Степной орел на территории резервата «Бокейорда» и Ащиозекского заказника (Западно-Казахстанская область) в 2022–2023 годы

Степной орёл в Алтае-Саянском регионе – результаты исследований 2019–2023 годов

The article presents the results of the Steppe Eagle ( Aquila nipalensis ) monitoring in the Orenburg region in 2010–2015. For 2010–2015 the population of Steppe Eagle in Orenburg region decreased by 20.6% and is 266–349, at average 293 breeding pairs. In 2015 the average density of occupied breeding territories on the main part of the Steppe Eagle breeding population (Trans Ural – Western part of the region) in the Orenburg region was about 8.6 per 100 km 2 , in the other habitats of the low and middle density of species – 1.3 (0.67–2.7)/100 km 2 . Observed breeding success in 2013 is 0.55±1.04, in 2015 is 0.40±0.78 nestlings per occupied breeding territory. Substantial increase in the proportion of young birds in the breeding pairs from 21.7% in 2012 to 44.4% in 2015 was noticed. The main threats to the Steppe Eagle in the Orenburg region are steppe fires and death on power lines. It is likely that the decline of eagles’ population is due to increasing of negative factors on the migration routes and wintering grounds

Covariation among factors that may affect nest success of dabbling ducks in the Prairie Pothole Region of North America (e.g. productivity of upland and wetland habitat related to climate variation, and duck and predator densities) often confounds efforts to interpret the effect of any individual factor. A comparison of nest success of dabbling ducks at sites with and without predator management provided an opportunity to separate the effect of predation pressure from other factors because predator management has occurred over a range of climatic conditions. We updated an existing study on temporal trends of nest success for prairie ducks in the Prairie Pothole Region of North America by compiling recent estimates of nest success for five species of dabbling ducks (Mallard [Anas platyhrynchos], Northern Pintail [A. acuta], Northern Shoveler [A. clypeata], Blue-winged Teal [A. discors], and Gadwall [A. strepera]). In addition, we compared trends of nest success at unmanaged sites and sites where nest predators were excluded or removed. We used pond density calculated from annual surveys for breeding waterfowl as an index of upland and wetland productivity and a correlate of predator and duck density. At unmanaged sites, the best approximating local regression model suggested that, rather than having undergone a monotonic decline, average nest success has fluctuated through time, although those changes do not appear to be associated with changes in pond density. At sites where predators were excluded, nest success did not vary with time but varied positively with pond density in the previous year, although that effect was tempered by high pond density in the year of observation. At sites where predators were removed but could emigrate back into study plots, nest success varied widely over time and we found no evidence of an effect of pond density. We show that nest success of dabbling ducks is higher under predator management than at sites without predator management, and that this relationship varies with climatic conditions, possibly related to complex interactions within and among duck species, their predators, and their prey.

Although many Western Burrowing Owl (Athene cunicularia hypugaea) populations have been declining, a high-density population nests at the National Radio Transmission Facility (NRTF), Dixon, California. We compared density at NRTF to densities elsewhere, and nest-site use and reuse to available nest substrates. Breeding pairs numbered 24–44 per year, averaging 34 pairs on 83 ha, the fourth-highest on record. Occupancy of eight artificial nest sites installed in 2000 declined from six pairs in 2006 to one pair in 2007 and 2008, and none afterward. Nearest-neighbor distance among artificial nests averaged half the distance among nest sites in fossorial mammal burrows and concrete half-rounds covering aboveground power cables. Undisturbed clay soils supported pocket gophers (Thomomys bottae) but few ground squirrels (Spermophilus beecheyi), whereas disturbed soils supported both ground squirrels and Burrowing Owls. The presence of both ground squirrels and Burrowing Owls was associated with backfill soils over buried cable, cable covers, and areas where soils bordered impervious surfaces. Nest-site reuse was low, with only 12% of the sites occupied in all study years, 2006–2011. Most (78%) nest sites reused in a subsequent year involved nests in a different burrow or cable cover opening >1 m from the previous year's nest. We recommend research on whether concrete half-rounds might outperform buried utility boxes as artificial nests, especially in conjunction with efforts to conserve the fossorial mammals that naturally excavate burrows used by Burrowing Owls.

In this paper we make an estimation of the number of the Eagle Owl (Bubo bubo) in the Republic of Kalmykia by means of using the suitable habitat model in QGIS using data acquired by the Earth remote sensing. The research was carried out in May – July 2020. The distribution of breeding pairs, reproductive success, and diet were studied. 36 eagle-owl’s home ranges are identified, 26 of them were occupied in 2020, and nests were found in 22 breeding territories. The density of breeding territory is 1.29 pairs per 100 km² or 17.5 pairs per 100 km of the linear biotopes on average. The brood size varied from 3 to 5 nestlings, average 3.36±0,67 nestlings per occupied nest and 2.9±1,22 nestlings per successful nest. The current number of the Kalmyk eagle owl population is estimated in a range of 242-293, 266 pairs on average, including 165 pairs (151–181) on the Ergeny hills and 23 pairs (21–25) in the Kuma Manych depression. The breeding grouping of Chernye Zemli is estimated at 70–87 pairs, 78 pairs on average. A decrease in the population level caused by the habitat loss started from the second half of the 20th century is estimated at 52 %.

Geese, swans, and ducks that cooperate in raising young maintain long-term pair bonds (Kear 1970, Bolen 1971, Weller 1976, Patterson 1982). In most holarctic ducks the female raises the young alone, new pairs are formed every year on wintering and/ or migration areas, and males follow their philopatric female to breeding areas (Hochbaum 1944, Rowley 1983, and others). Female Barrow's Goldeneye (Bucephala islandica) return to the same breeding area every year and often use the same nesting sites (Palmer 1976). Males accompany their mates from wintering areas, defend territories on the breeding ground, and then leave for unknown molting areas when the female is incubating (Savard 1982). They are not seen again on the breeding ponds until the following spring. I present evidence here indicating that some Barrow's Goldeneye pairs remain intact from year to year in spite of a long separation and that pair reunion occurs on the wintering areas. During a study of the breeding ecology of Barrow's Goldeneye in central British Columbia, I captured 15 adult drakes and 81 adult females and marked them with nasal disks. The return rate of females to the study area was 77% (n = 36) in 1982 and 75% (n = 81) in 1983, indicating a high degree of site fidelity. Similar rates of return for females have been found in other cavity-nesting ducks (Erskine 1961, Dow 1983). The return rate of drakes was 71% (n = 7) in 1982 and 63% (n = 15) in 1983. Two of three pairs marked in 1982 returned intact in 1983; the other did not return. The females of the two returning pairs had raised a brood in 1982 and therefore were separated from their mates for at least 4 months. The existence of longterm pair bonds was confirmed in 1984, when 3 of 7 marked pairs returned intact. Of the remaining pairs, 1 split and only 1 member returned in the other 3. The 2 females that had lost their mates had repaired when resighted, but the 4 males had not. These 4 males returned to the same pond where they had been captured the previous year, and 1 even defended a territory for 2 days. Usually, unpaired males do not defend territories (Savard 1982). One Barrow's Goldeneye drake marked on his territory in 1982 defended the same territory in 1983 and 1984. Similarly, 3 other paired males were resighted on the same territory the following year. Although the females of these males were not marked, it is likely that they retained their previous mates because females apparently select the territory in most territorial waterfowl (Hochbaum 1944, Young 1970, Donaghey 1975). The preceding observations indicate that pairs in Barrow's Goldeneye can remain intact from year to year in spite of a long separation and that unpaired males home to their previous breeding area. Homing of unpaired drakes to breeding areas has been reported in several dabbling ducks (Poston 1974, Blohm 1978) and diving ducks (Bengtson 1972, Alison 1975, Donaghey 1975). Breeding philopatry in unpaired males would increase their chances of finding a mate, or of reuniting with a previous mate. It could also enhance their survival because of their familiarity with the resources of the area. I now consider where and how pairs reunite. Within a week of the arrival of Barrow's Goldeneye on their wintering areas in southern coastal British Columbia in early November, some pairs are already defending territories (Savard unpubl. data). Of 34 territories defended along a 5-km stretch of shoreline in Burrard Inlet near Vancouver, B.C. in February and March 1983, 59% were occupied by mid-December and 85% by late December. This rapid formation of pairs soon after the arrival on the wintering areas, when there is little courtship, suggests that pairs reunite then. In 1983, 55% of the 400 males present in Burrard Inlet on 17 November had arrived by 1 November, compared to only 11% of the 200 females. This earlier arrival of the males supports the contention that most pairs reunite on the wintering ground rather than on fall staging areas. Spurr and Milne (1976) found similar pair formation in the Common Eider (Somateria mollissima) that also involved little courtship. Butterfield (1970) also observed that pairs of Zebra Finch (Poephila guttata) that reunited after separation displayed little courtship. I was fortunate to document the reunion of one pair of Barrow's Goldeneye on the wintering area. A drake marked on his breeding territory in 1982 was resighted near Vancouver, B.C. defending a winter territory at the tip of a small jetty. He was paired with an unmarked female, and they remained in their territory all winter. In April 1983 the male defended the same breeding territory as in 1982. He was paired, presumably with the female with whom he had wintered. We marked her that summer, and she raised a brood while the male departed for the molting grounds. On 29 October we sighted the male in a small group of goldeneye (37 males, 3 females, 10 immatures) 2 km east of his winter territory. Daily checks indicated that he remained there until 12 November. On 8 November we sighted his mate in a large group of goldeneye (84 males, 39 females, 1 immature) 4 km from the location of the male. This coincided with the first big influx of adult females

We examined the influence of vegetation and predator community on nesting success of songbirds in the grasslands of eastern North Dakota, USA. Each year, eight sites were chosen: four were subject to predator removal, and four were non-removal sites. On each site, nests of grassland songbirds were monitored, and simulated nests were used to examine how vegetation characteristics at nests affect nest success. Vegetative characteristics at simulated nests did not differ from those at natural nests, but successful natural nests had greater forb and lesser grass cover than unsuccessful nests, whereas no differences in vegetation were detected between successful and depredated simulated nests. On non-removal sites, small mammals and ground squirrels (Spermophilus sp.) depredated nests in taller and denser cover when compared to nests destroyed by medium-sized mammals and birds. On removal sites, we found no difference in vegetation characteristics of nests depredated by different predator types. However, each group of mammalian predators depredated simulated nests with different vegetation characteristics on removal versus non-removal sites. On sites where predators were removed, small mammals and ground squirrels preyed on simulated nests in shorter vegetation containing fewer forbs, ground squirrels preyed on nests with higher grass cover and lower vertical density, and medium-sized carnivores preyed on nests in taller vegetation. These results support the hypothesis that high predator diversity may reduce the chance of “safe” nest sites, and suggest that the behavior of low-level predators may change when top-level predators are removed.

We studied duck nest success and predator community composition in relation to size of discrete patches of nesting cover in the Prairie Pothole Region (PPR) of the United States in 1993-95 We focused on nests in uplands that were seeded to perennial grasses and forbs and enrolled in the Conservation Reserve Program (CRP) in Minnesota, North Dakota, and South Dakota. We estimated daily survival rates (DSRs) of upland duck nests and indices of activity for red foxes (Vulpes vulpes), coyotes (Canis latrans), American badgers (Taxidea taxus), striped skunks (Mephitis mephitis) and Franklin's ground squirrels (Spermophilus franklinii) and related these variables to habitat patch size. The effect of patch size (small vs. large) on estimated annual mean DSR was dependent on date of nest initiation (early vs. late) and year. Examination of within-year comparisons for early and late nests suggested that DSR was generally greater in larger habitat patches Activity indices for the 5 mammalian nest predators were influenced differently by year, location, and patch size. Activity indices of the red fox were greatest in small patches. Coyote indices were the most inconsistent, demonstrating a year × location × patch size interaction. Activity indices of the striped skunk and American badger varied only among years. Franklin's ground squirrel indices were affected by study area location, with higher indices in the southeast than the northwest. Red fox activity was weakly correlated with that of the striped skunk and coyote. Although a positive relationship between habitat patch size and nest success probably exists, we believe the experiment to fully test this hypothesis will continue to be elusive.

Capsule Female Black Grouse demonstrated fidelity to breeding areas, selecting nest-sites in taller, more dense vegetation, with nest success related to concealment.Aim To investigate the fidelity to breeding areas and nesting habitat preferences of female Black Grouse.Methods Nest habitat data were collected from radio-tagged females and related to measures from random sites and in relation to nest success. To explore fidelity to breeding areas, distances between consecutive nests were assessed.Results Females preferred to select nest-sites in tall rushes, which provided greater vertical cover and concealment. Successful nests were in vegetation with greater concealment than those that failed. Females exhibited fidelity to their breeding areas whether successful or not, nesting on average within 225 m of the previous year's nest.Conclusion The availability of tall nesting cover is important to breeding Black Grouse even in areas with low densities of generalist predators.

Journal Article Plague Vector Studies Part II. The role of climatic factors in determining seasonal fluctuations of flea species associated with the California Ground Squirrel Get access Raymond E. Ryckman Raymond E. Ryckman 2Department of Microbiology, School of Medicine Loma Linda University, Loma Linda, California 92354, U.S.A. Research Associate in Entomology, Los Angeles County Museum, Los Angeles, California. Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Medical Entomology, Volume 8, Issue 5, 15 December 1971, Pages 541–549, https://doi.org/10.1093/jmedent/8.5.541 Published: 15 December 1971

Relationships among macrohabitat and depredation of northern bobwhite (Colinus virginianus) nests are poorly understood. Yet, macrohabitat composition may influence the nest predator community and, therefore, the vulnerability of northern bobwhite nests to depredation. We determined if macrohabitat composition surrounding bobwhite nests influenced nest placement, nest success, and which predators were responsible for depredating nests. We characterized macrohabitats at 2 scales, 8 and 16 ha, by surrounding both bobwhite nests, and an equal number of random locations, with a circular buffer. Random points were placed within the area used by bobwhites on our study area. We then determined the acreage of each macrohabitat category within each circular buffer to determine the macrohabitat composition. Macrohabitat categories included hardwood forested drains, upland pine forests burned in March of the same calendar year, upland pine forests burned in March of the previous calendar year, and fields. We documented nest predators using infrared video cameras placed at the nest site. We monitored 104 bobwhite nests on Tall Timbers Research Station (TTRS) during 1999 and 2000. Size of the circular buffer around nests did not qualitatively affect results. Area (ha) of upland pine forests and fields were similar at depredated nests, hatched nests, and random locations. However, there was an average of 81% and 56% more area of hardwood drain in the circular buffers associated with random locations than at successful and depredated nests, respectively. Area of upland pine forests and fields were similar for nests depredated by raccoon (Procyon lotor), armadillo (Dasypus novemcinctus) and snake (Elaphus spp.). However, there was an average of 6.1 and 3.3 times more area of hardwood drain surrounding nests that were depredated by snakes relative to nests depredated by raccoons and armadillos, respectively. While our sample sizes were low, bobwhites exhibited a tendency to place nests in landscapes with less hardwood drain than were generally available on the study area. Macrohabitat surrounding nests influenced the type of nest predator to depredate nests. To minimize depredation of bobwhite nests by snakes, we suggest nesting cover should be developed away from drain edges.

Red-headed woodpecker (Melanerpes erythrocephalus) populations have declined range-wide over the past 40 years, although the causal mechanisms implicated in the observed declines remain poorly understood. Population decline has been most severe at the periphery of their range, particularly in the northeastern United States, coinciding with a region where there is little information regarding red-headed woodpecker habitat use or demography. A detailed knowledge of habitat requirements and population dynamics is prerequisite for the effective conservation and management of imperiled wildlife populations, and this knowledge gap likely precludes informed management decisions for red-headed woodpeckers in the northeastern portion of their range. In response to the extreme paucity of information regarding red-headed woodpecker habitat selection and breeding ecology in the northeastern United States, I conducted a field study on Fort Drum Military Installation, New York where a small but regionally important population of 10--15 adult red-headed woodpecker pairs regularly breeds. From May to August 2012--2013 I surveyed the installation for red-headed woodpecker breeding territories and located 15 and 11 territorial pairs in 2012 and 2013, respectively. I subsequently located nest cavities of breeding pairs to monitor reproductive success and conducted extensive habitat sampling to assess nest-habitat selection.;I used boosted regression trees (BRT) to identify red-headed woodpecker nest-habitat thresholds at multiple spatial scales. Red-headed woodpeckers exhibited nest-tree thresholds related to tree (1) decay class, (2) dead-limb length, and (3) diameter at breast height (dbh), while forest patch (i.e., surrounding vegetation) thresholds were related to (1) total dead-limb length, (2) understory height, (3) average tree dbh, and (4) large tree (≥30-cm dbh) density. These results provide objective criteria for managing nesting habitat for red-headed woodpeckers, and indicate the relative importance of nest-tree and forest-patch characteristics on nest-site selection.;I modeled red-headed woodpecker daily nest survival rates (DSR) as a function of temporal and habitat-specific covariates using logistic-exposure models to identify factors influencing nest survival and better understand the underlying mechanisms affecting reproductive success and productivity. A total of 30 red-headed woodpecker nesting attempts by 22 breeding pairs were monitored over the course of the study and I documented low rates of reproductive success (overall nest success = 32%) and observed high rates (>80%) of nest predation. DSR was most influenced by cavity concealment, such that nests with greater vegetative structure surrounding (within 1 m 2 of) the nest cavity had higher survival rates--an attribute that likely reduced nest predation.;I also sought to identify factors influencing large-scale

The hypothesis that small mammal burrows can increase the amount of water infiltrating into the soil profile was tested. The amount of water added to the soil profile from spring recharge in areas adjacent to ground squirrel (Spermophilus townsendii and S. elegans) burrows was compared to nearby areas without burrows. Recharge amounts in burrow areas were significantly higher than nonburrow areas. An average of 21% more of the winter precipitation infiltrated into the soil near burrows. The amount of recharge was also found to be positively related to burrow density. Burrows also affected the distribution of the recharge by adding significantly more water to the deeper portions (>50 cm) of the soil profile.

The paper discusses the results of the analysis of the species dynamics of the myrmecofauna inside the acclimatization pens of the Przewalskis horse in the Orenburg State Reserve. Although the horse is a specially protected species, the impact it can have on steppe ecosystems needs to be assessed through annual monitoring. Like other ungulates, Przewalskis horses eat and trample vegetation as well as compact the soil due to the mechanical destruction of soil aggregates. It is shown that grazing of large ungulates has both direct and indirect effects on the myrmecocomplex. Based on the results of the study, the main patterns of species imbalances on the territory of sites in acclimatization paddocks subject to pasture influence were established. The results of the work have shown that there are such ant species as Cataglyphis aenescens N., Lasius alienus F., Tetramorium caespitum L., Messor muticus N., Cataglyphis aenescens N., Temnothorax sp., Tetramorium caespitum L., Proformica epinotalis Kuznetsov-Ugamsky on the territory. In open, well-heated areas, dominant positions were occupied by Cataglyphis aenescens N., while in the presence of vegetation, soil zoonecrophages Lasius alienus F. and Tetramorium caespitum L. dominated. The paper reflects the experimental results, analyzes them, and concludes about the probable reasons for the dominance of the species.

This paper presents the results of observations on the state of two bird species populations listed in the Red Book of the Russian Federation Recurvirostra avosetta L., Larus ichthyaetus Pall. The populations of these species in the State Natural Reserve Tryochozyorki Tract have been studied by the authors for 8 years. The wetland is a key ornithological area of international importance. The paper presents information obtained in 2020, which has been compared with the information received in 20132018 which was published. For R. avosetta L. the maximum number of breeding pairs (127) and the maximum value of the average clutch size (3,6) were noted for the entire observation period. The reproduction of R. avosetta L. started earlier than in previous years. For L. ichthyaetus L. a relatively high number (no less than 280300 pairs) and also the maximum value of the clutch size (3,0) were noted, the breeding time of the species turned out to be typical for this territory. The analysis showed a favorable state of the populations of these species. The previously stated assumption about the relationship of the studied indicators of the nesting biology of these species with the level of water content of the territory was further confirmed.