expert system shell and applied to various example problems with different constraints and to a berth allocation example to illustrate its applicability under different conditions.

Nesting Orientalisms:Case of Hungary,Its Imaginary Occidentalisation Process,and Inconsistencies

What is the border between Central and Eastern Europe?This is an unanswered question in the literature of contemporary European history and politics.In the modern state system,imaginary boundaries are products of the imagined communities,and these boundaries also cause either to occidentalize or to orientalize the lands due to its top-down/elitist imagination procedure.During the Cold War years,anti-USSR voices are important to see the certain demand for Europeanization among people in today’s Central Europe where there especially had the communist legacy.In general,the ultimate goal is to identify themselves as more western among Central and Eastern European states for the sake of civilizational values of the Enlightenment and to reach today’s contested Neoliberal welfare.This desire causes Nesting Orientalisms,Milica Bakic-Hayden’s concept.Nesting Orientalisms are about re-constructing new Orient in the same region to hierarchizeitself as occidental.Through the process of mapping its location and construction of occidental identity,Hungary defines itself as a part of Central Europe.But what are the legitimated reasons of Hungary to define itself as Central European instead of Eastern Europe?Do these reasons perfectly fit in today’s Central European formulation and stereotype?What are the possible reasons to reject Hungary’s Central European self-definition?Moreover,under the shadow of the discussion on Central Europe vs.Eastern Europe,to what extent does the rise of authoritarianism block ongoing occidentalisation process of Hungary?In this research,I will answer these questions by analyzing modern political history of Hungary by the method of interpretivist process tracing.

Does nest sanitation elicit egg rejection in an open-cup nesting cuckoo host rejecter?

Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.

Nesting patterns of raptors;White backed vulture (<i>Gyps africanus</i>) and African fish eagle (<i>Haliaeetus vocifer</i>), in Lochinvar National Park on the kafue flats, Zambia

This study assessed the nesting patterns of raptors, Gyps africanus and Haliaeetus vocifer in Lochinvar National Park. The main objective of the study was to determine whether tree species, height, girth size, and habitat influenced raptor’s nest placement within Lochinvar National Park. Two species were selected as indicator species for the raptors. Habitat types and tree species were identified and measurements of tree species with nests measured. It was found that the minimum height of nest placement was 10 meters above ground and Acacia woodland was found to be the most preferred habitat for nest placement. Raptors avoided human disturbance by placing their nests at least 100 meters away from human disturbance and from the National park boundary inwards or abandoning if human encroachment comes close to the nest. More research is required to assess nesting materials used, and to determine whether raptors can swap nets or return to the abandoned nests when human disturbance ceases.

Light matters:Nest illumination alters egg rejection behavior in a cavity-nesting bird

Egg discrimination by cavity-nesting birds that build nests under dim light conditions was presumed to depend on nest luminance,although this hypothesis has rarely been tested.Tests of egg discrimination ability by cavity-nesting tits under dim light conditions may reveal the selection pressure from brood parasitism that they encounter under natural interactions.We manipulated the intensity of luminance of nests of the Green-backed Tit(Parus monticolus),a potential cuckoo host that possesses a strong discrimination ability of non-mimetic foreign eggs.We performed experiments to test their egg discrimination ability under different light conditions.Our results showed that Green-backed Tits discriminate against non-mimetic foreign eggs under normal light conditions in nest boxes,and this ability persisted at nest luminance as low as 4.78±1.31 lux that is several times lower than normal luminance(38.11±24.02 lux).However,egg discrimination by Green-backed Tits disappeared when nest luminance was reduced to a minimum of 0.35±0.15 lux.The latter value represents total darkness for humans.The present study shows that nest luminance plays a key role in egg discrimination by Green-backed Tits that build nests under dim light conditions.This study provides strong experimental evidence for nest illumination altering egg rejection behavior in cavity-nesting birds.

Developing and validating a nestling photographic aging guide for cavity-nesting birds: an example with the European Bee-eater(Merops apiaster)

Background: Accurate estimation of nestlings’ age is essential in avian demography studies as well as in population ecology and conservation. For example, it can be useful for synchronizing nest visits with events of particular interest, such as the age at which young can be safely ringed, or in choosing the best period to attain the most accurate calculation of laying or hatching dates.Methods: We constructed a photographic guide for aging European Bee-eaters(Merops apiaster) nestlings to 3-day age classes and evaluated the aging method by performing a validation exercise with several observers with no previous experience in aging bee-eater nestlings.Results: The aging guide for bee-eater nestlings allowed estimating age to within 3 days with an average accuracy of 0.85. We found the optimal period for aging nestlings was between days 13-18(with accuracy between 0.94 and 0.99), during which the status of feather development was more easily distinguishable from the preceding and subsequent age classes. During the first 3 days after hatching, nestlings could also be aged with high accuracy(0.93). The small size of the nestling in relation to the eggs and the nestling’s inability to raise its head during these first days allowed for good discrimination from the subsequent age class. Between days 25 and 28, nestlings were correctly aged in only half of assignments(0.55 sensitivity) and nestlings belonging to class 7(days 7-9) were the least correctly identified(0.38 sensitivity). However, by visiting the nests at 12 days intervals it is possible to achieve the highest accuracy in age estimation with the smallest disturbance and logistic investment.Conclusions: This study highlighted how indirect methods and a simple protocol can be established and employed to quickly estimate nestling age in cases where handling nestlings is challenging or impossible, while minimizing disturbance in and around the nest.