D. W. Yalden

CATALOGUE OF THE MAMMALS OF ETHIOPIA

SUMMARYThe present work lists 32 species of carnivore which certainly occur within the borders of Ethiopia, while Poecilictis libyca (Hemprich & Ehrenberg, 1833) probably extends marginally into th...

Catalogue of the mammals of Ethiopia and Eritrea. 7. Revised checklist, zoogeography and conservation

This review of the Ethiopian and Eritrean mammal fauna recognises provisional totals of 277 terrestrial and 11 marine species. The terrestrial fauna is dominated by savanna forms (47.2% of the total), most of which are widespread but with significant numbers being derived from either the East African savannas or the sub-Saharan savanna belt. Deserticolous species (16.2%) include many which are clearly associated with the Somali-arid zone. The 29 endemics are almost exclusively confined to the central plateaux at altitudes in excess of 1800 m and most are denizens of grassland or moorland habitats; few are forest species. Sylvicolous mammals are equally poorly represented amongst non-endemic forms (6.5%) and it is concluded that Ethiopian forests have an impoverished fauna compared with those of Uganda and Zaire. Conservation of wildlife, perennially starved of resources, has suffered greatly from neglect, poaching and destruction of property during the political crises of recent years. This situation is n...

Golden Plover Pluvialis apricaria breeding success on a moor managed for shooting Red Grouse Lagopus lagopus

Capsule The best estimate of breeding success was a mean of 0.57 fledglings per pair, which when combined with adult survival rates, successfully explained the observed population trend. Aims To quantify Golden Plover breeding success on a moor managed for shooting Red Grouse Lagopus lagopus. Methods An intensive study recorded the fate of individual Golden Plover nests and, using radiotelemetry, chicks. The factors associated with mortality were examined, allowing the construction of a model of breeding success. Adult survival was estimated from return rates of colour-ringed birds. Results Estimated rates of daily nest survival during laying (0.8636) were significantly lower than during incubation (0.9913). The daily survival rate of chicks less than nine days (0.8868) was significantly lower than for older chicks (0.9792). A population model based on these parameters overestimated the rate of nest losses, but accurately described brood survival and fledging success. Although predation rates were low, poor survival of young chicks through starvation or exposure suggest other factors were limiting breeding success at the study site. Conclusions Predation rates of Golden Plover nests and chicks can be low on moorlands managed for shooting Red Grouse. However, in the absence of predation, other factors may still reduce chick survival and limit breeding success.

The effect of resurfacing the Pennine Way on recreational use of blanket bog in the Peak District National Park, England.

Abstract The effects on the level of recreational disturbance of resurfacing a stretch of the Pennine Way have been quantified. Resurfacing appears to have resulted in a two fold increase in the number of visitors using the improved stretch of the Pennine Way. Following resurfacing, 3·8% of walkers strayed from the path, compared to over 30% before the footpath was altered. Thus, despite the increased pressure along the route of the footpath, the overall level of recreational disturbance to the surrounding moorlands has fallen dramatically. The pattern of use throughout the day and the season, and the extent to which poorly supervised dogs accompany the walkers, have changed little, compared with a previous survey. The implications of this successful management of disturbance along the Pennine Way for other sensitive areas are discussed.

Decline of the Merlin in the Peak District

As a breeding species, the Merlin has almost disappeared from the Peak District. A discussion of causes singles out pesticides as probably the most important factor.

Difficulties of counting breeding Golden Plovers Pluvialis apricaria

Capsule Commonly used methods of surveying Golden Plover may be less accurate than previously thought.

SOME OBSERVATIONS ON THE GIANT MOLE-RAT TACHYORYCTES MACROCEPHALUS (RÜPPELL, 1842) (MAMMALIA RHIZOMYDAE) OF ETHIOPIA

SUMMARY The available material of the giant mole-rat Tachyoryctes macrocephalus (Ruppell, 1842) has been examined and compared with material of T. splendens (Ruppell, 1835) from Ethiopia, leading to a clearer understanding of the differences between them. T. macrocephalus is much larger, reaching a body weight of at least 900 g; most of its skull measurements are also larger, but its incisors are relatively and the interorbital width absolutely narrower than in T. splendens. Additional skull characters which separate the two races of T. macrocephalus confirm their status as subspecies. Observations were also made on the behaviour of a small colony of giant mole-rats, and on other aspects of their biology. Individuals spend up to 47 min gathering food and up to 18 min shovelling earth at the surface in a day; in total, the animals in the colony, probably six adults and one immature, were exposed at the surface for 165 and 178 min on 2 successive days. The food gathered included both grasses and dicotyledon...

The Archaeological Record of Birds in Britain and Ireland Compared: Extinctions or Failures to Arrive?

AbstractThe archaeological evidence can help to discriminate between species which never arrived on islands, the species that once were present but later became extinct, and the species that only arrived late, because of human introduction, or human modification of the island to provide suitable habitat. The archaeological record from Ireland is sufficient to allow some useful comparisons with Great Britain, identifying species (e.g. Capercaillie: Tetrao urogallus L., Black Grouse: T. tetrix (L.), Great Spotted Woodpecker: Dendrocopus major (L.)) which were once present but have probably been lost through deforestation, and others whose archaeological record is sufficient in Britain to indicate with moderate confidence that they never occurred in Ireland (e.g. Tawny Owl: Strix aluco L.).

The effect of habitat geology on calcium intake and calcium status of wild rodents

SummaryCalcium is essential for normal physiological function, reproduction and growth in mammals but its distribution in the natural environment is heterogeneous. Spatial variation in calcium soil content is especially marked in the Peak District, United Kingdom, where both calcium-rich limestone and calcium-poor gritstone rock types occur. Wood mice Apodemus sylvaticus (L) and bank voles Clethrionomys glareolus (Schreber 1780) from limestone areas had significantly higher calcium concentrations in stomach contents and in faeces compared with their counterparts from gritstone areas. Calcium status was assessed from serum calcium concentration, femur weight, ash content of the body, calcium concentration in the femur and body ash. There was no significant difference in serum calcium concentration, femur calcium concentration and body ash calcium concentration between animals from the limestone and the gritstone. However, on the limestone, bank voles, but not wood mice, had significantly heavier femora and a greater proportion of ash in the body compared with their gritstone counterparts.

The effect of variation in calcium intake on the growth of wood mice and bank voles

SummaryCalcium intake by wild rodents varies with season and habitat. This may have important ecological consequences; several studies have suggested that calcium availability may limit growth and reproduction. We studied the effect on growth of varying the calcium intake of captive wood mice Apodemus sylvaticus (L.) and bank voles Clethrionomys glareolus (Schreber 1780). To determine whether effects observed in the laboratory could be detected in free-living animals, we also compared the body weights and lengths of free-living animals on calcium-poor gritstone areas with those of rodents on calcium-rich limestone habitats where the dietary calcium concentration was between 2 and 5 times higher. Captive wood mice fed high calcium (0.87%) diet grew at the same rate as mice fed low calcium (0.30%) diet but continued growing for longer, thereby achieving higher asymptotic weights. In contrast, captive bank voles fed the high calcium diet grew more slowly and had lower asymptotic weights than voles fed the low calcium diet. As expected from the laboratory growth study, the higher calcium intake of free-living wood mice on the limestone was associated with greater body size compared with mice on the gritstone. However, bank voles were also larger on the limestone, even though high calcium intake impaired growth in captive animals. The contrast between wood mice and bank voles in the effects of calcium on growth, the reason why impaired growth may not be apparent in bank voles from calcium-rich habitats and the ecological significance of these results are discussed.