M. R. Perrin

Fruiting in two afromontane forests in KwaZulu-Natal, South Africa: the habitat type of the endangered Cape Parrot Poicephalus robustus

Monthly fruiting data including general fruit-fall of species fruiting, and stage of fruit development and quantity of Podocarpus spp. were collected for two southern African afromontane forests, Hlabeni and Ingeli, over a period of three years. Fruits of the dominant Podocarpus species were the most abundant fruit resource at Hlabeni. The percentage of species fruiting (fruit-fall) differed significantly between months for each study site. Peak fruiting period, expressed as a percentage of species in fruit, occurred during winter months (June – August) and was lowest during spring (September – November). Peak fruiting production occurred during winter at Ingeli, but was not significantly different between months at Hlabeni. Most of the dominant canopy fruiting species, particularly the Podocarpus spp., showed unpredictable fruiting patterns. Fruiting periods were extended (greater than 2 months) in some species including the Podocarpus spp. However, total fruit production of some canopy fruiting species differed monthly rather than seasonally. During periods of low fruit production, spring, Kiggelaria africana and Ptaeroxylon obliquum were available. However, these are not keystone species as they are not a food source for avian frugivores, including Cape Parrots Poicephalus robustus.

Temperature regulation and activity pattern of the round-eared elephant shrew Macroscelides proboscideus

Abstract 1. 1. Oxygen consumption ( V O 2 ), thermal conductance ( C ), body temperature ( T b ) and evaporative water loss (EWL) of Macroscelides proboscideus were measured at air temperatures from 5 to 38°C. 2. 2. The lowest V O 2 was approximately that predicted for a eutherian of equal body weight. Minimal C was higher than predicted. EWL was high for an arid adapted small mammal. T b s were stable between 10 to 25°C but increased above 30°C. 3. 3. Captive elephant shrew activity was predominantly nocturnal, although animals were active both day and night. 4. 4. Temperature regulation does not show the usual trends found in arid adapted small mammals.

Comparative aspects of the thermal biology of the short-tailed gerbil, Desmodillus auricularis, and the bushveld gerbil, Tatera leucogaster

Abstract 1. 1. The response of oxygen consumption (VO 2 ), thermal conductance ( C d and C min , body temperature ( T b ), and evaporative water loss (EWL) of Tatera leucogaster and Desmodillus auricularis were measured over the range of ambient temperatures ( T a ) from 5–35°C. 2. 2. Basal metabolic rate (BMR) of T. leucogaster was 0.841 ± 0.049 ml O 2 g −1 h −1 and lower than predicted, while that of D. auricularis was similar to the expected value (1.220 ± 0.058 ml O 2 g −1 h −1 ). D. auricularis had a high, narrow thermoneutral zone (TNZ) typical of nocturnal, xerophilic, burrowing rodents. 3. 3. D. auricularis and T. leucogaster regulated T b over the range T a = 5–35°C and kept EWL and dry thermal conductance at a minimum below the TNZ. However, the EWL of T. leucogaster increased rapidly above T a = 30°C. 4. 4. After comparison with data from other species, it was concluded that there is an optimum size for xeric, nocturnal, burrowing rodents.

THE THERMAL BIOLOGY OF THE WHITE-TAILED RAT MYSTROMYS ALBICAUDATUS, A CRICETINE RELIC IN SOUTHERN TEMPERATE AFRICAN GRASSLAND

This study examines the hypothesis that Mystromys albicaudatus, a cricetine relic in southern Africa, has thermal characteristics typical of a rodent adapted to a cold temperature regime. Metabolic rate (oxygen consumption) of M. albicaudatus was measured using open-flow respirometry at ambient temperatures ranging from 5 degrees C to 35 degrees C. Lowest specific oxygen consumption was 1.352 +/- 0.089 ml O2 g-1hr-1 (n = 8; body mass = 93.78 +/- 6.27 g) at 25 degrees C, equivalent to 121.8% of the predicted value of Kleiber (1975), 128.8% of the value predicted for eutherians and 113.7% of the value predicted for cricetidae (Hayssen and Lacy, 1985).

Diet of serval Felis serval in a highland region of Natal

Serval Felis serval diet was determined using faecal analysis. A combination of quantification techniques best illustrated the relative importance of various prey species. Small mammals (Rodentia and Insectivora) accounted for 94% of prey item occurrences. Otomys irroratus was the most important prey species in terms of biomass and number. There was no evidence for servals eating lambs or other medium-sized mammals in the study area.

Thermal biology and water turnover rate in the Cape gerbil, Tatera afra (Gerbillidae)

Abstract 1. 1.|Oxygen consumption ( V O 2 ), thermal conductance (Cd and Cmin), body temperature (Tb) and evaporative water loss (EWL) of the Cape gerbil Tatera afra were measured at ambient temperatures (Ta) between 5 and 35°C. 2. 2.|T. afra is not well adapted to high Ta. Above 30°C, hyperthermia occurs, despite elevated Cd, Cmin and EWL. Peripheral vasodilation, salivation and urination are short term responses that contribute to delaying the onset of hyperthermia. 3. 3.|The water turnover rate (WTR) is higher (48%) in the field than in the laboratory owing to activity associated with foraging behaviour, predator avoidance and socialization. The relatively mild and mesic environment permits a higher WTR than in arid zone gerbils. 4. 4.|Basal metabolic rate (BMR) is higher (49%) than the average value for other cricetid rodents. It is hypothesized that this is associated with herbivory and a relatively low Ta.

Thermal parameters of serval Felis serval (Felidae) and blackbacked jackal Canis mesomelas (Canidae)

1. 1.|Oxygen consumption (VO2) and body temperature (Tb) of servals Felis serval and blackbacked jackals Canis mesomelas wer measured at ambient temperatures between 10 and 35°C. 2. 2.|F. serval has a broad thermoneutral zone, exhibits thermolability and relies on decreasing conductance to retain heat at low temperatures. 3. 3.|It is hypothesized that F. serval allows thermolability to conserve energy. 4. 4.|C. mesomelas has a definite thermoneutral zone and exhibits less thermolability than F. serval. 5. 5.|F. serval has a lower, and C. mesomelas a higher, than predicted basal metabolic rate based on body mass.

The thermal biology of three southern African elephant-shrews

1. 1. The thermal characteristics of Petrodromus tetradactylus, Elephantulus intufi and E. brachyrhynchus were investigated and compared with other elephant-shrews that occur in the southern African subregion. 2. 2. E. intufi and E. brachyrhynchus appear to have lower than expected basal metabolic rates (1.1185 ± 0.1623 and 0.9649 ± 0.1638 ml O2 g−1 h−1, respectively) and high, narrow thermoneutral zones, similar to other elephant-shrews investigated previously. In contrast P. tetradactylus has a basal metabolic rate (0.871 ± 0.027 ml O2 g−1 h−1) close to expected for body mass, and a broad, low thermoneutral zone. 3. 3. The thermal biology of macroscelids is discussed in terms of their distribution, microhabitat and body size.