Comparison of Bird Populations in Remnants of Wandoo Woodland and in Adjacent Farmland.

1987 ◽  
Vol 14 (3) ◽  
pp. 331 ◽  
Author(s):  
GW Arnold ◽  
RA Maller ◽  
R Litchfield

Data were obtained during 2 yr at Baker's Hill, Western Australia, in farmland with no trees, scattered trees or clumps of trees and 3 types of open woodland. There were differences in the number of bird species found in each habitat, ranging from 25 in woodland habitats to 11 in open farmland. In autumn, there were more aerial feeders in open farmland and farmland with few trees than in farmland with many trees and woodland, but fewer in spring. There were more ground-feeding seed-eaters in farmland with trees than elsewhere, except in autumn. There were large seasonal reciprocal changes in the numbers of thornbills in farmland with many trees and woodland, indicating movement between habitats. Within the woodland habitats there were only small seasonal changes, but there were large differences in numbers of some groups between the 3 habitats.

2013 ◽  
Vol 19 (2) ◽  
pp. 110 ◽  
Author(s):  
R A Davis ◽  
J A Wilcox

Birds in urban landscapes must contend with fragmented and degraded remnants of native vegetation and their survival may be dependent on factors such as their ability to disperse through and/or utilize the urban matrix. We examined the frequency of occurrence of birds in native bushland in Kings Park, Perth, Western Australia, and in nine adjacent suburban gardens. We quantified dispersal capacity by observing bird crossing frequency and height over a major six-lane road separating the bushland from adjacent gardens. Finally we quantified matrix utilisation by recording foraging behaviour in urban gardens and bushland. Native bushland had a higher species richness than urban gardens (30 versus 17 species) and 18 species were associated more strongly with bushland. Of these 18 species, 61% were never recorded in urban gardens. Gardens were typified by three generalist species, the Singing Honeyeater Lichenostomus virescens and the introduced Laughing Dove Spilopelia senegalensis and Spotted Dove S. chinensis. Three generalist species, the Red Wattlebird Anthochaera carunculata, Rainbow Lorikeet Trichoglossus haematodus, and Brown Honeyeater Lichmera indistincta were equally abundant in all habitats. Four of 18 bird species (Singing Honeyeater Red Wattlebird, Rainbow Lorikeet, and Australian Ringneck Barnardius zonarius) accounted for the majority of road crossing events. Urban gardens provided a rich resource for generalists and urban exploiters, all of which spent significantly more time foraging on nectar in gardens and significantly more time foraging on insects in bushland. We conclude that urban gardens provide habitat for some species that exploit nectar, but most species in bushland, particularly insectivores, do not use gardens. Our results indicate the importance of retaining well-managed bushland for supporting viable urban bird populations.


Author(s):  
Kenneth Diem

An Avian Atlas for the State of Wyoming is being developed by the Wyoming Game and Fish Department. Baseline information on the avifauna of the riparian communities is especially sparse. Consequently, the objective of this project is to collect information on the composition, density, distribution and habitat of the bird species inhabiting a portion of the narrowleaf cottonwood, Populus angustifolia, community in Grand Teton National Park. The study was initiated in June 1980 on a portion of the western floodplain of Pilgrim Creek. The metal, southeast corner stake of this 300 m x 400m (12 ha) plot is located on a bearing line 4° E of N. 77 mm from the fiducial center of the infrared aerial photo N31 (U.S. Bur. of Reclamation Series B/R17, 7-16-79). This floodplain community is predominantly narrowleaf cottonwood with scattered trees of quaking aspen, Populus tremuloides, engelmann spruce, Picea engelmannii, and lodgepole pine, Pinus contorta. In the moister areas several small patches of alder, Alnus incana occur under the larger trees and a few patches of willow (Salix, sp.) are located in moist openings of the woodland.


1985 ◽  
Vol 12 (3) ◽  
pp. 461 ◽  
Author(s):  
I Abbott ◽  
PV Heurck

A study of foraging by 10 bird species suggests that selective logging of large Eucalyptus marginata will only have affected Melithreptus lunatus, but that proposed silvicultural treatments, including removal of Banksia grandis, may affect several other bird species.


2012 ◽  
Vol 5 (3) ◽  
pp. 36-56 ◽  
Author(s):  
Petr Suvorov ◽  
Jana Svobodová

ABSTRACT Anthropogenic changes in a landscape create new cues for birds, which must permanently adapt to these. If landscape changes occur too quickly, individuals have insufficient time to develop adequate reactions. They may, therefore, preferentially nest in low-quality habitats, which can lead to diminished nesting success and to reduction of their population size. This is usually termed the ecological trap hypothesis. We reviewed 38 studies investigating this phenomenon and analysed whether relationships exist between ecological trap occurrence and geographical region, habitat type, and/or life strategies of bird species. Ecological traps were most often associated with the presence of exotic species. Exotic species can modify environmental conditions in ways to which native communities are not adapted. They have been mainly detected in open habitats. Such open habitats as arable fields and meadows are under greater human pressure, and rapid changes probably occur there more frequently. Although more studies from North America were investigated, the hypothesis was supported more frequently in European studies. This is possibly due to higher human population density and, hence, more frequent habitat changes. Our results show that an ecological trap is not likely associated with migration. Ground nests suffered fewer consequences of such traps than did other nest types. Although the implications of the ecological trap hypothesis in species conservation are undisputable, a more detailed approach is still needed. For instance, some habitat types, such as suburban areas, have been neglected in the context of ecological traps, as has been the phenomenon’s appearance in pristine habitats.


2018 ◽  
Vol 29 (03) ◽  
pp. 339-360 ◽  
Author(s):  
MARIANA BULGARELLA ◽  
MARTÍN A. QUIROGA ◽  
GEORGE E. HEIMPEL

SummaryThe declining-population paradigm holds that small populations are particularly vulnerable to anthropogenic influences such as habitat destruction, pollution and species introductions. While the effects of particular stressors, such as parasitism, may be unimportant in a large, healthy population, they can be serious and even devastating in situations characterised by a restricted geographic range, or by fragmented or reduced population sizes. We apply this idea to nest parasitism of threatened Neotropical bird species that exist in small populations, focusing on dipteran nest parasites in the genusPhilornis. We review the literature onPhilornisparasitism exerting negative pressure on bird populations that have become small and isolated due to human actions and present a new case ofPhilornisparasitism of a threatened hummingbird species. Our aim is to raise awareness about the exacerbating effect that nest parasites can have on small and declining bird populations; especially when biological information is scarce. The five reviewed cases involve two species of Darwin’s Finches in the Galápagos Islands attacked by the invasiveP. downsi, two species of hawks on islands in the Caribbean attacked by the nativeP. piciandP. obscura, and the Yellow CardinalGubernatrix cristatain southern South America attacked by an unknownPhilornisspecies. We also present new documentation of parasitism of a threatened hummingbird species in mainland Ecuador by an unidentifiedPhilornisspecies. We recommend more field studies to determine the presence of nest parasites in bird populations worldwide to improve understanding how nest parasites affect bird fitness and population viability and to allow time to act in advance if needed. Parasitism byPhilornismay represent a severe mortality factor in most already threatened bird species, putting them at greater risk of extinction. Therefore, parasitism management should be included in all threatened species recovery plans.


2020 ◽  
Vol 16 (1) ◽  
pp. 20190763 ◽  
Author(s):  
Nicola Hemmings ◽  
Simon Evans

Prenatal mortality is typically overlooked in population studies, which biases evolutionary inference by confounding selection and inheritance. Birds represent an opportunity to include this ‘invisible fraction’ if each egg contains a zygote, but whether hatching failure is caused by fertilization failure versus prenatal mortality is largely unknown. We quantified fertilization failure rates in two bird species that are popular systems for studying evolutionary dynamics and found that overwhelming majorities (99.9%) of laid eggs were fertilized. These systems thus present opportunities to eliminate the invisible fraction from life-history data.


1995 ◽  
Vol 2 (2) ◽  
pp. 191 ◽  
Author(s):  
Peter R. Mawson ◽  
John L. Long

Mail surveys were sent to field staff of the Agriculture Protection Board of Western Australia to assess the distribution and status of four species of parrot in the agricultural region of south-west Western Australia in 1970, 1980 and 1990. The surveys indicated that the populations of the Regent Parrot (Polytelis anthopeplus) and the Western Rosella (Platycercus icterotis) have declined in range considerably since 1970. The populations of the Red-capped Parrot (Purpureicephalus spurius) and the Port Lincoln Ringneck (Barnardius zonarius) have suffered little or not at all during the same period. Factors which appear to have contributed to the observed changes in distribution and status include clearing for agriculture, dietary preferences, physiology, habitat requirements, altered fire regimes, grazing by exotic herbivores and reduced winter rainfall. These surveys have shown that species which were formerly considered common and widespread have declined with little comment having been made of these changes. The implications of this are serious, both for these formerly common species and for rarer bird species which have similar ecological requirements. The technique of mail surveys has considerable merit for quickly assessing the status of some species of birds, but will be limited by the expertise of the respondents and the degree to which the species in question can be observed.


Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 304 ◽  
Author(s):  
Francesca Marotta ◽  
Anna Janowicz ◽  
Lisa Di Marcantonio ◽  
Claudia Ercole ◽  
Guido Di Donato ◽  
...  

Poultry is considered a major reservoir of human campylobacteriosis. It also been reported that not only poultry, but also wild birds, are capable of carrying C. jejuni, thus demonstrating to be a risk of spreading the bacteria in the environment. To gain insight into the population structure and investigate the antimicrobial resistance genotypes and phenotypes, we analyzed a collection of 135 C. jejuni from 15 species of wild birds in Italy. MLST revealed the presence of 41 sequence types (STs) and 13 clonal complexes (CCs). ST-179 complex and the generalist ST-45 complex were the most prevalent. Core genome MLST revealed that C. jejuni from ST-45 complex clustered according to the bird species, unlike the ST-179 complex which featured 3 different species in the same cluster. Overall we found a moderate prevalence of resistance to tetracycline (12.5%), ciprofloxacin and nalidixic acid (10%). The novel ST isolated from one pigeon showed resistance to all the antibiotics tested. The ST-179 complex (33.3%) was identified with significantly higher nalidixic acid resistance relative to other tested STs. Nine AMR genes (tet(O), cmeA, cmeB, cmeC, cmeR, aad, blaOXA-61, blaOXA-184 and erm(B)) and 23S rRNA and gyrA-associated point mutations were also described, indicating a concordance level between genotypic and phenotypic resistance of 23.3%, 23.4% and of 37.5% for streptomycin, tetracycline and quinolones/fluoroquinolones, respectively. We recommend that particular attention should be given to wild birds as key sentinel animals for the ecosystem contamination surveillance.


The Condor ◽  
2006 ◽  
Vol 108 (3) ◽  
pp. 661-677 ◽  
Author(s):  
Jeffrey E. Moore ◽  
Jeffrey M. Black

AbstractArctic-nesting geese depend on nutrients acquired during spring migration for reproduction, and thus should attempt to maximize nutrient intake while on staging areas. We investigated site use of Black Brant (Branta bernicla nigricans) at an important staging location—Humboldt Bay, California—to determine whether birds selected the most profitable feeding areas available. Migrating Brant feed almost exclusively on eelgrass (Zostera marina), which is restricted in availability due to daily and seasonal tidal cycles. We mapped foraging Brant locations during low tides and collected eelgrass samples to describe food resources in 31 areas in the bay. We used negative binomial regression to evaluate goose densities during different tidal levels and times of season as a function of food biomass and nutrient content, distance from grit sites, and substrate elevation. Results varied by time of season and tidal depth, but Brant densities were positively correlated with eelgrass protein, calcium, and biomass in most analyses. Brant usually fed in the deepest possible areas permitted by tides, and closer to tidal channels, where biomass and nutrient content of eelgrass were greater and where depletion from grazing was probably less. During higher low tides, Brant fed closer to previously visited grit sites. Tide cycles change over the course of the Brant's staging period on the bay, enabling longer and more frequent access to deeper eelgrass meadows as spring progresses. These seasonal changes in tidal pattern coincide with seasonal changes in Brant use of the bay. Thus, migration patterns for estuarine bird species might be shaped by latitudinal gradients in both food phenology and seasonal tidal patterns.


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