Community structure and ecology of snakes in fields of oil palm trees (Elaeis guineensis) in the Niger Delta, southern Nigeria

Abstract

Aspects of community structure and ecology of snakes were studied in the years [2004][2005][2006] in fields of oil palm trees (Elaeis guineensis) of three study areas in Southern Nigeria. A total of 284 individual snakes, belonging to twelve species of three families (seven Colubridae, four Elapidae, one Viperidae), were recorded, including both sighted and captured individuals (not including in this count the individuals that escaped before identification to species level could be made). All the study areas were nearly identical in terms of species composition. Most snakes (about 67%) were recorded during the dry season months, when the fruits of the oil palm ripe, thus attracting lots of organisms that are potential prey for snakes. The most important food items for oil palm snakes were Agama lizards, birds and rodents, but they also fed on skinks, geckos, fruit bats and tree frogs. Snakes were spotted climbing with peak frequencies occurring in the range of 16-18 m above the ground level. In general, oil palm trees within the range of 16-27 m high harboured higher number of snakes. Climbing snakes were nonrandomly positioned on the trees: the highest percentage of snakes (68%) was lodged between the leaf bases and oil palm fruit bunches. The general implications of the given data are discussed.Key words: community ecology, diet, Nigeria, oil palm tree, snake diversity hauteur la plus fréquentée étant entre 16 et 18 mètres au-dessus du sol. Ce sont en général les palmiers qui culminaient entre 16 et 27 mètres qui recelaient le plus grand nombre de serpents. Les serpents grimpeurs ne se répartissaient pas au hasard dans les arbres : le plus fort pourcentage (68%) d'entre eux se positionnaient entre la base des feuilles et le régime de fruits. Les implications générales des données sont discutées.

Correlation between annual activity patterns of venomous snakes and rural people in the Niger Delta, southern Nigeria

“…Harvesting is carried out exclusively by men and youth, who climb up to the palm fruit (8–20 meters high) to cut down three to five bunches. Occasionally they encounter venomous snakes ( Dendroaspis jamesoni, Atheris squamiger, Naja nigricollis, Pseudohaje goldii, Thelothornis kirktlandi , and Dispholidus typus ), which may be very abundant in local palm oil plantations [22]. In this case, the potential danger due to snakes is not merely because of their bites.…”

“…First of all, it is necessary to emphasize that our data are cumulative from several places in the plantation-bushland-secondary forest mosaic, whereas it is well known that the specific composition of snake assemblages may change considerably at the local level, probably due to local environmental conditions and adaptability of each species [15,16,22-25]. For instance, there were remarkable differences in the relative frequency of occurrence of the venomous snakes studied in this paper at three distinct sites with different habitat features of the Niger Delta, with a higher frequency of appearance of target venomous species in palm-oil plantations (34.9% of the total snake specimens encountered) than in mangroves (16.3%) and swamp forest (25.6%).…”

Ecological diversity, community structure and conservation of Niger Delta mammals

“…(ii) Extinct and uncertain species list (Table 2)-a given species was considered regionally extinct when it satisfied concurrently two criteria: (a) it was neither observed by us nor recorded in literature since 2005; and (b) it does occur in the Niger Delta according to the IUCN (2014) maps (e.g., the pigmy hippo Choeropsis liberiensis). A given species was considered uncertain/wrongly cited for the Niger Delta, even if occasionally mentioned in the scientific literature, when it satisfied concurrently three criteria: (a1) it was neither observed by us nor recorded in Original field sightings were obtained opportunistically during long-term field researches (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) mainly performed during ecological investigations on reptiles (e.g., Akani et al 2008Akani et al , 2014a. Data presented in this paper collate both those presented in Petrozzi Angelici et al (1999) Euoticus elegantulus ND ND ND ND ND ND Cited by Blench (2007) Potamogale velox 1 0 1 0 0 0 Cited by Heslop (1935a) and Angelici et al (1999) Hystrix cristata ND ND ND ND ND ND Cited by Blench (2007) Lepus microtis ND ND ND ND ND ND Cited by Blench (2007) Gerbilliscus validus ND ND ND ND ND ND Cited by Blench (2007) Anomalurus derbianus (2007) Herpestes naso 0 0 1 0 0 0 Unobserved recently, probably due to suboptimal research…”

The Role of Plantations of the African Palm (Elaeis Guineensis) in the Conservation of Snakes in Colombia

“…Snake studies in African palm plantations are rare; I am aware of one study in Nigeria that focused upon the snake community of climbing snakes (Akani et al, 2007).…”