Decline of the breeding population of <Emphasis Type="Italic">Pygoscelis antarctica</Emphasis> and <Emphasis Type="Italic">Pygoscelis adeliae</Emphasis> on Penguin Island,South Shetland,Antarctica

This work is a quantitative analysis of the population of breeding pairs of Pygoscelis adeliae and Pygoscelis antarctica, which use Penguin Island as a breeding area. There was a decrease in the populations of P. adeliae and P. antarctica by 75 and 66%, respectively, from the breeding season of 1979/1980 to 2003/2004. A mixed breeding colony of both species was also documented, according to published data which has existed since 1979/1980. The P. antarctica has an advantage over P. adeliae in this mixed breeding situation, where the breeding pairs of the former increased by 127%, indicating an interspecies competition for nesting ground.     

Relations between the Yellowhammer (<Emphasis Type="Italic">Emberiza citrinella</Emphasis>) and the Pine Bunting (<Emphasis Type="Italic">Emberiza leucocephalos</Emphasis>) in the Forested Steppe of the Trans-Urals

We studied the phenotypic composition of the populations and variability of songs in two bunting species in three localities on the western border of the sympatry zone: in the southern part of Tyumen’ oblast and in the center and southern of Kurgan oblast. Over the last several decades, the zone of contact of the studied species has expanded significantly. The pine bunting started breeding regularly in the area at the end of the 20th century, and at present it is considered a common species comparable in abundance to the yellowhammer. The share of phenotypic hybrids varies from 25 to 50% reaching its maximum at the boundary of the pine bunting’s nesting range. East of this boundary, the hybridization level is reduced, this being seen in a sharp decrease in the share of “leucocephala hybrids.” An analysis of the phenotypic variability of the hybrids shows that they can be divided into two groups similar in coloration to the parental species. The study results let us presume that the hybridization is limited and hybrids return mostly to backcrossing with the parental species. This presumption also finds support in an analysis of the song structure: the yellowhammer and the pine bunting have songs of different, easily distinguishable dialects.     

Seasonal patterns of egg production in field colonies of the termite <Emphasis Type="Italic">Reticulitermes speratus</Emphasis> (Isoptera: Rhinotermitidae)

This is the first report on the annual egg production patterns in mature termite colonies in the field. Data on the seasonal patterns of egg production in field colonies are very important for understanding the annual colony growth schedule, resource allocation, and population dynamics of the termites. However, collecting the eggs from a sufficient number of colonies is extremely difficult in Reticulitermes termites because their multiple-site nesting makes it difficult to find the reproductive center of the colonies. Here, we first show the seasonal pattern of egg production in the subterranean termite Reticulitermes speratus by collecting the reproductive center of ten colonies each month from April through October. We had to destructively examine dozens of nests to find eggs from enough field colonies each month. Mature field colonies began to produce eggs in late May, soon after the swarming season, and the egg production rate (EPR) reached its maximum in early July. The eggs hatched until late October. The EPR was significantly correlated with the average monthly temperature. Additional investigation of the egg distributions in the nests showed that most eggs were kept around the royal cell, which contained the reproductives. The largest colony had 109 supplemental queens and 94,023 eggs, suggesting that each queen produced an average of 24.7 eggs per day, based on the known mean hatching period of an inseminated egg of 34.95±0.12 (SE) days.     

Extreme Polygyny: Multi-seasonal “Hypergynous” Nesting in the Introduced Paper Wasp <Emphasis Type="Italic">Polistes dominulus</Emphasis>

In temperate climates, female paper wasps typically initiate new colonies in the spring. Several nest-founding tactics have been documented in Polistes species, including solitary nest initiation, joining a cooperative association, usurping an existing nest, or adopting an abandoned nest. Occasionally, exceptionally large groups of females have also been found reusing nests from the previous season. Here we report this phenomenon in introduced populations of the Eurasian species Polistes dominulus. We describe in detail the demographic and genetic characteristics of one such spring colony from Los Angeles, California, USA, which was collected with 84 associated adults and all stages of developing brood in its 613 cells. Genetic and morphological data indicate the presence of multiple reproductively active females of varying relatedness, as well as many nonbreeding females, including probable early-produced offspring. Despite some evidence of chaotic social conditions, the colony appeared to have been highly productive. Additional observations of similar colonies are needed to determine how control is maintained within such a large breeding aggregation.     

Genetic structure of silver Prussian carp <Emphasis Type="Italic">Carassius</Emphasis> (Superspecies <Emphasis Type="Italic">auratus</Emphasis>) (Linnaeus, 1758) colonies from the Middle Dnieper Basin

Population genetic structure of silver Prussian carp from the Middle Dnieper basin was established by means of biochemical gene marking and cytometric analysis. In addition to diploid goldfish Carassius auratus, which was the basic species of bisexual colonies, a number of biotypes of triploid silver Prussian carp C. gibelio were identified. These biotypes either formed isolated unisexual populations, or were an admixture to the bisexual colonies. In addition, in bisexual colonies, triploid females of non-clonal origin were identified. Despite the fact that all forms of C. gibelio reproduced by means of gynogenesis, some of them (C. gibelio-1) formed isolated unisexual populations, while the others (C. gibelio-2, -3, and -4) usually coexisted with C. auratus.     

Contrasting genetic structuring between colonies of the World’s smallest penguin, <Emphasis Type="Italic">Eudyptula minor</Emphasis> (Aves: Spheniscidae)

The Little Penguin, Eudyptula minor, is a seabird that nests in colonies throughout New Zealand and southern Australia. Individuals from different colonies in southeast Australia differ significantly in morphology and ecology, suggesting that some genetic structuring may exist among colonies. In contrast, the marking of individuals with flipper bands has revealed some, albeit infrequent, movement between colonies. To determine the extent of genetic structuring, we tested the null hypothesis of substantial gene flow within southeast Australia by examining patterns of genetic variation across seven colonies separated by up to 1,500 km. Phylogeographic structuring was absent for mitochondrial control region sequences (2–3 individuals per colony). Microsatellite allele frequencies at five loci and mitochondrial haplotype frequencies (50 individuals per colony) were also homogenous among the majority of colonies sampled, although two colonies at the western periphery of the sampling range were distinct from those to the east. The genetic homogeneity among the majority of colonies can be explained by low but consistent contemporary gene flow among them, or a recent founder event in Bass Strait following the last marine transgression. The genetic break towards the western end of the sampling distribution appears best explained by differences in sea surface temperature and, consequentially breeding phenology, the latter hindering genetically effective migration.     

Wind differentiates reproduction in the non-expansive Black Tern <Emphasis Type="Italic">Chlidonias niger</Emphasis> and the expansive White-winged Tern <Emphasis Type="Italic">Chlidonias leucopterus</Emphasis>

Identifying the key factors governing the expansion of a species’ range is difficult because of the multiple interactions of environmental and biological factors. Among the biological factors are breeding parameters, which at the edge of a species’ range may indicate the traits involved in limiting species distribution. To evaluate whether the hatching success of two sympatric species of terns was dependent on weather parameters, a study was carried out in the valley of the River Bug in eastern Poland. During 2007–2010, nine colonies with 113 clutches of White-winged Tern (CHL, an expansive species, new to the region since 1997) and 92 clutches of Black Tern (CHN, a non-expansive species, nesting in stable numbers in this region for many years) were monitored. CHN arrived on average 9 days earlier than CHL. While CHN arrived in east-central Poland earlier and earlier during the 1998–2013 period, no such trend was recorded for CHL. The clutch initiation median in CHL was 8 days later than in CHN. The hatching success of CHL was statistically less than that of CHN (41.6 vs. 69.6%). A general discriminant analysis model showed that successful CHL clutches depended on the maximum daytime wind speed (strong winds can be disastrous for breeding terns), colony identity and clutch initiation date. In the case of CHN, none of these factors had a statistically significant influence on hatching success, although the clutch initiation date was very close to being significant. These results suggest that a species which nested in the same location for a long time in relation to ambient weather conditions has higher hatching success than the one which is in the process of expanding its distribution range.     

Colony interactions in <Emphasis Type="Italic">Reticulitermes grassei</Emphasis> population assessed by molecular genetic methods

The cryptic habits of subterranean termites impair studies of colony delimitation and the organization of foraging. Whereas feeding sites can be identified and the movements of foragers between them can be assessed using traditional mark-release techniques, the assignment of the termites found at feeding sites to their parent colonies remains problematical. Thus the extent and overlap of individual colony foraging territories are unknown. We used microsatellite markers to delineate colonies of R. grassei and compared the results with data from a mark-release-recapture study (Nobre et al., 2007) carried out in the same population and over the same period of time. The majority of colonies exhibited only a single-feeding site, but presented, even at a local scale, a high degree of variability in colony structure and no evidence of inbreeding. F-statistics for some colonies were consistent with pleometrosis. The population as a whole contained individual colonies that were separately identified as Mendelian, mixed family or pleometrotic families. Furthermore, microsatellite data suggest that what was represented by the MRR technique as a single foraging group could be drawn from more than one colony. Colony delineation is discussed as a tool for understanding overall population structure and termite feeding strategies. Received 5 July; revised 3 October 2007; accepted 19 October 2007.     

Female reproductive characteristics of the Balkan wall lizard (<Emphasis Type="Italic">Podarcis taurica</Emphasis>) in the northwestern periphery of its range

We present data on the female reproductive traits of the Balkan wall lizard in the Deliblato Sand, a large continental sandland in the Pannonian area in the northwestern periphery of the species range. The clutch and egg characteristics of the population were investigated on the basis of clutches laid in laboratory conditions by gravid females captured in one locality. Balkan wall lizards produced at least two clutches in a breeding season. Individual females laid clutches of commonly two (range 1–4) eggs. The female body size had no effect on clutch and egg size. There was no trade-off between egg size and clutch size.     

Distribution Peculiarities of the Sand (<Emphasis Type="Italic">Riparia riparia</Emphasis> Linnaeus 1758) Martin and the Pale Sand (<Emphasis Type="Italic">Riparia diluta</Emphasis> Sharpe et Wyatt 1893) Martin (Passeriformes,Hirundinidae) in the Sympatry Zone in Southern Central Siberia

The relationships between the sand martin (Riparia riparia Linnaeus 1758) and the pale sand martin (Riparia diluta Sharpe et Wyatt 1893) in sympatric conditions in southern Central Siberia are discussed. New data on the distribution patterns of these two closely related martin species in the study area, the location of the breeding colonies, and nesting in mixed-species colonies are presented. Information on the morphology and habitat preferences of R. riparia and R. diluta, including conesting species, is provided. In the sympatry zone in southern Central Siberia, the pale sand martin is shown to be more abundant, with mixed colonies of R. riparia and R. diluta also being found. Both species studied differ significantly in the morphometric characters. When looking for the location of a breeding colony, R. riparia and R. diluta display different habitat requirements.     

Nesting patterns,ecological correlates of polygyny and social organization in the neotropical arboreal ant <Emphasis Type="Italic">Odontomachus hastatus</Emphasis> (Formicidae,Ponerinae)

Queen number varies in the population of O. hastatus in SE Brazil. Here, we evaluate how nesting ecology and colony structure are associated in this species, and investigate how reproduction is shared among nestmate queens. Queen number per colony is positively correlated with nesting space (root cluster of epiphytic bromeliads), and larger nest sites host larger ant colonies. Plant samplings revealed that suitable nest sites are limited and that nesting space at ant-occupied bromeliads differs in size and height from the general bromeliad community. Dissections revealed that queens in polygynous colonies are inseminated, have developed ovaries, and produce eggs. Behavioral observations showed that reproduction in polygynous colonies is mediated by queen–queen agonistic interactions that include egg cannibalism. Dominant queens usually produced more eggs. Field observations indicate that colonies can be initiated through haplometrosis. Polygyny in O. hastatus may result either from groups of cofounding queens (pleometrosis) or from adoption of newly mated queens by established colonies (secondary polygyny). Clumping of bromeliads increases nest space and probably adds stability through a strong root system, which may promote microhabitat selection by queens and favor pleometrosis. Rainstorms that frequently knock down bromeliads can be a source of colony break-up and may promote polygyny. Bromeliads are limited nest sites and may represent a risk for young queens leaving a suitable nest, thus favoring secondary polygyny. Although proximate mechanisms mediating queen number are poorly understood, this study suggests that heterogeneous microhabitat conditions probably contribute to the coexistence of variable forms of social structure in O. hastatus.     

<Emphasis Type="Italic">Asthenes dorbignyi</Emphasis> (Passeriformes: Furnariidae) host of <Emphasis Type="Italic">Argas neghmei</Emphasis> (Acari: Argasidae)

Argas neghmei Kohls & Hoogstraal is a Neotropical tick species parasite of poultry and man in the arid western of the southern cone of America in Argentina and Chile. Males, females and nymphs of an argasid were collected from 20 to 22 of June, 2007 in nests of Creamy-breasted Canastero, Asthenes dorbignyi (Reinchenbach) (Passeriformes: Furnariidae) at about 7 km S of La Poma (24°46′S, 66°12′W) and a male tick at 24°48′S, 66°10′W on Nov 27, 2008, Salta province, Argentina. Scanning electron microscope micrographies and sequences of 16S rDNA confirmed that the ticks found were A. neghmei. Development in breeding areas of A. dorbignyi is probably a source of infestation for animal premises and houses. However, the role of other unknown wild birds may also contribute to the invasion of A. neghmei in chicken houses or residences.     

A microsatellite-based test of the <Emphasis Type="Italic">Reticulitermes speratus</Emphasis> genetic caste determination model in <Emphasis Type="Italic">Coptotermes lacteus</Emphasis>

Coptotermes lacteus, a termite found in eastern Australia, is a central-site nester that constructs mounds up to 2 m in height. Mature colonies typically contain the primary king and queen, and up to a million or more worker and soldier offspring. Once a year, male and female nymphs are produced in approximately equal numbers and develop into new alates. Experimental removal of the queen in the field and subsequent mating of the king with a replacement queen, results in an unusual phenomenon whereby the production of female nymphs completely ceases, while the production of male nymphs, and workers of both sexes, continues. The proximate cause of this nymph male-bias is yet to be discovered. The production of male nymphs and workers of both sexes in de-queened C. lacteus colonies is equivalent to offspring production patterns in laboratory crosses of male nymphoid (nymph-derived) with female ergatoid (worker-derived) replacement reproductives in the related species Reticulitermes speratus. An X-linked genetically influenced caste determination (GCD) mechanism has been proposed to account for such offspring patterns in R. speratus. We examined microsatellite genotypes in C. lacteus to test a prediction arising from the R. speratus GCD model: that nymphs should result from reproduction by neotenics, rather than the primary pair. In five of six colonies examined, genotypes indicated that all workers and nymphs were derived from a single reproductive pair. In three of these cases, the primary queen was also located and examined; her genotype matched that inferred from worker and nymph genotypes. These results suggest that the GCD model proposed for R. speratus does not apply to C. lacteus, at least under field conditions. The male-nymph bias following queen removal therefore remains an unresolved issue in C. lacteus.     

Population genetic and behavioural variation of the two remaining colonies of Providence petrel (<Emphasis Type="Italic">Pterodroma solandri</Emphasis>)

Knowledge of the dispersal capacity of species is crucial to assess their extinction risk, and to establish appropriate monitoring and management strategies. The Providence petrel (Pterodroma solandri) presently breeds only at Lord Howe Island (~32,000 breeding pairs) and Phillip Island-7 km south of Norfolk Island (~20 breeding pairs). A much larger colony previously existed on Norfolk Island (~1,000,000 breeding pairs) but was hunted to extinction in the 18th Century. Differences in time of return to nesting sites are presently observed between the two extant colonies. Information on whether the Phillip Island colony is a relict population from Norfolk Island, or a recent colonization from Lord Howe Island, is essential to assess long-term sustainability and conservation significance of this small colony. Here, we sequenced the mitochondrial cytochrome b gene and 14 nuclear introns, in addition to genotyping 10 microsatellite loci, to investigate connectivity of the two extant P. solandri populations. High gene flow between populations and recent colonization of Phillip Island (95 % HPD 56–200 ya) are inferred, which may delay or prevent the genetic differentiation of these insular populations. These results suggest high plasticity in behaviour in this species and imply limited genetic risks surrounding both the sustainability of the small Phillip Island colony, and a proposal for translocation of Lord Howe Island individuals to re-establish a colony on Norfolk Island.     

Gynogenesis in the vine cacti <Emphasis Type="Italic">Hylocereus</Emphasis> and <Emphasis Type="Italic">Selenicereus</Emphasis> (Cactaceae)

Gynogenesis was investigated on the allotetraploid Selenicereus megalanthus and the diploid Hylocereus polyrhizus and Hylocereus undatus vine cactus species. Unpollinated ovules from developing flower buds containing microspores at middle uninucleate developmental stage were cultured on MS basal medium containing 2,4-D/TDZ with different sucrose concentrations. Ovule size increased under dark culture conditions in all the three species and the level of response was species and sucrose concentration dependent. The best responses were achieved in the two S. megalanthus accessions, E-123 and J-80, at 0.18 and 0.26 M sucrose. Only ovule enlargement was obtained in H. undatus and both ovule enlargement and callus were obtained in H. polyrhizus. Development in both species ceased and embryoids were not formed. Plant regeneration was directly and indirectly obtained in both S. megalanthus accessions. Ploidy level was determined for a total of 29 S. megalanthus gynogenic plants using flow cytometry: 15 were found to be dihaploid (plants with the gametophytic chromosome number) and the other 14 were found to have higher ploidy levels. This is the first report of successful gynogenesis in Cactaceae. The dihaploids of S. megalanthus successfully produced by ovule culture techniques opens new perspectives in vine cacti breeding.     

Breeding success of the Eurasian eagle owl (<Emphasis Type="Italic">Bubo bubo</Emphasis>) and rodent population dynamics

The dependence of the breeding success of the eagle owl on the population dynamics of rodents, which are a staple of its diet in Mordovia, was traced. At peak numbers of rodents, large clutches and a high survival rate of fledglings were observed in the breeding pairs; after a year of depression of rodent populations, in the following year, the pairs do not nest at all or their breeding success is reduced to a minimum due to the death of the clutches. In 52% of the cases, the nesting pairs laid three eggs; in 31%, two eggs; in 9%, four eggs; in 4%, one egg or five eggs. The average clutch size was 2.78 ± 0.17. The average number of chicks grown from a successful nest was 2.41 ± 0.27. The nests in Mordovia were located at a distance of 1.1–3.7 km from residential areas.     

Multiple host-ant use by the predatory social parasite <Emphasis Type="Italic">Phengaris</Emphasis> (=<Emphasis Type="Italic">Maculinea</Emphasis>) <Emphasis Type="Italic">arion</Emphasis> (Lepidoptera,Lycaenidae)

Phengaris (=Maculinea) arion is an endangered social parasite of Myrmica ants, and for a very long time was considered as specific to Myrmica sabuleti. Previous studies carried out in Poland suggested some discrepancies within this assumption, and therefore a much more intensive survey was undertaken. The host ant use of P. arion was studied at five sites in different types of biotopes in Poland, i.e. xerothermal grasslands where Thymus pulegioides was used as a larval food plant by the butterfly, and more or less sandy biotopes with Thymus serpyllum. Altogether nine Myrmica species were recorded, and considerable variation in species composition and density of nests was recorded. At four localities M. sabuleti proved to be the most common ant. A total of 529 Myrmica nests were examined, and only 20 of them contained larvae and pupae of P. arion. Host ants belonged to five different species, i.e. M. sabuleti, Myrmica scabrinodis, Myrmica schencki, Myrmica lobicornis and Myrmica hellenica. Only at one site (NE Poland) was a significant heterogeneity in parasitation rates among Myrmica species detected. M. lobicornis was the most often infested ant there, which may suggest local specialisation of the butterfly. Overall low parasitism rates may explain the vulnerability of P. arion in Central Europe but further studies are also necessary.     

Population genetic structure and historical population dynamics of the South American sea lion, <Emphasis Type="Italic">Otaria flavescens</Emphasis>, in north-central Patagonia

The north-central Patagonian coast is the sea lions most abundant area in Argentina. As occurs along the entire Atlantic coast, the distribution of breeding colonies at this smaller geographical scale is also patchy, showing at least three areas with breeding activity. We study the genetic structure and historical population dynamics of the species in five colonies in this area, analysing a 508 base-pair segment of the D-loop control region. Otaria flavescens showed 10 haplotypes with 12 polymorphic sites. The genealogical relationship between haplotypes revealed a shallow pattern of phylogeographic structure. The analysis of molecular variance showed significant differences between colonies, however, pairwise comparisons only indicate significant differences between a pair of colonies belonging to different breeding areas. The pattern of haplotype differentiation and the mismatch distribution analysis suggest a possible bottleneck that would have occurred 64,000 years ago, followed by a demographic expansion of the three southernmost colonies. Thus, the historical population dynamics of O. flavescens in north-central Patagonia appears to be closely related with the dynamics of the Late Pleistocene glaciations.     

Interactions between killer whales (<Emphasis Type="Italic">Orcinus orca</Emphasis>) and Steller sea lions (<Emphasis Type="Italic">Eumetopias jubatus</Emphasis>) in the vicinity of Brat Chirpoev Island,Kuril Islands

The behaviors of breeding Steller sea lions in response to encounters with killer whales near the shore were observed on Brat Chirpoev Island, Kuril Islands between May and July 2002–2007. Approaches by killer whales and sea lion behavior was observed visually and recorded. Killer whales approached the rookery 104 times during the entire period of observations (289 days). In most cases (n = 95), beached sea lions did not show any apparent reactions to the presence of killer whales, and there were no observed interactions. Sea lions showed agitation during nine of the approaches; five of these events were considered to be predation attempts. The killer whales attacked the sea lions three times, however all the attacks were unsuccessful. We recorded two different types of responses towards the killer whales: (1) beaching on the shore (three times) and (2) mass exodus from the rookery with subsequent formation of a tight, actively swimming and vocalizing group (six times). The latter is the first recorded observation of this behavior for Steller sea lions. The observation suggests a low degree of interactions between these two species near the studied rookery. Despite the numerous observations of killer whales near the rookery, there were no observations of direct predation on sea lions. It is likely the killer whale predation has little or no direct impact on the Steller sea lion population on Brat Chirpoev Islands during the breeding period.