Breeding Pairs Research Articles

First breeding of Egyptian vulture (Neophron percnopterus) in Sardinia and temporal and environmental factors affecting its frequentation of a supplementary feeding station

The Egyptian vulture Neophron percnopterus, a medium-sized scavenging bird, is the most-threatened bird species in Italy, with only 10–12 breeding pairs in 2019 distributed in three regions of Southern Italy. With this study, we aim to describe the first documented breeding of Egyptian vulture in Sardinia and to understand which temporal and environmental factors affected its frequentation of a supplementary feeding station. We monitored the nest used during 2019 through direct observations, and the use of the feeding station through camera traps. We fitted a Bayesian Generalised Additive Model to model the effect of the day of the year, the hour of the day, wind direction and wind speed on the presence of Egyptian vulture in a specific hourly time slot at the supplementary feeding station. The chick hatched around 5 July 2019, and it fledged around 21 September. The Egyptian vulture had two peaks of frequentation at the supplementary feeding station: a first one in June, and a second, more important one, between late August and early September. The probability of recording Egyptian vulture peaked between 10:00 and 16:00, and was affected by wind direction, with a slightly higher chance of recording Egyptian vulture when winds came from South-West, West or even North-West, and a lower chance when winds were eastward. This study marks an important step in the conservation of the Egyptian vulture in Italy; it provides an example of spontaneous colonisation, and of the increased attractiveness of the habitat for scavenging birds linked to the actions implemented within a LIFE project. To better target future conservation efforts, it is important to continue with the monitoring and to perform genetic analyses to assess the origin of the individuals.

Persistence of autozygosity in crossbreds between autochthonous and cosmopolitan breeds of swine: a simulation study

Crossbreeding might be a valid strategy to valorize local pig breeds. Crossbreeding should reduce homozygosity and, as a consequence, yield hybrid vigor for fitness and production traits. This study aimed to quantify the persistence of autozygosity in terminal crossbred pigs compared with purebreds and, in turn, identify genomic regions where autozygosity’s persistence would not be found. The study was based on genotyping data from 20 European local pig breeds and three cosmopolitan pig breeds used to simulate crossbred offspring. This study consisted of two steps. First, one hundred matings were simulated for each pairwise combination of the 23 considered breeds (for a total of 276 combinations), ignoring the sex of the parent individuals in order to generate purebred and crossbred matings leveraging all the germplasm available. Second, a few preselected terminal-maternal breed pairs were used to mimic a realistic terminal crossbreeding system: (i) Mora Romagnola (boars) or Cinta Senese (boars) crossed with Large White (sows) or Landrace (sows); (ii) Duroc (boars) crossed with Mora Romagnola (sows) or Cinta Senese (sows). Runs of homozygosity was used to estimate genome-wide autozygosity (FROH). Observed FROH was higher in purebreds than in crossbreds, although some crossbred combinations showed higher FROH than other purebred combinations. Among the purebreds, the highest FROH values were observed in Mora Romagnola and Turopolje (0.50 and 0.46, respectively). FROH ranged from 0.04 to 0.16 in the crossbreds Alentejana × Large White and Alentejana × Iberian, respectively. Persistence of autozygosity was found in several genomic segments harboring regions where quantitative trait loci (QTLs) were found in the literature. The regions were enriched in QTLs involved in fatty acid metabolism and associated with performance traits. This simulation shows that autozygosity persists in most breed combinations of terminal crosses. Results suggest that a strategy for crossbreeding is implemented when leveraging autochthonous and cosmopolitan breeds to obtain most of the hybrid vigor.

The influence of landscape composition and configuration on breeding waterfowl pair abundance in Wisconsin

AbstractHabitat loss and fragmentation have negatively impacted breeding birds across the world. Across guilds, grassland‐dependent birds have experienced the largest proportional loss of their breeding population while wetland‐dependent birds have realized overall net gains in part due to focused conservation efforts. However, some species within the wetland‐dependent guild have a strong dependence on non‐wetland land cover types during the annual cycle and therefore may be equally sensitive to reductions in the composition and altered configuration of upland landcover, such as grasslands. We explored the influence of landcover composition and configuration on the number of breeding pairs of a breeding habitat generalist, the mallard (Anas platyrhynchos), and a grassland‐dependent breeding species, the blue‐winged teal (Spatula discors), in agriculturally‐intensive landscapes of Wisconsin, USA. Because of the extensive landscape alteration and habitat fragmentation that has occurred, we expected mallards to have a more utilitarian response to varying landscape composition compared to a grassland nesting obligate like blue‐winged teal. We used helicopter surveys conducted across 8 years (2001–2003, 2006–2009, and 2012) and remotely‐sensed land cover data to investigate the influence of habitat associations on relative abundance of breeding pairs. Model selection indicated that landscape composition models outperformed landscape configuration and null models for both species. Consistent with our predictions, we found that mallard pair counts were positively influenced by a greater number of land cover covariates compared to blue‐winged teal. Both blue‐winged teal and mallard breeding pairs were positively related to increased composition of emergent and scrub‐shrub wetlands as well as upland grassland. Additionally, we found that mallard pairs were positively related to forested, cattail (Typha sp.), and open water wetland types, whereas predicted blue‐winged teal pair abundance was negatively related to forested wetlands and had a nonlinear relationship and declined when surveyed land sections were comprised of more than 30% cattail‐dominated wetlands and 20% open‐water wetlands. Increased quantities of cattail‐dominated and open‐water wetland cover types comparatively provide less habitat for blue‐winged teal and may reflect broader shifts in habitat composition that have likely resulted from agricultural intensification and stabilized hydrology. Conservation activities that preserve existing nesting land cover types or restore hydrologically‐dynamic emergent wetlands in proximity to upland grassland cover could mutually benefit both species.

Monitoring Canadian Arctic seabirds at the Prince Leopold Island Field Station, 1975–2023

The research station at Prince Leopold Island (PLI), initiated in 1975, was the first seabird monitoring site created in the Canadian Arctic. The island supports 150 000 breeding pairs of seabirds, principally thick-billed murres ( Uria lomvia Linnaeus 1758), black-legged kittiwakes ( Rissa tridactyla Linnaeus 1758) and northern fulmars ( Fulmarus glacialis Linnaeus 1761), along with ∼70 pairs of glaucous gulls ( Larus hyperboreus Gunnerus 1767) and several thousand black guillemots ( Cepphus grylle Linnaeus 1758). Baseline observations of seabird breeding biology were made during 1975–1977. Subsequent monitoring has taken place in 22 of the 47 seasons, with work during 2001–2003 replicating the original baseline studies. Population trends of breeding seabirds have shown kittiwakes (sharply) and murres (gradually) increasing, while gulls (definitely) and fulmars (likely) have declined. The most striking scientific findings from PLI were related to the effect of annual ice break-up on seabird phenology, clutch size, and reproductive success. For contaminant research, PLI has become one of the core monitoring sites in Canada and internationally, documenting dramatic changes in concentrations of various contaminants in the Arctic marine environment. Given the international impact of research and monitoring at PLI for almost five decades, the continuation of seabird research at PLI, the most important seabird colony in the Canadian Arctic, is essential.

Comparison of nest site selection in Mute Swan Cygnus olor and the expanding Whooper Swan Cygnus cygnus

The warming climate is giving migratory birds new opportunities to extend their breeding ranges. These expansions may have a significant impact on other local bird communities. Here, we investigate the nest site selection of Mute Swan Cygnus olor, and the expanding Whooper Swan Cygnus cygnus. The study aims to assess the differences in habitat use by these two swan species in a lowland anthropogenic landscape. It examines the number of breeding pairs and the surface areas of nesting zones in different habitat types. The field procedures involved the use of unmanned aerial vehicles (UAVs) to survey and locate nests, with geotagged photographs taken to map nest locations. Our results show that Mute Swans primarily occupy oxbows, while Whooper Swans predominantly nest in pond complexes. Moreover, GLM models indicate that Mute Swans tend to choose open areas within a radius of 200 m around the nests, whereas Whooper Swans avoid built-up areas, often choosing forested sites within a radius of 500 m of their nests. These findings suggest that the expansion of the Whooper Swan population has led to changes in the breeding behaviour and habitat use of sympatric Mute Swan populations. The territorial behaviour and aggression of Whooper Swan may be driving Mute Swan away from fishpond habitats. We conclude that interactions between the two swan species are dynamic and have not yet stabilized, so this is an issue that needs to be closely monitored. Understanding these dynamics is essential for the effective conservation and management of wetland habitats in the face of ongoing climate change and shifting breeding ranges of birds.

Population structure and connectivity among coastal and freshwater Kelp Gull (Larus dominicanus) populations from Patagonia.

The genetic identification of evolutionary significant units and information on their connectivity can be used to design effective management and conservation plans for species of concern. Despite having high dispersal capacity, several seabird species show population structure due to both abiotic and biotic barriers to gene flow. The Kelp Gull is the most abundant species of gull in the southern hemisphere. In Argentina it reproduces in both marine and freshwater environments, with more than 100,000 breeding pairs following a metapopulation dynamic across 140 colonies in the Atlantic coast of Patagonia. However, little is known about the demography and connectivity of inland populations. We aim to provide information on the connectivity of the largest freshwater colonies (those from Nahuel Huapi Lake) with the closest Pacific and Atlantic populations to evaluate if these freshwater colonies are receiving immigrants from the larger coastal populations. We sampled three geographic regions (Nahuel Huapi Lake and the Atlantic and Pacific coasts) and employed a reduced-representation genomic approach to genotype individuals for single-nucleotide polymorphisms (SNPs). Using clustering and phylogenetic analyses we found three genetic groups, each corresponding to one of our sampled regions. Individuals from marine environments are more closely related to each other than to those from Nahuel Huapi Lake, indicating that the latter population constitutes the first freshwater Kelp Gull colony to be identified as an evolutionary significant unit in Patagonia.

Population, nesting characteristics, and breeding ecology of the critically endangered Gyps indicus in Mudumalai Tiger Reserve, South India

The species extinction rate has recently accelerated worldwide and is a thousand times higher than through natural processes alone. Small, isolated populations are especially vulnerable to extinction due to deterministic and stochastic threats. Hence, the conservation of such populations is challenging. The present study from 2015 to 2021 aimed to understand the population, nesting characteristics, and breeding ecology of the country’s southernmost population of Gyps indicus in Mudumalai Tiger Reserve, South India. The population estimation was performed on the roosting and nesting sites of Gyps indicus in the Mudumalai Tiger Reserve. To study the nesting characteristics and breeding ecology, each nesting colony was systematically visited four times per month during the breeding season (October to May). Assessments of threats were estimated during the field visits. In 2015–2021, four breeding sites were identified. Two nesting sites were identified in 2016 and two more in 2017 and 2020. The mean altitude of the nesting sites was 1122.25 ± 170.06 m a.s.l., ranging from 821 m a.s.l. to 1600 m a.s.l. In the Protected Area, two nests were located on east-facing exposure, one nest on southeast-facing exposure, and one nest on south-facing exposure. In terms of population composition, the mean number of adult individuals steadily increased from 9.5 ± 0.46 in 2016 to 14.08 ± 0.67 in 2021. Consequently, the mean total number of individuals per colony increased from 13.66 ± 0.56 in 2016 to 27.83 ± 0.62 in 2021. A total of 40 (in average, 6.66 ± 0.49 pairs/year) territorial pairs with occupied nests were observed in 2015–2021. Of them, 31 (in average, 5.16 ± 0.30 pairs/year) breeding pairs had laid eggs. Successful incubation was recorded, and the mean incubation period was 63.64 ± 1.74 days. Out of 31 incubated nests, 23 fledglings (3.83 ± 0.47 individuals/year) successfully came out with 74% breeding success. The entire nesting period was 128.43 ± 1.16 days. In total, out of 17 failed breeding attempts nine (53%) were detected before egg laying, and eight (47%) were found during incubation. There were no significant differences between nests abandoned before and after egg laying (t = 0.4152, p > 0.05). During the breeding seasons of 2015–2017, a human-made forest fire posed a serious threat to nesting colonies of Gyps indicus, resulting in no observed nesting. A species-specific conservation-oriented action programme is necessary to secure this last southernmost wild viable Gyps indicus population in the Mudumalai Tiger Reserve. At this juncture, we highly recommend declaring the buffer zone of the Mudumalai Tiger Reserve as a «Vulture Sanctuary» to provide a legal protection of the Gyps indicus population living in the studied area.

Effects of Refined Handling on Reproductive Indices of BALB/cJ and CD-1 IGS Mice.

Current mouse handling methods during cage change procedures can cause stress and potentially compromise animal welfare. Our previous study of breeding C57BL/6J mice found modest increases in pup production and a significant reduction in preweaning litter losses when mice were handled using a tunnel as compared with a tail-lift with padded forceps. The current study evaluated how these 2 handling methods affected reproduction by 2 additional mouse strains, BALB/cJ (a low- to intermediate-fecundity strain) and CD-1 IGS (a high-fecundity stock). We predicted that refined handling would have minimal effects on the high-fecundity line with a satisfactory production rate and greater effects on the low-fecundity line. Handling method (tunnel compared with tail-lift) was randomly assigned to monogamous breeding pairs of mice. Reproductive metrics (litter size at birth and weaning, numbers of litters, litter attrition, between-litter intervals, pup wean- ing weight, and sex ratio) were prospectively monitored for 80 BALB/cJ and 77 CD-1 pairs that were bred continuously for 6 mo. Both strains of mice were highly productive, exceeding previously published breeding data. However, neither strain demonstrated operational or statistically significant differences between handling methods for any reproduction metric. As we detected no negative effects in these 2 strains and the benefits are clear in other strains, refined handling should be considered for all breeding mice.

Current status and expansion of Western Red-rumped Swallow Cecropis daurica rufula (Temminck, 1835) (Aves Hirundinidae) in Sicily

The recent paper published by Corso et al. (2021) about the status of the Western Redrumped Swallow, Cecropis daurica rufula (Temminck, 1835) (Aves Hirundinidae), in Sicily was mainly focused on updating the distribution of breeding pairs in the south-eastern part of the region; hence the decision to provide a more complete and up-to-date regional picture of the current status of this species collecting unpublished data and investigating the most suitable locations in the period 2011–2022. This survey highlights as, also in western and central Sicily, the species has been showing an increase in number of breeding pairs, found in 18 new UTM squares (11 of these for which the breeding was ascertained and 7 for which was very probable) in comparison to the last updated data. A new map of the distribution of the Western Red-rumped Swallow in Sicily is therefore presented here.

Expansion of distribution ranges and current population status of Cheer pheasant (Catreus wallichii) in Northern Pakistan (AJ&K).

We studied the distribution and population status of the Cheer pheasant (Catreus wallichii) in Azad Jammu and Kashmir (AJ&K). Study was mainly conducted in four localities Jhelum Valley (JV), Machiara National Park (MNP), Haveli and Nar Sher Ali Khan (NSAK) from 2016-2020, for five breeding seasons. Population status of Cheer pheasant was determined by the call counts method. In total 105 breeding pairs (210 birds) were estimated highest (134) being recorded from Jhelum valley followed by MNP, Haveli and Nar Sher Ali Khan While applying correction factor 158 birds were recorded. Extensive surveys were carried out in an area of 19.23 km2. Our results indicate an expansion in distribution ranges of Cheer pheasant and population has established in several new sites. Highest Mean population density of 6.11pair/km2 was recorded in Qazi Nag area of Jhelum Valley. The mean population density of Cheer pheasant was slightly higher in the month of May. Furthermore, 58% of the calling birds were detected at elevations ranging from 2300-2600m, while 17% were found at elevations between 1900-2200m. Expansion in distribution ranges of Cheer might be due to reason that bird might have been underestimated in the past or conservation measures and community awareness programs taken by the Department of Wildlife and Fisheries, AJ&K.

The Breeding Population of the Rook, Corvus frugilegus (Aves, Corvidae) in Kharkiv, Ukraine: Nearly 22-times Decline in Numbers Over an 80-year Period

Based on regular surveys of the distribution of rookeries and the number of nesting birds of Corvus frugilegus Linnaeus, 1758 carried out in 2002–2020 using the TRIM (TRends & Indices for Monitoring data), the trajectory of change in the rook population has been estimated. The total size of the breeding population of rooks in Kharkiv City has decreased by 95.4 % over the last 80 years, from 940 to 43 breeding pairs. The general trend for 1939–2020 is a moderate decline (multiplicative slope 0.980, standard error 0.004; p < 0.01). A similar trend was observed for 2002–2020 when surveys were regular, i. e. a moderate decline (multiplicative slope 0.920, standard error 0.021; p < 0.01). Rooks still use the centre of the city for nesting, as they did in the early 1940s, but from the 1980s they began to breed in the eastern part of Kharkiv, where most of the population is now concentrated. Rooks breed in two clustered colonies, one in the central and one in the eastern part of Kharkiv City, about 13 km apart. The colonies are not numerous (all less than 50 pairs) in the last 10 years. The possible causes of the decline of the rook population in Kharkiv City are discussed.

Co-feeding na sobrevivência e crescimento de larvas de botia yoyo Botia lohachata durante a transição alimentar

ABSTRACT: This study evaluated the effect of the co-feeding (C) period on the growth and survival of larvae of the yo-yo loach Botia lohachata ornamental species during the weaning period from live food (LF) to inert food (IF). The breeders were subjected to induced spawning using crude pituitary homogenate. A total of 2,400 larvae were used with an average initial weight of 0.39 ± 0.09 mg and an average total length of 4.08 ± 0.21 mm, from a single breeding pair. The live food was newly hatched nauplii of Artemia franciscana, and the inert diet was a commercial ration with 55% crude protein and two particle sizes (142-350 µm and 350-500 µm). As the first food, all larvae received A. franciscana during the first six days, except for the fasting (NC) and inert food (IF) groups. The following co-feeding strategies were employed: C4 = 4 days of co-feeding, C8 = 8 days of co-feeding, C12 = 12 days of co-feeding, and LF = Artemia during the entire experimental period. The longest period with live food promoted better larval growth rates. The specific growth rate of larvae fed live food during the entire period (LF) was higher than that of the other groups, followed by the co-feeding strategies. There was no effect (P > 0.01) on larval survival in the LF, C12, C8, and C4 groups, which ranged from 41% to 53% after 30 days. Treatment R resulted in high mortality and low growth, suggesting that live food should be the first food source for B. lohachata larvae.

Increasing the operational parameters of worm gears

An analysis of factors that reduce the operational parameters of worm gearboxes has been carried out. Equations for calculating the efficiency of a worm gear, contact pressure, and the residual service life are given. It is shown that the friction angle and friction coefficient depend on the material of the worm and wheel teeth, the roughness of the working surfaces of the worm pair matings, the quality of the lubrication, and the sliding speed. Significant contact pressures and friction losses in meshing lead to heat generation, a decrease in efficiency and service life of the worm gear. To produce a worm gear with a maximum radius of a conjugate globoid-cylindrical pair with an involute profile, it is proposed to use rotational turning of the globoid worm turns with a multi-blade forcedly rotating tool, and the wheel teeth with a hob cutter. A nickel antifriction solid lubricating coating containing carbon nanotubes has increased hardness and resistance to abrasion. A method for manufacturing a ZT-type worm gear is proposed, as well as methods that reduce contact stresses and the coefficient of friction during operation of a mating worm pair to increase the service life of worm gears.

Palaeoparasycorax globosus Stebner et al., 2015 from the mid-Cretaceous amber of Myanmar: Description of a mating pair.

A mating pair of Palaeoparasycorax globosus Stebner et al., 2015 from the mid-Cretaceous Burmese amber is illustrated and described. The male is redescribed, and the female genitalia of this species is described for the first time. This discovery allows for a better understanding of this fossil sycoracines characteristics and further demonstrates the bioinclusion richness of the mid-Cretaceous Burmese amber. A list of all Cretaceous Psychodidae is given.

Study of the effect of laser textured rotors on the starting performance of metal–rubber mating pairs under different lubricating media environments

To solve the problem of premature failure of the rubber stator of the screw pump due to wear, reduce the frictional resistance torque of the screw pump to solve the problem of difficulty in starting after the shutdown of the screw pump production system in Daqing Oilfield. The effects of micron dot texture and lubricating medium on the tribological properties of 42CrMo metal and acrylonitrile–butadiene rubber mating surfaces were studied by theoretical analysis and tribological tests. The friction coefficient, wear amount, and rubber wear morphology were used as the measurement indexes of drag reduction, wear resistance, and wear degree, respectively. The results showed that the best combination of texture area ratio and the lubricating medium was 10% silicone grease, the friction coefficient and wear amount were reduced by 11% and 10.7%, respectively, compared with untextured, and the main order of chip storage and oil supply effect was 10% > 5% > 15%.

Aquaponics Fish Selection and Care

This article provides a thorough exploration of key factors crucial for the success of aquaponics systems, with a focus on fish health and welfare. It addresses critical considerations in selecting fish species, emphasizing factors such as water temperature requirements, growth rates, compatibility with plants, and market demand. The article further delves into maintaining optimal fish health, covering topics like water quality management, disease prevention, nutrition, and stress reduction. Additionally, it highlights the significance of proper stocking density and feeding practices for system performance, emphasizing their role in fish growth, nutrient cycling, and system sustainability. The article also provides insights into effective water quality management strategies, offering practical guidance for maintaining optimal conditions in aquaponics systems. Lastly, the article addresses breeding and fry rearing, essential components for sustaining fish populations, offering expert advice on selecting breeding pairs, providing suitable breeding conditions, and managing fry rearing. By incorporating these comprehensive insights, aquaponics practitioners can ensure the well-being of their fish population and optimize the overall performance and productivity of their systems.

Modelling the Distribution of the Little Owl Athene noctua in Bulgaria

The Little owl Athene noctua (Scopoli 1769) is believed to be widespread in Bulgaria but its actual distribution and ecology are insufficiently studied. Historical records and unpublished information on its abiotic requirements, habitat preferences, breeding biology and distribution were analyzed to generate an Ecological Niche Model and documented that A. noctua is found across 90.8% of Bulgaria. We also estimated its potential distribution and ecological requirements within part of its range using Maxent. The Environmental Niche Model has a high degree of predictability. The climate changes are affecting the distribution. Our results revealed that the vertical distribution of the species expands by 100 m a.s.l. In Bulgaria, the main factors which determine the status of the population are elevation, type of land use, human population density and demographic structure which seem to account for most of the variation in suitable climatic conditions, and climatic factors – Annual Mean Temperature and Mean, Driest Quarter. Threats to the Little owl in Bulgaria include habitat loss, destruction of breeding sites, vehicle collisions, poisoning, predation, and persecution due to negative stereotypes or beliefs. Bulgaria, with a high number of breeding pairs as compared to elsewhere in Europe has an opportunity and obligation to preserve the species. The results of this study will help inform conservation decisions and efforts to maintain Little owl populations in Bulgaria.

Monitoring wader breeding productivity

A robust understanding of the mechanisms driving demographic change in wild animal populations is fundamental to the delivery of effective conservation interventions. Demographic change can be driven by variation in adult survival, recruitment of juveniles into the breeding population or breeding productivity – the number of fledglings produced per breeding pair. Across Europe, low breeding productivity in wader populations has been a significant driver of population decline, increasing the importance of gathering accurate data on breeding productivity. Monitoring wader breeding productivity is challenging because finding nests can be time‐consuming and requires experienced fieldworkers; wader chicks are nidifugous and difficult to count due to their cryptic behaviour; and waders often have high re‐laying rates following nest failure, meaning that hatching or fledging can be highly asynchronous. This paper reviews approaches to estimating breeding productivity where fieldworkers either record the agitation or alarm‐calling behaviour of adults with dependent young, make direct observations of broods on survey visits, or both. Using a systematic literature search (restricted to Europe where most of these studies have taken place) we identified 38 peer‐reviewed papers which used this approach. The productivity metrics produced can be divided into the following categories: (i) ‘Hatching Success’ (HS), (ii) ‘Fledging Success’ (FS) and (iii) ‘Young Fledged Per Pair’ (YFP), from the coarsest to the most precise. The first two metrics are most often used when direct observations of broods are not possible due to the behaviour of broods or vegetation structure; YFP is preferred if brood counts are possible. Design of an appropriate metric depends on (i) whether accurate brood counts are possible; (ii) whether adults exhibit diagnostic agitation behaviour when young are present; (iii) whether individual breeding territories are separable; (iv) whether re‐nesting rates are assumed to be high; and (v) the availability of experienced surveyors (particularly where behavioural observations are required). Globally there are many wader species for which the methods described here could provide valuable information and we hope this review encourages further development or adoption of these methods.

Genetic aspects in working with the kholmogory cattle breed in the arkhangelsk region

Monitoring of the genetic structure of cattle breeds allows conducting studies that provide information about the cross-section in the timeline by the frequencies of genotypes of blood groups. In particular, the study was carried out on 10 time intervals of observations in herds for the Kholmogorsky breed of breeding plants of the Arkhangelsk region (n = 10983). The dynamics is shown by the decrease and increase in the frequencies of individual alleles. The genetic structure of the herd becomes more homozygous, as the loss of alleles goes on. A similar situation has developed in the samples of cows of the first and ninth generations, their genetic structures are sharply different. According to the results of the research, it was found that the quantitative and qualitative composition of the allelofund of the Kholmogorsky cattle of the Arkhangelsk region has changed under the influence of breeding processes. It was found that the degree of homozygosity (theoretical) tends to decrease from 10.5% (3rd generation) to 6.5% (9th, 10th generation) in the context of the analyzed generations of females, and the number of effective alleles, respectively, increases from 9.4% to 15.4%. At the same time, it was revealed that the breeding stock of the herds of breeding plants of the Arkhangelsk region was heterogeneous according to the genetic panel of the EAV locus. The greatest genetic distance is shown by purebred cows of the Kholmogorsky breed of cattle of the 1-2 observation intervals with Holstein in the 9-10 intervals. Breeding work and assessment of genetic variability is a tool for successful breeding in cattle herds of breeding plants by generations. The event to create new and improve existing factory lines using genetic markers of breed affiliation is promising. This will reduce the negative consequences of related mating of parent pairs, as well as avoid an increase in the level of homozygosity in the controlled herds of the Arkhangelsk population of the Kholmogorsky cattle breed.

Laboratory evaluation of interspecific mating between Zeugodacus fruit flies and Bactrocera dorsalis

AbstractThe increasing number of tephritid pest invasions worldwide highlights the importance of interspecific interactions among tephritid pests. The melon fly [Zeugodacus cucurbitae (Coquillett)], the pumpkin fruit fly [Zeugodacus tau (Walker)], and the oriental fruit fly [Bactrocera dorsalis (Hendel)] (all Diptera: Tephritidae) are neotropical fruit flies with overlapping distributions. Their interactions during mating hours have rarely been observed in nature due to their nocturnal behavior. Here, laboratory studies were conducted under no‐choice and choice conditions to quantify interspecific mating. The interactions during mating hours resulted in interspecific mating, which reduced conspecific mating success and interrupted mating activity patterns. Successful interspecific mating pairs of Z. cucurbitae and Z. tau were recorded in no‐choice and choice tests. Interspecific mating between male Z. cucurbitae and female Z. tau significantly reduced conspecific mating in Z. tau. Observations of the diel mating activity patterns showed that male Z. cucurbitae initiated calling behaviors earlier than Z. tau males, giving Z. cucurbitae more chances to court Z. tau. Though males of neither Zeugodacus species formed mating pairs with B. dorsalis, Zeugodacus males reduced conspecific mating in B. dorsalis in the choice trials. Thus, interspecific interactions among Z. cucurbitae, Z. tau, and B. dorsalis affected conspecific mating; interrupted conspecific mating activity patterns were recorded in all three species. This information could be used to improve management practices.