Predicted susceptability of Dasyurus geoffroii to canid baiting programmes: variation due to sex, season and bait type

1993 ◽  
Vol 20 (3) ◽  
pp. 287 ◽  
Author(s):  
TR Soderquist ◽  
M Serena
Keyword(s):  
Body Weight ◽  
Adult Males ◽  
Laboratory Assessment ◽  
Fresh Meat ◽  
Adult Females ◽  
Original Weight ◽  
Seasonal Factors ◽  
Lactating Females ◽  
Juvenile Males

A laboratory assessment of the susceptibility of Dasyurus geoffroii to baits used to control foxes and dingoes was conducted using five types of non-poisoned baits: polony, fresh meat, meat dried by 50% and 70% of the original weight, and compressed beef crackle. Trials were designed to simulate the initial encounter of a bait by hungry wild juveniles and adults of both sexes, including lactating females. In overnight trials, juveniles and lactating females ate significantly more fresh meat per body weight (mean consumption: 23.7% for juvenile males, 21.5% for juvenile females, 23.1% for lactating females) than non-lactating adult females and adult males (combined mean, 18.3%). Maximum overnight bait consumption was 43% of body weight. These values greatly exceed those previously reported for other species of Dasyurus. Moist baits were eaten more rapidly and in larger amounts than drier baits. Seasonal factors lead to the prediction that the period when canid baiting can be conducted with the least danger to Dasyurus geoffroii is January-March.

scholarly journals The Influence of Age, Sex, Pregnancy, Starvation, and Other Factors on the Cytoplasmic Ribonucleoproteins of Rat Liver

1958 ◽  
Vol 4 (6) ◽  
pp. 771-776 ◽  
Author(s):  
Mary L. Petermann ◽  
Mary G. Hamilton
Keyword(s):  
Body Weight ◽  
Rat Liver ◽  
Liver Tissue ◽  
Microsomal Protein ◽  
Male Rats ◽  
Differential Centrifugation ◽  
Adult Males ◽  
Analytical Ultracentrifuge ◽  
Total Rna ◽  
Adult Females

Rat liver was homogenized in 0.88 M sucrose. The DNA and total RNA were determined, and the homogenate was fractionated by differential centrifugation. The pellets obtained between 30 minutes at 20,000 g and 180 minutes at 105,000 g were analyzed for RNA and nitrogen. The ribonucleoproteins were determined in the analytical ultracentrifuge. The non-pellet RNA was calculated by difference. The results are reported as amounts per 6.7 x 10-9 mg. of DNA. In young, growing male rats the amounts of microsomal protein and ribonucleoprotein B (83S) increased with age. Non-pregnant adult females showed less non-pellet RNA and much more ribonucleoprotein C (63S) than did adult males. During pregnancy both of these cell constituents reverted to levels characteristic for male animals. Starvation for 5 days resulted in a reduction in the mass of liver tissue, the non-pellet RNA, the microsomal protein, and ribonucleoproteins B and C. During recovery from starvation the return of the liver to normal paralleled the rate at which body weight was restored. Treatment with cortisone, 25 mg. per rat per day for 5 days, caused an increase in microsomal protein and a decrease in ribonucleoprotein B. Treatment with 6-mercapto-purine, 50 mg. per kilo per day for 5 days, caused little change in liver composition in either males or females.

Nutrient reserve dynamics of lesser snow geese staging at James Bay, Ontario

1979 ◽  
Vol 57 (1) ◽  
pp. 213-219 ◽  
Author(s):  
Ronald C. P. Wypkema ◽  
C. Davison Ankney
Keyword(s):  
Body Weight ◽  
Follicular Development ◽  
James Bay ◽  
Fat Reserves ◽  
Adult Females ◽  
Snow Geese ◽  
Lesser Snow Geese ◽  
Nutrient Reserve ◽  
Breeding Grounds ◽  
Juvenile Males

We compared mean body weights, nutrient reserves (fat and protein), and an index of feeding of lesser snow geese arriving at and leaving southern James Bay in spring and fall 1976. Feeding increased in spring and decreased in fall. Body weight and protein of adults increased in spring, and fat reserves were maintained. The protein increase of adult females was equivalent to the protein in one egg. Ovarian follicular development in adult females appeared to proceed as reserves became available. Juvenile males had completed body growth by the end of the fall staging period but juvenile females had not. Fat and protein reserves of adults arriving on James Bay in the fall were significantly larger than those of adults after wing molt on the breeding grounds. Fat reserves of adults and juveniles increased significantly during the fall; body weight of juvenile females increased also. The fat gain greatly increases the theoretical maximum flight range of the geese and we suggest it is an important determinant of normal fall migration.

Reduced fecundity of Psoroptes ovis (Hering) (Acari: Psoroptidae) on calves treated with ivermectin

1984 ◽  
Vol 74 (4) ◽  
pp. 657-662 ◽  
Author(s):  
Frank S. Guillot ◽  
Fred C. Wright
Keyword(s):  
Body Weight ◽  
Reproductive Potential ◽  
Adult Males ◽  
Female Fecundity ◽  
Psoroptes Ovis ◽  
Adult Females

AbstractIvermectin injected subcutaneously into calves at the rate of 200 μ/kg body weight completely eliminated females of Psoroptes ovis (Her.) in 22 days. Injection of ivermectin also adversely affected the number and hatch of eggs and the proportion of adult males forming attachment pairs. The reduced number of eggs recovered in skin scrapings was apparently the result of a significantly lower fecundity among females that temporarily survived on treated calves. Females that were exposed to ivermectin for only three days did not recover their full reproductive potential even though they were transferred to calves not injected with ivermectin. The proportion of ovigerous females among survivors was not significantly affected five days after injection. Since the number of eggs recovered in skin scrapings was substantially reduced after only three days, the effect of ivermectin on female fecundity was not primarily gonadal. Reduction in the number of P. ovis eggs three days after treatment probably occurred because of a combination of mortality of adult females and reduced oviposition by ovigerous females surviving in the population.

Demography of a population of Peromyscus leucopus

1979 ◽  
Vol 57 (2) ◽  
pp. 323-328 ◽  
Author(s):  
Richard M. Harland ◽  
Peter J. Blancher ◽  
John S. Millar
Keyword(s):  
Peromyscus Leucopus ◽  
Adult Males ◽  
Adult Mice ◽  
Adult Females ◽  
Young Of The Year ◽  
Juvenile Males ◽  
Initial Capture

Livetrapping and removal trapping were used to monitor a population of Peromyscus leucopus. Breeding adult arid young of the year females averaged 2.0 and 1.1 litters per year, respectively. Nest mortality was 12–31%, while 58% of the juveniles disappeared within 2 weeks after weaning. The rate of disappearance of juvenile males (77%) was higher than that of juvenile females (44%); the greater loss of males was attributed to mortality. Loss of subadult and adult mice within 2 weeks after initial capture averaged 45 and 51%, respectively, and did not differ between the sexes. However, more males than females were recorded as entering the trapping grids, indicating that males tend to explore new areas more than females. Among resident mice, adult males had the highest rate of disappearance (0.31/week) while adult females had the lowest (0.05/week).

scholarly journals Microhabitat preferences of the freshwater prawn Macrobrachium jelskii (Decapoda: Palaemonidae)

2019 ◽  
Vol 109 ◽  
Author(s):  
Jersei N. Silva ◽  
Guilherme de Oliveira ◽  
Sérgio S. da Rocha
Keyword(s):  
Sex Ratio ◽  
Water Reservoir ◽  
Habitat Choice ◽  
Freshwater Prawn ◽  
Adult Males ◽  
Adult Females ◽  
Males And Females ◽  
Microhabitat Preferences ◽  
Lower Depth ◽  
Juvenile Males

ABSTRACT We analyzed the microhabitat preferences of Macrobrachium jelskii (Miers, 1877) males and females inhabiting an urban water reservoir in Cruz das Almas, Bahia, Brazil. Prawns were collected monthly, from March 2015 to February 2016, in three microhabitats, using a sieve. Each microhabitat was dominated by one macrophyte species: Eleocharis sp. (M1), Cabomba sp. (M2), and Nymphaea sp. (M3). The prawns were measured (carapace length), and categorized as juvenile males, adult males, juvenile females, non-ovigerous adult females and ovigerous adult females. An analysis of variance (ANOVA) was used to compare the number and size of individuals. The sex ratio and frequency of ovigerous females in the three microhabitats were also calculated. The sex ratio was biased towards females in M1 and did not deviate from 1:1 in M2 and M3. When prawns were separated into five categories we observed that non-ovigerous adult females were more abundant in M1, while adult males were the most abundant demographic category in M2 and M3. Juveniles of both sexes and ovigerous females showed no microhabitat preference, although M1 and M2 appeared to be more suitable for the latter. Adult females were the largest individuals in all microhabitats. Food availability, lower depth and lower predation pressure in M1 are the main factors that make M1 more suitable for M. jelskii, particularly non-ovigerous adult females and larger adult males. Intraspecific competition for shelter in M1 might also occur and adult females win this competition due to their larger body size. Therefore, adult males are found in higher abundance in M2 and M3 and the juvenile of both sexes spread evenly across all microhabitats. Our results help to understand the ecological role and the niche used by M. jelskii. Future studies on the habitat choice and predation under laboratory conditions should help to understand the behavior of this species.

Morphological variation in deer mice in relation to sex and habitat

1987 ◽  
Vol 65 (3) ◽  
pp. 527-533 ◽  
Author(s):  
Xuhua Xia ◽  
John S. Millar
Keyword(s):  
Body Length ◽  
Tail Length ◽  
Deer Mice ◽  
Body Measurements ◽  
Adult Males ◽  
Adult Females ◽  
Foot Length ◽  
Hind Foot ◽  
Similar Body ◽  
Juvenile Males

Peromyscus maniculatus borealis were collected in two habitats with contrasting physiognomic features in the Kananaskis Valley, Alberta, in the summer of 1983. We tested for differences between sexes and habitats using 4 body measurements (body length, tail length, hind foot length, and ear length) and 10 cranial (including mandibular) measurements of 222 and 192 adult P. m. borealis, respectively. Body measurements of 132 juveniles and five cranial (including mandibular) measurements from 124 juvenile skulls were analysed similarly. When differences in body length were controlled, adult males had significantly longer hind feet than adult females. The mandible was also significantly longer in adult males than in adult females. We interpreted the longer hind foot length in adult males as an adaptation to provide greater mobility, and the differences in mandibular morphology as a consequence of differential habitat use between the two sexes. No significant differences were found between juvenile males and females. Sexual dimorphism appeared to be age dependent rather than size dependent when adults and juveniles of similar body size were analysed.

Population dynamics of a thelastomatid nematode of cockroaches

Parasitology ◽  
1988 ◽  
Vol 96 (2) ◽  
pp. 353-368 ◽  
Author(s):  
S. Zervos
Keyword(s):  
Adult Female ◽  
Egg Production ◽  
Goodness Of Fit ◽  
Host Size ◽  
Infection Prevalence ◽  
Adult Males ◽  
Chi Square ◽  
Faecal Pellets ◽  
Adult Females ◽  
Juvenile Males

SummaryBlatticola monandros Zervos lives in the hind gut of the endemic New Zealand cockroach Parellipsidion pachycercum Johns. A field survey showed that infection prevalence was high (54 %) in small nymphs and increased further with cockroach size to a maximum (92 %) in penultimate nymphs. Variance to mean ratios and the Chi-square test for goodness of fit of a Poisson distribution provide strong evidence that the distribution of the nematode was not clumped (over-dispersed) or Poisson (random) but under-dispersed in most host size classes. The modal infrapopulation type consisted of 1 adult male and 1 adult female. Other infrapopulations were transitional to this type. Monogamous infrapopulations increased in prevalence with increased host size. Juvenile males were uncommon and probably develop faster into adults than juvenile females. Infrapopulations with 2 juvenile males were very rare and no cockroach contained 2 adult males, although some contained 2 adult females. Seasonal variations in prevalence and infrapopulation structure were slight over a 3 year period, except during one unusually dry summer. During the drought, prevalence of monogamous infrapopulations and of transitional infrapopulations were lowest, while prevalence of single-worm and single-sex infrapopulations were greatest. It is evident that competition between females reduces fecundity. When only 1 adult female nematode is present in an adult cockroach, more eggs are produced than the total produced if 2 adult females are present. Eggs were produced cyclically with short periods of high egg production interspersed with several days of very low or no egg production. Most eggs produced on any one day were attached to the outer surface of only 1 of the up-to-6 faecal pellets produced by the host/day. Mechanisms which may regulate infrapopulations and control reproductive competition and cyclical egg production are discussed. It is suggested that B. monandros regulates its own infrapopulation.

scholarly journals Influence of elevated ambient temperature upon some physiological measurements of New Zealand White rabbits

2011 ◽  
Vol 56 (No. 4) ◽  
pp. 180-186 ◽  
Author(s):  
L. Ondruska ◽  
J. Rafay ◽  
AB Okab ◽  
MA Ayoub ◽  
AA Al-Haidary ◽  
...  
Keyword(s):  
Body Weight ◽  
New Zealand ◽  
Mortality Rate ◽  
Blood Cell ◽  
Ambient Temperature ◽  
Feed Intake ◽  
Control Group ◽  
Adult Males ◽  
Adult Females ◽  
Experimental Group

This study was conducted to investigate the effect of heat stress (i.e., elevated ambient temperature &ndash; Ta; 36 &deg;C &plusmn; 3 &deg;C) on growth performance, mortality rate, and on some haematological and biochemical parameters in different categories of gender and age of New Zealand White (NZW) rabbits. Animals were divided into two main groups (control and treatment), in each group there were 56 rabbits: adult females (n = 20), adult males (n = 4), growing females (n = 16), and growing males (n = 16). Results revealed that total and daily feed intake, feed conversion ratio, and total and daily gain in body weight for growing NZW rabbits were affected negatively by elevated Ta. Decreases in feed intake led to less protein biosyntheses and less fat deposition, which led to lower body weight gain. These observations were made in growing and adult rabbits of both genders. Analysis showed that red blood cell (RBC) counts showed alterations. Packed cell volume (PCV) (in adult females and males), white blood cell (WBC) counts (in growing females), lymphocytes (in growing males), monocytes (in growing females and adult males), basophils (in growing females and growing and adult males) were significantly (P &lt; 0.05) decreased, and total proteins (TP) (in adult females), glucose (Glu) (in adult females), and calcium (Ca<sup>2+</sup>) (in growing males and females) were significantly (P &lt; 0.01) lower in the experimental group. Furthermore, elevated Ta increased the mortality rate (MR) in both age groups. The mortality rate was 30.36% for growing and adult rabbits of the experimental group, compared with 7.14% for the control group, and was 25% for adult compared with 34.38% for growing experimental rabbits. Exposure of NZW rabbits of both ages and genders to elevated ambient temperature (36&deg;C &plusmn; 3 &deg;C), negatively affected their internal homeostasis which was reflected in their growth rate and various physiological signs.

scholarly journals Comparison of the population biology of Epialtus bituberculatus from two rocky shores with distinct hydrodynamic patterns

2012 ◽  
Vol 93 (3) ◽  
pp. 693-702 ◽  
Author(s):  
Samara de Paiva Barros-Alves ◽  
Douglas Fernandes Rodrigues Alves ◽  
Valter José Cobo
Keyword(s):  
Normal Distribution ◽  
Population Biology ◽  
Carapace Width ◽  
Wave Exposure ◽  
Rocky Shores ◽  
Adult Males ◽  
Adult Females ◽  
Size At Sexual Maturity ◽  
Sargassum Cymosum ◽  
Juvenile Males

The population biology of Epialtus bituberculatus was compared between two different intertidal localities with differing levels of wave exposure. Sampling was conducted monthly between January and December, 2001 on seaweed banks of Sargassum cymosum in the intertidal zone of the rocky shores Grande (GR) (23°23′S–45°03′W) and Domingas Dias (DD) (23°29′S–45°08′W). Four hundred and twenty-eight crabs were captured at the GR site: 111 juvenile males, 106 adult males, 57 juvenile females, 17 adult females and 137 ovigerous females; while 455 specimens were obtained at the DD site: 76 juvenile males, 113 adult males, 37 juvenile females, 40 adult females and 189 ovigerous females. The population from GR showed a non-normal distribution and from DD a normal distribution. The sex-ratio (female/male) was 1:0.97 at GR (χ2 = 0.77, P = 0.084), whereas it was 1:1.41 at DD (χ2 = 13.03, P < 0.001). The largest individuals occurred at DD (U = 78249.0, P < 0.001). The estimated size at sexual maturity was 6.3 and 5.0 mm carapace width (CW) for males, and 5.4 and 5.2 mm CW for females, from GR and DD, respectively. The observed differences in E. bituberculatus between the studied localities might be explained by the different degrees of wave exposure between sites. However, other factors that might also explain the observed differences (e.g. temperature, salinity and food availability) cannot be discarded as relevant in influencing the population structure between sites herein studied.

scholarly journals Chemical characterisation of potential pheromones from the shoulder gland of the Northern yellow-shouldered-bat, Sturnira parvidens (Phyllostomidae: Stenodermatinae)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7734
Author(s):  
Chris G. Faulkes ◽  
J. Stephen Elmore ◽  
David A. Baines ◽  
Brock Fenton ◽  
Nancy B. Simmons ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Solid Phase ◽  
Species Recognition ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Components ◽  
Volatile Components ◽  
Adult Males ◽  
Mature Adult ◽  
Adult Females ◽  
Juvenile Males

Bats of the genus Sturnira (Family Phyllostomidae) are characterised by shoulder glands that are more developed in reproductively mature adult males. The glands produce a waxy secretion that accumulates on the fur around the gland, dyeing the fur a dark colour and giving off a pungent odour. These shoulder glands are thought to play a role in their reproductive behaviour. Using gas chromatography–mass spectrometry, we analysed solvent extracts of fur surrounding the shoulder gland in the northern-shouldered bat, Sturnira parvidens to (i) characterise the chemical composition of shoulder gland secretions for the first time, and (ii) look for differences in chemical composition among and between adult males, sub-adult/juvenile males and adult females. Fur solvent extracts were analysed as liquids and also further extracted using headspace solid-phase microextraction to identify volatile components in the odour itself. Odour fingerprint analysis using non-metric multidimensional scaling plots and multivariate analysis revealed clear and significant differences (P < 0.001) between adult males vs both juvenile males and adult females. The chemical components of the shoulder gland secretion included terpenes and phenolics, together with alcohols and esters, most likely derived from the frugivorous diet of the bat. Many of the compounds identified were found exclusively or in elevated quantities among adult (reproductive) males compared with adult females and non-reproductive (juvenile) males. This strongly suggests a specific role in male–female attraction although a function in male–male competition and/or species recognition is also possible.

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