Effects of ungulate availability on wolf reproductive potential in Alaska

1992 ◽  
Vol 70 (12) ◽  
pp. 2441-2443 ◽  
Author(s):  
R. D. Boertje ◽  
R. O. Stephenson
Keyword(s):  
Litter Size ◽  
Canis Lupus ◽  
Prey Availability ◽  
Subcutaneous Fat ◽  
Reproductive Potential ◽  
Functional Relationships ◽  
Adult Females ◽  
Prey Vulnerability ◽  
Average Litter Size

We compared wolf (Canis lupus) reproductive data for March and April, when ungulate biomass per wolf was high, moderate, and low. The percentage of reproductively active adult females was significantly lower (66% compared with ≥96%, P < 0.001) when ungulate biomass per wolf was low versus moderate or high. Reproductively inactive adult females had significantly less subcutaneous fat (P < 0.01) than reproductively active females when ungulate biomass per wolf was relatively abundant. Average litter size, estimated by counting blastocysts or fetuses, declined significantly (P < 0.001), from 6.9 to 4.6, as ungulate biomass per wolf declined. We conclude that wolf productivity declines as prey availability per wolf declines. However, only when ungulate biomass per wolf declined below levels previously reported in the literature did we observe significant declines in reproductive potential. Ungulate biomass per wolf was low because of large, rapid declines in ungulates and lesser declines in wolves. We recognize that functional relationships, e.g., prey vulnerability and feeding dominance, can influence wolf productivity independently of ungulate biomass per wolf.

REPRODUCTIVE POTENTIAL AND SEX RATIOS OF SNOWSHOE HARES IN NORTHERN ALBERTA

1956 ◽  
Vol 34 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Wm. Rowan ◽  
L. B. Keith
Keyword(s):  
Litter Size ◽  
Sex Ratios ◽  
Reproductive Potential ◽  
Post Mortem ◽  
Comparable Data ◽  
Snowshoe Hares ◽  
Average Litter Size ◽  
Northern Regions ◽  
Two Factors ◽  
Northern Alberta

In conjunction with studies of the "10-year cycle" of snowshoe hares, almost 900 hares were collected in the Anzac district of Alberta during the period May, 1949, to April, 1956. Embryo numbers and sex ratios were among the data gathered from post-mortem examinations of these hares. It was found that the average litter size was 3.82; the modal litter size was four and the range was from one to seven. The average number of litters each season was calculated at 2.75. The annual reproductive potential is thus 10.51 (3.82 × 2.75) young per female hare. This is more than 50% greater than that indicated by comparable data from Minnesota. It is suggested that herein lies the cause of higher peak populations in northern regions. Sex ratios shifted from a marked excess of females in the year 1949–1950 to about even numbers of both sexes during the two subsequent years. Since the change in sex ratio occurred at the peak of the cycle, the two factors are believed to be in some manner correlated.

Wolf (Canis lupus) litter size in Spain

2021 ◽  
Vol 67 (2) ◽  
Author(s):  
Elisa Ferreras-Colino ◽  
Anna García-Garrigós ◽  
Christian Gortázar ◽  
Luis Llaneza
Keyword(s):  
Litter Size ◽  
Canis Lupus

Characteristics of reproductive organs and estimates of reproductive potential in Scandinavian male grey wolves (Canis lupus)

2021 ◽  
Vol 226 ◽  
pp. 106693
Author(s):  
Amanda Petersen ◽  
Mikael Åkesson ◽  
Eva Axner ◽  
Erik Ågren ◽  
Camilla Wikenros ◽  
...  
Keyword(s):  
Canis Lupus ◽  
Reproductive Potential ◽  
Reproductive Organs

Development of a Strain of Rabbits with Congenital Simple Nonsyndromic Coronal Suture Synostosis Part I: Breeding Demographics, Inheritance Pattern, and Craniofacial Anomalies

1994 ◽  
Vol 31 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mark P. Mooney ◽  
H. Losken Wolfgang ◽  
Michael I. Siegel ◽  
Janice F. Lalikos ◽  
Albert Losken ◽  
...  
Keyword(s):  
Litter Size ◽  
Rabbit Model ◽  
Pedigree Analysis ◽  
Human Populations ◽  
Incomplete Penetrance ◽  
Coronal Suture ◽  
Inheritance Pattern ◽  
Average Litter Size ◽  
Midfacial Hypoplasia ◽  
Congenital Condition

The lack of an animal model of congenital coronal suture (CS) synostosis has prompted the widespread use of an experimental rabbit model using adhesive Immobilization of the CS. Such postnatal models have helped make significant scientific contributions but may still not fully represent all aspects of the human congenital condition. In the March 1993 issue of The Cleft Palate-Craniofacial Journal we reported a female rabbit born in our laboratory with complete bilateral CS synostosis. This follow-up study presents our attempts to breed this animal and establish a strain of cranlosynostotic rabbits. To date, we have accomplished 10 back- and intercrosses with these animals and have produced a total of 71 live offspring; 10 animals exhibited complete nonsyndromic unilateral (plagiocephalic) or bilateral (brachycephalic) CS synostotic deformities at birth, and 19 animals exhibited partial CS synostosis that showed more than 75% growth retardation across the CS (well below the 95% confidence interval for normals). Results revealed that gestational time and litter size averages were consistent with those reported for the strain, although the average litter size decreased with increased inbreeding. By 1.5 weeks of age the completely synostosed animals already exhibited brachycephalic cranial vaults and midfacial hypoplasia compared to unaffected siblings. Initial pedigree analysis suggested an autosomal dominant inheritance pattern with incomplete penetrance and variable expressivity. The development of such a congenital rabbit model may prove useful In helping to understand the etiopathogenesis of this condition In human populations.

A note on ovulation rate and embryonic survival in D'man ewes

1981 ◽  
Vol 32 (2) ◽  
pp. 227-229 ◽  
Author(s):  
A. Lahlou-Kassi ◽  
M. Marie
Keyword(s):  
Litter Size ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Embryonic Survival ◽  
Average Litter Size ◽  
Simultaneous Activity

ABSTRACTThe elements of prolificacy have been analysed for the D'man sheep, a prolific Moroccan breed, by laparotomy on 38 animals. The average ovulation rate was 2·50 (s.e.0·45); a slight difference was observed between nulliparous and multiparous ewes due to high simultaneous activity by both ovaries in the latter group. Embryonic survival (42% overall) was 94% (87 to 100%) for multiparous and 44% (36 to 52%) for the nulliparous ewes at one ovulation, decreasing with increasing numbers of corpora lutea. The average litter size showed an optimum at four ovulations.

Wolf predation risk associated with white-tailed deer movements

1991 ◽  
Vol 69 (10) ◽  
pp. 2696-2699 ◽  
Author(s):  
Michael E. Nelson ◽  
L. David Mech
Keyword(s):  
Predation Risk ◽  
Odocoileus Virginianus ◽  
Canis Lupus ◽  
Climatic Conditions ◽  
Male And Female ◽  
Wolf Predation ◽  
Adult Females ◽  
Disproportionate Number ◽  
Short Time ◽  
Antipredator Strategy

The survival of 159 yearling and adult deer (Odocoileus virginianus) was monitored by telemetry during 282 spring and 219 fall individual migrations to winter deeryards in northeastern Minnesota. A disproportionate number of deer were killed by wolves (Canis lupus) during fall migration relative to the short time they spent migrating, but not during spring migration. Predation was also significantly greater for male and female yearlings and adult females outside deeryards during winter. Survival of 79 yearlings dispersing from natal ranges was high (1.00). It appears that changing climatic conditions combined with unfamiliar terrain and undetermined factors predispose migratory deer to wolf predation during fall. These findings support an earlier hypothesis that winter yarding is an antipredator strategy.

Growth of the Eastern Quoll, Dasyurus viverrinus (Shaw), (Marsupialia) in Captivity

1984 ◽  
Vol 11 (1) ◽  
pp. 21 ◽  
Author(s):  
JC Merchant ◽  
K Newgrain ◽  
B Green
Keyword(s):  
Litter Size ◽  
Adult Female ◽  
Growth And Development ◽  
Mammary Glands ◽  
Adult Females ◽  
In Captivity ◽  
Molar Teeth ◽  
Males And Females ◽  
At Will

The growth and development, from 10 to 270 days old, of eastern quolls in a captive colony was recorded. Young were able to detach from the teat by 65 days of age and their eyes were open by 80 days. Statistically significant differences in some measurements from males and females were found as early as 85 days of age. The weaning period commenced at 102 days ofage, and coincided with eruption ofthe first molar teeth. Total independence, determined by the cessation of lactation in the mother, was as early as 142 days in litters of one or as late as 200 days in larger litters. There was a high correlation between litter size and age at independence. Lactation was maintained in all previously suckled mammary glands of adult females after the death of young aged 65 days or over if some siblings remained. This was due to the ability of young of this age to detach and reattach to the teats at will. The implication of this observation is that the commonly held view that the numbers of surviving young in marsupial litters corresponds to the number of lactating teats in the adult female may not always be correct.

scholarly journals Reproductive potential of Spodoptera eridania (Stoll) (Lepidoptera: Noctuidae) in the laboratory: effect of multiple couples and the size

2016 ◽  
Vol 76 (2) ◽  
pp. 526-530 ◽  
Author(s):  
A. Specht ◽  
D. G. Montezano ◽  
D. R. Sosa-Gómez ◽  
S. V. Paula-Moraes ◽  
V. F. Roque-Specht ◽  
...  
Keyword(s):  
Reproductive Potential ◽  
Reproductive Parameters ◽  
Spodoptera Eridania ◽  
Adult Females ◽  
Controlled Conditions ◽  
Pupal Size ◽  
Lepidoptera Noctuidae

Abstract This study aimed to evaluate the effect of keeping three couples in the same cage, and the size of adults emerged from small, medium-sized and large pupae (278.67 mg; 333.20 mg and 381.58 mg, respectively), on the reproductive potential of S. eridania (Stoll, 1782) adults, under controlled conditions (25 ± 1 °C, 70% RH and 14 hour photophase). We evaluated the survival, number of copulations, fecundity and fertility of the adult females. The survival of females from these different pupal sizes did not differ statistically, but the survival of males from large pupae was statistically shorter than from small pupae. Fecundity differed significantly and correlated positively with size. The number of effective copulations (espematophores) and fertility did not vary significantly with pupal size. Our results emphasize the importance of indicating the number of copulations and the size of the insects when reproductive parameters are compared.

scholarly journals Production systems of swine in the rural areas of Rangamati and Khagrachari districts of Bangladesh

2012 ◽  
Vol 40 (1-2) ◽  
pp. 28-33
Author(s):  
ME Hossain ◽  
S Chakma ◽  
MM Khatun ◽  
M Hasanuzzaman ◽  
MY Miah ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Rural Areas ◽  
Economic Condition ◽  
Production Systems ◽  
Economic Benefits ◽  
Disease Prevalence ◽  
Pig Production ◽  
Average Litter Size ◽  
The Mean

The study was undertaken for a period of 60 days to investigate the production systems of swine in Rangamati and Khagrachari districts, Bangladesh. Production systems, particularly housing, feeding, breeding, disease prevalence, vaccination, bio-security, marketing, socio-economic condition and constraints of pig production were investigated during the study period. It was found that the propensity of rearing pig differed significantly (P<0.01) among the pig owners. Pigs were reared mostly by poor and landless peoples (54.7%) followed by marginal (32.1%), medium (9.4%) and large (3.8%). Rearing systems were also different (P<0.01) and the mean figures were 43.4% for free range, 24.5% for tin shed housing , 20.8% for fencing and 11.3% for girth tethering systems. The average litter size, birth weight, post-weaning weight and weaning period were 9.3, 1.72 kg, 9.0 kg and 40.8 days respectively. Prevalence of diseases differed (P<0.01) and most prevalent diseases were diarrhea (35.8%), coccidiosis (20.8%), pneumonia (17.0%) and hemorrhagic septicemia (13.2%). The economic benefits generated from farming were selling of piglets.DOI: http://dx.doi.org/10.3329/bjas.v40i1-2.10787Bang. J. Anim. Sci. 2011. 40 (1-2): 28-33

scholarly journals Pedigree and Molecular Analyses in the Assessment of Genetic Variability of the Polish Greyhound

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 353
Author(s):  
Małgorzata Goleman ◽  
Ireneusz Balicki ◽  
Anna Radko ◽  
Iwona Rozempolska-Rucińska ◽  
Grzegorz Zięba
Keyword(s):  
Genetic Variability ◽  
Litter Size ◽  
Gene Diversity ◽  
Population Based ◽  
Pedigree Analysis ◽  
Molecular Testing ◽  
Pedigree Data ◽  
Kinship Matrix ◽  
Average Litter Size ◽  
The Mean

The aim of the study was to assess the genetic variability of the Polish Greyhound population based on pedigree analysis and molecular DNA testing and to determine the degree of relatedness among individuals in the population. Pedigree data of 912 Polish Greyhounds recorded in pedigree books since they were opened for this breed were analyzed. For molecular testing, DNA was obtained from cheek swabs taken from 235 dogs of the tested breed. A panel of 21 markers (Short Tandem Repeat—STR) was used. The mean inbreeding determined for the Polish Greyhound population based on pedigree analyses was low and amounted to 11.8%, but as many as 872 individuals of the 912 dogs in the studied population were inbred. A total of 83 founders (at least one unknown parent) were identified, among which 27 founders had both unknown parents. Full-sibling groups consisted of 130 individuals, with a minimum and maximum litter size of 2 and 16, respectively. The average litter size was 5.969. Gene diversity calculated based on the mean kinship matrix was 0.862 and the population mean kinship was 0.138. The founder genome equivalent based on the mean kinship matrix was 3.61; the founder genome surviving level was 12.34; the mean Ne was estimated at 21.76; and the Ne/N ratio was 0.135. The FIS inbreeding coefficient for 21 STR was negative, and the mean FIS value for all loci had a low negative value (−0.018). These values suggest a low level of inbreeding in the examined breed as well as the avoidance of mating related animals.

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