Migrations and sojourn in Africa of Egyptian vultures ( Neophron percnopterus) tracked by satellite

By means of satellite telemetry, the migrations of three young Egyptian vultures (Neophron percnopterus) from France and Bulgaria were studied and data obtained (over 4,300 Argos locations) to describe movement patterns, timing of migration, routes followed, speed of flight and ranging behaviour in Africa. Two French vultures migrated at almost the same time and, after travelling ca. 3,570 km, remained in the Sahelian zone, in southern Mauritania. The Bulgarian bird, after travelling 5,340 km, ended in south-east Chad, in the Sudano-Sahelian zone. It was possible to determine two remarkably long daily flight distances of this bird of over 500 km on two successive days (1,017 km in total) when crossing the Sahara. In January and February, the Bulgarian bird wandered extensively over 2,600 km, even as far as north-east Nigeria. Both French vultures remained in their home ranges in Mauritania once they had adopted them, which extended to 69,000 km² and 50,000 km², respectively. One continuously-tracked vulture from France first left its African home range when 3 years old (probably in its fourth plumage type).Communicated by F. Bairlein     

Breeding habitat and nest-site selection of Bearded Vulture Gypaetus barbatus in the Annapurna Himalaya Range of Nepal

Quantitative studies on nesting habitat selection are important to understand and predict the resource requirements for breeding habitat. In this study, we analysed nest-site (cliff) and territory selection patterns of the Bearded Vulture in the Annapurna Range of the Himalayas (Nepal). Our study area represents high-elevation mountain range systems, where information on nest selection is lacking, despite having the largest remaining populations of Bearded Vultures in the world. Our models indicated selection patterns at both nest and territory spatial scales that are consistent with previous studies at lower altitudes (Pyrenees, the Caucasus), such as a preference for landscape patches with greater food availability. However, our models also indicated selection patterns that are probably a response to the higher altitudes and sheer reliefs of the Annapurna massif, such as avoidance of the steepest slopes and selection of cliffs facing south and west for nest-sites. We did not detect an impact of human activities on the distribution of nests or territories. However, the Annapurna massif is experiencing development of infrastructures (e.g. road construction). Further research efforts will be needed to monitor human impacts on Bearded Vulture populations in the Annapurna Range, as this is a global stronghold for this species.     

Landfills determine the distribution of an expanding breeding population of the endangered Egyptian Vulture Neophron percnopterus

Human activities provide food resources for animals that are predictable in space and/or time. These resources, sometimes referred to as predictable anthropogenic food subsidies (PAFS), can be either the result of human‐generated waste or provided intentionally, sometimes as a conservation measure. Some PAFS, including landfills, are used by common species. However, little information exists about the effects that these feeding points have on rarer species that feed there, some of which are of conservation concern. This study focuses on the influence of PAFS and their spatial location on the distribution of territories of the endangered Egyptian Vulture Neophron percnopterus. We analysed a population in the NE Iberian Peninsula that has in recent decades expanded its range. We used both null model and linear model analyses to ascertain the effect of PAFS and other covariates on the occupancy of territories by the study species. PAFS appeared to play an important role in territory selection by Egyptian Vultures, as occupied territories were nearer landfills than expected by chance. Furthermore, the distance from PAFS (landfills and vulture feeding stations, or ‘restaurants’) played an important role in the probability of territory occupancy by Egyptian Vultures, in addition to other environmental variables such as surface areas of rocky south‐facing slopes, human settlement and the proximity of conspecifics. However, recent EU legislation aims to phase out open‐air landfills to reduce the negative environmental effects of these facilities. This could have an undesired impact on the endangered species that use these feeding points. We recommend management measures that can control abundant pest species but, in the long term, other measures as supplementary feeding should be considered to counteract the probable negative effect of the disappearance of landfills on endangered species.     

Factors influencing Hen Harrier Circus cyaneus territory site selection and breeding success

ABSTRACT

Capsule: Our findings regarding Hen Harrier Circus cyaneus territory site selection and breeding success in Ireland offer an opportunity for the development of initiatives and conservation actions aimed at enhancing the suitability of upland areas for breeding Hen Harriers and ensuring the long-term persistence of the species.

Aims: To investigate landscape-scale associations between habitat composition and Hen Harrier territory site selection, and to explore the influence of habitat and climate on breeding success.

Methods: We used multi-model inference from generalized linear models and Euclidean distance analyses to explore the influence of habitat, topographic, anthropogenic and climatic factors on Hen Harrier territory selection and breeding success in Ireland, based on data from national breeding surveys in 2010 and 2015.

Results: Hen Harrier territories were associated with heath/shrub, bog and pre-thicket coniferous forests. Comparisons between territories and randomly generated pseudo-absences (upland and lowland) showed that breeding pairs preferentially select for these habitats. Breeding success was negatively influenced by rainfall early in the breeding season and by climatic instability, and was positively influenced by the presence of heath/shrub and bog.

Conclusions: The results suggest that Hen Harrier breeding success is compromised by the synergistic effects of climate, landscape composition and management. Effective conservation of Hen Harriers in Ireland will therefore rely on landscape-scale initiatives.     

影响灰脸鵟鹰巢址选择的主要生态因素

1996～1997年,在吉林省左家自然保护区及土门岭地带对灰脸鵟鹰(Butastur indicus)的巢树和巢址特点进行了系统研究。运用逐步判别分析的方法,通过对因子进入判别方程的先后顺序检测因子的重要性,通过对Wilk’sλ值的检测确定各因子对判别模型的贡献率,根据生态因子的重要性和贡献率大小确定影响灰脸鵟鹰巢址选择的主要生态因素。两年共观测灰脸鵟鹰的巢址12处,其中83．3％(n=10)位于山坡的上部位置,66．7％(n=8)位于山北坡;在灰脸鵟鹰所利用的巢树中,松科(Pinaceae)植物占的比例最大,为75％(n=9)。逐步判别分析结果表明,胸径大于30cm乔木的基面积、针叶林的基面积和灌木数量等生态因子是影响灰脸鵟鹰巢址选择的主要生态因素。     

Factors affecting breeding habitat selection in a cliff-nesting peregrine Falco peregrinus population

We studied factors affecting breeding habitat selection in a population of cliff-nesting peregrines Falco peregrinus across multiple spatial levels (cliff site, cliff context and land-use of the surrounding landscape), over a 2,100 km² study area in the Alps (Italy and Switzerland). We detected 30 breeding pairs (density: 1.43 territorial pairs/100 km²), whose territories were uniformly distributed over the study area. We compared 15 habitat features characterising occupied cliffs and 30 randomly selected unoccupied cliffs by means of stepwise forward logistic regression and hierarchical partitioning. The logistic regression analysis showed that occupied cliffs were longer (horizontal length), steeper, and had a greater extension of urban areas in the surrounding landscape compared to non-occupied cliffs. The model had a discrimination ability of 0.95. Hierarchical partitioning indicated that the logistic regression model was appropriate. Neither the distance of cliffs to the nearest site occupied by a potential competitor and predator, the eagle owl Bubo bubo, which occurred at a low density (0.67 pairs/100 km²), nor the distance to the nearest site occupied by peregrines had any effect on the cliff suitability model. Therefore, habitat selection in cliff-nesting peregrines was mainly influenced by cliff site features and surrounding landscape characteristics, whereas the proximity to conspecifics and to an intraguild predator had no apparent effects on peregrine settlement in our study population.     

副珠蜡蚧阔柄跳小蜂的寄生影响因子

副珠蜡蚧阔柄跳小蜂Metaphycus parasaissetiae是橡副珠蜡蚧Parasaissetia nigra成虫的重要内寄生蜂。寄生蜂的寄生效果受多种因素影响,就温度、光周期、寄主成虫日龄、雌蜂日龄及交配等因子对副珠蜡蚧阔柄跳小蜂的寄生率、每头寄主的出蜂量及后代雌性率的影响进行研究,以期探明几种因子对该蜂寄生效果的影响。结果表明:温度为27—30℃时寄生率最高为91.7%,出蜂量以27℃最高为7.5头,雌性率以24℃条件最高为72.1%,其次27℃为62.6%,说明24—30℃是寄生效果较好的适温范围;光周期对副珠蜡蚧阔柄跳小蜂的影响明显,光暗比为12 h∶12 h条件下,其寄生率、出蜂量、后代雌性率均最大,分别为70.6%、5.3头、68.3%;副珠蜡蚧阔柄跳小蜂寄生用20—21日龄橡副珠蜡蚧成虫的寄生率、出蜂量及后代雌性率均为最高,分别为87.0%、5.6头、51.2%,说明20—21日龄的橡副珠蜡蚧成虫是副珠蜡蚧阔柄跳小蜂最适合寄生的阶段;雌蜂日龄对寄生效果的影响明显,3日龄的出蜂量最多为5.6头,4日龄的小蜂寄生率最高为81.7%,5日龄的雌性率最大为55.2%;交配是另一影响寄生效果及性比的重要因子,已交配的寄生率及出蜂量显著高于未交配的,分别为91.7%、7.5头,交配的雌性率为62.1%,而未交配所育后代均为雄蜂。综合以上结果分析,可考虑选用20—21日龄橡副珠蜡蚧成虫、充分交配的3—6日龄小蜂、温度27℃及光周期L∶D=12∶12作为室内扩繁副珠蜡蚧阔柄跳小蜂的理想条件组合。     

Factors affecting the breeding success of the grey heron ( Ardea cinerea) in northern Poland

The aim of this study was to estimate the importance of factors affecting the breeding success of the grey heron (Ardea cinerea) in three colonies in the northern Poland (Mosty, Kiersity and Kty Rybackie), differentiated in population size, habitat type and feeding areas used by birds. The highest mean number of fledglings (39–51 days old) per nest in 2000–2002 combined was recorded at Kty Rybackie (3.2±0.91 SD). Lower values were recorded at Kiersity (2.5±1.11) and Mosty (2.8±1.20). Breeding success increased with the size of the heronry (r₇=0.77, P<0.05) and was the highest in the biggest, at Kty Rybackie (716–879 nests). In the studied colonies, the number of feeding visits was the most important factor affecting breeding success. At Kty Rybackie and Kiersity, chick mortality significantly decreased with increasing numbers of feeding visits per nest. The highest breeding success was recorded in the colonies with feeding areas situated nearby (Kty Rybackie and Mosty). Siblicide was also a very important reason of chick mortality in those colonies (54% and 32% chicks died in nests where sibling aggression was observed). Other factors, independent of the level of feeding, like predation, human disturbance, weather condition and experience of parent birds, seem to be of negligible importance.Communicated by F. Bairlein     

Factors affecting facultative polygyny and breeding results in the Great Reed Warbler (Acrocephalus arundinaceus)

Summary In a population of Great Reed Warbler (42–53 stationary males) the sex ratio was balanced and occurence of polygynous males (on average 15 % of the males) was more or less compensated by respective number of unmated males. Prospective polygynists arrived earlier in spring on average than monogamists, and got the first female quicker. Their territories were larger (statistically insignificant) and more often situated close to good foraging grounds. The reeds around primary female nests were on average thicker (and taller) and not so dense as in the case of monogamous, secondary and tertiary females. The intensity of nestling feeding (no. of visits per nestling per hour) was higher in the nests of monogamous females, than in primary females, and lowest in secondary and tertiary females nests. Nestlings in secondary and tertiary female broods were on average lighter than in monogamous and primary female broods. The male helped feed nestlings in secondary female nest only exceptionally. In monogamous situation their share in feeding was ca. 50%, and less so in primary female nests. Production of fledglings per female was highest in primary females and lowest in secondary and tertiary females, mainly due to the high starvation rate in the nests of secondary and tertiary females. Generally, collected data strongly suggest that female choice is determined by territory quality, and polygyny threshold hypothesis cannot be rejected. The deception hypothesis cannot be rejected as well in some observed special situations (disruptive territories or polyterritoriality; four cases).

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Voraussetzungen für fakultative Polygynie beim Drosselrohrsänger (Acrocephalus arundinaceus)

Zusammenfassung Das Geschlechterverhältnis in der untersuchten Drosselrohrsänger-Population von 42 bis 53 war ausgeglichen. Das Auftreten polygyner (durchschnittlich 15 % der ) wurde mehr oder weniger durch eine entsprechende Anzahl unverpaarter kompensiert. Prospektiv polygyne kamen durchschnittlich früher an als monogame und waren schneller verpaart. Ihre Reviere waren (statistisch nicht signifikant) größer und lagen näher zu günstigen Nahrungsgebieten. Das Schilf in der Nähe der Nester von Erst- war durchschnittlich dicker (und höher) als und nicht so dicht wie bei Einzel- oder Zweit- und Dritt- . Die Fütterungsfrequenz der Nestlinge (Anzahl der Besuche beider Altvögel mit Futter pro Nestling pro Stunde) war bei Nestern von Einzel- höher als bei Erst- und am niedrigsten bei Nestern von Zweit- und Dritt-. Nestlinge von Zweit- und Dritt- waren durchschnittlich leichter als solche von Einzel-und Erst- . halfen nur ausnahmsweise bei der Fütterung von Nestlingen von Zweit- . Bei monogamen Paaren beteiligten sich die ungefähr zur Hälfte an der Fütterung der Nestlinge, bei Nestern von Erst- in geringerem Umfang. Der Ausfliegeerfolg war am höchsten beim Erst- und am niedrigsten bei Zweit- und Dritt- , hauptsächlich bedingt durch Verhungern der Nestlinge. Allgemein legen die Daten nahe, da\ die die nach der Revierqualität auswählen und daß das Polygynieschwellenmodell vonOrians undVerner nicht abgelehnt werden kann. Einige Beobachtungen stützen die Hypothese, daß in bestimmten Situationen (unübersichtliche Reviere, Polyterritorialität) durch Täuschung polygyn werden.

     

Parent-offspring Conflict during the Post-fledging Period in the Egyptian Vulture Neophron percnopterus (Aves,Accipitridae)

Egyptian vultures were studied during their post-fledging dependence period in northern Spain in order to detect if there were parent-offspring and sibling tensions during the transition of young to independence. The frequency of parental feedings and the frequency of movements of the parents towards their young decreased during the post-fledging period, especially in its final part. At the same time, the frequency of movements and of aggression by the young towards their parents increased. Aggression by adults to their young was not observed. Siblings disputed feedings, but there was no other evidence for sibling conflict. The results suggest that parent-offspring and sibling conflict exists and that its development is broken by the departure of young on migration. Some behavioural traits of adults (maintenance of distance from young and of intensity of nest-defence, tolerance of young during foraging trips through the home range) do not accord with parent-offspring conflict perhaps because they are related to factors other than family tension.     

Factors influencing forage selection by the North American beaver (Castor canadensis)

Across their range, a large number of biotic and abiotic factors are known to influence the choice of browse plant and the foraging behaviour of the North American beaver (Castor canadensis). We used generalized linear mixed-effects models to investigate sets of variables that may influence the foraging choices of beaver: forage species, distance of forage from water, forage density, and site. Communities across the study sites in central British Columbia, Canada, were dominated by Salix sitchensis, Salix lucida, and Alnus spp. Density had no impact on forage selection, while site, distance from water, and species identity all influenced the foraging decisions of beaver. We postulated that these factors may be ordered hierarchically: large-scale factors, such as site, followed by the medium-scale distance from water, and species of plant at the finest scale. Forage items in some sites had a higher probability of being browsed than in others, while in all sites the probability of being browsed decreased with increasing distance from water. Beaver appeared to be foraging as “picky” generalists; of the 9 plant species examined, 3 species of Salix (S. scouleriana, S. drummondiana and S. sitchensis) were selected by beaver, Salix bebbiana was avoided, and 5 species were neither selected for nor against. Browse selection within the genus Salix implied that beaver were able to differentiate among closely related species. Detailed information on forage selection is a crucial first step in designing and interpreting models that predict large-scale distributional patterns of beaver.     

Scale effects of habitat selection in breeding Nuthatches (Sitta europaea) in two different woodlands

Summary Observations over a 14 year study revealed that Nuthatches had significantly higher breeding densities in a deciduous woodland than in coniferous-mixed woodland. However, the variability in breeding densities between years correlated in the two woodlands. In selecting a breeding site, birds may have to decide on different spatial scales. Possibly, these scales are reflected in a hierarchical series of decisions that might differ according to habitat quality. We correlated the frequency of nest box occupation by Nuthatches over 14 years with habitat parameters and PCA scores of different spatial scales (roughly 0.1 ha and 1 ha). In the coniferous-mixed woodland Nuthatches preferred similar habitat parameters at the small and the large scale like oaks, open areas and forest edge. In the deciduous woodland, however, a marked difference in habitat preference between small and large scale was shown: on the small scale parameters directly associated with nest box characteristics were significantly preferred. On the large scale only structural and floristic parameters associated with the general quality of the woodland were important for breeding site selection. Here tree stands with a superabundance of pine trees were avoided and the abundant oak trees were not important for the selection of a nest box. By further subdividing the very heterogeneous deciduous woodland into two parts, a stand of young trees and the rest of the woodland, opposing habitat choices could be shown. Thus scale effects of habitat choice are dependent upon habitat quality and heterogeneity.

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Einfluß des räumlichen Maßstabs auf die Habitatwahl von Kleibern (Sitta europaea) zur Brutzeit in zwei unterschiedlichen Waldgebieten

Zusammenfassung In einer Langzeituntersuchung über 14 Jahre wurde die Nistkastenbelegung durch Kleiber in zwei unterschiedlichen Waldgebieten, einem Laubwald und einem Nadel-Laub-Mischwald, untersucht. Im Laubwald waren 80 Nistkästen, im Nadel-Laub-Mischwald 92 Nistkästen in 30 × 30 m Rastern aufgehängt. In jedem dieser Rasterquadrate wurden 18 Habitatparameter aufgenommen. Beide Waldgebiete unterschieden sich in den meisten Parametern signifikant. Die Brutpaardichten waren im Laubwald signifikant höher als im Nadel-Laub-Mischwald. Jedoch korrelierte die Variabilität der Brutpaardichten zwischen den Untersuchungszeiträumen in beiden Gebieten. Nistplatzwahl wurde in zwei räumlichen Maßstäben untersucht. Der kleine Maßstab umfaßte die Fläche von 30 × 30 m um jeden Nistkasten (ca. 0,1 ha), der große Maßstab hatte die Fläche von ca. 1 ha (9 Nistkästen, 90 × 90 m). Auf dem kleinen Maßstab wurde die Nistkastenbelegung für jeden Nistkasten über den Untersuchungszeitraum aufsummiert. Auf dem großen Maßstab wurde für jeden Nistkasten und die ihn umgebenden 8 Nistkästen die Belegung gemittelt. Dadurch ergaben sich für großen und kleinen Maßstab identische Stichprobengrößen. Die so ermittelten Nistkastenbelegungen wurden mit den Habitatparametern und entsprechenden Hauptkomponentenfaktoren korreliert.Im Nadel-Laub-Mischwald bevorzugten Kleiber bei beiden Maßstäben Eichen, offene Flächen und Waldränder. Im Laubwald unterschied sich die Habitatpräferenz zwischen den Maßstäben: bei kleinem Maßstab wurden Nistkasten-Parameter (wie z. B. die Höhe) signifikant bevorzugt. Bei großem Maßstab hingegen waren nur Strukturparameter sowie Pflanzenarten für die Nistplatzwahl entscheidend. Waldbereiche mit einem Überangebot an Kiefern wurden gemieden, die häufig und gleichmäßig vorkommenden Eichen hatten bei der Nistplatzwahl keine Bedeutung. Bei weiterer Unterteilung des sehr heterogenen Laubwaldes in zwei Einheiten, einen jungen Baumbestand und den Rest des Waldes, wurde gegensätzliche Habitatwahl nachgewiesen. Daraus folgt, daß bei der Habitatwahl durch unterschiedliche Maßstäbe verursachte Effekte von Habitatqualität und -heterogenität abhängen.

     

Within and between season nest-site and mate fidelity in Common Terns(Sterna hirundo)

Summary We studied nest-site and mate fidelity in renesting Common Terns (Sterna hirundo), from 1993 to 1997, in a Common Tern colony breeding on six small artificial islands in the harbour area in Wilhelmshaven (German North Sea coast). Implanted transponders made possible individual recognition of the adults throughout their lifetime. We compared intra-season rates of nest-site and mate fidelity with between-year rates. Intra-season divorce was never observed. On the other hand, inter-year divorce was estimated at about 25%, suggesting that the costs of intra-season divorce are higher or opportunities for divorce are lower than between years. For 75% of 26 pairs that renested within the same season, the distance moved was less than 4.3 m. For 75% of 57 faithful pairs between two consecutive seasons, the distance moved was less than 1.25 m. Dispersal distances between and within years did not differ significantly but were clearly shorter than a paired random distribution of nests. Most of the birds changed the nest-site either when renesting or between years, but most of the new scapes can be considered as lying within the original territory. Thus, failure of the first breeding attempt increased neither divorce nor nest-site dispersal as compared with between-year rates. We also studied the influence of parental age and the date of breeding failure on distances moved in renesting birds. Late renesting pairs did not change the nest-site. A multiple regression analysis revealed that the longer the duration of the first breeding attempt and the older the pair, the shorter the nest dispersal distance.

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Neststandort- und Partnertreue ersatzbrütender Flußseeschwalben(Sterna hirundo)

Zusammenfassung Von 1993–1997 untersuchten wir Neststandort- und Partnertreue ersatzbrütender Flußseeschwalben (Sterna hirundo) in einer Kolonie, die im Banter See, Wilhelmshaven, auf sechs künstlichen Inseln brütet. Transponder ermöglichten die lebenslange individuelle Erkennung der Altvögel. Neststandort- und Partnertreue innerhalb der Brutsaison und zwischen den Jahren wurden verglichen. Innerhalb der Brutsaison kam Scheidung nicht vor. Eine Trennungsrate von 25% zwischen den Jahren deutet darauf hin, daß die Kosten einer intrasaisonalen Scheidung höher sind als die diejenigen einer Scheidung zwischen den Jahren. 75% der ersatzbrütenden Paare wählten den neuen Neststandort weniger als 4,3 m vom Platz des Erstgeleges entfernt (n=26). 75% der partnertreuen Paare brüteten im Folgejahr nur 1,25 m entfernt vom Neststandort des Vorjahres (n=57). Die Entfernungen zum Neststandort des Folgegeleges innerhalb und zwischen den Jahren unterschieden sich nicht signifikant, waren aber deutlich geringer, als nach einer Zufallsverteilung zu erwarten war. Die meisten Flußseeschwalben wechselten den Neststandort bei einer Ersatzbrut oder im Folgejahr, aber meist wurde das folgende Gelege im ursprünglichen Territorium angelegt. Folglich führt ein Verlust der Erstbrut weder zu erhöhter Scheidungsrate noch zu stärkerer Verlagerung des Neststandorts, verglichen mit der Situation zwischen Jahren. Auch der Einfluß des Alters und Termins des Brutverlusts auf die Distanzen zwischen Erst- und Ersatzgelege wurden untersucht. Späte ersatzbrütende Paare verlegten ihren Neststandort nicht. Eine multiple Regressionsanalyse verdeutlichte, daß die Distanz zum Ersatz-Neststandort abnimmt, je länger der erste Brutversuch andauerte und je älter das Paar war.

     

猫儿山小鲵(Hynobius maoershanensis)繁殖期生境选择

在广西猫儿山自然保护区的山顶湖、三江源、野人湖等地区,基于植被类型、水体类型、岸边条件、卵袋悬挂物、水中覆盖物、人为干扰程度等20种生境因子,通过61个样方（26个选择样方和35个对照样方）,对猫儿山小鲵繁殖期的生境选择做进行了研究,并得出以下4个主要结论：（1）在基于描述型生态因子的研究中,结果显示选择样方与对照样方在水体类型、岸边条件、水中覆盖物3种因子上差异显著,而植被类型、卵袋悬挂物、人为干扰程度3种生态因子对其生境选择无显著影响。（2）基于14种数值型生态因子的研究结果显示,选择样方和对照样方间的植被盖度、水体面积、水体流速和水底泥沙比方面具有显著差异。植被盖度较低、水体面积较大的水域、水体流速低和水底泥沙比较低的水域是猫儿山小鲵的优选繁殖地。（3）基于14种数值型生态因子的逐步判别表明,通过植被盖度和水底泥沙比2个生态因子可分辨选择样方和对照样方,正确判别率达80.3%,且对于检验也具有最大的贡献值,分别为0.840和0.622。（4）对猫儿山小鲵卵袋对数和14种数值型生态因子的逐步回归分析结果显示猫儿山小鲵在繁殖期生境选择与地表湿度显著正相关,与植被盖度呈显著负相关,高地表湿度和低植被盖度对猫儿山小鲵的产卵量起促进作用。猫儿山小鲵繁殖期间偏好的微生境为较低植被盖度、较大面积水体和较低流速、低水底泥沙、多水中覆盖物、复杂岸边条件的静水型水塘,与选择偏好的微生境相关的生态因子是猫儿山小鲵繁殖期生境选择的主要因子。     

Size matters: mole (Talpa europaea) hills and nest-site selection of the ant Formica exsecta

Moles are fossorial mammals that can act both as zoogeomorphic agents and species diversity drivers. These popular animals regularly push heaps of earth from their subterranean tunnel systems to the surface. Thereby they rearrange and improve the local microtopography for ant nesting. Here we use a strongly molehill (Talpa europaea) mediated nest system of the unicolonial wood ant Formica (Coptoformica) exsecta to test for ecological factors influencing nest-site selection at the microhabitat scale. Our results show that the size of molehills plays an important role in the multifactorial process of the ant’s nest-site choice with solar insolation as a paramount factor. The ants clearly favored larger and better sun-exposed molehills, suggesting that the coaction of a zoogeomorphic modified microrelief and solar insolation can drive the spatial colonization of F. exsecta.     

Factors affecting egg dimensions and breeding success in the Cory''s Shearwater(Calonectris diomedea) of Selvagem Grande

Summary Eggs of the Cory's ShearwaterCalonectris diomedea borealis of Selvagem Grande (Madeira, 30°09N, 15°52W), show high variability in size and shape between females, while for each individual both are correlated over two seasons. During the first breeding years, females lay larger and more rounded eggs as their experience (number of years since first breeding) increases. Age (number of years since birth) probably has an effect on egg size but adult size has none. No important differences between the two years of study has been observed and no inter-colony variation is apparent. Finally, breeding success is directly linked to egg size but not to egg shape.

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Eigröße und Bruterfolg von Gelbschnabelsturmtauchern(Calonectris diomedea borealis) auf Selvagem Grande

Zusammenfassung Die Größe und Form der Eier des GelbschnabelsturmtauchersCalonectris diomedea borealis von Selvagem Grande (30°09N, 15°52W) variieren zwischen verschiedenen Weibchen erheblich, die einzelnen Weibchen legen jedoch in Folgejahren gleich große Eier. Erfahrenere Weibchen legen größere und rundere Eier. Ältere Weibchen legen größere Eier. Das Alter hat keinen Einfluß auf die Eigröße. Zwischen den beiden Untersuchungsjahren (1996 und 1997) gab es keine Unterschiede, auch nicht zwischen verschiedenen Kolonien. Bruterfolg und Eigröße waren positiv korreliert.

     

栗斑腹鹀的栖息地和巢址选择

于1999到2001年5月至7月连续3a在吉林省镇赉县大岗林场,采用样地法和样方法,对栗斑腹鹀的栖息地选择和巢址选择进行了研究.结果表明此鸟的繁殖是在草甸草原+杏树环境下进行的,对栖息地样方和对照样方的对比分析得出,杏树最大高度、50 m半径圆内杏树数量、贝加尔针茅数量、大油芒数量、植物盖度、火绒草平均高度、贝加尔针茅最大高度、兴安胡枝子平均高度8个因子是影响其栖息地选择的主要因子.通过对46个巢的研究发现,大多数栗斑腹鹀把巢建在贝加尔针茅下面,巢出入口方向多为东南45°和西南45°.对46巢的27个因子的主成分分析,结果发现植物盖度、火绒草高度、鸢尾数量、巢出入口方向、10 m内杏树数量、30 m内杏树数量、裸地面积这6个因子是巢址选择的主要因子.对46巢26个巢址和非巢址因子进行判别分析,植物盖度、大油芒、乳浆大戟高度、石竹数量、线叶菊高度和30m内杏树数量等6个因子,为巢位选择的主要因子 .两种分析结果基本相似.总之,栗斑腹鹀喜欢在植被盖度大、杏树相对多、贝加尔针茅和大油芒的密度大、食物资源丰富的区域内营巢.