Breeding by Peromyscus in seasonal environments

1979 ◽  
Vol 57 (4) ◽  
pp. 719-727 ◽  
Author(s):  
John S. Millar ◽  
F. B. Wille ◽  
Stuart L. Iverson
Keyword(s):  
Breeding Season ◽  
Litter Size ◽  
Sexual Maturity ◽  
Peromyscus Maniculatus ◽  
Peromyscus Leucopus ◽  
Reproductive Rate ◽  
Reproductive Characteristics ◽  
Breeding Seasons

Reproductive characteristics of Peromyscus maniculatus in Manitoba and Peromyscus leucopus in Ontario were compared in order to determine the extent to which breeding compensates for relatively short breeding seasons. Peromyscus maniculatus had a shorter breeding season than P. leucopus, but frequency of litters, litter size, and age of females at sexual maturity were the same for both species. A comparison of breeding characteristics among Peromyscus from different geographic areas indicated that basic reproductive characteristics do not vary in relation to length of the breeding season.In general, we have no evidence that the basic reproductive characteristics of Peromyscus vary in relation to length of the breeding season. Peromyscus with short breeding seasons, on average, must have a lower annual reproductive rate than Peromyscus with long breeding seasons.

Diet and breeding of the rufous spiny bandicoot Echymipera rufescens australis, Iron Range, Cape York Peninsula

2007 ◽  
Vol 29 (2) ◽  
pp. 169 ◽  
Author(s):  
D.I. Shevill ◽  
C.N. Johnson
Keyword(s):  
Breeding Season ◽  
Litter Size ◽  
Reproductive Rate ◽  
High Fecundity ◽  
Iron Range ◽  
Seed Disperser ◽  
Faecal Analysis ◽  
Live Trapping ◽  
Cape York ◽  
Trapping Grid

A population of the rufous spiny bandicoot Echymipera rufescens australis was studied for 14 months by live-trapping, and diets were determined by faecal analysis. The population had a high density (approximately 48 individuals on a trapping grid of 2.25 ha). A wide variety of foods were eaten, but fruits and seeds contributed the largest proportion of material to faeces, followed by invertebrates, fungi and dicot plants. Echymipera rufescens may potentially be a significant seed disperser for some plants, such as Pandanus zea. There was a short breeding season, with births occurring between December and March. Females produced one or two litters per year. Mean litter size was just under three, and litter size increased with the mother?s mass. Females produced a mean of 4.9 young per year. We conclude that although E. rufescens is a ?typical? bandicoot in that it is omnivorous and has high fecundity, it is more frugivorous and has a somewhat lower reproductive rate than other Australian bandicoots.

Comparative demography of forest Peromyscus

1988 ◽  
Vol 66 (10) ◽  
pp. 2170-2176 ◽  
Author(s):  
David T. Krohne ◽  
Joseph F. Merritt ◽  
Stephen H. Vessey ◽  
Jerry O. Wolff
Keyword(s):  
Peromyscus Maniculatus ◽  
Deciduous Forest ◽  
Peromyscus Leucopus ◽  
Late Summer ◽  
The Other ◽  
Peak Density ◽  
Adult Females ◽  
Forest Sites ◽  
Comparative Demography ◽  
Breeding Seasons

The demography of Peromyscus leucopus and Peromyscus maniculatus was studied from 1979 to 1986 in four deciduous forest sites in Indiana, Virginia, Ohio, and Pennsylvania. In two sites (Virginia and Pennsylvania) the two species were sympatic; at the other two sites, Peromyscus leucopus was the only species present. Peak densities varied greatly among sites (range: Indiana Peromyscus leucopus peak = 30/ha; Pennsylvania Peromyscus maniculatus peak = 120/ha). Except for an apparent synchronous high in 1981, there was no strong temporal concordance of peaks or lows among sites. Breeding seasons were of comparable length at all four sites and typically showed a late summer (August–September) hiatus followed by some fall breeding. There was no consistent relationship among sites between over-winter survival and peak density the following summer or between the percentage of adult females pregnant and peak density. Thus, our data suggest that local processes are more important than regional ones in Peromyscus demography.

scholarly journals Evidence for use of both capital and income breeding strategies in the mangrove tree crab, Aratus pisonii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jade Carver ◽  
Morgan Meidell ◽  
Zachary J. Cannizzo ◽  
Blaine D. Griffen
Keyword(s):  
Breeding Season ◽  
Breeding Strategy ◽  
Reproductive Period ◽  
Breeding Strategies ◽  
Mangrove Tree ◽  
Income Breeding ◽  
Aratus Pisonii ◽  
Breeding Seasons ◽  
And Storage ◽  
Capital And Income Breeding

AbstractTwo common strategies organisms use to finance reproduction are capital breeding (using energy stored prior to reproduction) and income breeding (using energy gathered during the reproductive period). Understanding which of these two strategies a species uses can help in predicting its population dynamics and how it will respond to environmental change. Brachyuran crabs have historically been considered capital breeders as a group, but recent evidence has challenged this assumption. Here, we focus on the mangrove tree crab, Aratus pisonii, and examine its breeding strategy on the Atlantic Florida coast. We collected crabs during and after their breeding season (March–October) and dissected them to discern how energy was stored and utilized for reproduction. We found patterns of reproduction and energy storage that are consistent with both the use of stored energy (capital) and energy acquired (income) during the breeding season. We also found that energy acquisition and storage patterns that supported reproduction were influenced by unequal tidal patterns associated with the syzygy tide inequality cycle. Contrary to previous assumptions for crabs, we suggest that species of crab that produce multiple clutches of eggs during long breeding seasons (many tropical and subtropical species) may commonly use income breeding strategies.

scholarly journals Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season

Ring ◽  
2006 ◽  
Vol 28 (2) ◽  
pp. 119-125
Author(s):  
Michał Ciach ◽  
Dominik Wikar ◽  
Małgorzata Bylicka
Keyword(s):  
Breeding Season ◽  
Early Spring ◽  
Food Resources ◽  
High Density ◽  
Line Transect ◽  
Flock Size ◽  
Early Winter ◽  
Corvus Corax ◽  
Line Transect Method ◽  
Breeding Seasons

Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season During the 2002/2003-2004/2005 non-breeding seasons the density of the Raven in the open habitats of the Orawa - Nowy Targ Basin was studied by line transect method. The results were analysed in four periods (autumn, early winter, winter and early spring). The median density of Ravens did not differ significantly between individual periods and was respectively: 3.5, 3.8, 4.8 and 3.8 indiv. / 10 km. Number of birds during particular controls varied from 1.0 to 24.8 indiv. / 10 km. However, while excluding flocks, the median density of single individuals and pairs of the Raven was considerably lower and in subsequent periods reached respectively: 2.2, 2.4, 2.2 and 1.7 indiv. / 10 km. Flock size did not differ significantly between individual periods. Single individuals and, less often, groups of two birds were recorded mostly. Small (3-5 indiv.) and medium (6-15 indiv.) flocks were recorded rarely and large flocks (16 indiv. and above) - only exceptionally. The high density and strong fluctuations of abundance of Ravens were determined by flocks presence, which was probably linked to irregular occurrence of food resources.

scholarly journals Association of RBP4 Genotype with Phenotypic Reproductive Traits of Sows

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
A. Marantidis ◽  
G. P. Laliotis ◽  
M. Avdi
Keyword(s):  
Litter Size ◽  
Negative Impact ◽  
Reproductive Traits ◽  
Retinol Binding Protein ◽  
Rapid Improvement ◽  
Retinol Binding Protein 4 ◽  
Reproductive Characteristics ◽  
Pcr Rflp ◽  
Hardy Weinberg Equilibrium ◽  
Rbp4 Gene

PCR-RFLP was applied to a commercial crossbred pig population in order to investigate the association between polymorphism (SNP) of Retinol-binding protein 4 (RBP4) gene and reproductive performance. 400 sows were genotyped and 2000 records of reproductive traits were used in order to retrieve information about the allele frequencies and the association of the RBP4 gene with main reproductive characteristics of the population. A deviation from the Hardy-Weinberg equilibrium was observed as a result of the AB genotype excess. In addition, the AA genotype saw statistically significant higher values of (i) the total number of born piglets (p<0.05), (ii) the number of piglets born alive (p<0.01), and (iii) the number of weaned piglets (p<0.01). The number of the mummified piglets and the number of the piglets born dead did not differ between the various RBP4 genotypes. Interestingly, the AA genotype had a negative impact (p<0.05) on the number of piglets born dead, resulting indirectly in a larger litter size. In conclusion, the AA genotype and in extension the A allele of RBP4 gene are in favor of producing larger litter size, suggesting that the RBP4 gene may be used in Marker-Assisted Selection (MAS) programs for a rapid improvement of the reproductive characteristics in pigs.

The effect of melatonin treatment during the seasonal anoestrus on the superovulatory response and embryo production of high-prolificacy Rasa Aragonesa ewes before culling

2003 ◽  
Vol 2003 ◽  
pp. 82-82
Author(s):  
F. Forcada ◽  
J.A. Abecia ◽  
J.A. Valares
Keyword(s):  
Embryonic Development ◽  
Breeding Season ◽  
Litter Size ◽  
Direct Effect ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Melatonin Treatment ◽  
Embryo Production ◽  
Spring Equinox

The efficacy of melatonin implants inserted around the spring equinox to improve fertility and ovulation rate or litter size in Mediterranean ewes has been previously reported (Chemineau et al., 1996; Forcada et al., 2002a.), indicating the ability of the hormone to regulate the hypothalamic activity (Viguié et al., 1995). Moreover, a direct effect of melatonin on corpora lutea and embryonic development has been also reported (Wallace et al., 1988; Abecia et al., 2002). The use of prolific Rasa Aragonesa (RA) ewes (a Mediterranean breed) before culling as embryo donors has been previously tested in the breeding season (Forcada et al., 2002b.). The aim of this experiment was to improve embryo production during the seasonal anoestrus period in selected superovulated RA ewes at the end of their reproductive lives through the use of melatonin.

scholarly journals Growth and reproduction properties of endemic Capoeta kosswigi and Barbus ercisianus in the Deliçay Stream (Van, Turkey)

2021 ◽  
Vol 38 (3) ◽  
pp. 293-302
Author(s):  
Ataman Altuğ Atıcı ◽  
Ahmet Sepil ◽  
Fazıl Şen ◽  
Asude Çavuş
Keyword(s):  
Sexual Maturity ◽  
Condition Factor ◽  
Fork Length ◽  
Lake Van ◽  
Reproductive Characteristics ◽  
Lake Van Basin ◽  
Growth And Reproduction

In this study, the growth and reproductive characteristics of Capoeta kosswigi Karaman, 1969 and Barbus ercisianus Karaman, 1971, which are endemic to the Lake Van Basin, in Deliçay (Van) were investigated. A total of 309 C. kosswigi and 288 B. ercisianus specimens were caught by electrofishing between April and August 2018. The fork length of C. kosswigi and B. ercisianus ranged from 3.7-26.1 cm and from 4.3-22.7 cm, and the total weights ranged from 0.6-227.4 g and from 1.2-140.0 g, respectively. The most intensive catching was in C. kosswigi population of 5.0-6.9 (27.5%) cm and 0-19.9 (67.0%) g in the groups, and 12.0-13.9 (24.7%) cm and 0-9.9 (23.3%) g groups in B. ercisianus. Condition factor was determined as 1.305±0.008 (0.798-1.886) in C. kosswigi and 1.158±0.006 (0.864-1.559) in B. ercisianus. The length-weight relationships were calculated as W = 0.01435 × L2.952 (r2 = 0.996) for C. kosswigi and W = 0.01276 × L2.959 (r2 = 0.994) for B. ercisianus. The M:F ratio was calculated as 1:0.15 in C. kosswigi and 1:0.64 in B. ercisianus. It was established that C. kosswigi attained sexual maturity when they reached to 11 cm fork length for males, 18 cm fork length for females. Maturation of B.ercisianus individuals occurred at 9 cm fork length in males and 12 cm fork length in females. The spawning in C. kosswigi was observed from 1st week of May to 2nd week of July, and in B. ercisianus from 1st week of May to 1st week of August. It may be suggested that minimum catching size must be 20 cm fork length for C. kosswigi and 15 cm fork length for B. ercisianus.

scholarly journals Evaluasi Produktivitas Domba Ekor Gemuk Berdasar Reproductive Rate

2018 ◽  
Vol 20 (2) ◽  
pp. 64
Author(s):  
Sigit Prastowo
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Reproductive Rate ◽  
Ovulation Rate ◽  
Variable Component

<p>Fat Tailed Sheep represent one of Indonesian livestock that having excellence of comparability with other ruminants livestock. The excellence is quickly adult, short of pregnant age, and has the nature of bearing twin, so if evaluated from development aspect will be very beneficial. Reproductive Rate (RR) is a mount of reproduction ability from a group of ewes. Reproductive Rate defined as amount of weaned lamb by ewe every year. Variable/component related to RR are litter size, lamb mortalities before weaning and lambing interval.</p><p>Litter size is general influenced by difference of breeds, age and sufficiency of nutrition. Litter size is peculiarly influenced by ovulation rate that determined by breed, age, nutrition and parity. Lamb age, litter size, birth weight, season, nutrition and parity are influenced lamb mortalities before weaning. Lambing interval determined by nutrition factor and management, which is matting pattern and lamb weaning.</p>

Phenotypic plasticity of the montane vole (Microtus montanus) in unpredictable environments

1992 ◽  
Vol 70 (11) ◽  
pp. 2121-2124 ◽  
Author(s):  
Norman C. Negus ◽  
Patricia J. Berger ◽  
Aelita J. Pinter
Keyword(s):  
Phenotypic Plasticity ◽  
Breeding Season ◽  
Growth Rates ◽  
Adaptive Strategy ◽  
Severe Drought ◽  
Microtus Montanus ◽  
Age Cohort ◽  
Montane Meadow ◽  
Study Sites ◽  
Breeding Seasons

From 1987 to 1989, the cohort dynamics of Microtus montanus populations were studied at two montane meadow sites approximately 160 km apart, in northwestern Wyoming. The 1987 and 1988 breeding seasons differed markedly from each other. In 1987, melt off occurred in April, and the first cohort was born in May (cohort 1). The entire breeding season was favorable owing to frequent rainfall throughout the summer. Cohort 1 animals grew rapidly and females began breeding at 4–5 weeks of age. Likewise, cohort 2 (June) animals exhibited rapid growth and females were breeding at 7–8 weeks of age. Cohort 3 (July and August) animals grew more slowly and most entered the winter as prepubertal animals of subadult size. At the end of the summer, cohort 3 animals represented >70% of the voles recruited during the breeding season. In 1988, following melt off in late April, precipitation was below normal and the situation intensified to severe drought through the summer. The growth rates of cohort 1 and 2 animals were significantly lower than 1987 growth rates, and very few females attained sexual maturity. At the end of the summer, cohort 3 animals represented <25% of the total recruitment at both study sites. Such apparent phenotypic plasticity of growth and maturation appears to be an evolved adaptive strategy that is responsive to several environmental cues. Both study sites, although widely separated, exhibited virtually identical patterns throughout the study.

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