Late Incubation Research Articles

Experimental investigation of the precursor characteristics and early warning of coal burst based on quantitative analysis of acoustic emission signals

Coal burst is one of the most frequent and destructive dynamic disasters encountered during underground mining engineering. However, the understanding of quantitative precursor characteristics of coal burst is still in its infancy, rendering it difficult to provide effective early warning of disaster. In this study, to quantitatively study precursor characteristics and warning signs of coal burst, the coal burst experiments were carried out on coal-rock combination with a crack. The acoustic emission (AE) technique was employed to quantitatively analyse the precursor information during coal burst process. Testing results indicated that coal burst process is classified into three stages based on evolution in AE energy, i.e., early incubation stage, late incubation stage and occurrence stage. The first significant increase in AE energy could be identified as the beginning of the late incubation stage of coal burst, accompanying by the phenomenon of macro-failure initiation. AE signals during the whole process could be classified as five types according to their dominant frequency and amplitude characteristics, i.e., HF-HA, LF-HA, EHF-LA, HF-LA and LF-LA respectively. The dramatic increase in number proportion of HF-HA and LF-HA signals is highly correlated with occurrence of coal burst. In addition, a comprehensive classification criterion for the coal burst prediction was proposed under a quantitative analysis of three AE parameters, i.e., first energy index (FEI), coal burst risk indicator based on AE energy (CRIE) and frequency spectrum (CRIF−A). The findings in this study could facilitate accurate coal burst prediction.

Contaminants of emerging concern in an endangered population of common eiders (Somateria mollissima) in the Baltic Sea

Contaminants of emerging concern (CECs) are ubiquitous in aquatic environments and pose a range of biological effects including endocrine disruption. Yet, knowledge of their occurrence in wildlife including seabirds remains scarce. We investigated the occurrence of selected bisphenols, benzophenones, phthalate metabolites, benzotriazoles, benzothiazoles, parabens, triclosan, and triclocarban in plasma of 18 breeding female common eiders (Somateria mollissima) from an endangered population in the Baltic Sea as most of these CECs have never before been examined in eiders. We sampled blood at the start (T1) and end (T2) of incubation to investigate concentration changes during incubation. As early- and late-breeding eiders tend to differ in how they finance reproduction (local vs stored nutrient reserves), we compared early and late breeders to assess whether CEC concentrations differed by breeding phenology. Of the 58 targeted CECs, 21 were detected in at least one female, with bisphenol A (BPA) and benzophenone-3 (BzP-3) occurring most frequently (T1: 78% and 61%; T2: 61% and 67%, respectively), while mono(2-ethyl-1-hexyl) phthalate (mEHP), BPA, and monoethyl phthalate (mEP) were detected in the highest concentrations (median concentrations 27.1, 12.7, and 11.2 ng/g wet weight, respectively, at T1). No CEC concentrations differed between early and late incubation. Late breeders had significantly higher concentrations of BzP-3, monomethyl phthalate (mMP), and mEP during early incubation (4.55 vs 1.24 ng/g ww, 7.05 vs 3.52, and 11.2 vs < limit of detection (LOD), respectively) and significantly higher concentrations of mMP and mEP during late incubation (6.16 vs <LOD and 7.51 vs <LOD, respectively) than early breeders. We showed that early and late breeders exhibited differential exposure to CECs. Our results support the need for long-term monitoring of CECs in eiders. Furthermore, it is important to examine these CECs in the eiders’ prey species from their wintering and breeding grounds.

Thermal Manipulation During the Embryonic Stage and the Post-Hatch Characteristics of Broiler Chickens.

The objective of this study was to evaluate the influence of thermal manipulation during incubation on the hatchability, the performance, the carcass characteristics, the intestinal villi, the nutrient metabolizability, and some physiological parameters in broiler chickens. Ross eggs were randomly distributed into four commercial automatic incubators. The treatments were as follows: incubator kept at 37.5 °C throughout the incubation period (Ctrl-control), and incubator temperature increased to 39 °C on days 16, 17, and 18 of incubation for 3 (T3h), 12 (T12h), or 24 h (T24h). The chicks were housed in an experimental performance barn and kept until 42 days of age under standard rearing conditions. The hatchability was lower when T24h was used. During the time after hatching, T3h caused higher levels of heat shock protein 70 (HSP70) in the liver, a faster breathing rate, and a drop in the cloacal temperature and hematocrit. T12h increased the respiratory rate. T24h decreased the hematocrit, the weight gain, and the feed intake. The thermal manipulation during incubation did not affect the carcass characteristics, intestinal villi, or metabolizability of nutrients. It was concluded that raising the incubator temperature for 3 h during late incubation may be beneficial for thermoregulation, but raising it for 24 h during this period impairs animal performance.

Linking resource selection to population performance spatially to identify species' habitat across broad scales: An example of greater sage-grouse in a distinct population segment.

Management decisions often focus on the habitat selection of marked individuals without considering the contribution to demographic performance in selected habitats. Because habitat selection is not always adaptive, understanding the spatial relationship between habitat selection and demographic performance is critical to management decisions. Mapping both habitat selection and demographic performance for species of conservation concern can help guide population-scale conservation efforts. We demonstrate a quantitative approach to differentiate areas supporting selection and survival at large spatial extents. As a case study, we applied this approach to greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), an indicator species for sagebrush ecosystems. We evaluated both habitat selection and survival across multiple reproductive life stages (nesting, brood-rearing) in the Bi-State Distinct Population Segment, a genetically distinct and geographically isolated population of sage-grouse on the southwestern edge of the species' range. Our approach allowed us to identify both mismatches between selection and survival and trade-offs between reproductive life stages. These findings suggest resource demands vary across time, with predation risk being a dominant driver of habitat selection during nesting and early brood-rearing periods when chicks are smaller and flightless, whereas access to forage resources becomes more important during late brood rearing when resources become increasingly limited. Moving beyond identifying and managing habitat solely based on species occupancy or use by incorporating demographic measures allows managersto tailor actions to their specific goals; for example, protections of areas that support high selection and high survival and restoration actions focused on increasing survival in areas of high selection and low survival.

Free‐roaming horses exceeding appropriate management levels affect multiple vital rates in greater sage‐grouse

AbstractSince the passage of the Wild Free‐Roaming Horses and Burros Act of 1971, federal agencies have been responsible for managing free‐roaming equids in the United States. Over the last 20 years, management has been hampered by direct opposition from advocacy groups, budget limitations, and a decline in the public's willingness to adopt free‐roaming horses (Equus caballus). As a result, free‐roaming equid numbers have increased to &gt;3 times the targeted goal of 26,785 (horses and burros [E. asinus] combined), the cumulative sum of the appropriate management levels (AML) for all 177 designated herd management areas (HMA) managed by the Bureau of Land Management. This increase is one of the causes of greater sage‐grouse (Centrocercus urophasianus) population declines, owing to habitat alteration from free‐roaming equids exacerbated by ongoing drought. To evaluate potential demographic mechanisms influencing these declines, we compiled survival data from 4 studies in central Wyoming, USA, including 995 adult female (first‐year breeders or older) sage‐grouse during the breeding season, 1,075 nests, 372 broods, and 136 juveniles (i.e., overwinter survival for fledged young), from 2008–2022. During this period, we also obtained population information for free‐roaming horses from 9 HMAs used by individual grouse in our sample. Population estimates of free‐roaming horses for these HMAs ranged from 59% to 7 times of the maximum appropriate management level (AMLmax). Sage‐grouse monitored outside of HMAs represented control populations and, because we assumed they were not exposed to populations of free‐roaming horses, we set values of AMLmax to zero for all grouse located outside of HMAs. To evaluate whether free‐roaming horses were negatively affecting sage‐grouse, we modeled daily survival of breeding age females, nest, broods, and juveniles. There was strong or moderate evidence that overabundant free‐roaming horses negatively affected nest, brood, and juvenile survival. When horse abundance increased from AMLmax to 3 times AMLmax, survival was reduced 8.1%, 18.3%, 18.2%, and 18.2% for nests, early broods (≤20 days after hatch), late broods (&gt;20 days to 35 days after hatch), and juveniles, respectively. These results indicate increasing free‐roaming horse numbers affected vital rates for important life stages of sage‐grouse, and that maintaining free‐roaming horse numbers below AMLmax would reduce negative effects to sage‐grouse populations.

Influence of light exposure during late incubation, early feeding, and litter access posthatch on the stress response and body weight gain in laying hen chicks

Influence of light exposure during late incubation, early feeding, and litter access posthatch on the stress response and body weight gain in laying hen chicks

Sex allocation is color morph-specific and associated with fledging condition in a wild bird.

Melanin-based color polymorphism is predicted to evolve and maintain through differential fitness of morphs in different environments, and several empirical studies indicate that life history strategies, physiology, and behavior vary among color morphs. Sex allocation theory predicts that parents should adjust their sex allocation based on differential costs of raising sons and daughters, and therefore, color morphs are expected to modify their brood sex ratio decisions. In color polymorphic tawny owls (Strix aluco), the pheomelanistic brown morph is associated with higher energy requirements, faster growth, and higher parental effort than the gray morph. As hypothesized, we find that brown tawny owl mothers produced more daughters in early broods and more males in late broods, whereas gray mothers did the opposite. At fledging, daughters of early broods and of brown mothers were heavier than those of late broods or gray mothers. Hence, larger and more costly daughters appeared to benefit more than males from being born to brown mothers early in the season. Brown mothers breeding later in the season produced more cheap sons, while gray mothers face fewer challenges under limited resources and favor daughters. These findings suggest that environmental conditions influence brood sex allocation strategies of genetically determined color morphs differently.

Waterfowl and Shorebirds: Formation and evolution of “cold” wintering grounds in Inner Asia (Baikal Siberia)

Despite the widespread occurrence of “cold” wintering of waterfowl, the causes of their formation have been studied very poorly. Very harsh winter conditions are typical for Eastern Siberia, but wintering grounds with a high number of 55.0-60.0 thousand birds are also formed here. Such wintering grounds include the source and upper course of the Angara River (thermal refugium). The high death rate of nests in the summer due to the unstable mountain floodplain water regime of the rivers of the region is compensated by the repeated nesting of birds. As a result, their total breeding season is greatly increased. By the time of migration, the late broods do not have time to accumulate enough plastic substances (fat) necessary for migration to the southern wintering grounds. Favorable conditions at the beginning of winter in thermal refugiums contribute to long delays of birds in feeding and resting places. However, by the time they are able to continue migration, it becomes impossible. Snow falls in the adjacent territories, reservoirs are covered with ice and a constant negative air temperature is established. Consequently, the “cold” wintering of shorebirds and waterfowl is forced. The basis of their species composition is formed by the animal-eating diving duck species. In this regard, their protection and maintenance of numbers in extreme years are difficult and expensive tasks.

Habitat restoration to conserve the Little Vermilion Flycatcher on Santa Cruz Island, Galapagos.

The endemic Little Vermilion Flycatcher (LVF), Pyrocephalus nanus, has suffered a drastic decline on Santa Cruz Island, where it was common 30 years ago. Currently, less than 40 individuals remain in the last remnants of natural humid forest in the Galapagos National Park on this island. This small population has low reproductive success, which is contributing to its decline in Santa Cruz. Previous studies have identified Avian Vampire Fly, Philornis downsi, parasitism, changes in food sources, and habitat alteration as threats to this species. In Santa Cruz, invasive plants may strongly affect the reproductive success of the LVF because they limit accessibility to prey near the ground, the preferred foraging niche of these birds. Since 2019, we restored the vegetation in seven plots of one hectare each by removing invasive blackberry plants and other introduced plant species. In all nests that reached late incubation, we also reduced the number of Avian Vampire Fly larvae. In this study, we compared foraging and perch height, pair formation, incubation time and reproductive success between managed and unmanaged areas. As predicted, we found significantly lower foraging height and perch height in 2021 in managed areas compared to unmanaged areas. In 2020, daily failure rate (DFR) of nests in the egg stage did not differ between management types; however, in 2021, DFR in the egg stage was significantly lower in managed areas than in unmanaged areas. The DFR during the nestling stage was similar between managed and unmanaged areas in 2020, but in 2021, only nests in managed areas reached the nestling stage. Females brooded significantly more during the incubation phase in managed areas. Additionally, we found significantly higher reproductive success in managed areas compared to unmanaged areas in 2021, but not in 2020. Habitat restoration is a long-term process and these findings suggest that habitat management positively affects this small population in the long term.

Habitat use of urban nesting yellow-legged gulls in Croatia during the breeding season

Because of increasing urbanization, some opportunistic birds such as gulls, started to exploit various artificial marine and terrestrial food sources. To better understand urban gull ecology and habitat use, a study was done on a yellow-legged gull (Larus michahellis) during the breeding season in Zadar, a coastal city on the Adriatic Sea. Ten adult breeding yellow-legged gulls (five females and five males) were caught on building rooftops during the late incubation period and were fitted with GPS-GSM solar power transmitters. In total, 2377 trip segments (no. GPS points = 19906) were analyzed, with most of them being classified as nest attendance (56.32 %) and foraging movements (37.10 %). Tracking data showed that the gulls mostly use marine and urban areas, agricultural lands, a dump site, and grasslands. Females were more active while foraging, with a longer duration and trip segment length, travelling further away from the breeding colony, while males tended to rest more than females. Both males and females exploit various habitats for foraging and resting, however females used agricultural lands significantly more than males. Even though gulls are generalists, some individuals showed a preference for certain habitats. After calculating the proportional similarity index, individuals showed high specialization for a certain habitat.

Comparison of nestling diet between first and second broods of great tits Parus major in urban and forest habitats

To understand why early broods tend to be more successful than late broods we investigated the nestling diet and reproductive success of great tit pairs that had both a first and a second brood in the same breeding season. We found that in forest habitats great tit parents delivered similar composition and amount of food per nestlings throughout the breeding season, resulting in similar nestling body mass and survival in both first and second broods. In urban habitats, however, although parents provided similar amounts of food to the second broods they tended to deliver fewer caterpillars. In parallel with this, we observed lower nestling survival in second urban broods than in first broods even though the body mass of surviving nestlings was similar to that of the first broods. These findings suggest that although parents produce smaller second broods in both habitats, they are able to compensate for lower food availability in forest habitats but not in urban habitats, thus leading to reduced food quality and lower offspring survival in urban second broods.

Female and male body condition in the Whiskered Tern Chlidonias hybrida, a species with female offspring desertion: a test of the differential parental capacity hypothesis

AbstractOffspring desertion by a single parent, mainly the female, occurs in many charadriiform birds. According to the differential parental capacity hypothesis (DPCH), females are more likely to desert, since they may be in poorer body condition than males as a consequence of egg-laying costs. This study investigated the body condition of 122 male and 118 female Whiskered Terns. In this species half of females desert during the chick-rearing period, the remainder during the post-fledging period. Body condition was investigated during the late incubation and early chick-rearing phases during the biparental care period in: (1) females that deserted during the chick-rearing period, (2) females that did not desert during this time, (3) males deserted by females, and (4) males not deserted by females. Among females that stayed, body condition during the pre-hatching period did not vary with relative catching date (clutch/brood age), whereas females that later deserted showed a very poor body condition when caught around seven days prior to hatching. After hatching, body condition was lower in both deserting and non-deserting females caught later. Among males whose females stayed, body condition remained nearly stable, whereas the body condition of males whose females deserted was lower the later they were caught. These results tally only partially with the DPCH: the pattern of parental body condition changes during breeding is apparently more complex than assumed by the DPCH and the cost of egg laying may be lower than suggested. Desertion by Whiskered Tern females is better explained by the sex role differences in parental care. The male’s ability to compensate for the missing female may be playing a role in the evolution of desertion.

The delayed effect of climatic conditions on pre‐fledging nestling haematocrit in a suboscine species in Patagonia

Haematocrit, the proportion of blood comprising erythrocytes, is often used as a proxy of individual condition. Nestling haematocrit is influenced by several factors but ambient temperature is generally agreed as a key driver. It is unclear which day(s) in embryonic or nestling development are most influential in determining pre‐fledgling haematocrit. This is important, because if we are able to identify what day(s) nestlings are physiologically most vulnerable to climatic conditions, this may inform future conservation management and help mitigate the effects. We investigated the effect of ambient temperature, precipitation, body size, brood size, age, food abundance and habitat on nestling haematocrit in Aphrastura spinicauda (thorn‐tailed rayaditos). We collected this data from two climatically different locations in Chile: northern Patagonia (Pucón) and Sub‐Antarctic Patagonia (Navarino Island), located ~ 1800 km further south. We aimed to identify the key drivers of nestling haematocrit and find when nestlings are physiologically most vulnerable to climatic conditions. We confirm that ambient temperature is the key driver of nestling haematocrit, with increasing ambient temperatures nestling haematocrit decreased. However, precipitation also affected haematocrit in the late incubation stage. At low and high precipitation, nestling haematocrit was low and is optimum in light rainfall. Our results show a delayed effect of ambient temperature and precipitation in late incubation and on the day of hatching which can determine pre‐fledgling haematocrit, which may cause lower post‐fledgling fitness. We found that climatic conditions on the day haematocrit was collected was not important in determining haematocrit. We found that haematocrit was higher in the sub‐Antarctic area and that higher temperatures and precipitation on the day of hatching will result in lower nestling haematocrit and poorer pre‐fledgling condition. As atmospheric temperatures rise, nestling fitness is at risk. This is a threat to many bird species, especially those in locations vulnerable to climate breakdown.

Characterization of Monoamine Oxidase-A in tropical liver fluke, Fasciola gigantica.

Fasciola gigantica, responsible for the zoonotic disease fasciolosis, pose a great threat to the livestock and human health worldwide. The triclabendazole (TCBZ) has been used for decades as a broad spectrum anthelmintic to control this perilous disease but the emergence of resistance in flukes against TCBZ has prompted researchers across the world to explore for new drugs and antigenic targets. World Health Organization has strongly recommended the utilization of neurobiologically significant biomolecules as new drug/antigenic targets because of their significant role in the physiology of parasites. Monoamine Oxidase (MAO) is an important neurobiological enzyme which catabolizes aminergic neurotransmitters thus preventing prolonged excitation of neurons and in non-neuronal cells it prevents cellular toxicity due to accumulation of toxic monoamines. Owing to the important role of MAO in the survival and perpetuation of parasites, multipronged approaches were undertaken for the characterization of MAO-A in F. gigantica. The activity of MAO was found to be 1.5 times higher in the mitochondrial samples than the whole homogenate samples. The adult worms of the F. gigantica appeared to possess both the isoforms of MAO i.e., MAO-A and MAO-B. The zymographic studies revealed strong enzyme activity in its native state as assessed through prominent dark bands at 250KDa in the zymogram. The enzyme was also found to be highly immunogenic as revealed by high antibody titer at 1:6400 dilution. The immunogenicity of MAO-A enzyme was further established in the Western Blots in which a strong band of 50KDa was distinctly evident. Despite ubiquitous presence of MAO in F. gigantica some regions like tegumental surface and intestinal caecae displayed strong immunofluorescence as compared to other regions. The detection of MAO-A in the F. gigantica samples in Dot-Blot assay indicate a great potential of this molecule for the immunodiagnostics of fasciolosis, particularly in the field conditions. The enzyme activity was sensitive to the specific inhibitor clorgyline in a concentration dependant manner, particularly in the late incubation period. The zymographic results also exhibited similar trend. The strong intensity of spots in Dot-blots indicate high immunogenicity of the MAO protein. The intensity of bands/spots in the samples of worms treated with clorgyline also declined, clearly indicating that the tropical liver fluke possesses prominent MAO-A activity.

Long‐term increase in female body condition and its effect on reproduction in two European red‐listed species, Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula)

Body condition of breeding females is an important driver of an individual's fitness and the consequent dynamics of populations. Long‐term changes in female body condition are likely to be affected by recent shifts in climatic and environmental conditions that can result in changes to population demography. To help explain the drivers shaping body condition during the incubation period and its consequences for reproductive success, we examined the long‐term pattern in the body condition of breeding females of two declining sympatric diving duck species: Common Pochard Aythya ferina and Tufted Duck Aythya fuligula. We analysed the data obtained from 139 females of Common Pochard and 251 females of Tufted Duck breeding on fishponds in South Bohemia, Czechia, between 2004 and 2020. We calculated the body condition index of females during late incubation based on the residuals from the relationship between body mass and tarsus length and used the incubation stage as an additional predictor of body mass. Body condition of both species did not decline over the 17 years of the study. The effect of winter weather conditions (winter temperature), water transparency (a proxy for food availability) and reproductive investment on body condition was not confirmed. Female body condition positively affected mean egg mass and hatchability in both studied species, i.e. females in better body condition laid larger eggs and hatched eggs with a higher hatching probability. We conclude that the population declines of the studied species are probably not connected to decreasing body condition of breeding females, but other reasons such as change in breeding propensity or offspring survival and recruitment should be considered in future studies.

Nondestructive prediction of fertilization status and growth indicators of hatching eggs based on respiration

Respiration continues throughout the incubation of eggs and is closely related to fertilization status and changes in chick embryo growth. Here, we explored the relationship between egg respiration, fertilization status, and growth indicators during incubation. First, we studied the changes in respiration of eggs during incubation and found that O2 consumption and CO2 emission were increased gradually during incubation and reached a maximum value when the shells were broken by the chick (21 days). Next, we established models to classify eggs according to the difference in respiration between fertilized and unfertilized eggs early during incubation using random forest (RF), logical regression, and support vector machine (SVM). The accuracy rates of RF and SVM on the third day of incubation were 99.32% and 98.63%, respectively, and reached 100% on the fifth day. Finally, a linear model was used to establish the relationship between chicken embryo respiration and yolk free body mass (YFBM) (R2 values of 0.99 and 0.98 for the early and late incubation periods, respectively), heart mass (R2 = 0.94), liver mass (R2 = 0.97), and the digestive system (DS) mass (R2 = 0.98). The R2 values for the relationships between the real and the predicted YFBM values and heart, liver, and DS masses were 0.98, 0.89, 0.87 and 0.88, respectively, indicating the good fit of the model. This study provides a theoretical basis for the detection of sterile eggs and dead-embryo eggs during incubation.

Unfolding a sequence of sensory influences and interactions in the development of functional brain laterality.

Evidence of sensory experience influencing the development of lateralized brain and behavior is reviewed. The epigenetic role of light exposure during two specific stages of embryonic development of precocial avian species is a particular focus of the research discussed. Two specific periods of light sensitivity (in early versus late incubation), each depending on different subcellular and cellular processes, affect lateralized behavior after hatching. Auditory and olfactory stimulation during embryonic development is also discussed with consideration of interactions with light-generated visual lateralization.

Variaiton in the composition of small molecule compounds in the egg yolks of Asian Short-toed Larks between early and late broods

The egg yolks of birds contain most of the maternally derived materials required for embryo development and are an important factor influencing embryo development and offspring viability. Individual variation in egg-laying date frequently occurs in passerines inhabiting highly seasonal environments. Females laying in early and late stages of the breeding season encounter different environment temperatures and food conditions, which can affect the levels of metabolities in their bodies, thereby altering the transmission of these materials to the eggs. We test a hypothesis that yolk small molecule compounds of Asian Short-toed Lark (Alaudala cheleensis) could vary between early (mid-May) and late (mid-June) broods. Using the UHPLC-MS/MS method, 683 compounds belonging to 21 compound groups are detected in the yolks. The contents of 18 compounds are significantly different between early and late broods. Ten differential compounds are significantly higher in the early laid eggs, among which γ-aminobutyric acid, creatine, prostaglandins, palmitoleic acid, linoleic acid, and trans linoleic acid are related to low environment temperature response. The eggs laid in late stage exhibit significantly higher levels of 5-L-glutamyl-L-alanine and γ-glutamate-leucine, 1,3-dimethyluric acid and mannose, which may be attributed to females in the late group consuming more insects. We suggest conducting a comprehensive investigation to reveal the yolk small molecule compounds mediated maternal effects on offspring phenotypes under varying ecological conditions.

ФЕНОЛОГИЯ СИНИЦ НАДВИДА PARUS MAJOR В ПРИАМУРЬЕ В КОНТЕКСТЕ ИХ ВЗАИМООТНОШЕНИЙ В ЗОНЕ СИМПАТРИИ И ГИБРИДИЗАЦИИ

The paper considers the phenological parameters of the great tit (Parus major) and Japanese tit (Parus minor) in Priamurye. In the cohabitation zone of these species, there are places where pronounced hybridization occurs and the areas where it fades and stabilizes. This leads to the zone of sympatry subdivision into three main parts: western, central, and eastern. To understand the phenomenon of hybridization in these parts, its changes and differences, the phenological parameters of the eastern tit were studied and compared with those of the great tit. For the Japanese tit, the author has determined the dates of pre-spring migrations, flight and appearance at nesting sites, spring singing of males, the period of courtship and struggle for females, nest construction and egg laying, incubation of clutches, the appearance of chicks and fledglings, late broods, and also autumn migrations. It is given the data on this species wintering in Priamurye. The same indicators are compared with those for the great tit. It is revealed that the great tit males begin to sing early – from the end of December to the beginning of January, still in wintering groups. The aspects of behavior preceding direct reproduction: courtship of males for females, struggle between males for females, begging for food from males by females in already established pairs, are also manifested in great tits in wintering groups when there is not yet the Japanese tit main population at breeding sites. The spring flight and mass appearance of the Japanese tit at nesting sites occurs since March, and pairs form in nesting sites in April. However, the indicators of direct reproduction in these species coincide in time.

ФЕНОЛОГИЯ БОЛЬШОЙ СИНИЦЫ (PARUS MAJOR) В БИРОБИДЖАНЕ (ЕВРЕЙСКАЯ АВТОНОМНАЯ ОБЛАСТЬ)

The author reveals phenological parameters of the Great Tit in Birobidzhan (Jewish Autonomous region) and shows the dates for the first, mass, and early morning singing of males; the period of courtship and competition for females, laying eggs and incubation of full clutches; the appearance of chicks and fledglings, migrations, late broods and autumn singing. In the period from the end of December to the third decade of March, there occurs a distribution of birds over nesting territories and formation of pairs. The period of early morning singing of males, from the third decade of March to the third decade of June, is the height of the breeding season.