Two grouse clutches in the same nest: evidence for nest site adoption in capercaillie ( Tetrao urogallus)

We describe the case of an unusually large capercaillie Tetrao urogallus clutch consisting of 12 eggs, of which four chicks hatched. Eight eggs died in an early stage of development. Genetic analyses revealed that the putative mother of the chicks was different from the one laying the unhatched eggs. We compare our results with reports from clutches elsewhere and conclude that nest site adoption is a likely explanation for joint clutches in grouse.This revised version was published online in December 2004. The german abstract has been included.     

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.     

Nest site selection and efficacy of artificial nests for breeding success of Scarlet Macaws Ara macao macao in lowland Peru

Psittacidae (parrots) have the most threatened species of any bird family in the world. Most parrots are obligate secondary cavity nesters, and can be limited in their breeding success by the availability and quality of nest hollows. However, nesting opportunities for parrots can be increased by provision of artificial nest boxes. The Tambopata Macaw Project has been studying the breeding ecology and natural history of the Scarlet Macaw Ara macao macao in the south-eastern Peruvian Amazon for over 20 years by monitoring natural nest hollows and two types of artificial nest (wooden and PVC). We present data for breeding success in natural and artificial nests over 12 consecutive breeding seasons. The aims of this study were to: (a) determine the nesting requirements and reproductive success of breeding macaws; and, (b) compare the efficacy of the two types of artificial nests and natural nest cavities. Our data showed a high rate of reoccupation of successful nests in consecutive years and that nests in artificial and natural nests had very similar reproductive parameters. Our results indicate that artificial nest types can be used by conservation managers seeking to assist A. macao populations where nest hollows are in short supply, and that artificial nests can contribute important data to natural history studies of species where access to natural nests is limited.     

Nest sites and breeding success of Baywinged Cowbirds (Molothrus badius)

Summary Molothrus badius nested in a diversity of natural locations (foliage, cavities, palm trees, etc.) and in nest boxes in a study area in Argentina. No other local passerine showed such diversity of nest locations. Nests built by 3 other species of birds were used, but less frequently than holes. Nest piracy was rare. Some successful nest sites were used for 5–6 breeding seasons. Predation affected only 9 % of the nests. The timing of breeding was not earlier for females using nests built by other birds than for those nesting in other locations. The amount of nest building bybadius was similar for most nest sites. I found no significant differences in the incidence of brood parasitism byM. rufoaxillaris andM. bonariensis between different types of nests. Productivity of young forbadius was not higher for nests in structures built by other birds than for nests located elsewhere,

---

Neststand und Bruterfolg des Braunkuhstärlings (Molothrus badius)

Zusammenfassung Molothrus badius wird als der nächste nestbauende Verwandte der brutparasitischen Kuhstärlinge betrachtet. Seine Brutbiologie ist daher von besonderem Interesse. In einem Untersuchungsgebiet in Argentinien brütete die Art in einer Vielfalt natürlicher Neststandorte (Laub, Höhlen, Palmen usw.) sowie in Nistkästen. Kein anderer Singvogel des Gebiets wies eine ähnliche Vielfalt an Nistplätzen auf. Alte Nester dreier anderer Arten wurden benutzt, allerdings weniger häufig als Höhlen. Nestokkupation war selten. Einige erfolgreiche Nistplätze wurden 5–6 Brutperioden benutzt. Nestraub betraf nur 9 % der Nester. in alten Nestern anderer Arten brüteten nicht früher als solche in anderen Nestern. Die Investition in den Nestbau war bei den meisten Nistplätzen ähnlich. Das Ausmaß der Parasitierung durchM. rufoaxillaris undM. bonariensis war in allen Nesttypen gleich. Die Jungenproduktion in alten Nestern anderer Arten war nicht höher als in anderen Nestern.

     

Effects of vegetation on nest microclimate and breeding performance of lesser black-backed gulls (Larus fuscus)

For birds that breed in large colonies, the overall area occupied by the colony generally comprises several sub-areas that differ in physical and social features such as vegetation and breeding density. Birds arriving at a breeding colony select their nesting sites through a hierarchical process of selecting a sub-area, then a particular nest site with appropriate biotic and physical attributes. Optimal vegetation cover is one such important attribute. Many ground nesting gulls preferentially select nest sites that provide shelter during reproduction, but this presumably has to be balanced against any costs such as reduced visibility of potential predators. The effects of vegetation height in the sub-areas within a colony, and of the amount of vegetation in the immediate vicinity of the nest on nest microclimate were investigated in lesser black-backed gulls Larus fuscus in a colony in which overall vegetation height differed in different sub-areas and was patchily distributed within these areas. Tall vegetation did have a sheltering effect, and this was positively related with chick growth. However, this vegetation area was associated with lower breeding densities, relatively late laying birds and lower chick survival rate, suggesting that sub-areas with tall vegetation held more lower-quality or young breeders. Within the sub-areas, the birds preferentially selected nest sites with more surrounding vegetation, and this was positively correlated with their hatching success.     

Host nest defense against a color-dimorphic brood parasite: great reed warblers (Acrocephalus arundinaceus) versus common cuckoos (Cuculus canorus)

We tested great reed warbler (Acrocephalus arundinaceus) discrimination against two common cuckoo (Cuculus canorus) female color morphs (gray and rufous) in two areas with different parasitism rates and proportions of the two morphs. Hosts recognized the two cuckoo morphs from a control, the feral pigeon (Columba livia), at Apaj, Hungary (where brood parasitism was heavy), whereas no significant differences among the models were recorded at Lužice, Czech Republic (where the parasitism rate was moderate). At Apaj, the hosts discriminated the rufous morph (which is slightly predominant there) better than the gray morph from the control. Between-site comparison (after controlling for background aggression) revealed that great reed warblers were more aggressive towards the rufous morph at Apaj than at Lužice, whereas their responses to the gray morph did not differ, corresponding with much higher between-site difference in the relative abundance of the rufous morph. Our results suggest that both local parasitism pressure and relative abundance of two female color morphs of a brood parasite may significantly influence host nest defenses.     

Modelling the recent and potential future spatial distribution of the Ring Ouzel (Turdus torquatus) and Blackbird (T. merula) in Switzerland

We present here a multiscale modelling approach to predict the current and future spatial distribution of Ring Ouzel (Turdus torquatus) and Blackbird (T. merula) in Switzerland. Species distribution models (SDMs) are applied on three different scales in order to analyse the scale-dependency of predictors that describe the species’ realised niche. While the models on the macro- and mesoscales (grid of 100 and 1 km², respectively) cover the entire country, our small-scale models are based on a small set of territories. Ring Ouzels occur at altitudes above 1000 m a.s.l. only, while Blackbirds occur from the lowlands up to the timberline. Although both species coexist on the macro- and mesoscales, a direct niche overlap on territory scale is rare. Small-scale differences in vegetation cover and structure seem to play a dominant role in habitat selection. On the macroscale, however, we observed a high dependency on bioclimatic variables that mainly represent the altitudinal range and the related forest structure preferred by both species. Applying the models to climate change scenarios, we predict a decline of suitable habitat for the Ring Ouzel with a simultaneous median altitudinal shift of 440 m until 2070. In contrast, the Blackbird is predicted to benefit from higher temperatures and expand its range to higher elevations. Based on the species distribution models we (1) demonstrate the scale-dependency of environmental predictors, (2) quantify the scale-dependent habitat requirements of Blackbird and Ring Ouzel and (3) predict the altitudinal range shift of both species as related to climate change scenarios.     

The first stone artefacts to be found in situ within the Plio-Pleistocene Chiwondo Beds in northern Malawi

We describe the attributes and sedimentary context of an assemblage of stone artefacts recovered from Plio-Pleistocene deposits in northern Malawi. The assemblage was excavated from a palaeogully fill located within the Chiwondo Beds. It includes flaked pebbles and pebble fragments, flakes, and flake fragments. These currently provide the earliest evidence for the presence of hominids in Malawi and in the whole of the south central African region.     

Selection of sites for egg deposition and spawning dynamics in the waccamaw darter

Synopsis We provided 93 experimental spawning covers for the waccamaw darter. We grouped the covers (3 sizes of slate and one of concave tile) in three arrangements at six Lake Waccamaw locations to separate the variables of water depth, distance from shore, cover density and cover type. Tag returns of marked males suggest low fidelity for nest sites. Egg production under the 3 different sizes of slate was not significantly different. Egg production under the tile was significantly less than that under the slates. Egg production was significantly higher off the undeveloped southeastern shore in 2 m of water and lowest at the shallowest location with the highest experimental cover density. The number of eggs in nest is positively correlated with male size. We conclude that medium size slate covers placed in a linear arrangement in 2 m of water on a mixed sand bottom result in the highest egg production for the waccamaw darter.     

Dispersion distance of queens from natal sites in the two haplometrotic paper waspsPolistes riparius andP. snelleni (Hymenoptera: Vespidae)

Dispersion capabilities of new queens were studied in the two haplometrotic paper wasps Polistes riparius and P. snelleni. New queens were marked on the nests in the late summer and located in the next spring. Dispersion distances greatly varied among queens: although a large part of recovered queens nested in close proximity to their natal sites, some did disperse over 100–300 m. This suggests that queens' emigration from and immigration into the censused areas occurred to a substantial extent. On the whole, these species exhibited a weaker “philopatric” tendency than those so far studied for dispersion distance, and seem to have the potential for a long-distance dispersion.     

Identifying evolutionary trees and substitution parameters for the general Markov model with invariable sites

The general Markov plus invariable sites (GM+I) model of biological sequence evolution is a two-class model in which an unknown proportion of sites are not allowed to change, while the remainder undergo substitutions according to a Markov process on a tree. For statistical use it is important to know if the model is identifiable; can both the tree topology and the numerical parameters be determined from a joint distribution describing sequences only at the leaves of the tree? We establish that for generic parameters both the tree and all numerical parameter values can be recovered, up to clearly understood issues of 'label swapping'. The method of analysis is algebraic, using phylogenetic invariants to study the variety defined by the model. Simple rational formulas, expressed in terms of determinantal ratios, are found for recovering numerical parameters describing the invariable sites.     

Changing temperatures and prediction models for the liver fluke (Fasciola hepatica)

The principle of using mathematical modesl, based on temperature data, to predict the development times of the extra-mammalian stages of the liver fluke is described. The effect of temperature on survival of those stages are also modelled. The effect of temperature is also examined in relation to its effect on predation efficiency.     

Linkage analysis of sex determination in the honey bee (Apis mellifera)

A colony-level phenotype was used to map the major sex determination locus (designatedX) in the honey bee (Apis mellifera). Individual queen bees (reproductive females) were mated to single drones (fertile males) by instrumental insemination. Haploid drone progeny of an F1 queen were each backcrossed to daughter queens from one of the parental lines. Ninety-eight of the resulting colonies containing backcross progeny were evaluated for the trait low brood-viability resulting from the production of diploid drones that were homozygous atX. DNA samples from the haploid drone fathers of these colonies were used individually in polymerase chain reactions (PCR) with 10-base primers. These reactions generated random amplified polymorphic DNA (RAPD) markers that were analyzed for cosegregation with the colony-level phenotype. One RAPD marker allele was shared by 22 of 25 drones that fathered low brood-viability colonies. The RAPD marker fragment was cloned and partially sequenced. Two primers were designed that define a sequence-tagged site (STS) for this locus. The primers amplified DNA marker fragments that cosegregated with the original RAPD marker. In order to more precisely estimate the linkage betweenX and the STS locus, another group of bees consisting of progeny from one of the low-brood viability colonies was used in segregation analysis. Four diploid drones and 181 of their diploid sisters (workers, nonfertile females) were tested for segregation of the RAPD and STS markers. The cosegregating RAPD and STS markers were codominant due to the occurrence of fragment-length alleles. The four diploid drones were homozygous for these markers but only three of the 181 workers were homozygotes (recombinants). Therefore the distance betweenX and the STS locus was estimated at 1.6 cM. An additional linked marker was found that was 6.6 cM from the STS locus.     

Binding sites of acetylcholine in the aromatic gorge leading to the active site of acetylcholinesterase

Theoretical calculations performed on the interactions of acetylcholine with the aromatic gorge of acetylcholinesterase indicate the existence of a number of local minima for the substrate. These minima are clustered in four regions of increasing interactions from top to bottom of the gorge, culminating in the region of the active site. The results allow the delineation of the role of the different aminoacids lining the walls, emphasizing, in particular, that of Trp 279 and Trp 84 while smaller interactions involve tyrosines 70, 121, 130, 334 and Phe 330. The influence of D72 is stressed, as well as the orientating role of A 201 and the strong driving influence of E199.     

Migration, wintering and breeding of a lesser spotted eagle ( Aquila pomarina) from Slovakia tracked by satellite

In northern Slovakia an adult male Lesser Spotted Eagle (Aquila pomarina) occupied the same nest site for 11 years running (1992–2002), where it was ringed and fitted with two satellite transmitters. In six of these years it successfully reared a young. In 1994 and 2000–2002 its behaviour during migration could be followed in detail by means of satellite telemetry. The eagle took the known route for this species to South Africa. In 2001, it spent 43% of the year at its breeding site, 33% in its winter quarters, the remaining 24% being spent on migration. In three cases the autumn migration took 40, 48 and 61 days respectively. In two cases the spring migration took 49 days. All five recorded autumn and spring migrations averaged a daily flight distance of 178 km. In spring the daily flight distance was in general slightly greater than in autumn. The longest was recorded from 30 March to 2 April 2001, between Uganda and the Red Sea, during which the bird covered a total of 1,650 km, averaging 412 km per day. In 2001, the spring migration from the wintering grounds was 2 weeks later than in 2002. The wintering grounds, where in 2 years the bird spent around 3.5 months, covering at least 1,666 and 2,269 km, respectively, comprised a large part of Zimbabwe together with the Kruger National Park in South Africa and neighbouring parts of Mozambique. The annual journeys flown, including movements around the wintering grounds, amounted in 2000-2001 to at least 20,396 km and in 2001-2002 to 19,041 km. Except during its crossing of the Sahara, the eagle must have taken food on nearly all its days of migration.     

Paucity of the Sau3AI recognition sequence (GATC) in the genome of Methanococcus voltae

Summary High molecular weight genomic DNA isolated from the archaebacterium Methanococcus voltae by alkaline-SDS lysis was not effectively digested with the restriction enzyme Sau3AI, which recognizes the base sequence GATC. Mc. voltae DNA was also resistant to digestion by MboI and BamHI which recognize sites containing the same GATC sequence. Examination of a Mc. voltae genomic library prepared in Escherichia coli JM83 with a pUC vector revealed that the 5–10 kb inserts were still resistant to Sau3AI digestion, indicating a likely lack of the GATC sequence in Mc. voltae DNA.     

Notes on the breeding biology of the Sichuan Treecreeper (Certhia tianquanensis)

The Sichuan Treecreeper, Certhia tianquanensis Li 1995, was recently recognized as an independent species. Apparently, it is an endemic relict occupying an extremely small range in western Sichuan and Shaanxi provinces, China. During April–July 2003, its breeding biology was studied using field observation and data logger records of five nests found on Wawu Shan in Sichuan province, southwest China. Nest materials were mainly mosses; eggs are white with dense red spots concentrated at the large pole. During the incubation period, the male fed the female outside the nest with 6–13 min intervals between the single feeding events; afterwards, the female regularly returned to the nest within 47.8 ± 25.2 s. The female took 22.14 ± 3.24 recesses per day, with the mean recess length of 8.18 min throughout the incubation period. After the nestlings hatched, the female went out more often than during the incubation period: 55 and 56 times during the first 2 days of nestling period (off-nest time of 6.55 ± 3.15 min). Both parents fed the nestlings.     

Sphaceloma poinsettiae as a potential biological control agent for wild poinsettia (Euphorbia heterophylla)

Sphaceloma poinsettiae, a scab-causing fungus that attacks wild poinsettia (Euphorbia heterophylla) was evaluated as a mycoherbicide. Plants representing nine different E. heterophylla accessions were tested and variable resistance levels to 10 different isolates of S. poinsettiae were observed. One isolate was selected based on its high aggressiveness; it caused scab that led to stem-girdling in the majority of plants belonging to most wild poinsettia accessions. Plants inoculated with conidial suspension developed low disease severity; suspensions of mycelial fragments caused higher disease severity. Viability of mycelium declined rapidly either in storage under room temperature or at 4 °C. After 25 days, 60% of mycelial fragments kept in distilled water at 4 °C or in 35% sterile sucrose solution germinated. Cultures of S. poinsettiae were capable of growing at temperatures ranging from 10 to 30 °C (maximum growth at 25 °C) whereas the mycelial fragments germinated at 20–30 °C. The highest mycelial yield occurred in potato-dextrose broth after culturing for 12 days at 168 rpm at room temperature. A host-range test involving 37 plant species in addition to wild poinsettia indicated that S. poinsettiae is highly specific to E. heterophylla. The viability of S. poinsettiae as a mycoherbicide depends on the development of suitable mass production, formulation, and inoculum preservation methods. On several occasions, this fungus has been observed to cause devastating epidemics in the field on this host; therefore, it should be considered a potential biocontrol agent of wild poinsettia.