scholarly journals The invertebrate diet of northern bobwhite chicks in Georgia, United States

2012 ◽  
Vol 35 (2) ◽  
pp. 415-418
Author(s):  
D. A. Butler ◽  
◽  
W. E. Palmer ◽  
M. P. Cook ◽  
◽  
...  
Keyword(s):  
United States ◽  
Compositional Analysis ◽  
Northern Bobwhite ◽  
Population Declines ◽  
Brood Rearing ◽  
Important Prey ◽  
Invertebrate Composition ◽  
Faecal Samples ◽  
Intensively Managed ◽  
Study Sites

The establishment of brood–rearing habitats along field margins has become a popular agri–environmental prescription to help reverse population declines of northern bobwhite (Colinus virginianus) in Georgia, United States. Here, the invertebrate–diet of chicks foraging on farmland with established brood–rearing habitats is examined and compared to those of chicks on an intensively managed wild bobwhite shooting estate. In 2001 and 2002, faecal samples were collected and analysed from nocturnal roost sites of bobwhite broods. Differences in invertebrate composition between the study sites were investigated using compositional analysis. While the diet of chicks on both sites contained similar invertebrate groups, the composition of the diets varied significantly. Although chicks on farmland had eaten 1.7 times fewer Coleoptera, they had 1.7 times more Hemiptera in their diet. These data suggest that although the invertebrate composition in the diet of chicks differed between the two landscapes, both contained high proportions of important prey items.

scholarly journals Spatial distribution of the Barbary Partridge (Alectoris barbara) in Sardinia explained by land use and climate

2021 ◽  
Vol 67 (4) ◽  
Author(s):  
Gianpasquale Chiatante ◽  
Marta Giordano ◽  
Anna Vidus Rosin ◽  
Oreste Sacchi ◽  
Alberto Meriggi
Keyword(s):  
Land Use ◽  
Conservation Status ◽  
Distance Sampling ◽  
Strong Relationship ◽  
European Population ◽  
Factors Affecting ◽  
Brood Rearing ◽  
Management Actions ◽  
Negative Effect ◽  
Study Sites

AbstractMore than half of the European population of the Barbary Partridge is in Sardinia; nonetheless, the researches concerning this species are very scarce, and its conservation status is not defined because of a deficiency of data. This research aimed to analyse the habitat selection and the factors affecting the abundance and the density of the Barbary Partridge in Sardinia. We used the data collected over 8 years (between 2004 and 2013) by spring call counts in 67 study sites spread on the whole island. We used GLMM to define the relationships between the environment (topography, land use, climate) both the occurrence and the abundance of the species. Moreover, we estimated population densities by distance sampling. The Barbary Partridge occurred in areas at low altitude with garrigue and pastures, avoiding woodlands and sparsely vegetated areas. We found a strong relationship between the occurrence probability and the climate, in particular, a positive relation with temperature and a negative effect of precipitation, especially in April–May, during brood rearing. Furthermore, dry crops positively affected the abundance of the species. We estimated a density of 14.1 partridges per km2, similar to other known estimates. Our findings are important both because they increase the knowledge concerning this species, which is considered data deficient in Italy, and because they are useful to plan management actions aimed to maintain viable populations if necessary.

scholarly journals Sage-Grouse Nesting, Brood and Winter Habitat Characteristics in Montana

2016 ◽  
Vol 5 (1) ◽  
pp. 126
Author(s):  
Jennifer Woodward ◽  
Jenny Sika ◽  
Carl Wambolt ◽  
Jay Newell ◽  
Sean Schroff ◽  
...  
Keyword(s):  
Primary Objective ◽  
Habitat Characteristics ◽  
Shrub Cover ◽  
Sage Grouse ◽  
Winter Habitat ◽  
Brood Rearing ◽  
Study Sites ◽  
Wyoming Big Sagebrush ◽  
Central Montana ◽  
Cover Density

<p class="emsd"><span lang="EN-GB">Greater sage-grouse (Centrocercus urophasianus) habitat characteristics were studied in central Montana primarily on Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &amp; Young) dominated rangeland. The primary objective was to compare shrub and herbaceous parameters within (use, random or non-use) and between seasonal habitats (nest, brood, winter). Two study sites (Musselshell and Golden Valley counties), and 2 years (2004 and 2005) were compared. Nest, brood, and random sites were compared for herbaceous cover, and grass height (n = 648). Nest, brood, random, winter use and winter non-use sites were evaluated for shrub cover, density, and height. All differences were considered significant at P ≤ 0.05. Sage-grouse nested in areas with greater total shrub cover and height, and taller live and residual grass than was randomly available. No differences were found between brood and paired random sites for any of the herbaceous or shrub parameters measured. Shrub cover and density were greater at winter use sites than non-use sites. Winter use sites had less shrub cover than nest sites. The nest and brood habitat had similar shrub cover, density, and height on the study area. Sage-grouse habitats should be managed to include sagebrush, forbs, and grass. Herbaceous vegetation was more important during nesting and brood rearing than during the winter. Therefore, some portions of <span>sage-</span>grouse habitat may benefit from management for greater herbaceous cover, but not at the expense of removing sagebrush. Sagebrush cover from 10 to 15 percent was the most consistent component of sage-grouse habitat.</span></p>

scholarly journals Conspecific cues encourage Barn Swallow (Hirundo rustica erythrogaster) prospecting, but not nesting, at new nesting structures

2020 ◽  
Vol 133 (3) ◽  
pp. 235-245
Author(s):  
Andrew J. Campomizzi ◽  
Zoé M. Lebrun-Southcott ◽  
Kristyn Richardson
Keyword(s):  
Breeding Season ◽  
Hirundo Rustica ◽  
Population Declines ◽  
Barn Swallow ◽  
Nesting Habitat ◽  
Southern Ontario ◽  
Manipulative Experiments ◽  
Barn Swallows ◽  
Study Sites ◽  
Conspecific Cues

Shed-like structures are being built to provide Barn Swallow (Hirundo rustica erythrogaster) nesting habitat in response to population declines. However, Barn Swallow use of these structures is unavailable in the literature. We conducted three manipulative experiments to test if adding conspecific cues (i.e., vocalizations and decoys) to newly-built structures affected prospecting visits by Barn Swallows (1) during pre-breeding, (2) during post-breeding, and (3) during or after broadcasts of vocalizations compared to before broadcasts. Additionally, we monitored nesting following pre- and post-breeding cues. We built one nesting structure with and one without conspecific cues at each of 10 study sites in southern Ontario, Canada where nesting habitat was recently lost. We detected about twice as many Barn Swallows immediately after conspecific broadcasts compared to before. We did not find substantial differences in abundance and interactions with new nesting structures for other comparisons involving conspecific cues. Following pre-breeding cues at 10 sites, six nests were built in three of 10 structures treated with conspecific cues, compared to five nests in four of 10 structures without cues. In the subsequent breeding season following post-breeding cues at eight sites, four nests were built in two of eight structures treated with conspecific cues, compared to four nests in three of eight structures without cues. Conspecific vocalizations appeared to increase prospecting behaviour, but not the number of nests, at new nesting structures. The paucity of nests on new structures suggests that building shed-like structures may not be an effective method of mitigating loss of nesting habitat.

Microhabitat Selection by Nesting and Brood-Rearing Northern Bobwhite in Kansas

1999 ◽  
Vol 63 (2) ◽  
pp. 686 ◽  
Author(s):  
J. Scott Taylor ◽  
Kevin E. Church ◽  
Donald H. Rusch
Keyword(s):  
Northern Bobwhite ◽  
Microhabitat Selection ◽  
Brood Rearing

scholarly journals Investigation into the seasonal salmonellosis in lactating dairy cattle

2007 ◽  
Vol 136 (3) ◽  
pp. 381-390 ◽  
Author(s):  
T. S. EDRINGTON ◽  
T. T. ROSS ◽  
T. R. CALLAWAY ◽  
C. H. MARTINEZ ◽  
M. E. HUME ◽  
...  
Keyword(s):  
United States ◽  
Dairy Cattle ◽  
Antimicrobial Susceptibility ◽  
Late Summer ◽  
Soil Samples ◽  
Total Mixed Ration ◽  
Early Autumn ◽  
Faecal Samples ◽  
Lactating Dairy Cattle ◽  
Apparently Healthy

SUMMARYSporadic salmonellosis has been reported in mature lactating dairy cattle in the southwestern United States and is an intriguing problem in that Salmonella can be cultured from faecal samples of these cattle throughout the year. However, it is pathogenic only during late summer/early autumn and in certain years. We sampled apparently healthy (n=10) and diarrhoeic (n=10) cattle during an outbreak on a 2000 head dairy in 2003. The following year, monthly faecal (from the same 30 head), total mixed ration, water, and pen soil samples were collected for Salmonella culture. No serogroup, serotype, genetic, or antimicrobial susceptibility differences were observed in comparison of isolates from healthy and sick cattle. During year 2 of the study, Salmonella was routinely cultured (although highly variable from month to month) from the cattle and the environment, although no outbreak of salmonellosis was observed.

Compositional Analysis of Biowaste from Study Sites in Greek Municipalities

2015 ◽  
Vol 6 (5) ◽  
pp. 637-646 ◽  
Author(s):  
D. Malamis ◽  
K. Moustakas ◽  
A. Bourka ◽  
K. Valta ◽  
C. Papadaskalopoulou ◽  
...  
Keyword(s):  
Compositional Analysis ◽  
Study Sites

scholarly journals Site-selection bias can drive apparent population declines in long-term studies

2019 ◽  
Author(s):  
Auriel M.V. Fournier ◽  
Easton R. White ◽  
Stephen B. Heard
Keyword(s):  
Selection Bias ◽  
Site Selection ◽  
Population Decline ◽  
Population Data ◽  
Spatiotemporal Variability ◽  
Population Declines ◽  
Substantial Impact ◽  
Real Population ◽  
Study Sites

Detecting population declines is a critical task for conservation biology. The spatiotemporal variability of populations, along with logistical difficulties in population estimation, makes this task difficult. Here we call attention to a possible bias in estimates of population decline: when study sites are chosen based on abundance of the focal species, for statistical reasons apparent declines are likely even without an underlying population trend. This “site-selection bias” has been mentioned in the literature but is not well known. We show using simulated and real population data that when site-selection biases are introduced, they have substantial impact on inferences about population trends. We use a left-censoring method to show patterns consistent with the operation of the site-selection bias in real population studies. The site-selection bias is, thus, an important consideration for conservation biologists, and we offer suggestions for minimizing or mitigating it in study design and analysis.

scholarly journals Endozoochory by mallard in New Zealand: what seeds are dispersed and how far?

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4811 ◽  
Author(s):  
Riley D. Bartel ◽  
Jennifer L. Sheppard ◽  
Ádám Lovas-Kiss ◽  
Andy J. Green
Keyword(s):  
New Zealand ◽  
Seed Dispersal ◽  
Plant Species ◽  
Dispersal Distance ◽  
Terrestrial Plants ◽  
Indigenous Status ◽  
Plant Seeds ◽  
Faecal Samples ◽  
Viable Seeds ◽  
Study Sites

In Europe and North America waterfowl are major dispersers of aquatic and terrestrial plants, but in New Zealand their role has yet to be investigated. Mallards were introduced to New Zealand in the late 1800s, and today they are the most abundant and widespread waterfowl in the country. To assess seed dispersal, we radiomarked 284 female mallards from two study sites during the pre-breeding (June–August) and breeding (August–December) periods in 2014–2015, and examined movements that occurred within 24, 48 or 72 h when seed dispersal by endozoochory is considered likely. During June and July 2015, we collected 29 faecal samples from individual female mallards during radiomarking and 24 samples from mallard flocks. We recovered 69 intact seeds from the faecal samples and identified 12 plant taxa. Of the plant seeds identified and dispersed by mallards in this study, 40% were members of the Asteraceae family, nine plant species were alien to New Zealand, and the indigenous-status of three unidentified taxa could not be determined. Two taxa (and 9% of seeds) were germinated following gut passage: an unidentified Asteraceae andSolanum nigrum. During the pre-breeding and breeding periods, movement of females within 24 h averaged 394 m (SD = 706 m) and 222 m (SD = 605 m) respectively, with maximum distances of 3,970 m and 8,028 m. Maxima extended to 19,230 m within 48 h. Most plant species recorded are generally assumed to be self-dispersed or dispersed by water; mechanisms that provide a much lower maximum dispersal distance than mallards. The ability of mallards to disperse viable seeds up to 19 km within 48 h suggests they have an important and previously overlooked role as vectors for a variety of wetland or grassland plant species in New Zealand.

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