The effect of feeding melatonin during late summer on the onset of the breeding season of sheep

1984 ◽  
Vol 140 (4) ◽  
pp. 407-408 ◽  
Author(s):  
H.L. Williams
Keyword(s):  
Breeding Season ◽  
Late Summer ◽  
Effect Of Feeding

scholarly journals Temporal Variation in Breeding Season Survival and Cause-Specific Mortality of Lesser Prairie-Chickens

2018 ◽  
Vol 9 (2) ◽  
pp. 507-518
Author(s):  
Andrew R. Meyers ◽  
Scott A. Carleton ◽  
William R. Gould ◽  
Clay T. Nichols ◽  
David A. Haukos ◽  
...  
Keyword(s):  
New Mexico ◽  
Breeding Season ◽  
Late Summer ◽  
Male And Female ◽  
Brood Rearing ◽  
Management Actions ◽  
Specific Mortality ◽  
Prairie Chicken ◽  
Female Survival ◽  
Similar Survival

Abstract The lesser prairie-chicken Tympanuchus pallidicinctus has experienced significant declines in distribution and abundance since the early 1900s. A severe and prolonged drought from 2009 to 2013 resulted in further declines in population numbers and despite improved environmental and habitat conditions since 2013, populations of lesser prairie chickens have shown little improvement. To investigate whether breeding season survival of lesser prairie-chickens in eastern New Mexico could be driving this response, we developed the following objectives: 1) estimate male and female breeding-season survival; 2) determine whether male and female survival varies temporally among lekking, nesting, and brood-rearing periods; and 3) determine cause-specific mortality during the breeding season. We captured and radiocollared 76 lesser prairie-chickens (50 male, 26 female) during spring of 2014 and 2015 and estimated their survival throughout the breeding season (15 March–31 August). Male survival was nearly double that of females in both years (0.79–0.81 and 0.38–0.45, respectively). Males had similar survival across all periods (lekking, postlekking, late summer: 0.89–0.95). Females had the greatest period-specific survival during lekking and brood rearing (0.87 ± 0.08 and 0.85 ± 0.10, respectively) relative to the nesting period (0.58 ± 0.11). Mammalian predation was the primary cause of mortality in both years. Our results indicate that in New Mexico 1) lesser prairie-chicken breeding season survival was consistent with geographically similar studies, 2) females have lower survival during the nesting period, and 3) female lesser prairie-chicken survival was lower than male survival regardless of time period. Management actions that provide and protect high-quality nesting habitat may help ensure that female survival is maximized during the nesting period.

scholarly journals Hantavirus infections in fluctuating host populations: the role of maternal antibodies

2010 ◽  
Vol 277 (1701) ◽  
pp. 3783-3791 ◽  
Author(s):  
Eva R. Kallio ◽  
Michael Begon ◽  
Heikki Henttonen ◽  
Esa Koskela ◽  
Tapio Mappes ◽  
...  
Keyword(s):  
Breeding Season ◽  
Natural Populations ◽  
Late Summer ◽  
Maternal Antibodies ◽  
Infection Prevalence ◽  
Infection Dynamics ◽  
High Infection ◽  
Maternal Protection ◽  
First Time

Infected females may transfer maternal antibodies (MatAbs) to their offspring, which may then be transiently protected against infections the mother has encountered. However, the role of maternal protection in infectious disease dynamics in wildlife has largely been neglected. Here, we investigate the effects of Puumala hantavirus (PUUV)-specific MatAbs on PUUV dynamics, using 7 years' data from a cyclic bank vole population in Finland. For the first time to our knowledge, we partition seropositivity data from a natural population into separate dynamic patterns for MatAbs and infection. The likelihood of young of the year carrying PUUV-specific MatAbs during the breeding season correlated positively with infection prevalence in the overwintered parent population in the preceding spring. The probability of PUUV infection varied between seasons (highest in spring, lowest in late summer) and depended on population structure, but was also, in late autumn, notably, negatively related to summer MatAb prevalence, as well as to infection prevalence earlier in the breeding season. Hence, our results suggest that high infection prevalence in the early breeding season leads to a high proportion of transiently immune young individuals, which causes delays in transmission. This suggests, in turn, that MatAb protection has the potential to affect infection dynamics in natural populations.

Multiple warren use by subadult wild rabbits, Oryctolagus cuniculus, and its implications for disease transmission

2017 ◽  
Vol 44 (7) ◽  
pp. 582 ◽  
Author(s):  
Scott Jennings ◽  
Gregory Mutze
Keyword(s):  
Population Density ◽  
Breeding Season ◽  
Disease Transmission ◽  
Critical Role ◽  
Late Summer ◽  
Adult Size ◽  
Contact Rates ◽  
Rabbit Haemorrhagic Disease ◽  
European Rabbits ◽  
Haemorrhagic Disease

Context Contact rates are a key determinant of disease transmission. Territorial behaviour has generally been considered to limit contact between European rabbits occupying different warrens, particularly during the breeding season. Aims We investigated warren use by subadult rabbits during a period of low population density to determine their potential role in transmission of rabbit haemorrhagic disease and myxomatosis. Methods Subadult rabbits were radio-collared in late summer and relocated twice-weekly for 25 weeks, during which time they grew to adult size and breeding commenced. Key results Rabbits of both sexes used an average of four warrens each on a regular basis, even after older rabbits had commenced breeding. Warrens used by individual rabbits formed a continuously overlapping, irregular array. Subadult rabbits did not belong to separate social groups that utilised separate groups of warrens. Conclusions Subadult or young adult rabbits did not display the same territorial warren fidelity that had been previously described for rabbits. They have potential to carry pathogens between warrens at a landscape scale. Implications Movement of subadult rabbits between warrens is therefore likely to play a critical role in disease transmission, particularly when population density is low. This may help to explain the prevalent seasonality of RHD epizootics in spring when first-born litters of each breeding season typically reach that size.

Social-Behavior and Colony Formation in a Population of Crested Terns, Sterna-Bergii, in Southwestern Australia

1987 ◽  
Vol 14 (4) ◽  
pp. 529 ◽  
Author(s):  
JN Dunlop
Keyword(s):  
Social Behavior ◽  
Breeding Season ◽  
Small Groups ◽  
Social Behaviour ◽  
Colony Formation ◽  
Late Summer ◽  
Breeding Population ◽  
Southwestern Australia ◽  
Nest Sites ◽  
The Social

In a breeding population of crested terns near Fremantle, W.A., social behaviour involved complex patterns of social displays and paired behaviour. The social phase was probably truncated over much of the extended breeding season by the presence of incubating conspecifics, and may serve to synchronise laying in their absence. The responses of pre-laying crested terns to incubating conspecifics were studied by means of artificial 'colonies' of polyurethane models. These proved to be most attractive to prebreeding pairs searching for nest sites, and the earliest eggs were invariably laid among the decoys. Pre-breeding terns in the social phase were not attracted to the decoys. It is suggested that loose groups of incubating conspecifics acted as a key stimulus, releasing settlement and laying in birds in an advanced state of reproductive readiness. This key stimulus could change the learned location of colonies but during late summer and early autumn other factors, probably related to food availability, controlled the onset of laying. Small, spatially distinct, nesting groups were less synchronous in their laying than larger colonies. Such small groups are thought to result from discontinuities in reproductive phase between groups of terns, which are not apparent when the number of pre-laying birds is large.

Breeding-season frugivory by Harris' sparrows (Zonotrichia querula) and white-crowned sparrows (Zonotrichia leucophrys) in a low-arctic ecosystem

1997 ◽  
Vol 75 (5) ◽  
pp. 670-679 ◽  
Author(s):  
Christoper J. Norment ◽  
Martin E. Fuller
Keyword(s):  
Protein Content ◽  
Body Mass ◽  
Breeding Season ◽  
Sugar Content ◽  
Late Summer ◽  
Zonotrichia Leucophrys ◽  
Widespread Distribution ◽  
Empetrum Nigrum ◽  
Low Arctic ◽  
Mountain Cranberry

We studied breeding-season frugivory by Harris' sparrows (Zonotrichia querula) and white-crowned sparrows (Z. leucophrys) in the forest–tundra ecotone of the Northwest Territories during a 3-year period. Density of fruits produced during previous summers and preserved beneath the snow averaged between 83 and 94/m2 during June. Mass of alpine bearberry (Arctostaphylos alpina) fruits collected during June was significantly greater than that of crowberry (Empetrum nigrum) or mountain cranberry (Vaccinium vitis-idaea), while the relative sugar content of mountain cranberry fruits in June was greater than that of alpine bearberry or crowberry fruits. The protein content of all fruits was relatively low (≤ 3.1%). Harris' and white-crowned sparrows maintained body mass and fat condition while feeding heavily on fruits during the early breeding season and shifted to arthropods when feeding nestlings. The results of our study, plus the widespread distribution of arctic and subarctic subshrubs that produce fleshy fruits consumed by other species, particularly ptarmigan (Lagopus spp.) and shorebirds, suggest that community-wide studies are needed to evaluate the importance of over-winter and late-summer fruits in the diets of terrestrial arctic and subarctic birds.

scholarly journals Ungfågelspridning och höstflyttning hos svart rödstjärt Phoenicurus ochruros i södra Sverige

Ornis Svecica ◽  
2013 ◽  
Vol 23 (2) ◽  
pp. 65-71
Author(s):  
Reino Andersson
Keyword(s):  
Breeding Season ◽  
Population Study ◽  
Late Summer ◽  
Population Increase ◽  
Total Catch ◽  
Breeding Populations ◽  
Ringing Data ◽  
Postjuvenile Moult ◽  
Phoenicurus Ochruros ◽  
Second Peak

The number of ringed Black Redstarts at Ottenby, Falsterbo and Nidingen bird observatories showed two distinct peaks after the breeding season. During the first peak in July–August, with 63, 67 and 89 percent of the total catch, the proportions of yearlings were 92, 100 and 96 percent, respectively, and most of them had not yet begun their postjuvenile moult and showed relatively low weights. During the second peak in October–November, all yearlings had completed this moult and carried more fat. Black Redstarts have a delayed postjuvenile moult, a unique strategy among European thrushes. This allows for wide dispersal during late summer. Several ringed Belgian and German yearlings have moved up to 290 km northward during this time. This paper confirms, using ringing data and observations from a population study in western Sweden, that summer dispersal is well separated from autumn migration. I speculate that some of the birds of the July–August peak could have their origin in southern breeding populations, for example Denmark, where a major population increase has occurred in recent decades.

Effects of temperature and feeding level on growth and feed efficiency of farmed rainbow trout

1992 ◽  
Vol 1992 ◽  
pp. 71-71
Author(s):  
K. McCavana ◽  
K.J. McCracken
Keyword(s):  
Feed Efficiency ◽  
Stocking Density ◽  
Late Summer ◽  
Fish Farming ◽  
Early Winter ◽  
Feeding Level ◽  
Commercial Practice ◽  
Effects Of Temperature ◽  
Four Levels ◽  
Effect Of Feeding

Feeding level is a major factor in maximising feed efficiency and reducing effluent pollution in fish farming. In previous studies on stocking density, feeding levels used in normal commercial practice were employed. The results tended to suggest that these levels were too high for maximum feed efficiency. Consequently a series of trials was undertaken at different times of year to study the effect of feeding level, at a range of water temperatures, on growth and feed efficiency.Three 21 d trials were conducted in early winter, spring and late summer, to avail of different water temperatures and dissolved oxygen concentrations. Four different feeding levels (22, 19, 16 and 13 g/kg bodyweight) were used in each trial. Trials one and two had three replicates of the four levels and trial three had two replicates. Identical adjacent ponds (18 m3) were used in each trial and were randomised for feeding level. Initial weights were 30, 50 and 20 g in trials one, two and three respectively.

Age, Sex and Season: Factors which Determine the Trap Response of the European Wild Rabbit, Oryctolagus cuniculus

1980 ◽  
Vol 7 (3) ◽  
pp. 421 ◽  
Author(s):  
JC Daly
Keyword(s):  
Individual Differences ◽  
Natural Population ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Oryctolagus Cuniculus ◽  
Adult Population ◽  
Late Summer ◽  
Wild Rabbit ◽  
Males And Females ◽  
Probability Of Capture

Factors determining the trap-response of the rabbit, investigated in a natural population at Urana, N.S.W., included the age and the sex of the rabbit and the season in which it was trapped. Differences were also observed between rabbits living in two adjacent habitats. Mark-recapture data, derived from 52 trips undertaken over 30 months, did not show a uniform probability of capture within the adult population. Adult rabbits were most trappable when they were not breeding (late summer to midwinter); at this time males and females were equally trappable but individual differences were noted. During the breeding season all adults were difficult to trap, males more so than females. Trappability increased with age in young rabbits and declined at sexual maturity. Trap-response was random with respect to the animal's genotype as determined by four polymorphic enzyme loci. Markrecapture- analysis is unlikely to be an accurate means of estimating the parameters of rabbit populations; full enumeration of the population is necessary.

CIRCANNUAL CHANGES IN SERUM LEVELS OF PITUITARY HORMONES AND TESTOSTERONE AND IN TESTIS SIZE OF SEXUALLY ACTIVE AND INACTIVE ADULT RAMS

1983 ◽  
Vol 63 (4) ◽  
pp. 811-821 ◽  
Author(s):  
LEE M. SANFORD ◽  
THADDEUS A. YARNEY
Keyword(s):  
Breeding Season ◽  
Late Summer ◽  
Serum Levels ◽  
Pituitary Hormones ◽  
Similar Data ◽  
Testis Size ◽  
Sexually Active ◽  
Nonbreeding Season ◽  
Scrotal Circumference ◽  
Ejaculation Frequency

The influence of the social environment of adult rams on testicular function and the secretion of pituitary hormones was investigated between May 1978 and October 1979. Twelve rams, 3–6 yr of age, were penned in three groups of four, either as a sexually inactive all-male group or as sexually active groups adjacent to or together with ovariectomized ewes that were hormonally induced into estrus every 10 days. At approximately monthly intervals measurements of testis size were recorded and rams were bled by venepuncture from the jugular vein at 20-min intervals for 8 h (0900–1700 h). Sera were assayed for luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and testosterone. Since seasonal changes in testicular and endocrine characteristics for the sexually active groups were similar, data for these groups were combined. Differences in the circannual testicular rhythm were not observed between ram groups until the onset of the second breeding season; at this time (August 1979), sexually active rams had significantly (P < 0.05) higher scrotal circumference measurements (36.0 ± 0.9 vs. 32.2 ± 1.0 cm) and circulating testosterone levels (10.7 ± 1.6 vs. 6.7 ± 1.5 ng/mL), and significantly (P < 0.05) lower LH levels (0.75 ± 0.10 vs. 2.04 ± 0.40 ng/mL) than sexually inactive rams. The increase in rate of testicular redevelopment for sexually active rams during late summer was not preceded by significantly (P > 0.05) higher seasonal elevations in circulating LH and FSH levels, although PRL levels in May through July were only 50% of those observed for the sexually inactive rams. Sexually active rams also exhibited significant (P < 0.01) increases in LH and testosterone secretion in the nonbreeding season when ewes were sexually receptive. Ejaculation frequency during a 4-h test period at the conclusion of the study was similar for both groups of rams. Data indicate that long-term exposure of adult rams to estrual ewes results in an increase in rate of testicular redevelopment during the summer in preparation for the fall breeding season. Key words: Circannual changes, pituitary hormones, testosterone, testis, mating, ram

scholarly journals Do stranded sand dollars indicate hydrodynamic conditions of sandy beaches?

2021 ◽  
Vol 10 (2) ◽  
pp. 81-86
Author(s):  
Walter Barrella
Keyword(s):  
Spatial Distribution ◽  
Breeding Season ◽  
Correspondence Analysis ◽  
Late Summer ◽  
Sandy Beaches ◽  
Lunar Phase ◽  
Moon Phase ◽  
Hydrodynamic Conditions ◽  
The Moon ◽  
Sand Dollars

This article aimed to evaluate sand dollars' distribution (Mellitaquinquiesperforata) by relating it to hydrodynamic variations on Santos Beach (Brazil). Twenty-nine samplings were carried out between March 2015 and July 2018, through 6 transects in the seawater limit, along 5.5km of the beach. The survey of data consisted of two processes: counting and biometrics of the whole individuals present. We noted the wind's direction, the height of the tide, the lunar phase, and the seasons. Canonical Correspondence Analysis and 2way ANOVAs showed that the season, the direction of the prevailing winds, and the moon phase significantly influenced the cookies' spatial distribution, results that coincide with the existing models for erosion and sedimentation. We only registered adult individuals (>4cm). The largest and heaviest individuals occurred in late summer and early autumn (March-April), which suggests that this is the species' breeding season.

Sign in / Sign up

Export Citation Format

Share Document