Fitness consequences of hybridization between house sparrows (Passer domesticus) and tree sparrows (P. montanus)

Gene transfer may occur following hybridization between closely related species if hybrids are viable and able to breed with individuals of one or both of the parental species. House (Passer domesticus) and tree sparrows (P. montanus) occasionally hybridize and produce viable offspring. Previously, we concluded that male tree × house sparrow hybrids are most probably fertile based on the observation of a male F1 hybrid feeding the nestlings with a female house sparrow in two consecutive clutches. However, recent DNA analyses based on blood samples revealed that all nestlings (4) in the first clutch were sired by a neighbouring house sparrow male, whereas nestlings in the second clutch (2) were not blood sampled and most probably died before fledging. This indicates that extensive extra-pair fertilization confounded our previous conclusion, and indicates that social partnership and attending behaviour can be imprecise measures of paternity.     

Hybridisation between House SparrowPasser domesticus and Tree SparrowPasser montanus

Hybridisation between House and Tree Sparrows is reported from islands off the coast of Northern Norway, including observed mating attempts in two different mixed pairs, and the breeding success in a third mixed pair. The biometrics of hybrid offsprings were intermediate between the parents. The hybridisation probably involve only inexperienced individuals and may have been facilitated by the spatially division of the population into small island subpopulations.

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Zusammenfassung Auf Inseln vor der Küste Nordnorwegens gelangen Beobachtungen zur Hybridisation zwischen Haus- und Feldsperling; bei zwei Mischpaaren wurden Kopulationsversuche und bei einem dritten eine erfolgreiche Brut festgestellt. Die Merkmale der F1-Generation waren intermediär. Wahrscheinlich waren nur unerfahrene Vögel an den Mischpaaren beteiligt, die ihrerseits wohl durch die Bildung und räumliche Verteilung von kleinen Inselpopulationen begünstigt wurde.

     

树麻雀表型的环境适应进化

树麻雀(Passer montanus)分布范围广、海拔梯度大,也是人类活动的伴随物种。对中国837个样本的10个形态特征与温度、日照、海拔和风速等4个主要环境因子进行相关分析,结果显示:树麻雀的体重、嘴裂、翅长、尾长、跗跖长、脑骨宽、眼间距与日照因子显著相关(P0.05),体重、体长、翅长、尾长、跗跖长与海拔因子显著相关(P0.05),体重、嘴峰、翅长、脑骨长与温度因子显著相关(P0.05),表明树麻雀的形态指标易随环境因子的变化而变化。通过控制经度和海拔两个变量,对形态指标与纬度的偏相关分析表明,体重、翅长、脑骨长和脑骨宽与纬度呈显著正相关(P0.05),体表突出部分嘴峰、嘴裂与纬度呈显著负相关(P0.05),即随着纬度的升高,树麻雀身体逐渐变大,符合贝格曼规律;体表突出部分嘴峰和嘴裂随纬度升高变短,符合阿伦规律。飞行能力与海拔因子呈极显著正相关(n=92,r=0.217,P=0.038),表明树麻雀在高海拔地区具有更强的飞行能力,这也许是它成为广布种的重要原因。     

House sparrow (Passer domesticus) habitat use in urbanized landscapes

The house sparrow (Passer domesticus) is showing population declines in many parts of Europe, with recent declines being particularly severe in urban areas. To date, relatively little is known about the species’ habitat associations within urbanized landscapes. We report here an investigation of the habitat associations of house sparrows using a survey of 1223 stratified randomly selected 500 × 500-m squares within urbanized landscapes of the UK, defined as at least 25% ‘human cover’. The densities of chirping male house sparrows and of all house sparrows were analysed separately to obtain insights into breeding habitat requirements and general habitat associations, respectively. Multi-model inference showed that residential areas (houses, flats), allotments (areas used for small-scale horticulture) and farm buildings were key predictors of house sparrow density and chirping male density. Separate analyses on landscapes of differing human cover showed similar results. Within residential areas, the increase of house sparrow density with habitat area (on a log scale) was approximately threefold greater when private gardens were present than when they were absent. The model predicted a rapid decline in house sparrow abundance when only a small area of private gardens is converted to continuous housing. Allotments and residential areas with gardens are likely to be under pressure due to increased demand for housing, specifically from the infilling of green space within urban areas. It would seem to be imperative that any action plan to protect urban house sparrow populations should include specific protection of such key habitats. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Seasonal patterns of habitat selection of the House Sparrow Passer domesticus in the urban landscape of Valencia (Spain)

The habitat selection and the factors influencing the distribution of the House Sparrow Passer domesticus in the municipality of Valencia (76 km²) were studied during the winter and breeding season. House Sparrows positively selected urban parks and gardens, patches of derelict land and horticultural fields; they avoided the built-up habitat and the orange groves. In the urban landscape, the abundance of sparrows peaked in areas providing intermediate cover of the built-up habitat; it was positively driven by the amount of park land per unit area, and negatively by the size of urban parks. Our results suggest that the conservation and habitat enhancement of even the smallest parks and gardens are likely key factors in addressing the decline of the House Sparrow in many cities.     

The House Sparrow Passer domesticus in urban areas: reviewing a possible link between post-decline distribution and human socioeconomic status

The House Sparrow Passer domesticus is traditionally associated with human habitation. However, the species has undergone dramatic declines in many urban areas in north-western Europe. There are many theories as to why this decline has occurred, but the lack of data on House Sparrow numbers prior to their decline has hampered efforts to investigate these theories in detail. This review summarises the demographic changes in urban House Sparrow populations since the 1970s, and considers evidence that the current distribution of House Sparrows may reflect changes in urban habitats caused by socioeconomic change. Evidence is mounting that, within urban landscapes, House Sparrows appear to be more prevalent in areas with a relatively low human socioeconomic status. Here, we present evidence to suggest that House Sparrows may have disappeared predominantly from more affluent areas, and that these areas are more likely to have undergone changes to habitat structure. We also show how these changes in habitat could influence House Sparrow populations via impacts upon nesting success, foraging and predation risk.     

Passer domesticus L. in Mexico

Ohne Zusammenfassung     

Reproductive success and individual variation in feeding frequency of House Sparrows (Passer domesticus)

Parental care is assumed to be closely associated with individual differences in reproductive success. We investigated how feeding frequencies varied among parents and how this affected the subsequent reproductive success in insular populations of House Sparrows Passer domesticus in northern Norway. Female parents fed their offspring more than male parents did, and the feeding rates were positively related to the feeding rates of the partner. A positive relationship between feeding rates and bill depth was present in females. In males, the feeding rates were negatively related to total badge size and positively related to visible badge size, after the effect of other variables had been taken into account. A non-linear convex relationship between feeding frequency and hatch day was present in males, which could reflect either the seasonal change in weather conditions or the seasonal variation in food availability. For both sexes, feeding frequencies increased with increasing brood size, but at the same time the average feeding rate per nestling decreased with increased brood sizes. Finally, our results indicate that the amount of parental investment, measured as feeding rates during the nestling stage, may have a positive long-term influence both on the number of fledglings that recruit as well as the probability that fledglings survive until recruitment.     

Zur Systematik und Verbreitungsgeschichte der Haus- und Weidensperlinge,Passer domesticus (L.) undhispaniolensis (T.)

Ohne Zusammenfassung     

Taxonomic differences among closely related pines Pinus sylvestris, P. mugo, P. uncinata, P. rotundata and P. uliginosa as revealed in needle sclerenchyma cells

The purpose of the present study was to test the taxonomic value of sclerenchyma in distinguishing Pinus sylvestris and P. mugo, P. uncinata, P. rotundata and P. uliginosa, all representing the subsection Sylvestres within the genus Pinus. Thirty-six samples were gathered in natural populations. Every sample was represented with 30 individuals, every individual with 10 brachyblasts. Three types of sclerenchymatic cells surrounding the resin canals and four between vascular bundles were distinguished. Relations among samples and taxa were verified using discriminant analysis and clustering based on Euclidean distances. The types of sclerenchymatic cells surrounding the resin canals and located between the vascular bundles differentiate the compared taxa when used as average frequencies but are extremely variable and do not allow the classification of every individual. The study demonstrated that the type of sclerenchymatic cells surrounding the resin canals and between the vascular bundles in needles could have an important taxonomic value in distinguishing the taxa of two-needle pines of the subsection Sylvestres in Europe at the population level. The distinguishing of individuals was difficult because of very high variation of sclerenchyma characters.     

两种近缘鸟种麻雀和山麻雀的咬合力比较

鸟类的咬合力受食性、种内竞争和捕食压力等多种生态因素的影响,可作为其生态适应特征的重要指标。但目前关于鸟类的咬合力及其影响因素却鲜有研究,为此,我们使用咬合力传感器,对同属的两个近缘鸟种,麻雀(Passer montanus)和山麻雀(P.cinnamomeus)的咬合力进行了比较研究。结果表明,山麻雀(n=12)的咬合力显著大于麻雀(n=59)(t=3.754,P0.01),但山麻雀(t=0.449,P0.05)和麻雀(Z=﹣1.198,P0.05)的雌雄个体间咬合力均无差异,同时,山麻雀的头宽(t=﹣3.713,P0.01)、头高(t=﹣5.405,P0.01)和喙宽(t=﹣6.201,P0.01)均显著大于麻雀。尽管个体的咬合力与其身体各参数指标无显著相关性,但在种间,头和喙的大小可能是影响两者咬合力的重要因素,由于两者的一些生态适应特征可通过头大小和喙型体现,推测两者生境和食性的差异可能是影响其咬合力大小的主要原因。     

The thermal properties of some nests of the Eurasian Tree Sparrow Passer montanus

Using an electronic apparatus simulating a bird roosting in a nest at night, we examined the insulating qualities of Eurasian Tree Sparrow (Passer montanus) nests built in nest boxes under winter conditions. Nests of different construction were compared with an empty box, and with roosting in open air. Energy savings in an empty box accounted for 18%, in boxes with incomplete nests for 23% and in boxes with complete nests up to 36%. The insulating value of nests mostly depended on their completeness and the proportion of feathers in the lining.     

Pigment limitation and female reproductive characteristics influence egg shell spottiness and ground colour variation in the house sparrow (Passer domesticus)

One of the hypotheses to explain egg colour variation in birds lays in the context of sexual selection, where egg colour may signal the female’s physical condition and antioxidant capacity. We tested one of the assumptions following from this hypothesis, that eggshell pigment deposition should be limited for females. The study was conducted in a captive house sparrow (Passer domesticus) population over several years under constant environmental conditions. This multi-brooded species lays eggs which vary in ground colour (biliverdin pigment) and in the intensity and distribution of brownish-red spots (protoporphyrin pigment). Spot darkness, spread and ground colour diminished along the laying sequence, suggesting that the deposition of both pigments was limiting for females over the short term. Also, the proportion of eggs with biliverdin diminished in consecutive clutches laid by the same female over the breeding season, suggesting a long-term cost of biliverdin deposition. On the other hand, spots were darker at the end of the breeding season, indicating that protoporphyrin deposition was probably not limited over the long term. This result could indicate a lower capacity for calcium deposition over the long term, which was compensated for by darker spots. Female age also significantly affected the proportion of bluish eggs and spot patterns. Egg pigmentation decreased with age, indicating that senescing passerine females lay less pigmented eggs. Clutch size was positively related to the proportion of bluish eggs and to spot patterns (darker and more evenly spotted). These results are in accordance with assumptions for the sexual selection hypothesis.     

Efficient Plant Regeneration System From Leaf Discs of Zonal (Pelargonium x hortorum) and two scented (P. capitatum and P. graveolens) Geraniums

An efficient and rapid plant regeneration system was established for zonal and scented geraniums using leaf discs as explants. Several explants, medium and culture conditions were studied to optimize shoot induction. Leaf discs taken from 4–5 weeks old in vitro grown plants, whatever the genotype, were more effective for shoot regeneration than those taken from greenhouse grown plants. Darkness proved to be a stimulating factor for shoot regeneration and the combination between NAA and two cytokinins gave the best results. Direct shoot regeneration (100%) was obtained from leaf discs of P. capitatum on half-strength MS medium supplemented with 0.5 mg l⁻¹ NAA in combination with 1 mg l⁻¹ of BAP and zeatin in darkness (11.4 shoots per explant). In the same medium and culture conditions, all P. graveolens leaf discs also exhibited direct shoot regeneration (7.3 shoots per explant). For P. x hortorum, 100% of leaf discs underwent shoot regeneration on a MS medium supplemented with 0.2 mg l⁻¹ NAA in combination with 0.5 mg l⁻¹ of BAP and zeatin in darkness (8.8 shoots per explant) or under low light conditions with 0.2 mg l⁻¹ NAA and 1 mg l⁻¹ of BAP and zeatin (7.5 shoots per explant). For this species, the best results for shoot elongation were obtained on half-strength MS medium gelled with Phytagel 0.3% (v/v). Whatever the genotype, all shoots rooted readily when transferred to diluted MS medium (MS/2) containing 1 mg l⁻¹ IAA. Acclimatized plants grew normally and flowered in greenhouse conditions. Flow cytometry analysis made on leaves of acclimatized plants revealed that all the scented geranium plants are similar to mother plants while 71% of P. x hortorum plants which showed strong growth were tetraploid.     

Zur Mauser spanischer Weiden- und Haussperlinge (Passer hispaniolensis unddomesticus)

Zusammenfassung Die Mauserperiode westspanischer Weidensperlinge(Passer hispaniolensis) und Haussperlinge(P. domesticus) reicht von Ende Juli bis Ende September/Anfang Oktober. Beim Weidensperling endet der Federwechsel im Durchschnitt etwa fünf Tage früher als beim Haussperling. Es gibt keine Geschlechtsunterschiede in der Chronologie der Mauser beim Weidensperling. Ad. beider Arten mausern schneller und synchronisierter als juv., die ihr Gefieder um so rascher erneuern, je später sie mit der Mauser begonnen haben. Die Handschwingenmauser dauert etwa 66 Tage beim Weidensperling und 69 Tage beim Haussperling. Beide Arten brauchen ca. 3 weitere Tage für die Verhornung der 5. und 6. Armschwingen. Die ad. beider Arten und die juv. Weidensperlinge beginnen die Mauser im Durchschnitt am selben Tag (24. Juli), die juv. Haussperlinge später (29. Juli). Der Mauserverlauf und die Beziehungen zwischen den verschiedenen Federreihen sind bei beiden Arten identisch. Die Synchronisation der Mauser ist beim Weidensperling höher. Brut und Mauserperiode überschneiden sich beim Haussperling; beim Weidensperling, bei dem noch kurze Wanderungen gleich nach der Fortpflanzungsperiode und vor der Mauser erfolgen, nicht. Das frühere und höher synchronisierte Mauserende beim Weidensperling scheint eine Anpassung an die stärkere Zugtendenz zu sein.

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On the moult of Spanish Sparrows(Passer hispaniolensis) and House Sparrows(Passer domesticus) in Iberia

Summary The moulting period of Spanish sparrows(Passer hispaniolensis) and House Sparrows(Passer domesticus) in Western Spain extends from late July to late September/early October. House Sparrows finish moulting on average some five days later than Spanish Sparrows. There are no sexual differences in the moulting chronology of adult Spanish Sparrows. Ad. of both species moult faster and better synchronized. The speed of moulting is also higher in later moulting juveniles. The estimated durations of wing feather replacement were 66 days for the Spanish Sparrow and 69 days for the House Sparrow. Some three more days are needed to complete the growth of the 5th and 6th secondary remiges in both species. Adults of both species and juvenile Spanish Sparrows start moulting on average on the same date: 24th July; juvenile House Sparrows start moulting on 29th July. The sequence of moult and the relations between different feather tracts are identical in both species. The synchronization of the moult is higher in the Spanish Sparrow. Breeding and moulting seasons slightly overlap in the House Sparrow, but not in the Spanish Sparrow. In this species the time lapse between both periods allows the birds to wander to suitable areas, where they moult. The earlier ending and higher synchronization of the moult in the Spanish Sparrow is related to its higher migratory tendency.

     

Chloroplast DNA Transgresses Species Boundaries and Evolves at Variable Rates in the California Closed-Cone Pines (Pinus radiata, P. muricata, and P. attenuata)

We studied phylogenetic relationships among populations and species in the California closed-cone pines (Pinus radiata D. Don, P. attenuata Lemm., and P. muricata D. Don) via chloroplast DNA restriction site analysis. Data on genetic polymorphism within and among 19 populations in the three species were collected using9 to 20 restriction enzymes and 38 to 384 trees. Because only five clades and extremely low intraclade diversity were found, additional phylogenetic data were collected using a single representative per clade and two outgroup species, P. oocarpa Schiede and P. jeffreyi Loud. In total, 25 restriction enzymes were employed and approximately 2.7 kb surveyed (2.3% of genome). The five clades recognized were Monterey pine, knob-cone pine, and the southern, intermediate, and northern races of bishop pine. On the basis of bootstrapping, both Wagner and Dollo parsimony analyses strongly separated the northern and intermediate races of bishop pine from the southern race; knobcone pine from Monterey and bishop pines; and the closed-cone pines from the two outgroups. Approximate divergence times were estimated for the lineages leading to knob-cone pine and to the intermediate and northern populations of bishop pine. The position of Monterey pine relative to bishop pine within their monophyletic clade was unresolved. Surprisingly, Montery pine and the southern race of bishop pine were much more similar to one another than was the southern race of bishop pine to its conspecific intermediate and northern races. Both the Monterey and southern bishop pine lineages also evolved severalfold more slowly than did the knobcone pine and intermediate-northern bishop pine lineages. These results differ significantly from a recent allozyme study, corroborating previous observations that chloroplast genome phylogeny can depart substantially from that of nuclear genes.     

Die Verbreitung des Weidensperlings (Passer hispaniolensis) in Marokko

Zusammenfassung In Marokko fällt die südliche Verbreitungsgrenze des Weidensperlings wahrscheinlich mit dem Nordrand des Antiatlas zusammen. Aus den Oasen der ehemaligen Spanischen Sahara liegen keine Beobachtungen vor. Aus dem Raum Oujda sind die östlichsten Populationen, die ständig zwischen Marokko und Algerien migrieren, bekannt. Landnutzung und Klima prägen entscheidend die Dispersion des Weidensperlings. Als euryöke Art ist er in der Lage, das reichhaltige Angebot an Schlaf- und Brutplätzen sowie an Nahrung und Wasser in den ackerbaulichen Nutzflächen zu verwerten. Auffallend ist, daß die Hauptverbreitungszonen mit den großen ackerbaulichen Nutzflächen zusammenfallen. Während die agrarischen Nutzflächen sich in den letzten Jahrzehnten im Zuge der Modernisierung der Landwirtschaft rapide änderten, und das erklärte Ziel für das Jahr 2000 in einer bewässerten Fläche von einer Million Hektar besteht, gingen die ursprünglichen Habitate des Weidensperlings, wie die Bereiche der mauretanischen Wüstensteppengebiete, drastisch zurück. Ferner konnte im Raum Marrakech eine Abnahme der Niederschläge beobachtet werden, die das für die Weidensperlinge verfügbare Nahrungsangebot entscheidend beeinflußt und somit die Populationsdynamik steuert.

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On the distribution of the Spanish Sparrow (Passer hispaniolensis) in Morocco

Summary In Morocco, the southernmost border of the distribution of the Spanish Sparrow coincides probably with the North-Antiatlas. From the oasis of the former Spanish Sahara don't exist any observations. In the region of Oujda the easternmost populations are found which are migrating permanently between Morocco and Algeria. The euryoecous species is able to use a high variability of different roosts, breeding sites, resources of food and water in the agricultural areas. A high overlap of the main distribution areas with the large agricultural regions is obvious. While the cultivated areas have been changed heavily during the modernisation periode of the Moroccan agriculture the original habitats of the Spanish Sparrow (i. e. the parts in the Mauretanian desert-steppe regions) disappeared dramatically. The goal of the year 2000 lies in an irrigated scheme of 1.000.000 ha. Moreover, a decrease of the precipitation in the region of Marrakech was observed, which has a great influence on the food available for the species and which therefore controls the population dynamics.

     

Simultaneous phosphate solubilization potential and antifungal activity of new fluorescent pseudomonad strains, Pseudomonasaeruginosa, P. plecoglossicida and P. mosselii

Of 80 fluorescent pseudomonad strains screened for phosphate solubilization, three strains (BFPB9, FP12 and FP13) showed the ability to solubilize tri-calcium phosphate (Ca₃(PO₄)₂). During mineral phosphate solubilization, decrease of pH in the culture medium due to the production of organic acids by the strains was observed. These phosphate solubilizing strains produced indole-3-acetic acid (IAA) and protease as well as exhibited a broad-spectrum antifungal activity against phytopathogenic fungi. When tested in PCR using the gene-specific primers, strain BFPB9 showed the presence of hcnBC genes that encode hydrogen cyanide. On the basis of phenotypic traits, 16S rRNA sequence homology and subsequent phylogenetic analysis, strains BFPB9, FP12 and FP13 were designated as Pseudomonas aeruginosa, P. plecoglossicida and P. mosselii, respectively. Present investigation reports the phosphate solubilization potential and biocontrol ability of new strains that belong to P. plecoglossicida and P. mosselii. Because of the innate potential of phosphate solubilization, production of siderophore, IAA, protease, cellulase and HCN strains reported in this study can be used as biofertilizers as well as biocontrol agents.     

Molecular cytogenetic study of three common Mediterranean limpets, Patella caerulea, P. rustica and P. ulyssiponensis (Archaeogastropoda, Mollusca)

The present paper shows the results of chromosome banding and rDNA-FISH study performed on several specimens of different populations of Patella caerulea, Patella rustica and Patella ulyssiponensis. The taxonomic attribution of specimens was ascertained by the molecular phylogenetic analysis of the mitochondrial 16S rRNA gene. P. caerulea and P. rustica had 2n = 18 chromosomes with first seven of biarmed pairs and the remaining two uniarmed pairs. P. ulyssiponensis had 2n = 16 with all biarmed chromosomes. Ag-NOR loci were on the short arms of the first metacentric pair in the three studied limpets, whereas they showed a different pattern of heterochromatin distribution and composition. A chromosome mosaicism was observed in several P. caerulea specimens, which exhibited an unpaired metacentric element and loss of a telocentric pair. The obtained results suggest that in the genus Patella specific diversification was accompanied by variations in heterochromatin distribution and composition and reduction of chromosome number by Robertsonian centric fusion.