Guano

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The Species-Genus Relationship in Antillean Bat Communities

The ratio of the number of species to the number of genera in an island community has long been recognised as a potential proxy indicator of competitive interaction. An analysis of this relationship in the bat fauna of the Antillean archipelago demonstrates that the observed species-genus ratios are significantly depressed below null-model expectations, and that the magnitude of this depression is inversely proportional to the log of the appropriate island area. These observations are consistent with the hypothesis that interspecific competition may play an important role in structuring Antillean bat communities

Liverpool University Expedition to Jamaica

During summer 1977, five members of the Liverpool University Potholing Club spent six weeks working and exploring in the caves of Jamaica. The team consisted of Don McFarlane, John Dye, Malcolm Macduff, Mike Roger and Barry Williams, all of whom contributed to this report. The expedition base was at Troy, where the villagers are owed a debt of gratitude for their hospitality. This placed the expedition in the heart of the cave region, and a number of new caves and shafts were discovered and explored. The main discovery was the Still Waters Cave, located near Accompong, where 11,800 feet of passages were explored during the second half of the stay in Jamaica. Studies were carried out not only in the cockpit karst around Troy, but also in the Hellshire Hills and Portland Ridge karsts on the south coast of the island. In addition, a flying visit was paid to the John Crow Mountains near the eastern end of the island. A single stalactite adorned cave (Hog House Hole at Map Ref. 763 445) was discovered. Though only 30 feet long, this is significant, as it is one of the very few caves known in the John Crow Mountains, even though they consist of massive limestone in a high relief terrain with a high rainfall

Jamaican Cave Vertebrates

Limestone caves in the tropics are typically associated with a more diverse assemblage of vertebrates than are caves in temperate regions. Chapman [87] for example, has reported 37 species from the caves of Gunung Mulu National Park, Sarawak, whereas Bailey [43] lists only 13 for the equally cavernicolous Guadeloupe Mountains National Park, New Mexico, USA. Twenty-eight vertebrate species have been recorded from Jamaican caves. The relative importance of the five Classes differ in these three areas as shown in Table 1 (overleaf)

The Design of Oxygen Rebreather Equipment for Use in Foul-Air Speleology

The design of a lightweight oxygen rebreather set suitable for short duration explorations in foul-air caves is described, together with a discussion of its performance, limitations, and possible improvement

A Note on Sexual Dimorphism in Nesophontes Edithae (Mammalia: Insectivora), an Extinct Island-Shrew from Puerto Rico

The island-shrew, Nesophontes edithae Anthony 1916, Mean is the only Puerto Rican representative of the monogeneric family Nesophontidae

Patterns of Species Co-occurrence in the Antillean Bat Fauna

The bat fauna of 25 Antillean islands is presented as a species presence-absence matrix, and used to construct a large population of randomized null-model matrices by Monte-Carlo simulation techniques. Comparison of the observed data matrix with the randomized population reveals a statistically significant departure from randomness which is interpreted as evidence of community structure. The Antillean bat fauna is marked by a pattern of high species co-occurrence, with endemics dominating in the northern Antilles and undifferentiated South American taxa dominating in the southern Antilles. The \u27checkerboard\u27 distributions which have been identified in the bird populations of some tropical archipelagos are absent in Antillean bat fauna

Late Quaternary Fossil Mammals and Last Occurrence Dates From Caves at Barahona, Puerto Rico

Puerto Rico supported at least five genera of endemic terrestrial mammals in the late Quaternary, all of which are extinct. Whether these animals died out in the late Pleistocene, the mid-Holocene, or in post-Columbian time has not been established. This paper is the first attempt at radiometrically dating the \u27last occurrences\u27 of these taxa, together with the first unambiguous descriptions of localities reported by previous workers. Last occurrence dates for Nesophontes, Elasmodontomys and Heteropsomys are shown to be mid-Holocene and overlap with Amerindian occupation of the island. Acratocnus is known only from the late Pleistocene. No Puerto Rican taxon has been shown to have survived into the historic (European) era, which contrasts with the situation on some other islands of the West Indies

Post-speleogenetic Biogenic Modification of Gomantong Caves, Sabah, Borneo

The Gomantong cave system of eastern Sabah, Malaysia, is well-known as an important site for harvesting edible bird-nests and, more recently, as a tourist attraction. Although the biology of the Gomantong system has been repeatedly studied, very little attention has been given to the geomorphology. Here, we report on the impact of geobiological modification in the development of the modern aspect of the cave, an important but little recognized feature of tropical caves. Basic modeling of the metabolic outputs from bats and birds (CO2, H2O, heat) reveals that post-speleogenetic biogenic corrosion can erode bedrock by between ~ 3.0 mm/ka (1 m/~300 ka) and ~ 4.6 mm/ka (1 m/~200 ka). Modeling at high densities of bats yields rates of corrosion of ~ 34 mm/ka (or 1 m/~30 ka). Sub-aerial corrosion creates a previously undescribed speleological feature, the apse-flute, which is semicircular in cross-section and ~ 80 cm wide. It is vertical regardless of rock properties, developing in parallel but apparently completely independently, and often unbroken from roof to floor. They end at a blind hemi-spherical top with no extraneous water source. Half-dome ceiling conch pockets are remnants of previous apse-fluting. Sub-cutaneous corrosion creates the floor-level guano notch formed by organic acid dissolution of bedrock in contact with guano. Speleogenetic assessment suggests that as much as 70–95% of the total volume of the modern cave may have been opened by direct subaerial biogenic dissolution and biogenically-induced collapse, and by sub-cutaneous removal of limestone, over a timescale of 1–2 Ma

A Note on the Thermal Ecology and Foraging Behaviour of the Egyptian Fruit Bat, Rousettus Aegyptiacus, at Mt. Elgon, Kenya

The Egyptian fruit bat, Rousettus aegyptiacus, is an abundant and widely distributed African pteropid (Nowak, 1999). The species is unusual amongst pteropids in being an obligate cave-dweller (Kwiecinski & Griffiths, 1999), sometimes reaching colony sizes in the thousands (Kingdon, 1974). In the caves of Mt. Elgon National Park, western Kenya (1° 08′N, 34° 39′E), precision temperature loggers placed in major Rousettus roosts and intervening passages have allowed us to precisely monitor bat emergence and return times. The major caves of Mt. Elgon National Park consist of geophagically modified tunnels and collapse chambers cut into Miocene-aged pyroclastic strata (Lundberg & McFarlane, 2006). These caves can be as much as 200-m deep (e.g. Kitum Cave) and can have volumes exceeding 4 × 104 m3 (e.g. Makingeny Cave). The caves support at least 11 species of bats (Bauer, Weis-Spitzenberger & Weis, 1981). The caves are of interest in the present context because, being located at relatively high altitudes (∼2500 m), the ambient rock temperatures are low and the large biomass of bats produces significant temporal fluctuations that more than doubles roost temperature