In contrast, the species for which we provide data in the current analysis primarily were taken elsewhere, during targeted trips, each of a few weeks in duration, to other localities in east Africa. gabonica) came from the Makonde Plateau, in the Newala District of Tanzania, within a 20-km radius of his home 26. The two species of snakes that Ionides collected in the largest numbers ( D. We have extracted information on five of those species (omitting Elapsoidea sundevallii, represented by only six records) from those notebooks. The remaining pages contain data on captures of six other east-African snake species. Pitman to enable preparation of co-authored papers 26, 27. The pages relating to some of the species that Ionides collected have been removed from the notebooks, and cannot be located they were presumably sent to C.R.S. Those data are contained within a series of notebooks, some of which were available to us through the generosity of Jonathan Leakey. Although Ionides published few scientific papers 24, he kept a detailed record of all of the large venomous snakes that he captured 25. During the latter part of his life, his focus shifted from big-game hunting to snake-collecting 23. 1a) was a prominent figure in early scientific collections of herpetofauna in eastern Africa, and his colourful life has been the subject of two biographies 20, 21 and an autobiography 22. Constantine John Philip Ionides (henceforth, “Ionides”, 1901 to 1968 see Fig. In the present study, we report information on abundances, demography (age-class distributions, sex ratios) and habitat use in five species of large venomous snakes that were collected primarily in the 1950s and 1960s by one of the pioneers of African herpetology. Even when replication is impractical, however, an analysis of historical data may clarify important aspects of ecosystems in earlier times. Ideally, researchers can quantify temporal shifts in organismal abundances and distributions by careful replication of earlier surveys 19. To understand the situation prior to this kind of habitat change, we must rely on historical records. Such changes may advantage some species of snakes, but disadvantage others 4, 16, 17, 18. Although that problem is worldwide, it is especially acute in some regions of the tropics, where land-clearing for agriculture has transformed the landscape 10, 11, 12 and affected aspects such as soil quality and rates of erosion 12, 13, 14, 15. The challenge of understanding ecological characteristics of tropical snakes is exacerbated by rapid degradation of habitats by the growing human population, with consequent shifts, and often, declines, in abundance of predators such as snakes 9. Research has been discouraged by logistical problems associated with travel and security, as well as by the difficulties inherent in studying large venomous snakes. Those taxa include some of the world’s largest and most spectacular snakes, such as mambas, cobras and vipers. Although ecological research on African snakes is beginning to fill that knowledge gap 2, 3, 4, 5, 6, 7, 8, many species, from temperate-zone as well as tropical areas, remain virtually unstudied in the wild. In particular, taxa from areas within the tropics have been understudied relative to those from temperate-zone habitats 1. Although fragmentary, the data from Ionides’ notebooks provide a unique glimpse into ecological patterns of snakes within an African landscape half a century ago.įor snakes, as for many kinds of organisms, our knowledge of ecological traits is based primarily on studies of a small subset of species from a limited set of locations. ![]() polylepis, adult males and females were recorded together in September-October, suggesting reproductive activity at this time of year. Habitat use was affected by species, sex and body size: for example, arboreality became less common with increasing body size in the rhinoceros viper and black mamba, and males were found in arboreal sites more often than were females. Sex ratios and age-class distributions differed among species and were affected by factors such as month of collection and time of day. The relative numbers of each species collected changed over the years and differed seasonally, reflecting targeting by Ionides. High capture rates suggest high abundances of all species. jamesoni, water cobras Naja annulata, and eastern forest cobras N. Ionides to extract quantitative information on captures of 484 snakes of five species (rhinoceros vipers Bitis nasicornis, black mambas Dendroaspis polylepis, Jameson’s mambas D. We used the 1960s notebooks of pioneering East African naturalist C.J.P. ![]() Historical data can clarify ecological attributes of fauna in sites that have subsequently been altered by anthropogenic activities.
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