Ecology of the Northern Bettong, Bettongia tropica, a Tropical Mycophagist

1997 ◽  
Vol 24 (5) ◽  
pp. 549 ◽  
Author(s):  
C. N. Johnson ◽  
A. P. McIlwee
Keyword(s):  
Seasonal Variation ◽  
Body Condition ◽  
Forest Type ◽  
Dry Season ◽  
Wet Season ◽  
Hypogeous Fungi ◽  
Eucalyptus Forest ◽  
Seasonal Ecology ◽  
North Eastern ◽  
Open Woodland

The diet and seasonal ecology of the northern bettong, Bettongia tropica, was studied at three sites along a moisture gradient from closed Allocasuarina-Eucalyptus forest to dry open woodland in north-eastern Queensland. At each site, fungi (sporocarps of hypogeous ectomycorrhizal species) were the major food, and most of the remainder of the diet consisted of grass leaf and stem, roots and tubers, and lilies. Forbs and invertebrates were also eaten, but in small quantities. Fungus consumption was greatest at the wettest forest type and least at the driest site. Seasonal variation was insignificant except at the driest site, where fungus consumption peaked in the late wet season and dropped during the dry season; this seasonal fall in fungus consumption was associated with an increase in consumption of grass and roots and tubers. There was little seasonal variation in body condition, except at the driest site, where the dry-season decline in the proportional representation of fungus in the diet was associated with a decline in body condition. Breeding was continuous and aseasonal. B. tropica is found only in a narrow zone of sclerophyll forest along the western edge of wet tropical rainforest in north-eastern Queensland. We suggest that this species (like bettongs and potoroos in southern Australia) depends on hypogeous fungi, and that expansion of its geographical range into drier forest types is prevented by shortages of fungus during the dry season.

Estimating seasonal abundance and habitat use of small carnivores in the Western Ghats using an occupancy approach

2014 ◽  
Vol 30 (5) ◽  
pp. 469-480 ◽  
Author(s):  
Riddhika Kalle ◽  
Tharmalingam Ramesh ◽  
Qamar Qureshi ◽  
Kalyanasundaram Sankar
Keyword(s):  
Habitat Use ◽  
Deciduous Forest ◽  
Forest Type ◽  
Camera Trap ◽  
Dry Season ◽  
Seasonal Abundance ◽  
Evergreen Forest ◽  
Wet Season ◽  
Palm Civet ◽  
Leopard Cat

Abstract:Rigorous population studies on many small carnivores are lacking in India. Presence-absence models with habitat covariates were applied to estimate seasonal occupancy and abundance of nine small-carnivore species from camera-trap data in Mudumalai Tiger Reserve (2010 and 2011). We deployed 25 camera-trap stations in the deciduous forest, 21 in the semi-evergreen forest and 26 in the dry thorn forest. In total, 7380 trap-nights yielded 448 photographs of small carnivores: jungle cat (n = 72), leopard cat (n = 6), rusty-spotted cat (n = 11), small Indian civet (n = 89), common palm civet (n = 37), brown palm civet (n = 20), stripe-necked mongoose (n = 66), ruddy mongoose (n = 96) and Indian grey mongoose (n = 51). In the dry season, rusty-spotted cat was the rarest carnivore with an average abundance (λmean) of 0.24 ± 0.26, while ruddy mongoose was the most abundant (λmean = 0.90 ± 0.40). In the wet season, leopard cat was the rarest species (λmean = 0.048 ± 0.041) while grey mongoose was the most abundant (λmean = 0.68 ± 0.35). Abundance of jungle cat, common palm civet, ruddy mongoose and grey mongoose increased in the dry thorn forest whereas in the dry season abundance of small Indian civet decreased in this forest type. Abundance of leopard cat and small Indian civet was not influenced by habitat in the wet season. Deciduous forest was positively associated with abundance of rusty-spotted cat. Deciduous and semi-evergreen forests had a positive effect on abundance of stripe-necked mongoose while the latter was a positive predictor of abundance and occupancy for brown palm civet. Improved modelling approaches can account for the spatio-temporal variation in habitat use of small carnivores occupying specialized niches in heterogeneous tropical forests of southern India.

scholarly journals Balami Sheep: Performance in North-Eastern Nigeria

2021 ◽  
Vol 17 ◽  
pp. 29-35
Author(s):  
V. Buvanendran ◽  
I. F Adu
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Survival Rates ◽  
Dry Season ◽  
Wet Season ◽  
North Eastern

Balami sheep is the largest indiginous breeds of sheep in Nigeria with a mature ewe weight of 43kg. The performance of this breed was studied using 454 lambing records of 142 ewes during a 6-year period. Lambing occurred throughout the year with a peak during the wet  season. First lambing was at 18 months of age and subsequent  lambing occurred at approximately 9 months intervals. Mean litter size increased from 1.02 at first lambing to 1.6 at 54 months years of age. Lambing interval was shorter by 50 days for lambing in the wet than in the dry season. Lamb mortality to 10 weeks of age was about 43%. Lambs born during the wet season those from primiparous ewes and twins had low survival rates. Mean birth weight was 3.3kg and weights at 4 and 10 weeks of age were 7.4 and 12.1kg respectively. Type of birth, age of dam and sex had significant effects on weights at all ages. Productivity of ewes estimated as weight of weaned lamb per kg metabolic weight per annum increased with the age of the ewe to about 55 months of age. Repeatability of litter size, lambing interval, birth and 10 weeks were 0.087, 0.091, 0.052 and 0.273 respectively.

scholarly journals Seasonal variation in quality of Louhajong river water, Tangail

2016 ◽  
Vol 28 (1) ◽  
pp. 9-16
Author(s):  
Md Rakib Hasan Sarker ◽  
Asadul Islam ◽  
Ariful Islam ◽  
Md Mahbubul Hoque ◽  
Shimul Roy
Keyword(s):  
Seasonal Variation ◽  
River Water ◽  
Water Samples ◽  
Dry Season ◽  
Fish Culture ◽  
Chemical Parameters ◽  
Wet Season ◽  
Physico Chemical ◽  
Standard Level

Water samples were collected from three points of Louhajong river (Dighulia, Kagmari Bridge and Oloa) to see the seasonal variation in physico-chemical parameters. The results revealed that some of the parameters such as TDS, alkalinity and acidity have exceeded the standard level in dry season in all of the points, which are unsuitable for different purposes including fish culture. During dry and wet seasons the highest concentrations of BOD was recorded as 2.0 and 0.8 ppm at Kagmari Bridge (point-2) respectively. DO ranged from 1.4 to 3.1 and 2.4 to 3.8 ppm during dry and wet seasons. Maximum and minimum EC was recorded as 890 and 130 ?s/cm at Dighulia (point-1) during dry and wet seasons. The results suggest that at wet season Louhajong river may be suitable for fish culture and other purposes.Bangladesh J. Sci. Res. 28(1): 9-16, June-2015

scholarly journals THE EFFECT OF SEASONAL VARIATION ON PERFORMANCE OF EGG TYPE POULTRY: A Case Study of Mitchell Farms, Mosogar, Delta State, Nigeria

2021 ◽  
Vol 24 (2) ◽  
pp. 101-105
Author(s):  
E. E. Guobadia
Keyword(s):  
Seasonal Variation ◽  
Feed Intake ◽  
Egg Production ◽  
Management Practices ◽  
Secondary Data ◽  
Dry Season ◽  
Wet Season ◽  
Egg Hatchability ◽  
Significant Difference

The study was designed to find out the effect of seasonal variation on poultry in Delta State of Nigeria. The variables considered were mortality rate, feed intake, egg production and egg hatchability in the wet and dry seasons of the year. Secondary data were also collected from records kept in the farm. Sites 4AHI-BLK,5AKI-BLK, 9H/BF and 10H/BF were used for the study with each having an average of 2,500-3,500 birds of the same breed and sex aged 1-9 weeks and 21-52weeks. The records were grouped into dry season (October-March) and wet season (April-September) covering three years, 1991-1994. The analysis of the result showed that seasonal variation does not have any significant effect (P < 0.05) on mortality and feed intake in the two seasons. However percentage egg production and egg hatchability revealed a significant difference (P < 0.05) between the two seasons, with a mean % egg production and hatchability of 74±.03 and 80.6 in the wet season and 53.67±0.01 and 55.9 respectively in the dry season. Recommendation is therefore made for proper planning which ensures the utilization of wet and dry season management practices to reduce the effect of high humidity and embient temperature on production.

scholarly journals The Cost of Reproduction in a Cooperatively Breeding Mammal: Consequences of Seasonal Variation in Rainfall, Reproduction, and Reproductive Suppression

2021 ◽  
Vol 12 ◽  
Author(s):  
Paul Juan Jacobs ◽  
Daniel William Hart ◽  
Tobias Suess ◽  
Andries Koch Janse van Vuuren ◽  
Nigel Charles Bennett
Keyword(s):  
Oxidative Stress ◽  
Seasonal Variation ◽  
Cost Of Reproduction ◽  
Dry Season ◽  
Breeding Period ◽  
Wet Season ◽  
Reproductive Suppression ◽  
Mole Rat ◽  
Cooperatively Breeding ◽  
The Cost

Biological investments, such as reproduction, are influenced by both biotic and abiotic factors and their interactions. The trade-off between reproduction and survival has been well established. Seasonally breeding species, therefore, may exhibit variations in these trade-offs, but there is a dearth of knowledge concerning this. This study investigated the physiological cost of reproduction (measured through oxidative stress) across seasons in the cooperatively breeding highveld mole-rat (Cryptomys hottentotus pretoriae), one of the few seasonal breeding mole-rats. Oxidative stress indicates elevated reactive oxygen species (ROS) levels, which can overwhelm antioxidant defences resulting in damaged proteins, lipids and DNA, which overall can reduce longevity and compromise reproduction. Oxidative markers such as total oxidant status (TOS-measure of total peroxides present), total antioxidant capacity (TAC), oxidative stress index (OSI), and malondialdehyde (MDA) are utilised to measure oxidative stress. In this study, breeding and non-breeding male (NBM) and female mole-rats were captured during the dry season (breeding period) and wet season (non-breeding period). There was an apparent cost of reproduction in the highveld mole-rat; however, the seasonality pattern to the cost of reproduction varied between the sexes. Breeding females (BFs) had significantly higher MDA during the breeding period/dry season in comparison to the non-breeding period/wet season; this is possibly a consequence of bearing and nursing offspring. Contrastingly, breeding males (BMs) showed increased oxidative damage in the non-breeding/wet season compared to the breeding/dry season, possibly due to increased activities of protecting their mating rights for the next breeding/dry season, but this was not significant. Interestingly, during the non-breeding period/wet season, non-breeding females (NBFs) are released from their reproductive suppression, which resulted in increases in TOS and OSI, which again indicated that just the mere ability to be able to breed results in a cost (oxidative stress). Therefore we can speculate that highveld mole-rats exhibited seasonal variation in redox balance brought about by variation in abiotic variables (e.g., rainfall), physiology and behaviour. We conclude that physiological changes associated with reproduction are sufficient to induce significant acute oxidative stress in the plasma of female highveld mole-rats, which become alleviated following transition to the non-breeding season/wet period suggesting a possible hormetic effect.

Prepartum supplementation effects on growth and fertility in Bos indicus-cross cows

1997 ◽  
Vol 37 (2) ◽  
pp. 141 ◽  
Author(s):  
G. Fordyce ◽  
L. A. Fitzpatrick ◽  
T. J. Mullins ◽  
N. J. Cooper ◽  
D. J. Reid ◽  
...  
Keyword(s):  
Body Condition ◽  
Post Partum ◽  
Bos Indicus ◽  
Late Pregnancy ◽  
Dry Season ◽  
Pregnancy Rates ◽  
Wet Season ◽  
Calf Growth ◽  
Treatment Groups ◽  
Calving Season

Summary. Three experiments were conducted in the dry tropics of north Australia using Bos indicus-cross cows. Cows in mid–late pregnancy were either unsupplemented during the late dry season or offered ad libitum (2 kg/day) molasses with 7.4% urea (w/w) (M8U) or cottonseed meal (1 kg/day) for up to 54 days commencing 2 months before the start of the calving season. Supplementation reduced weight loss in experiments 1 and 2 (P<0.05), but had no significant effect on weight or body condition in experiment 3. Supplementation had no effect on subsequent calf growth or cow lactation yields. Following early wet season rains in experiment 1, 9 and 49% of cows were ovulating 40 and 80 days post-partum, respectively, with no effect of supplementation. In experiment 2, 10 and 100% of cows had ovulated by 60 and 200 days post-partum, respectively. At any time between 80 and 180 days post-partum, supplemented cows were more likely to be cycling (P<0.05), independent of supplementation effects on weight or body condition. The average post-partum interval to oestrus was 30 days less in cows supplemented for 42 days (P = 0.08). In experiment 3, pregnancy rates in 1/2 and 3/4 Brahmans supplemented with M8U for 54 days (MU54) or whose calves were weaned at 2–3 months of age (WEAN) were 14% higher in the latter 2 months of mating than in cows supplemented for less than 40 days. Good seasonal conditions resulted in high pregnancy rates in all mature 5/8 Brahmans; when not weaned early, their average calving to conception interval (CCI) was 54 days (s.e. = 8.5 days). Pregnancy rates of first-lactation 5/8 Brahmans (average CCI of 125 days) supplemented for 39 days or less and weaned when calves averaged 6 months of age were 14–32% lower between 2 and 9 months post-partum than in contemporaries in the MU54 or WEAN treatment groups. It was concluded that dry-season supplementation of mid- to late-pregnant Bos indicus-cross cows with an energy concentrate for 42–54 days (‘spike’ feeding) may reduce post-partum anoestrus intervals via a mechanism which is not dependent on the effects on weight or body condition.

Seasonal variation in foraging behaviour of plains zebra (Equus quagga) may alter contact with the anthrax bacterium (Bacillus anthracis)

2014 ◽  
Vol 92 (4) ◽  
pp. 331-337 ◽  
Author(s):  
Zepee Havarua ◽  
Wendy C. Turner ◽  
John K.E. Mfune
Keyword(s):  
Seasonal Variation ◽  
Bacillus Anthracis ◽  
Foraging Behaviour ◽  
Dry Season ◽  
Wet Season ◽  
Contact Rates ◽  
Bacterium Bacillus ◽  
Environmental Pathogens ◽  
Host Foraging ◽  
Plains Zebra

Pathogens transmitted via the environment are often aggregated in space, and seasonal variation in wildlife foraging behaviour may alter contact rates with environmental pathogens. The soil-borne bacterium Bacillus anthracis Cohn, 1872 causes anthrax, and herbivores acquire gastrointestinal anthrax by ingesting spores. Therefore host foraging behaviour could be a fundamental component of anthrax epidemiology. This study investigated seasonal changes in bite density and diet of plains zebras (Equus quagga Boddaert, 1785) in relation to anthrax seasonality in Etosha National Park, Namibia, where most zebra anthrax cases are observed in wet seasons. The diet of zebras shifted from more short grasses during the wet season to more tall grasses in the dry season, suggesting a greater potential for soil ingestion in wet seasons. Zebras also foraged most intensively in the wet season with the number of bites/step declining through the dry season. This higher bite density in wet seasons may lead individuals to ingest greater concentrations of the pathogen if foraging in a localized infectious area. Although sex and reproductive state affected bite density, no sex difference in anthrax occurrence was observed. This study demonstrates how considering variation in host foraging behaviour may enhance our understanding of disease seasonality for pathogens with foraging-dependent transmission.

The Ecology of the Puparium of Glossina in Northern Nigeria

1939 ◽  
Vol 30 (2) ◽  
pp. 259-284 ◽  
Author(s):  
T. A. M. Nash
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Adult Population ◽  
Dry Season ◽  
Breeding Ground ◽  
Wet Season ◽  
Breeding Grounds ◽  
Open Woodland ◽  
Forest Islands

1. The female tsetse extrudes her larva on soils ranging from fairly heavy clay to coarse sand; the presence or absence of organic matter seems to be immaterial.2. The soil temperature varies greatly in different breeding-grounds in the dry season, but little in the rains.3. The soil water content varies greatly in different breeding-grounds in the rains, but little in the dry season.4. The soil water content in some of the breeding-grounds falls so low in the dry season that there can be no doubt that the atmosphere in these soils is below saturation.5. Evaporation measured at 5 inches above ground-level varies little from site to site; bigger and important differences occur at greater heights above the ground where the screening effects of thicket become operative.6. The seasonal changes are so great at Gadau that no one breeding-ground can satisfy the female's requirements throughout the year; instead, different breeding-places are selected for different seasons.7. The cycle for G. morsitans is as follows: In the rains breeding occurs under palm fronds and logs in the open woodland. In the early dry season breeding continues in the open woodland, but shifts from the palm and log sites to the small thickets; breeding also starts in the more open parts of the forest islands. At the beginning of the very hot weather all the thickets of the open woodland are evacuated, and breeding is confined to the densest parts of the forest islands. In the early rains the movement is reversed: breeding shifts out into the open woodland, and in the heavy rains is confined to the log and palm sites.This cycle fits in closely with the cycle for the seasonal concentration and dispersal of the adult population (Nash 1937, pp. 85–90).8. The major wet season breeding-ground of G. tachinoides is unknown, but the cycle is believed to be as follows: In the early dry season breeding shifts from the log, palm, and probably from the unknown site, to the small thickets and forest islands, and becomes maximal in the cold season. Breeding now decreases in all sites, suggesting that none is really suitable—a surmise which is strengthened when tremendous breeding activity starts in the river-bed, as soon as it becomes available at the beginning of the hot season. In the early rains this site is destroyed and breeding is believed to commence in the unknown site, as it certainly does under the logs and palms.

Transmission networks and ectoparasite mite burdens in Oecomys paricola (Rodentia: Cricetidae)

Parasitology ◽  
2020 ◽  
pp. 1-8
Author(s):  
Fernanda Rodrigues Fernandes ◽  
Somayra da Silva Abreu ◽  
Leonardo Dominici Cruz
Keyword(s):  
Spatial Organization ◽  
Dry Season ◽  
Absolute Difference ◽  
Contact Network ◽  
Wet Season ◽  
Transmission Networks ◽  
Eastern Brazil ◽  
Individual Host ◽  
North Eastern ◽  
Parasitic Burden

Abstract The host contact network structure results from the movement and behaviour of hosts (e.g. degree of sociability; vagility and greater or lesser fidelity of shelters), which can generate heterogeneity in the transmission of parasites and influence the parasitic burden of individual hosts. In the current study, we tested the hypothesis that the burdens of Gigantolaelaps oudemansi mites are related to the characteristics of the transmission networks of individuals of Oecomys paricola, a solitary rodent. The study was carried out in a savannah habitat in north-eastern Brazil. In the dry season, the rodent network presented sub-groups of rodent individuals interacting with each other, whereas in the wet season, no modules were formed in the network. Mite burden was positively related to the number of connections that an individual host had with other host individuals in the dry season. The pairwise absolute difference between the mean mite burdens among individual rodents was negatively correlated with the similarities of node interactions. No relationships were observed during the wet season. There was a higher heterogeneity of mite burden among hosts in the dry season compare to that in the wet season. In solitary species, spatial organization may show seasonal variation, causing a change in the opportunities of host contacts, thereby influencing the transmission and dispersion of their ectoparasite burdens.

scholarly journals Seasonal Variation and Ecological Risk Assessment of Heavy Metal in an Estuarine Mangrove Wetland

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2064
Author(s):  
Hualong Hong ◽  
Binghuang Zhang ◽  
Haoliang Lu
Keyword(s):  
Risk Assessment ◽  
Seasonal Variation ◽  
Metal Pollution ◽  
Toxic Metal ◽  
Dry Season ◽  
Wet Season ◽  
Mangrove Wetland ◽  
Mangrove Wetlands ◽  
Zn And Cu In ◽  
Potential Toxic Metals

Potential toxic metal pollution in mangroves has attracted extensive attention globally; however, the seasonal variation of potential toxic metals in mangrove wetlands is still poorly understood. Herein, we investigated the variation of content as well as chemical speciation of typical metals (Pb, Cr, Zn and Cu) in the sediments from the Zhangjiang Estuary mangrove wetland, China. The potential risk of metal contamination was also investigated. Compared to the wet season, we found that sediment metal content was higher in the dry season. Mangrove sites show accumulated significant metals than does the mudflat both in wet and dry seasons. Geo-accumulation (Igeo) shows moderate pollution, probably because of the dilution as result of runoff and tidal hydrodynamics in the wet season. Increased concentrations of all metals in the acid-soluble fraction and decreased metal contents in the residue fraction were found in the dry season. Risk assessment indicated that the concentrations of Pb poses a higher environmental risk in the dry season. These results can increase awareness of metal pollution in the dry season and provide information for potential toxic metal management in mangrove wetlands.

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