Breeding Stage Research Articles

Pairing status moderates both the production of and responses to anti‐parasitic referential alarm calls in male yellow warblers

AbstractDefending offspring incurs temporal and energetic costs and can be dangerous for the parents. Accordingly, the intensity of this costly behavior should reflect the perceived risk to the reproductive output. When facing costly brood parasitism by brown‐headed cowbirds (Molothrus ater), where cowbirds lay eggs in heterospecific nests and cause the hosts to care for their young, yellow warblers (Setophaga petechia) use referential “seet” calls to warn their mates of the parasitic danger. Yellow warblers of both sexes produce this call only in response to cowbirds or seet‐calling conspecifics. Seet calls are mainly produced during the laying and incubation stages of breeding, when risk of brood parasitism is highest, rather than during the nestling stage. On the other hand, general alarm calls (chips) are produced throughout the nesting cycle and are also used in conspecific interactions unrelated to nesting. We hypothesized that context shapes responses prior to breeding as well, such that yellow warblers without a mate and active nest would be less likely to respond to playbacks that simulate brood parasitism risk. To test this hypothesis, we presented playbacks of two nest threats, cowbirds (brood parasite) and blue jays (Cyanocitta cristata; nest predator), on territories of unmated male warblers (unpaired) and male warblers with a known mate (paired). We found that unpaired males were unresponsive toward playbacks indicating nest threats, whereas paired males were significantly more aggressive and vocal toward these playbacks compared to control playbacks. However, both paired and unpaired males were vocally responsive toward chip calls, which are informative for males regardless of pairing status. Male yellow warblers appear to adjust their responses during the earliest stages of breeding depending on the contextual relevance of specific threat stimuli, and together with prior studies, our work further supports that referential seet calls are associated with stage‐specific risk of brood parasitism.

Estudo das espécies de peixes cultivadas no Núcleo de Piscicultura do Centro de Ciências Agrárias da Universidade Federal de Alagoas

RESUMO: É fato que muitas são as preocupações que giram em torno da segurança alimentar e sustentabilidade mundial. Para tal fato, aponta-se a criação de peixes como alternativa. O estudo teve como objetivo conhecer e descrever as espécies de peixes que são cultivadas no Núcleo de Piscicultura do Centro de Ciências Agrária da Universidade Federal de Alagoas (CECA/UFAL), a rotina do manejo diário desta criação e a importância para a piscicultura alagoana no cenário atual. O estudo foi realizado com base em visitas no Núcleo de Piscicultura do Centro de Ciências Agrárias Campus Rio Largo, no período de maio a setembro de 2019, em Sistema Semi-intensivo e os dados técnicos foram levantados in loco e na literatura cientifica. Os indicadores de qualidade de água avaliados foram a temperatura, o pH e a amônia duas vezes semanalmente. A piscicultura é mantida e gerenciada por zootecnistas formados no CECA com parcerias entre a empresa Junior, o município de Rio Largo e a Companhia de Desenvolvimento dos Vales do São Francisco e do Parnaíba (Codevasf) e tem como carro chefe a produção de alevinos de tilápia do Nilo. Foram introduzidas novas espécies para fins de estudos na reprodução e policultivo. Os lotes da criação foram formados e divididos conforme a espécie, podendo ser remanejadas a depender da necessidade e objetivo do manejo, o ciclo produtivo de alevinos da tilápia do Nilo foi avaliado a cada 30 dias, com produção total estimada de 400 mil alevinos durante o período de observações. Os peixes foram alimentados com ração comercial e nível de proteína bruta (PB) correspondente a cada espécie e fase de criação, uma porção fixa por biomassa. Não foi possível nesse estudo, avaliar dados produtivos das espécies que foram introduzidas e observadas neste período, pois elas estavam na fase juvenil para posteriormente ser feita seleção para nova fase de criação. A despesca dos peixes no policultivo foi definida a finalização em oito meses, não havendo possibilidade de acompanhamento. As espécies observadas são de grande potencial socioeconômico para Alagoas e para o Brasil, em especial a tilápia e apostar na diversificação de espécies como fator de segurança economicamente viável, frente às influências ambientais na produção de alimentos. Deve-se considerar que a piscicultura do CECA há dez anos está consolidada na tilapicultura e desempenhou um papel importante que foi a doação de alevinos de tilápia para piscicultores da agricultura familiar e ao Programa de Aquisição para Alimentação (PAA) no Município de Rio Largo, o que diferencia comparada as pisciculturas tradicionais.
 PALAVRAS-CHAVE: Alevino, Piscicultura, Policultivo.

Dynamics of circulating lipoproteins and lipids in Brown Skua (Stercorarius antarcticus lonnbergi) during the breeding cycle

In central-place foragers the breeding cycle is often the period with the highest energy cost, where dietary and stored lipids play a key role. Lipids are mobilized through blood lipoproteins providing fuel to tissues. Thus, the use of food and endogenous resources with high-energy fats is important to sustain individuals’ nutritional demands. To evaluate the physiological components associated to energetic demands and their variation regarding life history processes, we analysed the plasma circulating lipoprotein levels, the lipid classes and fatty acid (FA) composition in Brown Skua (Stercorarius antarcticus lonnbergi) in breeding stages with different energy requirements: incubation (In), early rearing (Er) and late rearing (Lr). We expected to find differences according to the energy demands of each stage and the sex. The level of Very Low Density lipoproteins was affected by the sex and the breeding stage, whereas Low Density lipoproteins only by the stage. Total plasma lipid content and circulating lipid classes were invariant among the stages studied; however, differences in total plasma FA and monounsaturated FA (oleic and nervonic) abundances were observed among stages. Besides, a decrease in the n-3:n-6 ratio was observed towards the Lr stage. The differences found in lipoproteins may be linked to changes in the energy demands throughout the breeding period. Moreover, the variation observed in FA abundance and n-3:n-6 ratio may be related to a preferential mobilization of FA from stores as fuel or, possibly, to a differential use of the available food resources.

Variation in alarm calls during different breeding stages of the common kestrel (Falco tinnunculus).

ABSTRACTAcoustic signals play a key role in animal communication. Animals usually use alarm signals to warn mates or offspring of the presence of threats or to intimidate or distract predators. Birds commonly use acoustic signals as a means of communication. Alarm calls in passerines at different breeding stages can reflect their nest defense intensity. However, little is known about the characteristics, plasticity, and impact factors of alarm calls during the reproductive period in raptors. Here, from March to July in 2019, the alarm calls of eight pairs of common kestrels (Falco tinnunculus) during the breeding period were recorded using a portable recorder with a strongly directed microphone in the Zuojia Nature Reserve, Jilin province, China. The differences in acoustic parameters of parental alarm calls in different breeding stages were analyzed. The results showed that the alarm calls of common kestrels were composed of multi-harmonic arched frequency modulation with the maximum energy distribution in the second harmonic. The duration and rate of the alarm calls increased significantly as the breeding season progressed, showing that parents spent increasing amounts of time on nest defense. Additionally, the acoustic parameters of alarm calls in common kestrels were significantly different depending on offspring numbers, suggesting that offspring numbers influenced parental nest defense. These results showed that differences in alarm calls during different breeding stages may reflect a trade-off between defense costs and reproductive benefits.

Combined change of behavioral traits for domestication and gene-networks in mice selectively bred for active tameness.

Tameness is a major element of animal domestication and involves two components: motivation to approach humans (active tameness) and reluctance to avoid humans (passive tameness). To understand the behavioral and genetic mechanisms of active tameness in mice, we had previously conducted selective breeding for long durations of contact and heading toward human hands in an active tameness test using a wild‐derived heterogeneous stock. Although the study showed a significant increase in contacting and heading with the 12th generation of breeding, the effect on other behavioral indices related to tameness and change of gene expression levels underlying selective breeding was unclear. Here, we analyzed nine tameness‐related traits at a later stage of selective breeding and analyzed how gene expression levels were changed by the selective breeding. We found that five traits, including contacting and heading, showed behavioral change in the selective groups comparing to the control through the generations. Furthermore, we conducted cluster analyses to evaluate the relationships among the nine traits and found that contacting and heading combined in an independent cluster in the selected groups, but not in the control groups. RNA‐Seq of hippocampal tissue revealed differential expression of 136 genes between the selection and control groups, while the pathway analysis identified the networks associated with these genes. These results suggest that active tameness was hidden in the control groups but became apparent in the selected populations by selective breeding, potentially driven by changes in gene expression networks.

Problems of phytoimmunity of grain crops in the Euro-Northeast of the Russian Federation and ways their solution

Breeding of grain crops for phytoimmunity in the FSBSU FASC of the Northeast is carried out in the conditions of natural and artificial epiphytotics. Every year, more than 1000 samples of winter rye, spring soft wheat, barley and oats of their own breeding and from the VIR collection are studied. In winter rye, studies are conducted on snow mold, root rot, powdery mildew, brown and stem rust, septoria blight, fusarium head blight, and ergot; in spring wheat – on root rot, septoria blight, fusarium head blight, powdery mildew, brown rust, loose smut; in barley – on root rot, net, dark brown blotch and stripe disease, loose smut; in oats - on red-brown blotch, root rot, crown rust, panicle fusarium and loose smut. Resistant samples detected on infectious backgrounds will be included in the breeding process as sources of the trait. With the participation of source genes, new varieties of winter rye were created, Snezhana, Grefinya, and others, which are being studied at different breeding stages. Long-term studies (2014-2020) on infectious and provocative backgrounds among the breeding material of the FASC of the Northeast and collection samples of spring soft wheat, oats, barley revealed sources of nonspecific resistance (6-9 points). They are used in crossbreeding programs with the best varieties to obtain high-yielding and resistant to biotic stressors hybrids that are being studied at different breeding stages.

Gynogenesis in Cucurbita Species.

The development of F1 hybrid vegetable varieties emerges as a result of a great effort, long time, investment, knowledge, and advanced technology. The first stage of hybrid vegetable breeding is obtaining pure lines. It is possible to obtain homozygous parent lines used in the production of hybrid varieties with traditional breeding methods. This period takes 8-10years, especially in some vegetables which are highly open-pollinated, such as Cucurbita spp. Androgenetic- and/or gynogenetic-based dihaploidization methods provide 100% homozygous pure haploid lines in 1-2years and save time and effort.The DH frequency by irradiated pollen technique and anther culture strongly depends on the genotypic response, whereby their practical use in a breeding program is still limited. As a possible alternative technique, gynogenesis (unfertilized ovule/ovarium cultures) switches on to produce haploid plants in some Cucurbita species. In the Cucurbita genus, gynogenesis has been one of the most studied and popular DH techniques and presented remarkable results in recent years.

Phenotyping for Waterlogging Tolerance as a Proxy for Phytophthora medicaginis Resistance in Chickpea

Phytophthora root rot (PRR) caused by the soilborne oomycete Phytophthora medicaginis is a significant constraint to chickpea (Cicer arietinum) production across the northern grains region of Australia. In flooded soil, which is conducive to PRR disease development, up to 70% yield loss can occur in the most resistant Australian cultivars. Incorporating waterlogging tolerance in soybean (Glycine max) has been shown to improve quantitative resistance to Phytophthora sojae. Root growth of three chickpea genotypes was assessed at the seedling stage under waterlogging, PRR, and the combination of these abiotic and biotic constraints. Levels of waterlogging tolerance in chickpea are inherently low, yet selected genotypes displayed variability in root traits linked to improved waterlogging tolerance. The PRR moderately susceptible chickpea cultivar Yorker and PRR very susceptible Rupali demonstrated an eightfold increase in early adventitious root growth from the epicotyl region under waterlogging stress, compared with the PRR resistant interspecific backcross genotype 04067-81-2-1-1 (C. echinospermum × C. arietinum*2). Selection for primary root depth, which was significantly greater in 04067-81-2-1-1 under waterlogging, appears to improve PRR resistance compared with root replacement traits. Soilborne Phytophthora spp. are reportedly attracted to branch sites and leached exudates. We propose that compromised root barriers at emergence sites of adventitious roots under waterlogging conditions hasten hyphal entry, potentially increasing susceptibility to PRR. Hence, screening for root depth and absence of adventitious root development under waterlogged conditions may offer a novel proxy phenotyping method for PRR resistance traits at early stages of chickpea breeding.

Anther Culture in Cucurbita Species.

Production of homozygous pure parental lines is the first stage of hybrid vegetable breeding. Unfortunately, producing pure lines takes a long time by classical breeding methods, especially in open-pollinated vegetable species, and this period can be up to 8-10years. Recently, doubled haploid (DH) technology, as a set of biotechnological methods, has emerged as an alternative to classical breeding methods and allows for the generation of 100% homozygous pure double haploid lines in 1 or 2years. Although haploid plants were successfully produced via irradiated pollen technique and gynogenesis in some Cucurbita species, haploid plants have not been obtained from some lines due to genotype dependency, and haploidy frequency is still not sufficient for use in a breeding program. Thus, anther culture technique has emerged as an alternative technique in the DH process. The main objective of this chapter is to provide explanatory information on anther culture technique applied in the Cucurbita genus. For this purpose , key points and details of methods and protocols of the anther culture technique are described in summer squash (Cucurbita pepo L.), pumpkin (Cucurbita moschata Duch.), and winter squash (Cucurbita maxima Duch.).

Ранние свидетельства производящей экономики в материалах гиссарской культуры: обзор исследовательских концепций

The transition to farming is a revolutionary step in human history. Domesticated species of cereals and small ruminants which spread from the territory of the countries of the Fertile Crescent appear in Central Asia during the early Neolithic period (the 6th — 5th millennium BC). In the middle of the 20th century several Neolithic cultures prominent for the Central-Asian region were defined: Jeitun, Kelteminar and Hissar. This publication is devoted to the consideration of the Hissar culture and the existing reconstructions of its economic structure. The Gissar culture is widespread on the territory of the Gissar-Alai and dates from the 6th to the 2nd millennium BC. Since the late 1950s the researchers tried to determine the type of economy of the carriers of the Hissar culture: the early stage of agriculture and cattle breeding; hunting and gathering; nomadic cattle breeding. This article examines the main arguments “for” and “against” the existence of a productive economy in the Hissar culture, namely, cattle breeding. Based on a number of signs, such as the presence of long-term and short-term camps, a large number of bones of small ruminants, the availability of year-round pastures at the site, the absence of hunting tools in the toolkit, the team of authors agrees with the point of view of V. A. Ranova and G. F. Korobkova about the use of early cattle breeding by the Hissar people. However, this hypothesis requires additional elaboration using bioarchaeological research methods. Keywords: Central Asia, Hissaro-Alay, Hissar, Neolithic, pastopalism Acknowledgements: The analysis of the general problems was carried out with the support of the project of the Russian Science Foundation No. 19–78–10053 “Origin of the Industrial Economy in the Mountainous Part of Central Asia”, the analysis of materials from the Hissar culture was carried out within the framework of the research program No. 0329–2019–0002 “Ancient Cultural Processes in the Territory of Central Asia”.

Induction of Parthenogenesis by Irradiated Pollen in Cucurbita Species.

Due to their many superior agronomic traits (high yield and fruit quality, resistance/tolerance to biotic and abiotic stress factors, etc.), hybrid vegetable cultivars are widely used in vegetable production all over the world. The first stage of hybrid vegetable breeding is to obtain homozygous pure parental lines. Unfortunately, producing pure lines takes a long time by classical breeding methods, especially in open-pollinated vegetable species, and this period can be up to 8-10years. Recently, doubled haploid (DH) technology, as a biotechnological method, has emerged as an alternative to classical breeding methods and allows for the generation of pure (100% homozygous) DH lines in one or two years.However, the DH technique needs labor-intensive efforts and experiences as well as the use of appropriate production technologies. The main objective of this chapter is to provide explanatory information on the technique of induction of parthenogenesis by irradiated pollen applied to several species of the Cucurbita genus. For this purpose , key points and details of methods and protocols of this technique are described in summer squash (Cucurbita pepo L.), pumpkin (Cucurbita moschata Duch.), and winter squash (Cucurbita maxima Duch.).

The relations of broad nematode resistance to quality characteristics as a consequence of marker-assisted selection in potato breeding programs.

Cultivating resistant varieties of potato is the most effective and environmentally sound method of protecting potato crops against pests and diseases. Potato cyst nematodes (PCN) are major nematode pests causing severe constraints in potato production worldwide. There are five pathotypes of Globodrea rostochiensis (Ro1–Ro5) and three of G. pallida Pa1–Pa3. Cultivation of potato varieties with broad nematode resistance may influence the growth of the wide spectrum of PCN pathotypes, but there is limited availability of such varieties on the market. The use of molecular markers allows for the effective selection of resistant genotypes at early stages of breeding. However, the impact of early selection for nematode resistance on the agronomic value of the final selected clones is a cause of concern for potato breeders. This study investigates the relationships between the presence of the combined resistance genes H1, Gro1-4 and GpaVvrn, which confer resistance to the nematodes, and certain agricultural traits. Clones with broad nematode resistance conferred by the genes H1, Gro1-4 and GpaVvrn presented yields and tuber morphology traits similar to those of the clones without identified resistance genes.

ASSOCIATION BETWEEN FALLING NUMBER AND GRAIN CHARACTERISTICS TO EVALUATE PREHARVEST SPROUTING IN WHEAT

The falling number (FN) is a widely used parameter to evaluate sprouting damage in wheat. Despite its importance, many breeding programs lack facilities to determine the FN routinely. This study was conducted to elucidate the relationship of the falling number with germination percentage, visual sprouting score, hectoliter weight and the grain weight per spike, to improve the selection criteria in the pre-harvest sprouting (PHS) trials. Thirteen genotypes differing in PHS tolerance were evaluated in a rain simulator. The statistical analysis was conducted to understand the relationship of FN with grain characteristics. The path coefficient analysis revealed the highest association of the FN with the percentage of sprouted grains. Also, regression analysis determined that samples with more than 46% of sprouted grains had FN below 200s. The grains with 32 to 46% of germination resulted in FN values between 200 and 250s, and those with 19 to 32% of germination had FN between 250 and 300 s. Only those samples with less than 19% of germination resulted in FN values higher than 300s. The strong association between the germination percentage and the FN allows the selection of promising lines and the elimination of undesirable ones at an early stage of breeding.

The history of the breeding work on winter durum wheat development: results, problems, prospects

The current paper has considered the results of sixty years of breeding work on winter durum wheat development, a new grain crop for the steppe arid conditions of the Don area. This breeding period was represented by five stages, each of them was characterized by the solution of various problems, by the development of methods for obtaining and using the initial material and, on its basis, varieties being urgent for the definite period. Throughout the history of breeding work there were developed 32 winter turgid and durum wheat varieties, 21 of which were zoned or included into the State List, 16 were protected by patents, 6 were studied at the SVT. There have been presented the study results of the varieties of different breeding stages according to their main economically valuable traits and properties, obtained in the trial ‘History of the breeding work’ with green manure fallow in 2015–2019. There have been identified their positive advantages and disadvantages in the breding process. Significant progress has been achieved in changing plant architectonics by reducing straw length on 39.3–45.2 cm, increasing the resistance to lodging on 1.3–1.4 points, improving the agrocenosis on 300–400 heads per m 2 , and increasing the harvesting index from 26.1 to 41.1%. Productivity due to productive breeding for 60 years increased on 3.37 t/ha or 66.3%, and the productivity potential of the modern short-stemmed varieties reached 10 t/ha and more. There has been found out that productivity improvement during breeding positively affected on adaptive properties (winter resistance, drought resistance, resistance to brown and yellow rust, powdery mildew) and the indices grain and pasta quality. There have also been indicated the problematic areas which require further intensive work not only in breeding, but also in a wider distribution of the winter durum wheat varieties in agricultural production.

Hematocrit, age, and survival in a wild vertebrate population.

Understanding trade‐offs in wild populations is difficult, but important if we are to understand the evolution of life histories and the impact of ecological variables upon them. Markers that reflect physiological state and predict future survival would be of considerable benefit to unraveling such trade‐offs and could provide insight into individual variation in senescence. However, currently used markers often yield inconsistent results. One underutilized measure is hematocrit, the proportion of blood comprising erythrocytes, which relates to the blood's oxygen‐carrying capacity and viscosity, and to individual endurance. Hematocrit has been shown to decline with age in cross‐sectional studies (which may be confounded by selective appearance/disappearance). However, few studies have tested whether hematocrit declines within individuals or whether low hematocrit impacts survival in wild taxa. Using longitudinal data from the Seychelles warbler (Acrocephalus sechellensis), we demonstrated that hematocrit increases with age in young individuals (<1.5 years) but decreases with age in older individuals (1.5–13 years). In breeders, hematocrit was higher in males than females and varied relative to breeding stage. High hematocrit was associated with lower survival in young individuals, but not older individuals. Thus, while we did not find support for hematocrit as a marker of senescence, high hematocrit is indicative of poor condition in younger individuals. Possible explanations are that these individuals were experiencing dehydration and/or high endurance demands prior to capture, which warrants further investigation. Our study demonstrates that hematocrit can be an informative metric for life‐history studies investigating trade‐offs between survival, longevity, and reproduction.

Genotyping-by-Sequencing Identifies Historical Breeding Stages of the Recently Domesticated American Cranberry

The cranberry (Vaccinium macrocarpon Ait.) is a North American fruit crop domesticated less than 200 years ago. The USDA began the first cranberry breeding program in response to false-blossom disease in 1929, but after the first generation of cultivars were released in the 1950s, the program was discontinued. Decades later, renewed efforts for breeding cranberry cultivars at Rutgers University and the University of Wisconsin yielded the first modern cultivars in the 2000’s. Phenotypic data suggests that current cultivars have changed significantly in terms of fruiting habits compared to original selections from endemic populations. However, due to the few breeding and selection cycles and short domestication period of the crop, it is unclear how much cultivated germplasm differs genetically from wild selections. Moreover, the extent to which selection for agricultural superior traits has shaped the genetic and phenotypic variation of cranberry remains mostly obscure. Here, a historical collection composed of 362 accessions, spanning wild germplasm, first-, second-, and third-generation selection cycles was studied to provide a window into the breeding and domestication history of cranberry. Genome-wide sequence variation of more than 20,000 loci showed directional selection across the stages of cranberry domestication and breeding. Diversity analysis and population structure revealed a partially defined progressive bottleneck when transitioning from early domestication stages to current cranberry forms. Additionally, breeding cycles correlated with phenotypic variation for yield-related traits and anthocyanin accumulation, but not for other fruit metabolites. Particularly, average fruit weight, yield, and anthocyanin content, which were common target traits during early selection attempts, increased dramatically in second- and third-generation cycle cultivars, whereas other fruit quality traits such as Brix and acids showed comparable variation among all breeding stages. Genome-wide association mapping in this diversity panel allowed us to identify marker-trait associations for average fruit weight and fruit rot, which are two traits of great agronomic relevance today and could be further exploited to accelerate cranberry genetic improvement. This study constitutes the first genome-wide analysis of cranberry genetic diversity, which explored how the recurrent use of wild germplasm and first-generation selections into cultivar development have shaped the evolutionary history of this crop species.

Monitoring of the feed base and provision of dairy cattle with adequate feeding

At the current stage of dairy cattle breeding, one of the most pressing problems is monitoring of the feed base, which includes the procurement of high quality feed. Solution of this problem also requires a focus on ration formulation, since unbalanced feeding can cause metabolic disorders, which ultimately affects realization of the genetic potential of dairy breeds. In this regard, to increase the production of cows, it is necessary to constantly improve and optimize their feeding rates, since feeding is the most important factor to advance dairy cattle breeding. Appropriate feeding ensures cow production amounting to 6,000–8,000 kg of milk and more, with a milk fat content of 3.7–4.2%. The paper provides data on monitoring of the state of the feed base on the studied farm to ensure adequate feeding of cows. Within the stated problem, the study also focuses on the analysis and assessment of the rations of cow feeding with regard to the physiological state of the animal, which was confirmed through the use of the targeted ration. The basis of the practice-oriented study was the decision to use the information and analytical system RATIONS to calculate balanced feed rations for adequate feeding of dairy cows. In the future, the farm needs to pay special attention to introduction of adapted feeding norms for black-motley cows to satisfy their need for nutrients.

Молекулярные маркеры генов Pl6, Pl13 и Plarg для использования в селекции подсолнечника на устойчивость к ложной мучнистой росе

One of the most dangerous diseases on sunflower is downy mildew caused by oomycete Plasmopara halstedii. Introduction of dominant genes of resistance to this pathogen into a host-plant is the most effective economic and ecologically safe method of this pathogen control. The current DNA-technologies allow controlling these genes presence at the any stage of breeding. Currently, the genes Pl6, Pl13 and Plarg are the most effective ones controlling resistance to the most races of P. halstedii. We approbated known from the literary sources two STS and two SSR-markers of these genes on the lines and breeding samples. Three studied molecular markers – HаP3 (locus Pl6), ORS1008 (locus Pl13) and ORS509 (locus Plarg) – allowed us identifying the mentions genes in lines and breeding samples of VNIIMK. The studied DNA-markers can be interested in marker-associated sunflower breeding on resistance to a downy mildew pathogen.

A case of a Pustulated Carrion Beetle (&lt;i&gt;Nicrophorus pustulatus&lt;/i&gt;, Coleoptera: Silphidae) burying live Tree Swallow (&lt;i&gt;Tachycineta bicolor&lt;/i&gt;, Passeriformes: Hirundinidae) nestlings under the nest

The ecology of Pustulated Burying Beetle (Nicrophorus pustulatus, Coleoptera: Silphidae) appears distinct among Nicrophorus species, with evidence of it parasitizing snake eggs and foraging primarily above the ground and into the forest canopy. Here we document an extension of its aberrant ecology and behaviour: a case of N. pustulatus burying 2-day-old live and dead nestlings of Tree Swallow (Tachycineta bicolor, Passeriformes: Hirundinidae) under the nest, behaviour consistent with the early stages of breeding in N. pustulatus. Based on different levels of decomposition, we suspect that N. pustulatus responded to one dead swallow nestling in the brood of five and went on to bury all of the nestlings at the bottom of the nest box. The observation provides the first evidence, to our knowledge, of Nicrophorus burying live vertebrates.

Breeding stage, not sex, affects foraging characteristics in masked boobies at Rapa Nui

Sexual segregation in foraging occurs in some species and populations of boobies (Sulidae), but it is not a general pattern. Sexual segregation in foraging may occur to avoid competition for food, and this competition may intensify during specific stages of breeding. We examined sexual segregation in foraging in relation to breeding stage in masked boobies Sula dactylatra at Rapa Nui by tracking simultaneously incubating and chick-rearing birds using GPS recorders (n = 18) and collected a total of 11 regurgitate samples. Stable isotope analyses (δ13C and δ15N) of whole blood samples were carried out in 20 birds. There were no differences in foraging trip parameters or diet between females and males. Both sexes traveled farther and for longer while incubating than while rearing chicks. Isotopic niches (δ13C and δ15N) overlapped to some degree among all groups at all times, but the lowest overlap between sexes occurred during incubation. While preying on ephemerally distributed flying fish, vertical or horizontal competition avoidance may be almost impossible, and thus females and males share their foraging grounds. Since birds were tracked simultaneously, shorter foraging trips of chick-rearing birds must be an effect of the constraints of provisioning the chick. Differences observed in δ15N and δ13C values between sexes may be caused by subtle differences in their foraging behaviors, or by differences in physiology linked to breeding. Our findings suggest that local oceanography and its inherent food distribution are determinants for sexual segregation in foraging patterns in masked boobies and possibly also other booby species.Significance statementIn some animals, females and males forage on different areas or prey on different species to avoid competition for food resources. In boobies (Sula sp.), some studies show evidence of sexual segregation in foraging and others do not. Here, we tested if sexual segregation in foraging occurred in masked boobies on the Pacific island of Rapa Nui by studying simultaneously incubating and chick-rearing birds. We found no evidence of sexual segregation on foraging behavior or diet. We discuss that the difference between this and other studies in boobies may be an effect of the local prey availability. When the prey community is more diverse and heterogeneously distributed, each sex may access different resources and thus sexual foraging segregation will occur. In contrast, in areas like Rapa Nui where prey resources are distributed ephemerally, sexual segregation in foraging will not be useful and is thus less likely to occur.