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A note on the diet of the rock elephant shrew, Elephantulus myurus, in Zimbabwe
Journal of Zoology
... Sengis are insectivorous and preferentially feed on ants and termites (Churchfield, 1987;Kerley, 1995;Kerley, Knight, & Erasmus, 1990). The colonies of these insects are likely to be unevenly distributed due to intra-and inter-specific competition between ants and termites, but also depending on fluctuating resource availability (Lindsey & Skinner, 2001;Radford & Andersen, 2012). ...
... It may also be that fewer suitable habitats were available, due to the rainfall and flooding potentially destroying previously used patches. Due to the habitat specialization as well as the specialized diet of our species (Churchfield, 1987;Kerley, 1995;Kerley et al., 1990;Skinner & Chimimba, 2005), disrupted or destroyed patches in an already segregated landscape could lower density but force the few surviving animals to cluster around the isolated intact resource patch. Habitat quality, kin associations, and resource availability were not measured, however, so it is not clear which was the more likely factor resulting in the observed density and distances. ...
Limiting resources often differ between males and females. Reproductive success in females is constrained by resources such as food and shelter, while the availability of receptive females determines male reproductive success. In addition to limiting resources, low intra‐sexual tolerances among females can affect their spacing. High intolerances coinciding with low population densities have been suggested as a cause for the evolution of monogamy in mammals, but the evidence for female intolerance is limited. We investigated long‐term space use patterns (measured as home range sizes and centers of activity) in a wild population of eastern rock sengis (Elephantulus myurus) from Limpopo, South Africa. Between March 2012 and March 2016, we recorded capture locations for 93 sengis and home range size for 22 sengis and evaluated the contributions of study year, sex, and season on these measures. Sex had no significant effect on home range size, but ranges were significantly greater during the breeding compared to the non‐breeding season, consistent with the increased energetic demands during reproduction. We found corroborative support for the role of energetic demands on home range size fluctuations. The activity centers of female–female dyads were further apart than those of male–male or mixed‐sex dyads, suggesting lower female–female tolerances in the study species. Our results offer evidence that intolerances may affect female spacing behavior and may have contributed to the evolution of monogamy in sengis.
... Members of the order Macroscelidea, usually referred to as elephantshrews or sengis, are endemic to Africa (Skinner and Chimimba 2005). Elephantulus myurus is insectivorous and feeds mainly on ants and termites (Churchfield 1987). Like most sengis, E. myurus is monogamous (Ribble and Perrin 2005) and females almost always give birth to twins, which are highly precocial (van der Horst 1946). ...
... Smith, 1834)). In contrast to most rodents, E. myurus is insectivorous and consumes primarily ants and termites (Churchfield 1987). Willis et al. (1992) observed that more termites were ingested by the aardvark (Orycteropus afer (Pallas, 1766)) in summer than in winter, suggesting that termites are more readily available during the rainy season. ...
Many mammals use the change in day length to time physiological and behavioural activities on a seasonal basis. Particularly, mammals from temperate regions use photoperiod to regulate reproductive functions; however, information on the role of photoperiod in small mammals from the tropics and subtropics is scarce. We studied the response of the reproductive system of male eastern rock sengis (Elephantulus myurus Thomas and Schwann, 1906) from southern Africa to photoperiods of differing length. Elephantulus myurus breeds seasonally during the spring and summer months of the southern hemisphere despite its subtropical distribution. It is one of only three sengi species known to breed seasonally. Fourteen male E. myurus were subjected to either long-day (LD; 16 h light (L) : 8 h dark (D)) or short-day (SD; 8 h L : 16 h D) photoperiods and the photoperiodic effects on the testes, testosterone concentration, and body mass were examined. Testicular volume and mass, seminiferous tubule diameter, and body mass were not significantly different between LD and SD conditions. However, plasma testosterone concentration was significantly lower in males on LD photoperiods compared with SD photoperiods. Male E. myurus may not use photoperiod as a cue to control seasonal reproductive changes. Other environmental factors such as temperature, rainfall, food abundance, or social factors are possibly influencing seasonal reproduction in this species.
... The diet of European water shrew (Neomys fodiens bicolor) is composed mainly of lumbricids, isopods and dipterans (Churchfield, 2009). Isopterans (termites) and formicids were found to be the most frequent food items in the diet of elephant shrews (Elephantulus myurus; Churchfield, 1987). Lepidoptera larvae are the most common prey for masked shrew (Sorex cinereus) (Bellocq & Smith, 2003;McCay & Storm, 1997), followed by Coleoptera (beetles) and Aranea (spiders). ...
Diet analysis of potential small mammals pest species is important for understanding feeding ecology and evaluating their impact on crops and stored foods. Chinese mole shrew (Anourosorex squamipes), distributed in Southwest China, has previously been reported as a farmland pest. Effective population management of this species requires a better understanding of its diet, which can be difficult to determine with high taxonomic resolution using conventional microhistological methods. In this study, we used two DNA metabarcoding assays to identify 38 animal species and 65 plant genera from shrew stomach contents, which suggest that A. squamipes is an omnivorous generalist. Earthworms are the most prevalent (>90%) and abundant (>80%) food items in the diverse diet of A. squamipes. Species of the Fabaceae (fre-quency of occurrence [FO]: 88%; such as peanuts) and Poaceae (FO: 71%; such as rice) families were the most common plant foods identified in the diet of A. squa-mipes. Additionally, we found a seasonal decrease in the diversity and abundance of invertebrate foods from spring and summer to winter. Chinese mole shrew has a diverse and flexible diet throughout the year to adapt to seasonal variations in food availability, contributing to its survival even when food resources are limited. This study provides a higher resolution identification of the diet of A. squamipes than has been previously described and is valuable for understanding shrew feeding ecology as well as evaluating possible species impacts on crops. K E Y W O R D S Chinese mole shrew, ecology of pest, metabarcoding, molecular diet analysis, seasonal diet changes
... In mice, for which the EIA was developed, the chosen assay was able to detect a fGCM response following the same ACTH doses used in the present study in both males and females (Touma et al. 2003(Touma et al. , 2004. However, sengis are phylogenetically ancient mammals and are not closely related to rodents but insectivorous (Churchfield, 1987), which may explain the different results observed in the present study in comparison to mice. Further studies would be required to determine the presence and relative abundance of respective immunoreactive steroids in male and female sengi excreta and if required a suit of additional assays would need to be tested to identify a potentially better performing assay for determining fGCM concentrations in male sengi. ...
Non-invasive methods for measuring glucocorticoids and their metabolites are frequently used in ecological, behavioural and physiological studies of mammals. Using faeces, urine and other matrices for such a measurement has considerable advantages in comparison to more traditional methods, but also requires thorough validation of the methods used. Eastern rock sengis (Elephantulus myurus) are fascinating African mammals and the non-invasive monitoring of the adrenocortical activity opens up new opportunities to study their biology. We were able to validate two assays for measuring urinary (uGCM) and faecal glucocorticoid metabolite (fGCM) concentrations in this species using a dose-dependent challenge with adrenocorticotropic hormone (ACTH). A higher concentration of ACTH elicited higher uGCM and fGCM concentrations in both males and females. Interestingly, uGCM and fGCM concentrations and the responses to ACTH were higher in females than in males and small changes in faecal glucocorticoid metabolites could not be reliably detected in males. In contrast to ACTH, a saline injection did not result in an increase in uGCM or fGCM concentrations. The study also provided insight into when responses to a stressor are likely to be detected in the urine and faeces of sengis and opens up new opportunities to study the stress physiology of this and other sengi species. It further emphasises the importance of thoroughly validating non-invasive methods for measuring hormones in both sexes of a species and for incorporating dose-dependent approaches.
... E. myurus favoured mealworms over sunflower seeds, and almost ignored alfalfa pellets. Churchfield (1987) reported on invertebrates forming 60-100% by volume of its diet (largely ants and termites), and plant material comprising the remainder (up to 40% by volume). Micaelamys namaquensis harvested mostly sunflower seeds, followed by similar proportions of alfalfa pellets and mealworms. ...
We investigated the role of diet and substrate features in the coexistence and habitat affinities of the rock elephant shrew, Elephantulus myurus, and the Namaqua mouse, Micaelamys namaquensis. We measured giving-up densities at experimental food patches that varied in foraging substrate, escape substrate surrounding the food patch and food type. In terms of food consumption, E. myurus favoured pebble (63% total harvest) over sand and sawdust, whereas M. namaquensis favoured foraging in sand (48% total harvest) over sawdust (29%) and pebbles (23%). Mealworms comprised most of E. myurus's harvest, and M. namaquensis harvested seeds the most, followed by alfalfa and mealworms. In terms of escape substrates, M. namaquensis had significantly higher GUDs when the food patch was surrounded by tussocks of sedge (average 28.11 seeds/patch) than rock surfaces (17.41) or by bush/crevice (14.36). In conjunction with morphologic adaptations, E. myurus detects and recovers food using its snout and long tongue, and M. namaquensis digs and handles foods with its forepaws. The different foraging preferences of E. myurus and M. namaquensis suggest that the interaction of substrates with food types characterize their niches and promote coexistence. Elephantulus myurus travelled greater distances, whereas M. namaquensis was selective for microhabitats offering refuge or traction.
... E. myurus favoured mealworms over sunflower seeds, and almost ignored alfalfa pellets. Churchfield (1987) reported on invertebrates forming 60-100% by volume of its diet (largely ants and termites), and plant material comprising the remainder (up to 40% by volume). Micaelamys namaquensis harvested mostly sunflower seeds, followed by similar proportions of alfalfa pellets and mealworms. ...
We investigated aspects of the foraging behaviour and activity patterns of free-ranging common duikers (Sylvicapra grimmia) within the Soutpansberg, South Africa. We used giving-up densities (GUD) and camera traps to test for habitat selection and patch-use behaviour by common duikers inhabiting a grassland containing distinct 'islands' of woody vegetation. Foraging in or around a wooded island was affected by its surrounding vegetation. GUDs were significantly lower in portions dominated by tall grass and scattered ferns and highest in areas with open short grass and thick fern. Using grids of 5 9 5 stations, we mapped the duikers' foraging on a larger scale that incorporated neighbouring rocky hillsides. The duikers preferred feeding in areas with tall grass and scattered fern (sufficient cover and escape routes), followed by the wooded islands and thick fern (lack of sightlines/escape routes and presence of predator-ambush sites), whereas little foraging occurred at the edges and rocky areas (hard substrate that impede escape potential). Photos (total 873) revealed solitary activity, highest in the late afternoon. Photos of vigilant individuals were mostly from rocky and fern habitats. Our results suggest that the duikers allocated their feeding efforts, activity and vigilance patterns to attune to their perceived risk of predation within their heterogeneous environment.
Of the eighteen sub‐Saharan elephant‐shrew species, only eastern rock elephant‐shrews reproduce seasonally throughout their distribution, a process seemingly independent of photoperiod. The present study characterizes gonadal status and location/intensity of GnRH‐1 and kisspeptin immunoreactivities in this polyovulating species in the breeding and non‐breeding seasons. GnRH‐1‐immunoreactive (ir) cell bodies are predominantly in the medial septum, diagonal band and medial preoptic area; processes are generally sparse except in the external median eminence. Kisspeptin‐ir cell bodies are detected only within the arcuate nucleus; the density of processes is generally low, except in the septohypothalamic nucleus, ventromedial bed nucleus of the stria terminalis, arcuate nucleus and internal and external median eminence. Kisspeptin‐ir processes are negligible at locations containing GnRH‐1‐ir cell bodies. The external median eminence is the only site with conspicuously overlapping distributions of the respective immunoreactivities and, accordingly, a putative site for kisspeptin's regulation of GnRH‐1 release in this species. In the non‐breeding season in males, there is an increase in the rostral population of GnRH‐1‐ir cell bodies and density of GnRH‐1‐ir processes in the median eminence. In both sexes, the breeding season is associated with increased kisspeptin‐ir process density in the rostral periventricular area of the third ventricle and arcuate nucleus; at the latter site this is positively correlated with gonadal mass. Cross‐species comparisons lead us to hypothesize differential mechanisms within these peptidergic systems: that increased GnRH‐1 immunoreactivity during the non‐breeding season reflects increased accumulation with reduced release; that increased kisspeptin immunoreactivity during the breeding season reflects increased synthesis with increased release.
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We used live-trapping and foraging to test for the effect of habitat selection and diet on structuring a community of six small mammals and one bird within the Soutpansberg, South Africa. We established grids that straddled adjacent habitats: woodland, rocky hillside, and grassland. Trapping and foraging were used to estimate abundance, habitat use, and species-specific foraging costs. The species with the highest abundance and foraging activity in a habitat, activity time, or food was considered the most efficient and presumed to have a competitive advantage. All species exhibited distinct patterns of spatial and temporal habitat preference which provided the main mechanism of coexistence, followed by diet selection. The study species were organized into three assemblages (α diversity): grassland, Rhabdomys pumilio, Dendromus melanotis, and Mus minutoides.; woodland, Aethomys ineptus and Micaelamys namaquensis; and rock-dwelling, M. namaquensis and Elephantulus myurus. Francolinus natalensis foraged in open rocky areas and under wooded islands within the grassland. Species organization across the habitats suggested that feeding opportunities are available within all habitats; however, distinct habitat preferences resulted from differing foraging aptitudes and efficiencies of the competing species. At Lajuma, species distribution and coexistence are promoted through distinct habitat preferences that were shaped by competition and species-specific foraging costs. The combination of trapping and foraging provided a mechanistic approach that integrates behavior into community ecology by 'asking' the animal to reveal its perspective of the environment. Using spatial and temporal foraging decisions-as behavioral indicators-enables us to guide our understanding for across-taxa species coexistence.
In highly seasonal environments animals that use daily torpor usually do so during the rest phase. In subtropical and tropical environments, however, daily torpor may not necessarily be confined to the animals' rest phase. Animals may display torpor during the active phase. We investigated the daily rhythms and seasonal rhythms of body temperature (Tb) in normothermic and torpid free-ranging rock elephant shrews Elephantulus
myurus at Weenen Game Reserve, KwaZulu-Natal, South Africa. Tbs were recorded using miniature dataloggers from May 2001 to May 2002. Daily patterns of Tb in normothermic E.
myurus suggested polyphasic Tb patterns that nevertheless suggested a rest phase that was coincident with the daytime. When the elephant shrews used torpor, the lowest Tbs were observed during the night-time, such that torpor was used during the coldest part of the night and arousal was associated with the 3-h period around sunrise. We suggest that the principal benefit of a flexible daily rhythm of Tb was that it facilitated arousal by passive exogenous heating using ambient temperature cycles.
Field expeditions between 1986 and 1989 yielded information about the distribution of macroscelids in Tanzania. The rare Elephantulus brachyrhynchus was captured in a natural habitat complex of miombo woodland, Combretum savanna and grassland in Dakawa, Tanzania. Basic ecological data for this species were obtained from 46 animals in a removal-trapping study and 58 in a live-trapping study.
Sex ratio was near to parity. There was no evidence of a restricted reproductive period, although pregnancy incidence was higher around January-February. Litters in utero comprised one or two embryos. E. brachyrhynchus had a preference for the transitional Combretum savanna. Stomach contents analysis showed a remarkably high proportion of green plant material in the diet.
Elephant-shrews were classified as Insectivora and were traditionally considered to be insectivorous, although ancestral forms were herbivorous. Despite the presence of a functional caecum, many authors still describe elephant-shrews as insectivorous. Three data sets, totalling 143 samples, of the Round-eared Elephant-Shrew Macroscelides proboscideus diet from the semi-arid Karoo, South Africa, were analysed. Results indicate that this species is largely insectivorous, although plant matter makes up almost 45% of the diet by volume. Diet varies seasonally, with the intake of herbage peaking in winter, when herbage may comprise up to 97% of the diet The contribution of insects to the diet was not related to either insect availability (as indexed by pit-trapping) or body condition, suggesting that Round-eared Elephant-Shrews may be true omnivores, selecting a diet of both insects and herbage. The relatively long large intestine of this species of elephant-shrew may not be related to the water requirements, but may be a plesiomorphic character that has been retained as a consequence of the higher degree of omnivory displayed by Round-eared Elephant-Shrews, which appear to consume more plant matter than the other elephant-shrews.
(1) The relationship between seasonal food availability and the diet of Sorex araneus in scrub-grassland was investigated using pitfall traps and soil/vegetation core sampling for invertebrates and analysis of shrew faecal pellets. (2) A wide variety of prey was taken by shrews but the major prey types in all seasons were adult coleopterans, insect larvae, araneids, opilionids and isopods. (3) A mean of 40.8% of prey taken were less than or equal to 5 mm in body length, but very few were smaller than 3 mm. This was correlated with the preponderance of small invertebrates, particularly staphylinids, in the soil/vegetation cores. (4) The diet of S. araneus showed no correlation with the relative activity of prey on the ground surface. (5) There was little correlation between seasonal prey availability and the diet of shrews, but an increase in abundance of adult coleopterans was accompanied by an increase in predation by shrews. (6) The decrease in population density and body weight of shrews in winter was not accompanied by a decrease in biomass or numbers of invertebrate prey.
Notes on East African Mammalia (other than horned ungulates) collected or kept in captivity 1915–1919. Part 2
- Loveridge A.
Seasonal feeding habits of small mammals in Kenya
- Neal B. R.
Mammals of the Transvaal
- Rautenbach I. L.