Yellow-billed Magpie Population Status and Habitat Characteristics in Urban Sacramento, California

Western Birds ◽  
2021 ◽  
Vol 52 (3) ◽  
pp. 222-239
Author(s):  
Daniel A. Airola ◽  
Lily A. Douglas ◽  
Layla Airola
Keyword(s):  
Habitat Characteristics ◽  
Flowing Water ◽  
Population Status ◽  
Foraging Habitat ◽  
Oak Woodlands ◽  
Large Trees ◽  
Annual Grassland ◽  
Reproductive Rates ◽  
Pica Nuttalli ◽  
Direct Counts

Most research on the ecology of the Yellow-billed Magpie (Pica nuttalli) has been focused in oak woodlands and savannas in California’s Coast Ranges; urban and suburban populations, some of which are sizable, have received little attention. In 2020, we studied eight colonies in six parks around Sacramento and in 2021 expanded the survey to 43 sites, detecting 827 breeding magpies. Population estimates based on nest counts were generally higher than those from direct counts, and nest counts were more repeatable and efficient. Counts of recently fledged young in family groups yielded reproductive rates similar to those observed near the coast before arrival of West Nile virus in 2003, suggesting that the virus is not currently affecting nestlings’ survival. Sacramento magpies nested in the upper canopy of a wide variety of large trees, both native and non-native. They foraged preferentially in low herbaceous habitat—irrigated turf and unirrigated annual grassland that was mowed or grazed. The presence of rivers and streams influenced occupancy strongly. Colony size was strongly related to the amount of low herbaceous foraging habitat within 0.5 km of colony sites with nearby flowing water. Our results suggest that at least 4 ha of low herbaceous foraging habitat is needed to support a small nesting colony. Retention of herbaceous habitat near large trees and flowing water, plus mowing or grazing to keep herbaceous growth low, should benefit urban Yellow-billed Magpies.

scholarly journals Riparian old-growth forests provide critical nesting and foraging habitat for Blakiston's fish owl Bubo blakistoni in Russia

Oryx ◽  
2013 ◽  
Vol 47 (4) ◽  
pp. 553-560 ◽  
Author(s):  
Jonathan C. Slaght ◽  
Sergei G. Surmach ◽  
R.J. Gutiérrez
Keyword(s):  
Woody Debris ◽  
Habitat Characteristics ◽  
Suitable Habitat ◽  
Home Ranges ◽  
Foraging Habitat ◽  
Old Growth ◽  
Nest Sites ◽  
Old Growth Forest ◽  
Large Trees ◽  
Old Growth Forests

AbstractConservation efforts for Blakiston's fish owl Bubo blakistoni in Russia are limited, partly because habitat use by these rare owls is poorly known. We therefore studied nesting and foraging habitat characteristics of Blakiston's fish owls in Primorye, Russia. We sampled habitat at 14 nest sites, 12 nest stand sites and 13 random sites; we also sampled rivers within 14 fish owl home ranges across our 20,213 km2 study area. We found that large old trees and riparian old-growth forest were the primary characteristics of nest and foraging sites, respectively. Large trees were probably used as nest sites because they have cavities large enough to accommodate these birds. Big trees are also important because they are primary sources of large woody debris in rivers, which enhances suitable habitat for salmon, the owl's primary prey. Based on habitat characteristics, nest sites were correctly distinguished from random sites 74% (Kappa = 0.48) of the time, nest stands from random sites 56% (Kappa = 0.12) of the time, and used sites from available foraging sites 68% (Kappa = 0.36) of the time. The management and conservation of old-growth forests is essential for sustaining this species because they are central to the owls' nesting and foraging behaviour. Moreover, conservation of these forests sustains habitat for many other species.

scholarly journals The Relationship Between Habitat Characteristics and Demographic Performance of Northern Spotted Owls in Southern Oregon

The Condor ◽  
2005 ◽  
Vol 107 (4) ◽  
pp. 863-878 ◽  
Author(s):  
Katie M. Dugger ◽  
Frank Wagner ◽  
Robert G. Anthony ◽  
Gail S. Olson
Keyword(s):  
Winter Precipitation ◽  
Reproductive Rate ◽  
Habitat Characteristics ◽  
Forest Types ◽  
Apparent Survival ◽  
Breeding Experience ◽  
Old Growth Forest ◽  
Strix Occidentalis Caurina ◽  
Demographic Performance ◽  
Reproductive Rates

Abstract We used data from Northern Spotted Owl (Strix occidentalis caurina) territories to model the effects of habitat (particularly intermediate-aged forest stand types), climate, and nonhabitat covariates (i.e., age, sex) on owl reproductive rate and apparent survival in southwestern Oregon. Our best model for reproductive rate included an interaction between a cyclic, annual time trend and male breeding experience, with higher reproductive rates in even years compared to odd, particularly for males with previous breeding experience. Reproductive rate was also negatively related to the amount of winter precipitation and positively related to the proportion of old-growth forest near the owl territory center. Apparent survival was not associated with age, sex, climate or any of the intermediate-aged forest types, but was positively associated with the proportion of older forest near the territory center in a pseudothreshold pattern. The quadratic structure of the proportion of nonhabitat farther from the nest or primary roost site was also part of our best survival model. Survival decreased dramatically when the amount of nonhabitat exceeded ∼50%. Habitat fitness potential estimates (λ̂h) for 97 owl territories ranged from 0.29–1.09, with a mean of 0.86 ± 0.02. Owl territories with habitat fitness potentials <1.0 were generally characterized by <40%–50% old forest habitat near the territory center. Our results indicate that both apparent survival and reproductive rate are positively associated with older forest types close to the nest or primary roost site. We found no support for either a positive or negative direct effect of intermediate-aged forests on either survival or reproductive rate.

scholarly journals Selection of Incubation Mound Sites by Three Sympatric Megapodes in Papua New Guinea

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 395-406 ◽  
Author(s):  
J. Ross Sinclair
Keyword(s):  
Papua New Guinea ◽  
Environmental Variables ◽  
New Guinea ◽  
Habitat Characteristics ◽  
Small Subset ◽  
Widespread Species ◽  
Large Trees ◽  
Distribución Geográfica ◽  
Selection Of ◽  
Mound Sites

Abstract I report nonrandom selection of sites for incubation mounds and interspecific sharing of mounds by three sympatric megapodes (Wattled Brush-turkey [Aepypodius arfakianus], Brown-collared Talegalla [Talegalla jobiensis] and New Guinea Megapode [Megapodius decollatus]) in the Crater Mountain Wildlife Management Area in the eastern highlands of Papua New Guinea. Talegallas used mounds concurrently with New Guinea Megapodes, and renovated brush-turkey mounds after the latter species had finished breeding. New Guinea Megapodes and brush-turkeys did not use the same mounds. Analysis of 18 environmental variables at 80 mound sites and 91 random points showed that (1) mound sites of the three species differed significantly from random points. Mounds were associated with large trees and in less disturbed habitat, characteristics which contribute to the functioning of the mound. (2) Mound sites of the three species differed from each other. Brush-turkey sites were steeper, and had fewer and smaller trees in the mound and more herbs in the surrounding forest than those of the other two species. New Guinea Megapode and talegalla sites were not clearly separated. (3) Some important environmental variables had significant effects of study location and location × species, suggesting that inter- and intraspecific differences in mound sites are dependent on the habitat in which the mounds are located. Given this, caution should be applied to generalizations about widespread species from site-selection studies in a small subset of habitats. I recommended landowners be advised not to locate gardens or cut trees close to mounds, and exclude some areas from logging concessions and mining leases. Selección de Sitios para Montículos de Incubación en Tres Megapódidos Simpátricos de Papua Nueva Guinea Resumen. Se reporta la selección no azarosa de sitios para incubación y como comparten estos sitios tres especies simpátricas de la familia de Megapodiidae (Aepypodius arfakianus, Talegalla jobiensis y Megapodius decollatus) en tres sitios en el área de manejo de vida silvestre Crater Mountain en las tierras altas del este de Papua Nueva Guinea. Individuos de Talegalla usaron los sitios al mismo tiempo que Megapodius, pero utilizaron sitios de Aepypodius después que ésta los abandonara. Un análisis sobre 18 características ambientales de 80 sitios y 91 puntos ubicados al azar indicó que (1) Las características ambientales de los sitios de incubación de las tres especies fueron significativamente diferentes de las registradas en puntos al azar. Los sitios de incubación se concentraron en áreas con árboles grandes y en áreas con menos perturbación que los puntos azarosos, factores que contribuyen a la función del sitio. (2) Las tres especies utilizaron sitios diferentes: Aepypodius utilizó sitios con mayor pendiente, con menos árboles y de menor tamaños, y con mayor cobertura herbacea en el bosque circundante, que las otras dos especies. Los sitios de Megapodius y de Talegalla no se distinguieron claramente uno de otro. (3) Algunas variables ambientales importantes tuvieron efectos significativos de ubicación y de ubicación × especies, lo cual sugiere que las diferencias entre y dentro de cada especies dependieron del hábitat en el cual se encontraban. Dados estos resultados, se recomienda precaución al generalizar los resultados para especies con amplia distribución geográfica basados en áreas pequeñas. Se recomienda no sembrar, ni cortar árboles cerca de los sitios de incubación, y que algunas áreas sean excluídas de las conseciones para actividades forestales y de mineras.

Nocturnal bird diversity in forest fragments in north-west Ecuador

2017 ◽  
Vol 33 (6) ◽  
pp. 357-364 ◽  
Author(s):  
Scott T. Walter ◽  
Luke Browne ◽  
Juan Freile ◽  
Nelson González ◽  
Julio Loor ◽  
...  
Keyword(s):  
Forest Cover ◽  
Habitat Preferences ◽  
Relative Effect ◽  
Habitat Characteristics ◽  
Anthropogenic Factors ◽  
Bird Diversity ◽  
Forest Fragments ◽  
North West ◽  
Bird Richness ◽  
Large Trees

Abstract:Habitat preferences and response to habitat conversion remain under-studied for many groups in the tropics, limiting our understanding of how environmental and anthropogenic factors may interact to shape patterns of diversity. To help fill this knowledge gap, we surveyed nocturnal birds such as owls, nightjars and potoos through auditory transect surveys in 22 forest fragments (2.7 to 33.6 ha) in north-west Ecuador. We assessed the relative effect of habitat characteristics (e.g. canopy height and openness, and density of large trees) and fragment attributes (e.g. area, altitude and proportion of surrounding forest cover) on species richness and community composition. Based on our previous work, we predicted that nocturnal bird richness would be highest in relatively larger fragments with more surrounding forest cover. We recorded 11 total species with an average ± SD of 3.4 ± 1.4 (range = 2–7) species per fragment, with higher richness in fragments that were larger, at lower altitudes, and characterized by more open canopies. Nocturnal bird community similarity was not significantly correlated with any measured environmental variable. These results indicate that both landscape (e.g. altitude) and fragment-specific (e.g. size, forest structure) attributes are likely to interact to shape patterns of diversity among this poorly known but ecologically important guild in fragmented tropical landscapes.

scholarly journals Characterisation of breeding habitat of Grizzled Giant Squirrel Ratufa macroura (Mammalia: Sciuridae) in Chinnar Wildlife Sanctuary, Western Ghats, India

2021 ◽  
Vol 13 (8) ◽  
pp. 18993-19001
Author(s):  
Kiran Thomas ◽  
P.O. Nameer
Keyword(s):  
Tamil Nadu ◽  
Mangifera Indica ◽  
Breeding Habitat ◽  
Habitat Characteristics ◽  
Terminalia Arjuna ◽  
Wildlife Sanctuary ◽  
The North ◽  
Large Trees ◽  
Riverine Habitat ◽  
Ficus Microcarpa

The Grizzled Giant Squirrel (GGS) Ratufa macroura (Pennant, 1769) is a ‘Near Threatened’ and endemic giant squirrel distributed in southern India and Sri Lanka. In India, the species is distributed in more than 10 locations between Cauvery Wildlife Sanctuary in Karnataka in the north and Srivilliputhur Grizzled Squirrel Wildlife Sanctuary in Tamil Nadu in the south. A study was conducted in the riparian habitats of Chinnar Wildlife Sanctuary in Kerala to understand the habitat characteristics, including the drey site use of GGS. The vegetation of the GGS habitat was studied using the quadrat method, and the dreys were counted using the transects.  A total of 95 species of trees were identified from the riverine vegetation, and the GGS used 36 species of trees for drey construction. Most of the dreys were found on Mangifera indica, Terminalia arjuna, Ficus microcarpa, Diospyros ebenum, and Pongamia pinnata. However, the GGS may prefer trees such as Mitragyna parviflora, Diospyros ebenum, Ficus microcarpa, Albizia procera, Acacia nilotica, and Acacia leucophloea for drey construction. The study also highlights the usage of large trees with extensive crown by the GGS for various activities such as feeding, resting, moving, and nesting, thus signifying the necessity for protecting the remaining riverine habitat at Chinnar Wildlife Sanctuary to ensure the long-term conservation of GGS. We recommend an urgent restoration by restocking with already existing, native tree species of the riverine habitat due to the extremely poor regeneration of trees in the riverine habitat that support the only population of the GGS in Kerala.

scholarly journals Responses of Terrestrial Herpetofauna to Persistent, Novel Ecosystems Resulting from Mountaintop Removal Mining

2017 ◽  
Vol 8 (2) ◽  
pp. 387-400 ◽  
Author(s):  
Jennifer M. Williams ◽  
Donald J. Brown ◽  
Petra B. Wood
Keyword(s):  
Habitat Type ◽  
Habitat Associations ◽  
Habitat Characteristics ◽  
Novel Ecosystems ◽  
Habitat Types ◽  
Mountaintop Removal ◽  
Mountaintop Removal Mining ◽  
Forest Sites ◽  
Large Trees ◽  
Species Specific

Abstract Mountaintop removal mining is a large-scale surface mining technique that removes entire floral and faunal communities, along with soil horizons located above coal seams. In West Virginia, the majority of this mining occurs on forested mountaintops. However, after mining ceases the land is typically reclaimed to grasslands and shrublands, resulting in novel ecosystems. In this study, we examined responses of herpetofauna to these novel ecosystems 10–28 y postreclamation. We quantified differences in species-specific habitat associations, (sub)order-level abundances, and habitat characteristics in four habitat types: reclaimed grassland, reclaimed shrubland, forest fragments in mined areas, and nonmined intact forest. Habitat type accounted for 33.2% of the variation in species-specific captures. With few exceptions, forest specialists were associated with intact forest and fragmented forest sites, while habitat generalists were either associated with grassland and shrubland sites or were distributed among all habitat types. At the (sub)order level, salamander (Order Urodela) captures were highest at fragmented and intact forest sites, frog and toad (Order Anura) captures were lowest at intact forest sites, and snake (Suborder Serpentes) captures were highest at shrubland sites. Habitat type was a strong predictor for estimated total abundance of urodeles, but not for anurans or snakes. Tree stem densities in grasslands differed from the other three habitat types, and large trees (&gt;38 cm diameter at breast height) were only present at forest sites. Overstory vegetation cover was greater in forested than in reclaimed habitat types. Ground cover in reclaimed grasslands was distinct from forest treatments with generally less woody debris and litter cover and more vegetative cover. It is important to consider the distributions of habitat specialists of conservation concern when delineating potential mountaintop mine sites, as these sites will likely contain unsuitable habitat for forest specialists for decades or centuries when reclaimed to grassland or shrubland.

Tree–Habitat Relationships in Urban Hong Kong

1992 ◽  
Vol 19 (3) ◽  
pp. 209-218 ◽  
Author(s):  
Chi Yung Jim
Keyword(s):  
Hong Kong ◽  
Floristic Composition ◽  
Common Species ◽  
Habitat Characteristics ◽  
Ecological Niches ◽  
Long Run ◽  
Large Trees ◽  
Structure Tree ◽  
Almost All ◽  
Tree Habitat

Trees, as welcome and necessary components of Nature and functional landscape elements in cities, provide a worth-while theme for applied ecological study. Of the different approaches, the micro-scale evaluations of tree—habitat interactions can throw light on practical tree management. The roadside trees in Hong Kong, generally dwelling in a stressful physical and physiological environment, have been surveyed in detail in the field with regard to species composition, tree structure, tree defects, and habitat characteristics.Despite a diversified floristic composition, the street-tree population is dominated by a small number of common species, of which 12 have been chosen for in-depth evaluations. The recent emphasis on exotic and fast-growing species with limited final dimensions will modify the treescape in the long run. Many existing large specimens have been sacrificed to urban redevelopments. The differential performance of different species with reference to the occurrence of defects has been interpreted. Almost all the trees are inflicted by some structural or physiological problems, and large trees are practically collectors of diverse maladies.The urban tree habitats of Hong Kong are characterized by gravely cramped and stressful conditions from the soil-level upwards and especially as regards headroom. Tree-habitat correlations and associations suggest a need to plant rapid-growing, tall but narrow-canopied species that are able to resist a maximum proportion of the inevitable tree defects and diseases. The shortage of good-quality habitats with space for tree-growth, and the accompanying unfavourable ecological niches, are crucial factors for tree existence. The prospects of street trees in the long-term urban planning and upgrading for environmental quality, with special reference to the provision and preservation of proper habitats, are elaborated, with Hong Kong as a practical example.

scholarly journals Struktur Vegetasi dan Karakteristik Habitat Peneluran Penyu Hijau (Chelonia mydas) di Kawasan Konservasi Penyu Pangumbahan Sukabumi

2018 ◽  
Vol 4 (1) ◽  
pp. 36
Author(s):  
Yorianta Sasaerila ◽  
Dewi Elfidasari ◽  
Muhammad Qeis Tsal Sabil
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Habitat Characteristics ◽  
Physical Analysis ◽  
Nesting Habitat ◽  
Conservation Area ◽  
Terminalia Catappa ◽  
Large Trees ◽  
C 30 ◽  
Commercial Trade

<p><em>Abstrak</em> - <strong>Penurunan populasi penyu hijau yang terjadi secara terus menerus dari tahun ke tahun, menyebabkan penyu termasuk dalam daftar CITES Appendiks I plus zero <em>quota of wild capture for commercial trade</em> saat ini. Oleh karena itu perlu dilakukan upaya konservasi yang baik untuk menjaga kelestarian penyu hijau. Salah satu proses yang penting diketahui bagi kelangsungan sirkulasi hidup penyu adalah proses bertelur. Oleh karena itu perlu diketahui </strong><strong>kondisi</strong><strong> pantai yang menjadi habitat penyu bertelur. Penelitian ini bertujuan untuk melakukan identifikasi terhadap jenis dan struktur vegetasi, serta karakteristik habitat </strong><strong>bertelur </strong><strong>penyu hijau di kawasan konservasi penyu pangumbahan sukabumi</strong><strong>. A</strong><strong>nalisa kuantitatif </strong><strong>yang dilakukan </strong><strong>berupa penghitungan indeks nilai penting vegetasi dan analisa fisik lingkungan sekitar </strong><strong>habitat bertelur</strong><strong> penyu. Berdasarkan letak sarang telur penyu, ditemukan sebanyak 12 spesies vegetasi yang terdiri dari 4 jenis berupa pohon besar, 3 jenis berupa pohon kecil, 3 jenis berupa perdu, 3 jenis berupa herba, 1 jenis berupa semak. terdapat lebih dari 3 jenis vegetasi yang sangat penting di pangumbahan yaitu <em>Callophyllum inophyllum, Terminalia catappa, Ipoemoea pes-caprae</em>. Karakteristik fisik pantai pangumbahan juga masih mendukung proses bertelur penyu hijau. Pantai Pangumbahan memiliki rata- rata suhu 20 <sup>o</sup>C-30 <sup>o</sup>C, intensitas cahaya rendah (0) dan kecepatan angin 2,2 knots serta komposisi pasir yang sesuai.</strong></p><p> </p><p><strong><em>Kata </em></strong><strong><em>K</em></strong><strong><em>unci</em></strong><em> -</em><em> </em><em>H</em><em>abitat </em><em>B</em><em>ertelur, </em><em>P</em><em>enyu </em><em>H</em><em>ijau, </em><em>V</em><em>egetasi, </em><em>Pantai </em><em>Pangumbahan</em><em>, Karakter Fisik</em></p><p align="center"><strong> </strong></p><p><em>Abstract</em> - <strong>The decline in green turtle populations that occur continuously from year to year, causing turtles to be included in the list of CITES Appendix I plus zero quotes of wild capture for commercial trade today. Therefore it is necessary to do a good conservation efforts to maintain the sustainability of green turtles. Therefore it is necessary to know the condition of the beach that turtles laying habitat. This study aims to identify the type and structure of vegetation, as well as the green turtle nesting habitat characteristics in turtle conservation area Pangumbahan sukabumi. Quantitative analysis is done by calculating the index of vegetation important values and physical analysis of the environment around turtle nesting habitat. Based on the location of turtle egg nest, found 12 species of vegetation consisting of 4 types of large trees, 3 species of small trees, 3 types of shrubs, 3 types of herbs, 1 species of shrubs. There are more than 3 important vegetation types in pangumbahan namely Callophyllum inophyllum, Terminalia catappa, Ipoemoea pes-caprae. Physical characteristics of pangumbahan beach also still support the process of laying green turtle. Pangumbahan Beach has an average temperature of 20<sup>o</sup>C-30<sup>o</sup>C, low light intensity (0) and wind speed of 2.2 knots and suitable sand composition.</strong></p><p><strong> </strong></p><p><strong><em>Keywords - </em></strong><em>Habitat lay eggs, Green Turtle, Vegetation, Pangumbahan Beach, Physical Character</em></p>

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

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