Seasonal changes in activity patterns and the adaptive value of haying in pikas (Ochotona princeps)

1983 ◽  
Vol 61 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Douglas A. Conner
Keyword(s):  
Surface Activity ◽  
Seasonal Changes ◽  
Activity Patterns ◽  
Winter Season ◽  
Late Summer ◽  
Early Summer ◽  
Cold Temperatures ◽  
Vegetation Growth ◽  
Ochotona Princeps ◽  
Early Fall

Seasonal changes in the performance of four behaviors, perching, haying, feeding, and surface activity were studied in two populations of North American pikas (Ochotona princeps) living in Colorado. During late summer and early fall (July–September), haying, the gathering of meadow vegetation followed by storing it in their talus territories, made up almost 55% of the pikas' surface activity. After haying ceased, pikas continued to feed in the meadows until snowpack, cold temperatures, and the absence of surface vegetation made this impossible. Beginning in February, individuals remained under the snowpack feeding on vegetation from their hay piles and on lichens available below the snow. Surface activity was not seen again until May when spring vegetation began to appear. Haying appears to be an adaptive response to environmental unpredictability. Hay piles most likely become critical for survival when harsh weather prevents surface foraging and(or) delays the emergence of new vegetation growth in the spring or early summer. It is suggested that the evolution of territoriality in pikas is related to the need to gather sufficient vegetation to serve as a potential winter food supply during years when the winter season is unusually harsh or prolonged.

scholarly journals A biodiversity hotspot for Microgastrinae (Hymenoptera, Braconidae) in North America: annotated species checklist for Ottawa, Canada

ZooKeys ◽  
2016 ◽  
Vol 633 ◽  
pp. 1-93 ◽  
Author(s):  
Jose Fernandez-Triana ◽  
Caroline Boudreault ◽  
Joel Buffam ◽  
Ronald Maclean
Keyword(s):  
North America ◽  
General Pattern ◽  
Late Summer ◽  
The United States ◽  
Early Summer ◽  
Individual Species ◽  
Early Fall ◽  
Two Peaks ◽  
Annotated Checklist ◽  
First Time

Microgastrinae wasps (Hymenoptera, Braconidae) from the city of Ottawa and its surroundings (a 50-km radius circle, ~7,800 km2) were studied based on 1,928 specimens collected between 1894 and 2010, and housed in the Canadian National Collection of Insects. A total of 158 species from 21 genera were identified, which is by far the highest number of species ever recorded for a locality in North America. An annotated checklist of species is provided.Choerasparasitellae(Bouché, 1834) andPholetesornanus(Reinhard, 1880) are recorded for the first time in the Nearctic (previously only known from the Palearctic region),Cotesiadepressa(Viereck, 1912) is recorded for the first time in Canada (previously only known from the United States), andCotesiahemileucae(Riley, 1881) andProtapantelesphlyctaeniae(Muesebeck, 1929) are recorded for the first time in the province of Ontario. In Ottawa the most diverse genera areCotesia,Apanteles,Microplitis,Pholetesor,Microgaster, andDolichogenidea, altogether comprising 77% of the species found in the area. A total of 73 species (46%) were represented by only one or two specimens, suggesting that the inventory for Ottawa is still relatively incomplete. Seasonal distribution showed several peaks of activity, in spring, summer, and early fall. That general pattern varied for individual species, with some showing a single peak of abundance either in the summer or towards the end of the season, others species attaining two peaks, in late spring and late summer, or in early summer and early fall, and yet others attaining up to three different peaks, in spring, summer and fall. At least 72 of the Microgastrinae species from Ottawa have been previously associated with 554 species of Lepidoptera as hosts – but those historical literature records are not always reliable and in many cases are based on data from areas beyond Ottawa. Thus, our knowledge of the associations between the 158 species of microgastrine parasitoids and the caterpillars of the 2,064 species of Lepidoptera recorded from Ottawa is still very incomplete.

scholarly journals Reproductive and Environmental Drivers of Time and Activity Budgets of Striped Skunks

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
V Y Zhang ◽  
C T Williams ◽  
T C Theimer ◽  
C Loren Buck
Keyword(s):  
Activity Patterns ◽  
Winter Season ◽  
Late Summer ◽  
Weather Conditions ◽  
Environmental Drivers ◽  
Activity Levels ◽  
Lactation Period ◽  
Investment In Reproduction ◽  
Mating Interval ◽  
Striped Skunks

Synopsis The regulation of daily and circannual activity patterns is an important mechanism by which animals may balance energetic requirements associated with both abiotic and biotic variables. Using collar-mounted accelerometers, we assess the relative importance of reproductive stage and environmental conditions on the overall dynamic body acceleration (ODBA) of free-living striped skunks (Mephitis mephitis). We found that activity timing relative to photoperiod varied across seasonal stages for both sexes. Surprisingly, male skunks did not commence activity earlier than females during the mating interval. Moreover, while female skunks began activity before dusk and terminated activity after dawn during mid- through late summer (lactation period), the duration of activity bouts in females during this period was not different from other seasons. Both male and female skunks exhibited high variability and fragmentation in daily activity rhythms except during the lactation period, when females appear to switch to prolonged bouts of nocturnal activity. Overall, ODBA varied by season and sex, with changes in ODBA indicative of seasonal reproductive requirements such as conspecific competition for mates in males and lactation in females. Weather conditions had little effect on skunk activity levels except during the winter season, when snow cover and temperature negatively influenced daily ODBA. Taken together, the activity patterns of striped skunks appear to be primarily driven by seasonal investment in reproduction and secondarily by thermoregulatory constraints during the non-winter months. Our results highlight the importance of considering how environmental and reproductive drivers may interact to affect activity across both the daily and seasonal cycle.

Seasonal changes in prevalence and intensity of Cosmocercoides dukae (Nematoda: Cosmocercoidea) in Deroceras laeve (Mollusca)

1987 ◽  
Vol 65 (7) ◽  
pp. 1662-1665 ◽  
Author(s):  
Daryl J. Vanderburgh ◽  
R. C. Anderson
Keyword(s):  
Natural Population ◽  
Seasonal Changes ◽  
Late Summer ◽  
Early Summer ◽  
Late Spring ◽  
New Host ◽  
Histological Sections ◽  
Arion Fasciatus ◽  
New Host Records

A natural population of Deroceras laeve was examined regularly for the presence of Cosmocercoides dukae (Holl, 1928) Travassos, 1931. Transmission of C. dukae in D. laeve occurred in late spring and early summer before adult slugs from the previous year died in July. Transmission to juvenile slugs (hatched from eggs laid in spring) continued in late summer and fall. Histological sections of slugs exposed experimentally to larvae of C. dukae revealed that larvae penetrate slug tissues. Arion fasciatus, Arion hortensis, and Zonitoides nitidus represent new host records for C. dukae.

scholarly journals The COVID States Project #66: September 2021 update on executive approval

2021 ◽  
Author(s):  
Alauna Safarpour ◽  
Alexi Quintana ◽  
Matthew Baum ◽  
David Lazer ◽  
Katherine Ognyanova ◽  
...  
Keyword(s):  
National Policy ◽  
Late Summer ◽  
The Elderly ◽  
Early Summer ◽  
Policy Decisions ◽  
Public Places ◽  
Public Health Agencies ◽  
Department Of Labor ◽  
Early Fall ◽  
The U.S

The COVID States Project survey regularly asks people in all 50 states about their approval of their governors and the President. Since our last report on executive approval, which examined trends through March 2021, the pandemic has notably evolved, with huge surges of cases and deaths associated with the Delta variant throughout the summer and early fall. Most states reacted to the dip in coronavirus infections and increase in vaccinations in late spring and early summer by lifting indoor mask mandates, only to struggle to adapt as cases surged again in the late summer and early fall 2021. Some of these states were responding to CDC guidance, which announced in May that fully vaccinated people no longer needed to wear masks indoors or outdoors, only to reverse that guidance a few months later and recommend masks indoors for Americans living in areas of high transmission regardless of vaccination status. Other states rebuffed the guidance of public health agencies by, for instance, banning mask mandates in schools, businesses, and other public places. These policy decisions received wide criticism1 particularly as COVID-19 cases, hospitalizations, and deaths surged in those states with the loosest pandemic restrictions.September 2021 has also seen important political developments with respect to national policy around COVID-19. On September 9, President Biden issued an executive order requiring all federal employees and government contractors to be vaccinated. The President also announced that the U.S. Department of Labor would require all businesses with more than 100 employees to require vaccination or weekly testing and provide paid time off for employees to get vaccinated. On September 22, the FDA authorized booster shots for those vaccinated with the Pfizer/BioNTech vaccine for certain populations, including the elderly and those at higher risk of catching the disease due to their professions.In this report, we examine the approval of governors and the President for their handling of the pandemic -- and for the president's overall approval -- over time across the U.S. to assess how the public reacted to the policy decisions and developments surrounding the pandemic as well as state and federal governmental responses.

Seasonal changes in leaf and stem loline alkaloids in meadow fescue

2011 ◽  
Vol 62 (3) ◽  
pp. 261 ◽  
Author(s):  
Brian Patchett ◽  
Ravi Gooneratne ◽  
Lester Fletcher ◽  
Bruce Chapman
Keyword(s):  
Seasonal Changes ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Sharp Decline ◽  
Meadow Fescue ◽  
Accumulation Pattern ◽  
Loline Alkaloids

Leaf and stem loline alkaloid concentration in 10 European meadow fescue (Festuca pratensis Huds.) lines grown in a field in Canterbury, New Zealand, were determined in samples collected six times between early spring 2004 and late autumn 2005. Significant differences in loline alkaloid concentrations were noted between lines and between harvest times. Higher total loline alkaloid concentrations (up to 4990 µg g–1) were found in stems compared to leaf (up to 1770 µg g–1). However, the seasonal accumulation pattern of different loline alkaloid concentrations in leaf and stem varied. In most lines, stem loline concentration peaked sharply in late spring and declined during early summer and autumn. The seasonal pattern of leaf loline alkaloid concentration followed the stem concentration except for a sharp decline in early summer followed by an increase in late summer. In most instances, the concentration of N-formyl loline was the highest > N-acetyl loline > N-acetyl norloline > N-methyl loline. The possible role of stem and leaf loline alkaloids to deter pasture-feeding insects is briefly discussed.

scholarly journals GENETICS OF FLOWERING HABIT IN STRAWBERRY: A MAP-BASED APPROACH

HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 913C-913
Author(s):  
Thomas M. Davis ◽  
M. Sean Hill ◽  
Rebecca S. Gallien ◽  
James E. Pollard
Keyword(s):  
Bulked Segregant Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Late Summer ◽  
Early Summer ◽  
Genetic Determinants ◽  
Mature Fruit ◽  
Short Day ◽  
Early Fall

Strawberry flowering habit can be classified as either day-neutral (DN) or short-day (SD), depending on whether plants are insensitive or sensitive to photoperiod, respectively. Short-day (SD) cultivars produce mature fruit for just a few weeks in early summer. New floral initiation does not commence until triggered by the combination of short daylength and low temperature in the fall. Day-neutral (DN) cultivars do not require particular daylength conditions to initiate flowering, and so continue to produce flowers and mature fruit into late summer and early fall. We are using a map-based approach to characterize the genetic determinants of flowering habit in strawberry at both the diploid and octoploid levels. A recessive gene conferring DN flowering habit has been identified, and its position determined with respect to molecular markers on the Fragaria vesca genetic linkage map. We are using the technique of bulked segregant analysis (BSA) in an effort to find random amplified polymorphic DNA (RAPD) markers linked to a putative dominant gene conferring the DN habit in the octoploid, cultivated strawberry, F. ánanassa.

Environmental Influence on Bentgrass Treated with Silvex

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 193-196 ◽  
Author(s):  
Lloyd M. Callahan ◽  
Ralph E. Engel ◽  
Richard D. Ilnicki
Keyword(s):  
Environmental Influence ◽  
Late Summer ◽  
Creeping Bentgrass ◽  
Early Summer ◽  
Low Ph ◽  
Agrostis Palustris ◽  
High Moisture ◽  
Early Fall ◽  
Moisture Conditions ◽  
Long Photoperiod

Colonial bentgrass (Agrostis tenuis Sibth) and creeping bentgrass (Agrostis palustris Huds) exhibited the most tolerance to 1/2, 1, 1 1/2, and 3 lb/A of 2-(2,4,5-trichlorophenoxy)propionic acid (silvex) when grown under cool temperatures, a long photoperiod, and a low pH medium. Injury from treatments was slight to moderate when applied from early to mid-spring, severe when made from late spring to early summer, and very severe when made from late summer to early fall. Silvex appeared to cause the most injury at the 1 and 1 1/2 lb/A rates. Injury was much less from the lower rate of 1/2 lb/A. Root fructosan concentrations decreased with increasing rates under cool temperatures and increased with increasing rates under high temperatures. Bentgrass appeared to tolerate silvex treatments better under low available moisture conditions than under high moisture levels.

Observations on the Seasonal Changes of the Parasite Fauna of Yellow Perch (Perca flavescens) from the Bay of Quinte, Lake Ontario

1969 ◽  
Vol 26 (4) ◽  
pp. 833-843 ◽  
Author(s):  
Shibru Tedla ◽  
C. H. Fernando
Keyword(s):  
Seasonal Dynamics ◽  
High Intensity ◽  
Seasonal Changes ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Late Summer ◽  
Lake Ontario ◽  
Parasite Fauna ◽  
Early Fall ◽  
Larval Parasites

The seasonal changes in incidence and intensity of infestation of yellow perch, Perca flavescens, by adult and larval parasites, both external and internal, were studied over a period of 1 year. Eight species of parasites were numerous enough to permit analysis of seasonal dynamics. Bunodera luciopercae and Echinorhynchus salmonis showed a high infestation in the fall and declined gradually to zero by late summer. New infestation occurred in early fall. Protocephalus pearsei showed the highest incidence in summer and a lower level during the rest of the year without any marked fluctuations. The intensity of infestation remained relatively constant throughout the year. Ergasilus confusus reached its peak of incidence in the summer, declined through the fall and winter, and began increasing in spring. Intensity of infestation showed parallel changes. In February, however, both incidence and intensity were high. Diplostomulum huronense showed a high intensity of infestation in November. The incidence remained fairly constant throughout the rest of the year. Urocleidius adspectus showed no seasonal variability as regards incidence but the intensity of infestation was highest in August and September. Contracaecum spiculigerum showed no distinct seasonal changes in incidence or intensity. Glochidial infestation reached a high intensity in July. This was due to the glochidia of Lampisilis radiata siliquoidea.

Seasonal dynamics of nutrients in a Carex meadow

1982 ◽  
Vol 60 (9) ◽  
pp. 1671-1678 ◽  
Author(s):  
Allan N. D. Auclair
Keyword(s):  
Aboveground Biomass ◽  
Seasonal Dynamics ◽  
Seasonal Changes ◽  
Late Summer ◽  
Dry Weight ◽  
Early Summer ◽  
Nutrient Accumulation ◽  
Maximum Accumulation ◽  
Mobility Of Elements ◽  
Uptake And Release

Nutrient accumulation in aboveground biomass and mobilization of nutrients in litter were studied on a Carex meadow in southern Quebec, Canada. Seasonal changes were characterized by short periods of rapid element uptake and release. By late May the total element levels were 80% of maximum. Accumulation of N, P, and K was rapid relative to early increments in biomass. Ca, Mg, and micronutrients were taken up from the soil solution across the season and levels paralleled changes in biomass. In early summer elements were released from litter more rapidly than litter dry weight declined. Mobility of elements decreased in the order K > Mg > P > N > Ca. Overwinter, 83% of K was released, whereas Ca concentration in litter increased overwinter and through the following summer. Immobilization of Fe in litter was pronounced. Overall, > 90% of the element mass in green late-summer shoots was retained in litter overwinter.

The effects of temperature and daylength on the reproductive physiology of the viviparous seaperch, Cymatogaster aggregata Gibbons

1968 ◽  
Vol 46 (6) ◽  
pp. 1207-1219 ◽  
Author(s):  
John P. Wiebe
Keyword(s):  
Late Summer ◽  
Late Pregnancy ◽  
Early Summer ◽  
Reproductive Physiology ◽  
Cold Temperature ◽  
Late Winter ◽  
Warm Temperature ◽  
Cold Temperatures ◽  
Effects Of Temperature ◽  
Long Photoperiod

The effects of temperature and photoperiod on the reproductive physiology of Cymatogaster aggregata are examined experimentally and related to the conditions in nature. In males an increasing or long photoperiod in late winter, spring, or early summer results in spermatogenesis, development of secondary sex structures, and reproductive behavior; warm temperatures markedly enhance these processes. The cold temperature and short photoperiod of the winter months promote testicular restitution and growth of spermatogonia.In females, oocyte formation is enhanced by the warm temperature (and perhaps decreasing photoperiod) of late summer and eariy autumn, while oocyte maturation is fostered by the cold temperatures of early winter. Early gestation requires a cold temperature but during late pregnancy a warm temperature will enhance growth of embryos.

Sign in / Sign up

Export Citation Format

Share Document