scholarly journals Livestock grazing affects the egg size of an insectivorous passerine

2005 ◽  
Vol 1 (3) ◽  
pp. 322-325 ◽  
Author(s):  
Darren M Evans ◽  
Stephen M Redpath ◽  
Sharon A Evans ◽  
David A Elston ◽  
Peter Dennis
Keyword(s):  
Egg Size ◽  
Detrimental Effect ◽  
Bird Species ◽  
Stocking Density ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Ecosystem Change ◽  
Anthus Pratensis ◽  
Meadow Pipit ◽  
First Time

Livestock grazing is a major driver of ecosystem change, and has been associated with significant declines in various bird species worldwide. In Britain, there is particular concern that severe grazing pressure is deleteriously affecting vegetation and birds in upland regions. However, the mechanism by which grazing affects birds is unclear. Here, we report for the first time, to our knowledge, that sheep grazing pressure affects the egg size of a common upland passerine: the meadow pipit Anthus pratensis . We manipulated sheep stocking densities in a replicated field experiment, and found that plots with the highest stocking density contained nests with the smallest eggs, and that plots with low stocking density contained nests with the largest eggs. However, eggs laid in ungrazed plots were also small, suggesting that either too many sheep or their removal from upland areas might have a detrimental effect on pipit egg size. We found no significant effect on fledging success but the reduced post-fledging survival of young from smaller eggs, as seen in other studies, could partly explain declines in upland birds.

scholarly journals Low intensity, mixed livestock grazing improves the breeding abundance of a common insectivorous passerine

2006 ◽  
Vol 2 (4) ◽  
pp. 636-638 ◽  
Author(s):  
Darren M Evans ◽  
Stephen M Redpath ◽  
Sharon A Evans ◽  
David A Elston ◽  
Charles J Gardner ◽  
...  
Keyword(s):  
Prey Availability ◽  
Bird Species ◽  
Single Species ◽  
Livestock Grazing ◽  
Ecosystem Change ◽  
Mixed Species ◽  
Bird Populations ◽  
Low Intensity ◽  
Anthus Pratensis ◽  
Meadow Pipit

Abstract Livestock grazing is a major driver of ecosystem change and has been associated with significant declines in various bird species in Britain and worldwide. However, there is little experimental evidence to show how grazing affects bird populations. We manipulated livestock densities in a replicated field experiment and found that mixed sheep and cattle grazing, at low intensity, improved the breeding abundance of a common upland passerine, the meadow pipit Anthus pratensis , after two years. Plots stocked with sheep alone (at high or low density) or not stocked at all held fewer pipit territories. Despite a year-on-year decline in pairs of meadow pipits in intensively grazed plots, we found no effect of sheep number on breeding abundance. Our results support the hypothesis that mixed species of herbivores generate greater heterogeneity in vegetation structure, which modifies prey availability, resulting in a greater abundance of birds. The results of our study should inform the management of grassland areas and enhance the abundance of some bird species, particularly in areas that have seen significant shifts from mixed livestock grazing to grazing dominated by single species of animals.

scholarly journals Birds bias offspring sex ratio in response to livestock grazing

2011 ◽  
Vol 7 (6) ◽  
pp. 958-960 ◽  
Author(s):  
Gina L. Prior ◽  
Darren M. Evans ◽  
Stephen Redpath ◽  
Simon J. Thirgood ◽  
Pat Monaghan
Keyword(s):  
Sex Ratio ◽  
Experimental Studies ◽  
Bird Species ◽  
Complete Removal ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Offspring Sex Ratio ◽  
Local Conditions ◽  
Avian Reproduction ◽  
Offspring Sex

Livestock grazing, which has a large influence on habitat structure, is associated with the widespread decline of various bird species across the world, yet there are few experimental studies that investigate how grazing pressure influences avian reproduction. We manipulated grazing pressure using a replicated field experiment, and found that the offspring sex ratio of a common upland passerine, the meadow pipit Anthus pratensis , varied significantly between grazing treatments. The proportion of sons was lowest in the ungrazed and intensively grazed treatments and highest in treatments grazed at low intensity (by sheep, or a mixture of sheep and cattle). This response was not related to maternal body condition. These results demonstrate the sensitivity of avian reproductive biology to variation in local conditions, and support growing evidence that too much grazing, or the complete removal of livestock from upland areas, is detrimental for common breeding birds.

scholarly journals Hur påverkas fågelfaunan av upphörd betesdrift – data från en 26 år lång inventeringsstudie

Ornis Svecica ◽  
2013 ◽  
Vol 23 (3–4) ◽  
pp. 143-150
Author(s):  
Thomas Karlsson
Keyword(s):  
General Pattern ◽  
Bird Species ◽  
Farmland Birds ◽  
Survey Period ◽  
Breeding Bird ◽  
Point Count ◽  
Anthus Pratensis ◽  
Meadow Pipit ◽  
Bird Fauna ◽  
Point Count Method

The breeding bird fauna of a 1.6 km2 large grassland area in southwestern Sweden was monitored in 1987–2012, using the point count method. The area was grazed by approximately 500 cattle until 2006, and the grass height was then at most 10–15 cm except for higher tussocks. From 2007 onwards, when the grazing had ceased, the grass increased in height to 20–30 cm and became much thicker. The average number of bird species per year was 44.7 over the 26 year survey period. Numbers of some farmland birds such as Lapwing Vanellus vanellus, Skylark Alauda arvensis, Starling Sturnus vulgaris, and Linnet Carduelis cannabina decreased in the study area, following the general pattern in the whole of Sweden. Meadow Pipit Anthus pratensis, Corn Crake Crex crex, Whinchat Saxicola rubetra and Grasshopper Warbler Locustella naevia increased in the area, but decreased in Sweden in general over the same period. The local changes in bird numbers in the study area seem mainly to be caused by an increased grass height and thickness as a consequence of ceased cattle grazing.

scholarly journals Reindeer carcasses provide foraging habitat for several bird species of the alpine tundra.

2019 ◽  
Vol 42 ◽  
pp. 36-40 ◽  
Author(s):  
Rudy Badia
Keyword(s):  
Rangifer Tarandus ◽  
Food Resource ◽  
Bird Species ◽  
Anthus Pratensis ◽  
Meadow Pipit ◽  
Passerine Species ◽  
Calcarius Lapponicus ◽  
Southern Norway ◽  
And Behavior ◽  
Near Threatened

On August of 2016, 323 wild tundra reindeer (Rangifer tarandus) were struck by lightning on southern Norway, killing virtually the entire herd.  During fieldwork for parallel studies in 2017, we opportunistically registered the occurrence and behavior of avian species on carcasses from this mass die-off. Several passerine species other than corvids were observed actively foraging on arthropods that are typically associated with carcass decomposition, such as blowfly (Calliphoridae sp.) adults and larvae. In decreasing order of abundance, five passerine species (excluding corvids) were observed taking arthropods at the site: the Meadow Pipit (Anthus pratensis, least concern), Northern Wheatear (Oenanthe oenanthe, least concern), Common ReedBunting(Emberizaschoeniclus, near threatened), Bluethroat (Lusciniasvecica, near threatened), and Lapland Bunting (Calcarius lapponicus, vulnerable) (status according to IUCN). Previous studies on these passerines have documented a very sharp decline in their abundance in Norway. The insect abundance associated with ungulate carcasses may provide an important food resource for such species, and may impact their life history, fitness, and eventually population dynamics. This mechanism, however, has received almost no attention from the scientific community, and warrants further investigation.

Rangeland responses to pastoralists' grazing management on a Tibetan steppe grassland, Qinghai Province, China

2016 ◽  
Vol 38 (1) ◽  
pp. 1 ◽  
Author(s):  
Richard B. Harris ◽  
Leah H. Samberg ◽  
Emily T. Yeh ◽  
Andrew T. Smith ◽  
Wang Wenying ◽  
...  
Keyword(s):  
Plant Species ◽  
Temporal Trends ◽  
Winter Season ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Western China ◽  
Permanent Plots ◽  
Sheep Grazing ◽  
Qinghai Province ◽  
Preferred Species

Livestock grazing is the principal land use in arid central Asia, and range degradation is considered a serious problem within much of the high-elevation region of western China termed the Qinghai-Tibetan Plateau (QTP). Rangeland degradation on the QTP is variously attributed to poor livestock management, historical-cultural factors, changing land tenure arrangements or socioeconomic systems, climate change, and damage from small mammals. Few studies have examined currently managed pastures using detailed data capable of isolating fine-scale livestock–vegetation interactions. The aim of the study was to understand how differences among livestock (primarily sheep) management strategies of pastoralists during winter affected subsequent rangeland condition and productivity. Plant species composition, annual herbage mass, and indicators of erosion were quantified during four summers (2009–2012) on winter pastures managed by 11 different pastoralists on QTP steppe rangeland in Qinghai Province, China. Data came from repeated-measurements on 317 systematically located permanent plots, as well as pastoralist interviews and the use of GPS-equipped livestock. Relationships between annual weather variation and herbage mass were modelled using an independent set of vegetation measurements obtained from livestock exclosures. Account was taken of inherent site differences among pastures. Annual variation in herbage mass was found to be best fitted by a model containing a negative function of winter-season temperature and a positive function of spring-season temperature. Accounting for annual and site effects, significant differences among pastoralists were found for most response variables, suggesting that individual heterogeneity among management approaches had consequences, even among neighbouring pastoralists. Annual herbage mass of preferred plant species was positively associated, whereas that of unpreferred species was negatively associated, with mean sheep density and intensity of use. However, the proportion of bare soil, an index of erosion, and annual herbage mass of unpreferred forbs were found to have positive relationships with sheep grazing pressure during the preceding winter, whereas live vegetation cover and annual herbage mass of preferred grasses were negatively related. Thus, on a spatial scale, pastoralists responded adaptively to the cover of preferred plant species while not responding to total annual herbage mass. Pastoralists stocked pastures more heavily, and livestock used regions within pastures more intensively, where preferred species had a higher cover. However, where sheep grazing pressure was high, downward temporal trends in the herbage mass of preferred species were exacerbated. Pastures that were stocked at a lower density did not experience the negative trends seen in those with a higher density.

Effects of ectoparasites on breeding success of great tits (Parus major) and pied flycatchers (Ficedula hypoleuca) in an air pollution gradient

1994 ◽  
Vol 72 (4) ◽  
pp. 624-635 ◽  
Author(s):  
Tapio Eeva ◽  
Esa Lehikoinen ◽  
Jorma Nurmi
Keyword(s):  
Heavy Metals ◽  
Air Pollution ◽  
Breeding Success ◽  
Detrimental Effect ◽  
Bird Species ◽  
Parus Major ◽  
Ficedula Hypoleuca ◽  
Nest Size ◽  
Minor Importance ◽  
Ceratophyllus Gallinae

Numbers of ectoparasitic blow fly (Protocalliphora azurea) larvae (Diptera: Calliphoridae), adult and larval hen fleas, Ceratophyllus gallinae (Siphonaptera: Ceratophyllidae), and other nest-dwelling insects were counted from the nests of the great tit, Parus major, and the pied flycatcher, Ficedula hypoleuca, in southwestern Finland around a factory complex emitting large quantities of sulphuric oxides and heavy metals. Protocalliphora azurea larvae were more frequently found in the nests of P. major than in those of F. hypoleuca. The prevalence of P. azurea larvae tended to be lower in polluted areas. The number of P. azurea larvae correlated positively with nest size and brood size of P. major. This may be caused by difficulties in sanitation of large and crowded nests. The numbers of fleas and their larvae were negatively affected by moisture in the nests. Nests of F. hypoleuca contained more adult fleas in polluted areas. This may indicate reduced resistance of birds exposed to heavy metals, but other possibilities are also discussed. We found a detrimental effect of P. azurea larvae on the growth of P. major nestlings, and an effect of fleas on mortality of F. hypoleuca nestlings, but these effects were not enhanced by air pollution. We conclude that the ectoparasites studied, at densities observed in our study area, are of minor importance in determining the breeding success of these two bird species.

Enzootic Activity of Chlamydia in Farms Located in a Hotspot Area for Zoonosis Emergence

2021 ◽  
Author(s):  
Ezequiel Andres Vanderhoeven ◽  
Jessica P. Mosmann ◽  
Adrián Díaz ◽  
Cecilia G. Cuffini
Keyword(s):  
Bird Species ◽  
Farm Animals ◽  
Economic Losses ◽  
Wild Mammals ◽  
Specific Pcr ◽  
Chlamydial Species ◽  
Zoonotic Risk ◽  
Two Samples ◽  
In The Wild ◽  
First Time

Abstract Chlamydias are obligated intracellular Gram-negative bacteria, considered important zoonotic pathogens, broadly present in several bird species and responsible for economic losses in animal production. We analyzed the presence of Chlamydial species with zoonotic risk in farm animals in a highly biodiverse area and with great human circulation, the Argentine, Brazil and Paraguay tri-border area. We surveyed nine farms in an area and nasally swabbed a total of 62 animals. DNA was extracted and specific PCR was performed to identify chlamydial species. We detected Chlamydia spp . in 6.5% (4/62) of the animals tested, positive samples belonged to cattle and none of them showed symptoms of respiratory disease nor had been diagnose with reproductive diseases. Specific nested PCR confirmed two samples belonged to C. pecorum and two to C. psittaci . We report for the first time Chlamydia circulation with zoonotic risk in the region. Surveys in birds and wild mammals could give a better understanding to know what Chlamydial species are circulating in the wild interface. The zoonotic potential should be taking into account as farm workers and the surrounding population could be silent carriers or have respiratory diseases being underdiagnosed, and therefore should be considered in the differential diagnoses.

scholarly journals Feather mites (Acari, Astigmata) associated with birds in an Atlantic Forest fragment in Northeastern Brazil

2015 ◽  
Vol 75 (3) ◽  
pp. 726-735 ◽  
Author(s):  
HM Silva ◽  
FA Hernandes ◽  
M Pichorim
Keyword(s):  
Atlantic Forest ◽  
Bird Species ◽  
Rio Grande ◽  
Neotropical Region ◽  
Species Level ◽  
Northeastern Brazil ◽  
Forest Fragment ◽  
Visual Examination ◽  
Feather Mites ◽  
First Time

AbstractThe present study reports associations between feather mites (Astigmata) and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fifteen feather mite taxa could be identified to the species level, sixteen to the genus level and three to the subfamily level, distributed into the families Analgidae, Proctophyllodidae, Psoroptoididae, Pteronyssidae, Xolalgidae, Trouessartiidae, Falculiferidae and Gabuciniidae. Hitherto unknown associations between feather mites and birds were recorded for eleven taxa identified to the species level, and nine taxa were recorded for the first time in Brazil. The number of new geographic records, as well as the hitherto unknown mite-host associations, supports the high estimates of diversity for feather mites of Brazil and show the need for research to increase knowledge of plumicole mites in the Neotropical region.

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