Winter Survival and Territory Acquisition in a Northern Population of Black-Capped Chickadees

The Auk ◽  
1988 ◽  
Vol 105 (4) ◽  
pp. 727-736 ◽  
Author(s):  
André Desrochers ◽  
Susan J. Hannon ◽  
Kelly E. Nordin
Keyword(s):  
Survival Rates ◽  
Early Spring ◽  
Control Area ◽  
Winter Survival ◽  
Food Supplementation ◽  
First Year ◽  
Differential Survival ◽  
Northern Population ◽  
Parus Atricapillus ◽  
Lower Ranking

Abstract We assessed the effects of winter food supplementation on differential survival between sex, age and dominance classes, and the effects of feeding and territorial defense on breeding density in a northern population of Black-capped Chickadees (Parus atricapillus). Survival rates were higher in a food-supplemented area than in a control area, which suggests that food abundance limited winter survival. Survival was greater among males than lower-ranking females in 1 of 2 years, and greater in dominants than in subordinates, within sex and age classes. Survival of adults and first-year birds, however, did not differ significantly. In the 2 years of this study, a sharp decline of population size occurred at the onset of territoriality in spring. Birds that disappeared in spring were mainly subordinates of each sex. Breeding densities in control and feeder areas were similar in the two years. Eight of 14 territorial birds removed in 2 years were replaced, implying that a nonbreeding surplus was present in early spring.

Determination of optimal sowing dates and densities of winter wheat under Quebec growing conditions

2019 ◽  
Vol 99 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Francis Allard ◽  
Anne Vanasse ◽  
Denis Pageau ◽  
Gilles Tremblay ◽  
Julie Durand ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Survival Rates ◽  
Sowing Date ◽  
Winter Survival ◽  
Seeding Density ◽  
Good Survival ◽  
First Year ◽  
Sowing Dates ◽  
Yield Gain ◽  
Growing Conditions

The objective of this project was to determine the optimal sowing dates and densities for winter wheat to increase winter survival and yield under Quebec growing conditions. The trials were carried out from 2014 to 2016 at four sites, representing three cereal production zones (zones 1, 2, and 3). Three cultivars were assessed using four sowing dates and four seeding densities (250, 350, 450, and 550 seeds m−2). In the first year, the wheat at two of the four sites survived (82%–100%), and in the second year, all the sites showed good survival rates (69%–99%). In zone 2, winter survival was higher for the early sowing dates compared with later dates. Sowing date and seeding density had no effect on survival in zones 1 and 3. Maximum yields were attained with sowing dates from mid- to late September in zone 1; from early to mid-September in zone 2; and from mid-August to mid-September in zone 3. An increase in seeding density from 250 to 550 seeds m−2 led to an average yield gain of 9% in zones 2 and 3, but no gain in zone 1. Winter survival rates and yield differ between cultivars.

Influence of Planting Stock Clove Size, Nitrogen Rate, and Planting Method on Elephant Garlic Production

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 517f-518
Author(s):  
Jeanine M. Davis
Keyword(s):  
Survival Rates ◽  
Ground Level ◽  
Winter Survival ◽  
Nitrogen Rate ◽  
Planting Stock ◽  
Mild Winter ◽  
Allium Ampeloprasum ◽  
Planting Methods ◽  
Planting Method ◽  
Nitrogen Rates

To produce large elephant garlic (Allium ampeloprasum L.) bulbs in the southeastern United States, stock cloves must be planted in the fall. During extremely cold winters, however, winter survival rates can be very low. A 2-year study was undertaken to examine practices to increase winter survival rates. Two clove sizes (≤20 g or >20 g), three nitrogen rates (112, 224, and 336 kg/ha), and three planting methods (flat, mulched, and hilled) were tested in a RCB design with four replications. For all planting methods, cloves were set in a shallow trench and covered with soil to ground level. This was also the flat treatment. For the mulched treatment, 7 cm of straw was spread on top. For the hilled treatment, soil was mounded 10 to 15 cm high over the ground level. Cloves were planted in early October and harvested in mid-June. Use of large planting stock cloves increased winter survival rates during the harsh winter, but had no effect during the mild winter. Both years, winter survival was reduced with the flat treatment. Yields of marketable bulbs were 4 to 5 times higher when >20 g cloves were planted than when ≤20 g cloves were used. Nitrogen rate and planting method had no effect on yields. The >20 g cloves also produced larger bulbs than the smaller cloves. Of the three planting methods, the flat treatment produced the smallest bulbs. Bulbs were much larger following the mild winter than the harsh winter.

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey
Keyword(s):  
Soil Moisture ◽  
Adult Development ◽  
Survival Rates ◽  
Soil Surface ◽  
Early Spring ◽  
Lumbricus Rubellus ◽  
Late Winter ◽  
Cocoon Production ◽  
Density And Biomass ◽  
Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

Factors Affecting Winter Survival of Johnsongrass (Sorghum halepense) Rhizomes

1991 ◽  
Vol 5 (1) ◽  
pp. 108-110 ◽  
Author(s):  
Robert G. Hartzler ◽  
Art Gover ◽  
Joanne Stellingwerf
Keyword(s):  
Survival Rates ◽  
Winter Survival ◽  
Sorghum Halepense ◽  
Factors Affecting ◽  
Rhizome Biomass ◽  
Depth Of Burial

There were no differences in johnsongrass rhizome winter survival at central and southeastern locations in Pennsylvania in 1988 or 1989. At a 6-cm depth of burial, survival rates of 5 and 25% were found for rhizome segments 7.5 and 15.0 cm in length, respectively. Survival rates for rhizomes buried 25 cm averaged 86%, with no difference in survival between rhizome lengths. The majority of rhizome biomass produced by the biotype used in these studies was found at soil depths allowing a high percentage of survival.

scholarly journals MANAGEMENT OF LATE SPRING-EARLY SUMMER PASTURE SURPLUSES IN HILL COUNTRY

1984 ◽  
pp. 199-206 ◽  
Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly
Keyword(s):  
Early Spring ◽  
Early Summer ◽  
Late Spring ◽  
First Year ◽  
Hill Country ◽  
Continuous Grazing ◽  
Summer Pasture ◽  
Animal Performances ◽  
Grazing Policy ◽  
Made In

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control

scholarly journals Brasilia tapaculo (Scytalopus novacapitalis) seasonality and site occupancy in altitudinal riparian environments after non-natural burnings and feral pig invasion in Serra da Canastra National Park, Brazil

2020 ◽  
Author(s):  
I. L. D. Cunha ◽  
M. G. Reis ◽  
C. Z. Fieker ◽  
M. M. Dias
Keyword(s):  
National Park ◽  
Bird Species ◽  
Site Occupancy ◽  
Early Spring ◽  
Control Area ◽  
Southeastern Brazil ◽  
Breeding Period ◽  
Feral Pigs ◽  
Management Actions ◽  
Gallery Forests

Abstract The Brasilia Tapaculo, Scytalopus novacapitalis Sick, 1958, is a rare, geographically restricted, and endangered bird species that inhabits riparian vegetation of Cerrado, mainly Gallery Forests. In Serra da Canastra National Park, southeastern Brazil, wetlands are under threat due to frequent non-natural burnings and invasion by feral pigs, Sus scrofa, Linnaeus, 1758. We aimed to evaluate the possible effects of seasonal variations on S. novacapitalis records in undisturbed habitats and answer questions about how fire and feral pigs may affect site occupancy of the species. Transects alongside riparian environments were used to survey n=21 sites, totalizing 7.5 Km, from 2014 to 2019. Results indicated the season influenced both, spontaneous records and induced encounters by playback method, which were more abundant in breeding period, from early spring to summer. The use of playback significantly increased the amount of records in all seasons. The probability of site occupancy in all studied area was higher in late spring (ψ=0.91) and lower in autumn (ψ=0.73). In burned sites (n=8), the first post-fire month showed the lowest probability of occupancy, but there was a rapid recovery in 2nd month and stabilization similar to control area from the 3rd month ahead. After sites (n=11) were invaded by feral pigs, the estimation of site occupancy indicated a slight drop in first two months, but after the 3rd month of invasion the decreasing pattern enhanced the discrepancy with undisturbed areas. It is important to keep monitoring S. novacapitalis population and their threats, to subsidize management actions, especially to avoid frequently unusual burnings in riparian forests, and to block the access of feral pigs to wetlands.

scholarly journals Birthweight of the babies delivered by chronic energy deficient mothers in National Nutrition Program (NNP) intervention area

1970 ◽  
Vol 37 (1) ◽  
pp. 17-23 ◽  
Author(s):  
MR Karim ◽  
MS Flora ◽  
S Akhter
Keyword(s):  
Birth Weight ◽  
Odds Ratio ◽  
Weight Status ◽  
Potential Effect ◽  
Control Area ◽  
Current Status ◽  
Food Supplementation ◽  
Nutrition Program ◽  
Energy Deficiency ◽  
The Mean

An operational research was done to explore the effect of targeted food supplementation by comparing the birthweight of the babies of two areas (intervention & nonintervention). This record-based study was carried out in Kapasia and Savar upazila of Dhaka division, relying on the primary organizational data of 565 mothers. In the National Nutrition Program (NNP) area only fifty percent moderate to severe malnourished [Chronic Energy Deficiency (CED) II & III] mothers were preferably targeted for onsite food support while 34 of them managed to complete the full course. The mean (±SD) BMI of the supplemented mothers were lower (16.21±0.77) kg/m2, than non-supplemented mothers in Kapasia (17.14±.82) kg/m2 and Savar 17.03±1.19) kg/m2 area. The mean (±SD) birth-weight for non NNP (Savar) category Mean (±SD) 2470±366.03 grams, for NNP (Kapasia) non-supplemented group 2720.18 (±368.63) grams and in Kapasia good supplemented group it was 2752.94 (±344.86) grams. Supplemented and non-supplemented mothers of NNP mothers were four times more likely to deliver normal birthweight babies [odds ratio with 95%CI 3.84 (2.01, 7.34)] and [odds ratio with 95%CI 3.90 (2.17, 7.01)] than mothers of control area when adjusted for sociodemographic variables. Birth weight status improved with better CED levels. Birth weight adjusted for CED status, had no significant association with food supplementation. In this study, the basic findings were food supplementation could not increase birth-weight significantly as other effects contributed to improve birthweight were removed. As fully supplemented CED III mothers gave birth almost same weighted babies in comparison to the babies of CED I mothers; the recovery from the probability of being less weighted than the current status might be considered as a potential effect of food supplementation.   DOI:  http://dx.doi.org/10.3329/bmrcb.v37i1.7794 Bangladesh Med Res Counc Bull 2011; 37: 17 – 23

scholarly journals Arctic sea-ice albedo derived from RGPS-based ice-thickness estimates

2001 ◽  
Vol 33 ◽  
pp. 225-229 ◽  
Author(s):  
R.W. Lindsay
Keyword(s):  
Sea Ice ◽  
Empirical Relationship ◽  
Early Spring ◽  
Snow Accumulation ◽  
Arctic Sea Ice ◽  
Ice Thickness ◽  
First Year ◽  
Large Set ◽  
Radar Images ◽  
Arctic Sea

AbstractThe RADARSAT geophysical processor system (RGPS) uses sequential synthetic aperture radar images of Arctic sea ice taken every 3 days to track a large set of Lagrangian points over the winter and spring seasons. The points are the vertices of cells, which are initially square and 10 km on a side, and the changes in the area of these cells due to opening and closing of the ice are used to estimate the fractional area of a set of first-year ice categories. The thickness of each category is estimated by the RGPS from an empirical relationship between ice thickness and the freezing degree-days since the formation of the ice. With a parameterization of the albedo based on the ice thickness, the albedo may be estimated from the first-year ice distribution. We compute the albedo for the first spring processed by the RGPS, the early spring of 1997. The data include most of the Beaufort and Chukchi Seas. We find that the mean albedo is 0.79 with a standard deviation of 0.04, with lower albedo values near the edge of the perennial ice zone. The biggest source of error is likely the assumed rate of snow accumulation on new ice.

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