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Hot Dry Season (hot + dry_season)

Distribution by Scientific Domains

Life Sciences	75%

Selected Abstracts

Milk yields, physico-chemical properties and composition of milk from indigenous Malawi goats and their Saanen half-breds

INTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 3 2003
P.P. Mumba
Abstract A study to compare milk yield, some physico-chemical properties and the chemical composition of milk from 23 indigenous Malawi goats and 10 Malawi local × Saanen crosses was carried out from January to March 2000. The results showed that the average milk yield from the crosses (102.0 ± 11.21 kg) was higher (P < 0.01) than that from the indigenous goats (37.1 ± 4.79 kg). However, the pH and specific gravity of both milk samples did not differ significantly from each other. The latter was attributed to the fat and total solids contents, which did not differ significantly in the two milk samples. Although the crude protein content was not significantly different, lactose and minerals, namely calcium, sodium, magnesium, potassium and chloride, were higher (P < 0.01) in milk from the crosses than in milk from the indigenous goat. The results have shown that the levels of nutrients in goat milk are high, and this is indicative of its potential to improve the diets of rural Malawians. Also, as smallholder farmers sell raw unheated milk to the processing plants, such milk should not be kept for> 33 h in the cool dry season and for not> 20 h in the hot dry season. Farmers can also adopt a charcoal cooler to save the milk for an even longer time than they can at room temperature. In this case, the raw milk can only be stored for not> 20 h in the cool dry season and not> 16 h in the hot dry season. [source]

Daily and hourly movement of male desert-dwelling elephants

AFRICAN JOURNAL OF ECOLOGY, Issue 1 2010
Keith Leggett
Abstract The daily and hourly movements of eight male desert-dwelling elephants of various ages (12,45 years old) were determined hourly by global positioning system (GPS)/telemetry collars during the wet, cold dry and hot dry seasons of 2006 in northwest Namibia. The average daily movement in the wet season was greater than that observed during either the cold dry or the hot dry seasons. A similar difference was also observed for the movement rates, with the highest average rate of hourly movement recorded during the wet season. The diurnal movements (both distance and rate) were greater than those in the nocturnal hours during the wet season, whilst during the cold dry and hot dry season the reverse was true. The daily cycle of movement also changed seasonally, with greatest movement rates observed during the wet season between 11.00,20.00 hours, during the cold dry season between 14.00,21.00 hours; and between 04.00,11.00 hours during the hot dry season. Periods of decreased movement rates were observed between 09.00,10.00 and 02.00,03.00 hours in the wet season; 03.00,06.00 and 11.00,13.00 hours in the cold dry season; and 01.00,03.00 and 12.00,14.00 hours during the hot dry season. Résumé On a suivi heure par heure les déplacements quotidiens de huit éléphants du désert mâles, d'âge divers (12 à 45 ans), grâce à des colliers GPS (système de positionnement mondial) et télémétriques, au cours des saisons des pluies, sèche chaude et sèche froide de 2006, dans le nord-ouest de la Namibie. Le déplacement quotidien moyen durant la saison des pluies était supérieur à ceux observés en saison sèche froide ou en saison sèche chaude. Une différence semblable fut aussi observée pour le taux de déplacement, le taux moyen le plus élevé par l'heure étant enregistré pendant la saison des pluies. Les mouvements diurnes (aussi bien leur distance que leur rythme) étaient plus grands que les mouvements nocturnes en saison des pluies, alors que pendant la saison sèche froide et la saison sèche chaude, c'était l'inverse. Le cycle quotidien des déplacements changeait aussi avec les saisons, le rythme étant plus élevé en saison des pluies entre 11h00 et 20h00; en saison sèche froide entre 14h00 et 21h00; et en saison sèche chaude entre 04h00 et 11h00. On a observé des périodes de rythme ralenti entre 21h00 et 04h00 en saison des pluies; entre 03h00 et 05h00 et entre 11h00 et 13h00 en saison sèche froide; et entre 01h00 et 03h00 et entre 12h00 et 14h00 en saison sèche chaude. [source]

Activity budgets and activity rhythms in red ruffed lemurs (Varecia rubra) on the Masoala Peninsula, Madagascar: seasonality and reproductive energetics

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2005
Natalie Vasey
Abstract The activity budgets and daily activity rhythms of Varecia rubra were examined over an annual cycle according to season and reproductive stage. Given the relatively high reproductive costs and patchy food resources of this species, I predicted that V. rubra would 1) travel less and feed more during seasonal resource scarcity in an attempt to maintain energy balance, and 2) show sex differences in activity budgets due to differing reproductive investment. Contrary to the first prediction, V. rubra does not increase feeding time during seasonal food scarcity; rather, females feed for a consistent amount of time in every season, whereas males feed most during the resource-rich, hot dry season. The results are consistent with other predictions: V. rubra travels less in the resource-scarce cold rainy season, and there are some pronounced sex differences, with females feeding more and resting less than males in every season and in every reproductive stage except gestation. However, there are also some provocative similarities between the sexes when activity budgets are examined by reproductive stage. During gestation, female and male activity budgets do not differ and appear geared toward energy accumulation: both sexes feed and rest extensively and travel least during this stage. During lactation, activity budgets are geared toward high energy expenditure: both sexes travel most and in equal measure, and rest least, although it remains the case that females feed more and rest less than males. These similarities between female and male activity budgets appear related to cooperative infant care. The high energetic costs of reproduction in V. rubra females may require that they allot more time to feeding year round, and that their overall activity budget be more directly responsive to seasonal climate change, seasonal food distribution, and reproductive schedules. Am. J. Primatol. 66:23,44, 2005. [source]