Adaptive performance of hairy thin-tailed (Yankasa) and wooly fat-tailed (Ossimi) sheep in tropical hot-dry season

Abstract Background Fire is an important process that shapes the structure and functioning of African savanna ecosystems, and managers of savanna protected areas use fire to achieve ecosystem goals. Developing appropriate fire management policies should be based on an understanding of the determinants, features, and effects of prevailing fire regimes, but this information is rarely available. In this study, we report on the use of remote sensing to develop a spatially explicit dataset on past fire regimes in Majete Wildlife Reserve, Malawi, between 2001 and 2019. Moderate Resolution Imaging Spectroradiometer (MODIS) images were used to evaluate the recent fire regime for two distinct vegetation types in Majete Wildlife Reserve, namely savanna and miombo. Additionally, a comparison was made between MODIS and Visible Infrared Imager Radiometer Suite (VIIRS) images by separately evaluating selected aspects of the fire regime between 2012 and 2019. Results Mean fire return intervals were four and six years for miombo and savanna vegetation, respectively, but the distribution of fire return intervals was skewed, with a large proportion of the area burning annually or biennially, and a smaller proportion experiencing much longer fire return intervals. Variation in inter-annual rainfall also resulted in longer fire return intervals during cycles of below-average rainfall. Fires were concentrated in the hot-dry season despite a management intent to restrict burning to the cool-dry season. Mean fire intensities were generally low, but many individual fires had intensities of 14 to 18 times higher than the mean, especially in the hot-dry season. The VIIRS sensors detected many fires that were overlooked by the MODIS sensors, as images were collected at a finer scale. Conclusions Remote sensing has provided a useful basis for reconstructing the recent fire regime of Majete Wildlife Reserve, and has highlighted a current mismatch between intended fire management goals and actual trends. Managers should re-evaluate fire policies based on our findings, setting clearly defined targets for the different vegetation types and introducing flexibility to accommodate natural variation in rainfall cycles. Local evidence of the links between fires and ecological outcomes will require further research to improve fire planning.

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Effects of melatonin on cloacal temperature and erythrocyte osmotic fragility in layer hens during the hot-dry season

Journal of Applied Animal Research ◽

10.1080/09712119.2014.888003 ◽

2014 ◽

Vol 43 (1) ◽

pp. 52-60 ◽

Cited By ~ 10

Author(s):

Victor Olusegun Sinkalu ◽

Joseph Olusegun Ayo ◽

Ariyo Adelaja Abimbola ◽

Josiah Egbamushe Ibrahim

Keyword(s):

Osmotic Fragility ◽

Dry Season ◽

Erythrocyte Osmotic Fragility ◽

Hot Dry Season ◽

Layer Hens

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Effects of Ascorbic Acid on Diurnal Variations in Rectal Temperature of Shaver Brown Pullets During the Hot-Dry Season

International Journal of Poultry Science ◽

10.3923/ijps.2007.642.646 ◽

2007 ◽

Vol 6 (9) ◽

pp. 642-646 ◽

Cited By ~ 8

Author(s):

J.O. Ayo ◽

V.O. Sinkalu

Keyword(s):

Ascorbic Acid ◽

Rectal Temperature ◽

Dry Season ◽

Diurnal Variations ◽

Hot Dry Season

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Influence of sex, reproductive status and foetal number on erythrocyte osmotic fragility, haematological and physiologic parameters in goats during the hot-dry season

Veterinární Medicína ◽

10.17221/7778-vetmed ◽

2014 ◽

Vol 59 (No. 10) ◽

pp. 479-490 ◽

Cited By ~ 9

Author(s):

B. Habibu ◽

MU Kawu ◽

HJ Makun ◽

T. Aluwong ◽

LS Yaqub ◽

...

Keyword(s):

Heat Stress ◽

Rectal Temperature ◽

Osmotic Fragility ◽

Dry Season ◽

Corpuscular Haemoglobin ◽

Physiological Variables ◽

Erythrocyte Osmotic Fragility ◽

Hot Dry Season ◽

Mean Corpuscular Haemoglobin ◽

Twin Pregnancies

The current study was aimed at evaluating the effect of heat stress (during the hot-dry period) on some physiological variables, haematology and erythrocyte osmotic fragility (EOF) in bucks, pregnant (single and twin) and lactating Red Sokoto (RS) goats. Forty apparently healthy adult goats were used for the study and were allotted to four groups [bucks (n = 10), pregnant (n = 10) dry (n = 10), and lactating (n = 10) does]. The pregnant goats were further re-grouped according to number of foetuses (single foetus, n = 5 and twins, n = 5). The temperature-humidity index and physiological variables measured were significantly higher in the afternoon compared to morning hours. Pregnant does had higher respiratory and pulse rates than the dry does, but no significant change (P > 0.05) in rectal temperature was observed between groups. On the basis of sex, bucks had lower (P < 0.05) mean corpuscular volume (MCV) than other groups, in addition to having higher (P < 0.01) mean corpuscular haemoglobin (MCH) and total leucocyte counts than dry does. Pregnant does exhibited significantly lower (P < 0.05) packed cell volume, but significantly higher (P < 0.05) MCH and mean corpuscular haemoglobin concentrations (MCHC) than lactating does. Does with a single foetus had significantly lower (P < 0.05) MCV, but higher MCHC than does with twin pregnancies. Using EOF as a biomarker of oxidative stress, erythrocytes of bucks were significantly more resistant to hypotonic haemolysis than those of dry, pregnant and lactating does, with no significant difference in EOF between does of different groups. The erythrocytes of single and twin pregnancies showed similar haemolysis pattern. In conclusion, sex, lactation, and the number of foetuses carried by pregnant does significantly influences physiological and haematological variables in RS goats during the hot-dry season. Also, during heat stress, the changes in physiological variables seem to enhance favourable adaptation by preventing an increase in rectal temperature even in twin pregnancies.  

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Physiological responses of transported goats treated with ascorbic acid during the hot-dry season

Animal Science Journal ◽

10.1111/j.1740-0929.2007.00421.x ◽

2007 ◽

Vol 78 (2) ◽

pp. 164-172 ◽

Cited By ~ 35

Author(s):

Ndazo Salka MINKA ◽

Joseph Olusegun AYO

Keyword(s):

Ascorbic Acid ◽

Physiological Responses ◽

Dry Season ◽

Hot Dry Season

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Spacing behaviour and habitat use of axis deer (Axis axis) in lowland Nepal

Canadian Journal of Zoology ◽

10.1139/z94-234 ◽

1994 ◽

Vol 72 (10) ◽

pp. 1735-1744 ◽

Cited By ~ 29

Author(s):

Stein R. Moe ◽

Per Wegge

Keyword(s):

Home Range ◽

Major Effect ◽

Home Range Size ◽

Dry Season ◽

Range Size ◽

Home Ranges ◽

Axis Axis ◽

Hot Dry Season ◽

Sal Forest ◽

Axis Deer

A total of 17 axis deer (Axis axis) (12 females, 5 males) were radio-instrumented in Bardia National Park in lowland Nepal, and 1921 locations of females and 605 locations of males were obtained during the 2-year study period. Both the annual home ranges (135 ± 33 and 204 ± 38 (SD) ha for females and males, respectively) and the seasonal home ranges were quite small compared with those reported in another study in Nepal. We present evidence that this difference is due to a more fine-grained habitat mosaic in Bardia. Males used larger areas than females in the monsoon and the hot part of the dry season. The deer were sedentary, with a mean seasonal home range overlap between 49 and 86%, and seasonal occupancy centres were all located less than 1300 m apart. Mean seasonal home range size (68 and 110 ha for females and males, respectively) was smallest in the cool part of the dry season. The rutting period did not seem to have any major effect on the ranging behaviour, as neither males nor females increased home range size from the pre-rut to the rutting period. The deer used riverine forest preferentially during the cool-dry and hot-dry seasons, whereas sal forest was the preferred habitat during the monsoon and the cool-dry season. Grasslands were preferentially utilized by females at night during the hot-dry season, presumably because of improved forage quality following cutting and burning. Males were more associated with riverine and sal forest than were females, while females used grassland areas more than males did.

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