Reproduction in the northern brown bandicoot (Isoodon macrourus) in the Australian Wet Tropics

2009 ◽  
Vol 57 (2) ◽  
pp. 105 ◽  
Author(s):  
Karl Vernes ◽  
Lisa Claire Pope
Keyword(s):  
Environmental Factors ◽  
Wild Population ◽  
Dry Season ◽  
Adult Males ◽  
Wet Season ◽  
Timing Of Reproduction ◽  
Adult Females ◽  
Wet Tropics ◽  
Almost All ◽  
The Tropics

We investigated timing of reproduction in a wild population of northern brown bandicoots (Isoodon macrourus) in the Australian Wet Tropics. Almost all births occurred during the late dry season and early wet season, and most adult females (78–96%) were carrying pouch young during those times. Litter sizes ranged from 1 to 6 pouch young (mean = 3.1) and was not influenced by season. Adult males had significantly larger testes in the late dry and early wet seasons, corresponding with the peak in births. Daylength was the only environmental factor that predicted the presence of a litter; when daylength exceeded 12 h, more than 70% of captured females were carrying pouch young, and most (94%) births were estimated to have occurred on days with >12 h of daylight. Various environmental factors have been proposed as a cue for breeding in I. macrourus, with daylength though to be the primary cue initiating breeding in temperate Australia, but temperature and rainfall thought to be more important in the tropics. Our data suggest that in the Australian Wet Tropics, increasing daylength in the late dry season acts as the primary cue for breeding.

The Biology of the Northern Brown Bandicoot, Isoodon-Macrourus (Marsupialia, Peramelidae) at Mitchell Plateau, Western-Australia

1989 ◽  
Vol 37 (6) ◽  
pp. 627 ◽  
Author(s):  
C Kemper ◽  
DJ Kitchener ◽  
WF Humphreys ◽  
RA How ◽  
LH Schmitt ◽  
...  
Keyword(s):  
Blood Cells ◽  
White Blood Cells ◽  
Breeding Population ◽  
Dry Season ◽  
Physiological Parameters ◽  
Adult Males ◽  
Wet Season ◽  
Young Females ◽  
Adult Females ◽  
Overall Ratio

Breeding, population dynamics and seasonal changes in physical and physiological parameters were examined in Isoodon macrourus at the Mitchell Plateau between September 1981 and November 1982. Females gave birth to litters of 2.5 � 1.0 (16) young between September and April. They produced up to three litters in a breeding season with an average interval between successive litters of 89.5 (51-108) days. Adult testosterone levels and scrota1 size began to increase in July and peaked in September 1982. The overall ratio of adult males to adult females was 1:0.54; it was 1:0.80 for pouch young. Females were more frequently trapped on sequential trips than were males. Density on the grids increased towards the end of the dry season (July and September 1982)-mostly as a result of increased numbers of females. Adult males and females moving onto the grids during the dry season tended to select different habitats. Adult males moved significantly more in the wet season (September 1981, January and April) than they did in the dry season (July and September 1982); they also moved significantly more than adult females in the wet season. Seasonal variations were recorded for most physical and physiological parameters. During the wet period from September 1981 to January 1982, body weight, haemoglobin, haematocrit and total plasma albumin declined, while total white blood cells and proportion of lymphocytes to granular leucocytes rose. This indicated that this period was one of change in condition for this species. Compared to adult females, adult males were larger and heavier, had higher values of haematocrit and lymphocytes, and lower values of granular leucocytes, free steroids, CBGBd and albumin bound corticosteroid. There was considerable between-year variability in condition of individuals and both sexes differed significantly in September 1981 and 1982 in their weight, haematocrit, total white blood cells, granular leucocytes, MCBC and testosterone. Individuals at disparate localities at the Mitchell Plateau showed similar seasonal physiological and physical responses, except for one grid where they were heavier.

On-farm performance of Bunaji (White Fulani) cattle 1. Herd structures and cattle disposal

1993 ◽  
Vol 57 (2) ◽  
pp. 199-209 ◽  
Author(s):  
J. E. O. Rege ◽  
R. R. von Kaufmann ◽  
R. I. Mani
Keyword(s):  
Seasonal Pattern ◽  
Herd Size ◽  
Dry Season ◽  
Adult Males ◽  
Wet Season ◽  
Social Functions ◽  
Adult Females ◽  
Arable Farming ◽  
Herd Structure ◽  
Milk Market

AbstractA study urns conducted to examine herd structures and cattle disposal patterns of Bunaji herds kept under traditional management at four locations in the subhumid zone of Nigeria. Sale for meat was the single most important disposal reason, accounting for proportionately 0·55 of all disposals. Mean age of cattle sold for meat was 8 years but the age range was wide: animals as old as 17·4 years were involved in such sales. Male animals were sold at a younger age (6·2 years) than females (9·3 years). Sale of calves was an important exit avenue for rural herds with less access to milk market. Calves were sold at a mean age of 1·1 years and male calves accounted for a larger proportion (0·62) of such sales. Animal sales were highest in the early dry season and lowest in the early wet season. The predominantly arable farming location, Ganawuri, had the highest frequency of animal sales and lowest frequency of exits for ‘social functions’ (exchanges, transfers and gifts). Animal transfers, gifts and exchanges were important disposal routes in the traditionally pastoral communities, especially in locations with good grazing (e.g. Abet). Exits involving exchanges, transfers and gifts were more frequent during the dry season and least frequent in the wet season. An average herd had 77 head of cattle composed proportionately of 0·54 adult females (>3 years), 0·13 adult males (>3 years), 0·08 young bulls (1 to 3 years), 0·13 heifers (1 to 3 years) and 0·11 calves (0 to 1 year). There was a tendency toward smaller herds in later years (97 in 1980 to 51 in 1989) and a decrease in the ratio of adult females to males (from 6:1 in 1980 to 3:1 in 1989). Substantial between-location differences existed in herd size ami herd structure, ranging from the ‘beef orientation’ of the arable Ganawuri with a high proportion of immatures and calves, to the pastoral situation in Abet and Kurmin Biri with high proportion of adult animals. The proportions of adults were lowest in the early dry season, reflecting seasonal pattern in disposal and calving. The pattern in disposal reasons over time indicated a decrease in the proportion of animals exiting herds through exchanges, transfers and gifts and signified a possible shift from tradition, probably a response to population pressures and emergence of cash economies.

scholarly journals Timing of emergence and cave return, and duration of nocturnal activity in an endemic Malagasy fruit bat

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Riana V. Ramanantsalama ◽  
Steven M. Goodman
Keyword(s):  
Ecosystem Services ◽  
Body Condition ◽  
Dry Season ◽  
Adult Males ◽  
Nocturnal Activity ◽  
Wet Season ◽  
Fruit Bat ◽  
Adult Females ◽  
Narrow Passage ◽  
Age And Sex

Bats emerge from their day roost after dusk and different factors can affect the timing of departure, return, and duration of nocturnal activities. This study provides information on the time of emergence and return of an endemic Malagasy fruit bat, Rousettus madagascariensis, in a cave located in the Réserve Spéciale d’Ankarana, northern Madagascar. Individuals were captured in a narrow passage between the roost and cave exit and capture time for each individual was noted. Variation according to sex, age, and body condition, as well as the influence of season, and the sunset and sunrise time were analyzed. During the dry season, individuals started to emerge at 1913 hours and returned to the cave generally by 0505 hours; the duration of time outside the cave during the dry season was higher in adult females (0952 hours) followed by subadult males (0937 hours), sub-adult females (0931 hours), and adult males (0910 hours). During the wet season, individuals exited at 1926 hours and returned at 0351 hours; as in the dry season, adult females spent more time outside the cave (0833 hours), than sub-adult females (0800 hours), and adult males (0752 hours). The period of emergence varied according to the age and sex classes, and time of predawn return associated with the previous nocturnal activity. The period of return was influenced by season, and age and sex classes. Such information is useful to quantify shifts in bat ecology, especially for endemic species with limited distribution or those playing an important role in ecosystem services.

Fate of urea-nitrogen from cattle urine in a pasture-crop sequence in a seasonally dry tropical environment

1985 ◽  
Vol 36 (6) ◽  
pp. 809 ◽  
Author(s):  
I Vallis ◽  
DCI Peake ◽  
RK Jones ◽  
RL McCown
Keyword(s):  
Soil Depth ◽  
Soil Surface ◽  
Dry Season ◽  
Wet Season ◽  
Mineral N ◽  
Seasonally Dry ◽  
15N Urea ◽  
Almost All ◽  
Crop Sequence

The fate of urea-N in cattle urine applied during the dry season (in August) to the pasture phase of a pasture-crop sequence at Katherine, N.T., was investigated. Cattle urine labelled with 15N-urea was applied to three sets of microplots to measure the following parameters: (a) amount and distribution of 15N remaining in the microplots during the remainder of the dry season with 0, 0.5, 1.0 and 5.0 t ha-1 of pasture residues present initially; (b) the effect of placing the urine 5 cm below the soil surface on the amount of 15N remaining during the dry season; (c) uptake of 15N by the pasture during the early part of the wet season (October to December) and uptake by sorghum sown directly into the killed pasture in January. Residual 15N in the surface soil (0-15 cm) after the sorghum crop was also measured. Of the applied 15N, 26% was lost after 1 day, 32% after 7 days and 46% after 63 days. Losses were not affected by the amount of pasture residues on the microplots when the urine was applied. Almost all of the I5N remaining in the microplots was in the 0-7.5-cm layer of soil, and 65-75% of this was mineral N. The dry-season losses of 15N were presumably through volatilization of ammonia, because leaching was absent and no loss of 15N occurred when the urine was placed 5 cm below the soil surface. Pasture growth killed at the end of December contained 6.2% of the applied 15N, the sorghum crop recovered only a further 2.1%, and after harvest of the sorghum crop the 0-15.0-cm layer of soil contained 23%. Thus about half of the 15N remaining in the soil-plant system to the 15.0 cm soil depth at the end of the dry season disappeared during the following wet season, either as a gaseous loss or by leaching deeper into the soil.

Seasonal variations in the fat content and size of Glossina swynnertoni Austen.

1961 ◽  
Vol 51 (4) ◽  
pp. 705-713 ◽  
Author(s):  
J. P. Glasgow ◽  
E. Bursell
Keyword(s):  
Time Lag ◽  
Fat Content ◽  
Dry Season ◽  
Adult Males ◽  
Progressive Decrease ◽  
Causal Interpretation ◽  
Wet Season ◽  
Pupal Development ◽  
Saturation Deficit ◽  
Glossina Swynnertoni

A population of Glossina swynnertoni Aust., at Shinyanga, Tanganyika, has been studied in respect of size and fat content of non-teneral males by monthly samples over a period of 13 years.Flies are large from February to July and small from August to January, and this change in size suggests an effect of the wet season (December to May) and dry season (June to November) upon the parent females, allowing for the time-lag of two months representing pupal development and mean age of adult males at capture. Male flies have more fat in the rains and less in the dry season and it is possible that similar changes in the nutritional status of females are responsible for the observed size changes.The correlation found in earlier work between the size of male flies in any month and saturation deficit two months earlier is confirmed, but reasons are given for rejecting a simple causal interpretation of this correlation.Since 1951, there has been a progressive decrease in size of G. swynnertoni in the area studied, more especially as regards those produced in the dry season.

scholarly journals Yields of Organically Grown Sweet Pepper Cultivars and Lines during the Hot-wet and Cool-dry Season in the Tropics

2009 ◽  
Vol 19 (2) ◽  
pp. 418-422 ◽  
Author(s):  
Peter Juroszek ◽  
Hsing-Hua Tsai
Keyword(s):  
Organic Farming ◽  
Farming Systems ◽  
Sweet Pepper ◽  
Dry Season ◽  
Viable Alternative ◽  
Conventional Farming ◽  
Wet Season ◽  
Commercial Cultivars ◽  
The Tropics ◽  
Cool Dry Season

Organic production is considered by many researchers to be a viable alternative to conventional farming systems. Equivalent yields already have been demonstrated in several studies. The major objective of our study was to collect data on total and marketable fruit yields of sweet pepper (Capsicum annuum) under organic farming conditions in the tropics. Experiments were conducted during the hot-wet season from 7 Mar. 2007 to 30 July 2007 and during the cool-dry season from 27 Nov. 2007 to 7 Apr. 2008. The six experimental entries included four commercial F1 hybrids and two genotypes bred at AVRDC–The World Vegetable Center (Shanhua, Taiwan). During the hot-wet season, high total (44.6–55.7 t·ha−1) and marketable yields (36.9–45.6 t·ha−1) were achieved under organic farming conditions in the open field similar to yields of conventionally produced sweet pepper in previous field experiments at AVRDC. The total yield of the commercial cultivars Queen Star and Hercules exceeded 50 t·ha−1; however, this was not significantly different compared with the other trial entries. During the cool-dry season, the total (25.4–45.7 t·ha−1) and marketable yields (21.1–37.8 t·ha−1) of all trial entries were reduced, probably because the relatively late planting date in November and relatively low air temperature resulted in reduced fruit set. The commercial cultivars Andalus and Green Bell Improved realized in both seasons a total fruit yield of more than 40.0 t·ha−1, suggesting that these can be grown successfully in hot-wet and cool-dry seasons. The relatively high yields of sweet pepper achieved on-station under tropical climatic conditions may encourage farmers and agricultural stakeholders to consider organic farming approaches as a viable alternative to conventional farming systems.

7.3 Intensive mutton and wool production in the tropics

1981 ◽  
Vol 4 ◽  
pp. 407-410
Author(s):  
Marca Burns
Keyword(s):  
Dry Season ◽  
Kitchen Waste ◽  
Traditional Methods ◽  
Sheep And Goats ◽  
Wool Production ◽  
Door Opening ◽  
Small Family ◽  
Almost All ◽  
The Tropics

As with other species, traditional methods of sheep husbandry in the tropics are almost all extensive, usually involving shepherding on unfenced pastures in bush or even desert grazings. However, in both Nigeria and Ghana, it is not uncommon for small family flocks of sheep, or sheep and goats, to be confined to the compound behind the house. A room with a door opening on to the compound (either a part of the house or in another corner) is set aside to provide shelter from rain. The flock is fed partly on kitchen waste, such as plantain and cassava peelings, and partly on cut grass or the leaves of trees, the latter particularly in the dry season.

Survival of unfedRhipicephalus appendiculatus(Acarina: Ixodidae) in relation to host resistance and environmental factors in Kenya

1990 ◽  
Vol 80 (3) ◽  
pp. 251-258 ◽  
Author(s):  
J.W. Chiera ◽  
D.K. Punyua
Keyword(s):  
Environmental Factors ◽  
Host Resistance ◽  
Initial Period ◽  
Rhipicephalus Appendiculatus ◽  
Dry Season ◽  
Survival Times ◽  
Wet Season ◽  
Weather Factors ◽  
Hot Dry Season ◽  
Similar Survival

AbstractMean survival times for unfed ticks,Rhipicephalus appendiculatusNeumann exposed initially during the hot dry season (January) in Kenya were significantly higher than those of ticks exposed during the wet season (May). This was partly due to the timing of the next hot dry season which triggered the beginning of decline in survival, and partly due to the overall severity of the weather. The implication is that the time when the ticks feed affects the survival of the subsequent instar. The mean survival times for nymphs exposed initially during the wet and the hot dry seasons were 30 weeks and 44 weeks, respectively. Those for adult ticks ranged between 59–75 weeks and 62–79 weeks, respectively. Maximum survival times were, however, similar for adults but not for nymphs. Adult ticks had an initial period of 32–48 weeks of excellent survival, apparently independent of weather factors. Thereafter, mortality rates and adverse environmental factors were correlated. The survival of ticks fed on hosts of differing resistance status was also different. The most resistant host produced the smallest adult ticks and these gave the lowest survival, and vice versa. Male and female ticks from highly resistant hosts had similar survival, but the females from a moderately resistant host survived significantly better than the males. These results indicate the importance of weather and host resistance inR. appendiculatussurvival.

scholarly journals Life in a harsh environment: the effects of age, sex, reproductive condition, and season on hair cortisol concentration in a wild non-human primate

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9365
Author(s):  
Paul A. Garber ◽  
Anna McKenney ◽  
Evelyn Bartling-John ◽  
Júlio César Bicca-Marques ◽  
María Fernanda De la Fuente ◽  
...  
Keyword(s):  
Dry Season ◽  
Cortisol Concentration ◽  
High Rate ◽  
Northeastern Brazil ◽  
Hair Cortisol ◽  
Wet Season ◽  
Common Marmosets ◽  
Wild Mammals ◽  
Juvenile Mortality ◽  
Adult Females

Hair cortisol concentration (HCC) provides a long-term retrospective measure of hypothalamic–pituitary–adrenal axis activity, and is increasingly used to assess the life history, health and ecology of wild mammals. Given that sex, age, season and pregnancy influence HCC, and that it may indicate ongoing stress, we examined HCC in common marmosets (Callithrix jacchus) naturally inhabiting a hot and dry semi-desert like habitat, Caatinga, in northeastern Brazil. We trapped, measured, weighed, marked and collected shaved hair from the back of the neck of 61 wild marmosets during the wet and dry seasons. Using enzyme immunoassay, we found that HCC was higher in the dry season compared with the wet season among all age/sex classes. Females had significantly higher HCC than males, juveniles had higher HCC than adults, and reproductively active adult females and non-pregnant/non lactating adult females did not differ in HCC. There were no interaction effects of sex, age, group, or season on HCC. The magnitude of the effect of this extremely hot and dry environment (average yearly rainfall was only 271 mm) on HCC in common marmosets is difficult to ascertain as these animals are also experiencing a variety of other stressors. However, the elevated HCC seen in common marmosets during the 5–8 month dry season, suggests these primates face an extended period of heat, water and possibly nutritional stress, which appears to result in a high rate of juvenile mortality.

scholarly journals Seasonal Fluctuations In Luteinizing Hormones (lh), Follicle Stimulating Hormones (FSH) And Testosterone Levels In Male African Giant Rats.

2020 ◽  
Vol 2 (2) ◽  
pp. 161-170
Author(s):  
O. S Olawuwo
Keyword(s):  
Dry Season ◽  
Wet Season ◽  
Luteinizing Hormones ◽  
Testosterone Levels ◽  
Sexual Activities ◽  
In Captivity ◽  
And Performance ◽  
Follicle Stimulating Hormones ◽  
Cricetomys Gambianus ◽  
The Tropics

As part of the several efforts to understand the biology of the African Giant rats (AGR) (Cricetomys gambianus), seasonal changes in the gonadotropin and testosterone levels of the adult male African giant rats of about 1 – 1½ years of age in captivity were investigated during wet and dry seasons in the tropics. Male giant rats (n = 10) were kept for 12 months and blood samples were collected monthly (on 15th of each month), during the dry (November – February) and wet (March – June) seasons for Luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone assays. The hormones’ levels were evaluated to suggest the best breeding season for giant rat in South-West Nigeria. The result showed that there were significant variation (p<0.001) in LH and FSH levels in the giant rat in the wet season when compared with the dry season. However, testosterone level was significantly lower (p<0.001) in the wet season than in the dry season. The study showed that sexual activities in the male AGR might be higher in the dry season with peak activities in December in the tropics while the gonadotropins prepare the animals for sexual activities in the dry season. Further studies on the seasonal activities of gonadotropins in the female will give more insight into the sexual receptivity and performance in these animals.

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