Francesco M. Angelici

Sexual size dimorphism and natural history traits are correlated with intersexual dietary divergence in royal pythons (python regius) from the rainforests of southeastern Nigeria

Abstract Food habits of the royal python (Python regius) were studied in some localities of southeastern Nigeria by means both of faeces analysis and forced regurgitation of living individuals. Female pythons were significantly longer than the males. Both sexes preyed exclusively upon birds and mammals, but there were significant intersexual differences in terms of dietary, composition. Males preyed more frequently upon birds (70.2% of the total number of prey items) whereas females preyed more frequently upon mammals (66.7% of the total number of prey items). There was an apparent ontogenetic change in the diet of both sexes: specimens shorter than 70 cm total length preyed almost exclusively upon small sized birds (nestlings and immature), whereas the longer specimens (> 100 cm total length) preyed almost entirely upon small mammals. We suggest that the two sexes are different in terms of their main natural history traits (males being more arboreal than females), and that this behavioural difference can...

Food habits of the green lizard, Lacerta bilineata, in central Italy and a reliability test of faecal pellet analysis

Abstract Food habits of the green lizard (Lacerta bilineata) were studied in some Mediterranean sites of the vicinities of Rome (Latium, central Italy), by means both of stomach dissection of individuals found already dead in the field and faeces analysis of living individuals. The taxonomic diet composition of the lizards was accurately described by both methods, thus demonstrating the reliability of faecal pellet analysis as an non‐cruel method to study lizard diets. However, by using the faeces analysis technique, it is difficult to measure the exact food intake rate (items / unit of time) as well as the size distribution of prey ingested by lizards. There was a remarkable ontogenetic change in the taxonomic diet composition of green lizards: adults essentially consumed beetles and isopods, whereas juveniles fed mainly upon orthopterans, spiders, and Rhynchota. Cannibalism and predation upon small vertebrates (lizards) were very rare events. It is suggested that (i) age‐related differences in microhabi...

Patterns of specific diversity and population size in small mammals from arboreal and ground-dwelling guilds of a forest area in southern Nigeria

The small mammal fauna of a forest area in southern Nigeria is studied in order to understand the general patterns regulating the community composition. A set of different methods of trapping was used in order to evaluate the composition of the species at the level of both the ground-dwelling and the arboreal guilds. For the Insectivora, six shrew species were trapped, but only two (Crocidura nigeriae and C. poensis) appeared abundant and widespread in the various habitat types. No arboreal species were found. For the rodents, 17 species were captured, which were arranged by a Principal Component Analysis into four groups: (1) Rattus rattus and Anomalurus derbianus; (2)Xerus erythropus and Grammomys rutilans; (3) Graphiurus ef. murinus and Hylomyscus stella; (4) the remaining, more generalist species. For the ground-dwelling rodents, 14 species were found, which were arranged in three groups: (1) Malacomys edwardsi and Grammomys sp.; (2) Mylomys dybowskii and Rattus norvegicus; (3) all the other species, with stronger similarities between Praomys tullbergi, Mus musculoides, Aethomys sp. (unknown), and Lemniscomys striatus. Although an approximately equal number of species constituted the arboreal and ground-dwelling rodent fauna, the number of trapped animals was much higher on the ground than at the level of the arboreal guild (ratio 8.7: 1; total n= 2322). The general implications of the patterns observed are discussed.

Fate of captive-reared brown hares Lepus europaeus released at a mountain site in central Italy.

We conducted a radio-telemetry study of translocated brown hares Lepus europaeus during March 1992 - November 1994 in a mid-elevation mountain site in central Italy. Of 44 hares released in the study area, 38 died during our field studies. Most hares (68.2%) died within 10 days after release, 7.89% died within 11–20 days, 2.63% within 21–30 days and 21.05% later than 30 days after release. We found no difference in mortality rates between sexes. Most of the hares were preyed upon by red foxes Vulpes vulpes or beech marten Martes foina, but a few died of coccidiosis and various natural diseases. Some hares disappeared during the monitoring period. The average survival time was 52.7 days for males (N = 20), and 66.8 days for females (N = 21). We found no significant effect of sex, season or weight (g) on individual survival. Nearly all of the hares dispersed randomly from the release site within a radius of 1,200 m. We found no significant effect of survival time on dispersal rates, nor did we find any significant intersexual difference in the maximum distances moved by translocated individuals. We did not observe this trend among females. Season, survival time and individual weight did not influence individual dispersal, whereas sex had a significant effect, as males tended to disperse farther than females.

Food Habits of the Snake Psammophis phillipsi from the Continuous Rain-Forest Region of Southern Nigeria (West Africa)

Abstract The food habits of the snake Psammophis phillipsi were studied in the rain-forest region of southeastern Nigeria, where this is the most common snake species of the area. A total of 120 prey items were recorded from 327 specimens (73 juveniles; 55 gravid females); many gravid females contained prey. Lizards (mainly Agama agama and Mabuya skinks) were the most common prey type for adult snakes, both gravid and nongravid, and for subadults as well; small mammals were the second most common prey type for all snake categories. Insects and small snakes (including conspecifics) were occasionally consumed. Diet composition did not differ significantly between gravid and nongravid specimens, but gravid specimens more frequently contained small mammals and fewer lizards. Ontogenetic dietary change was relatively minor. Prey and predator mass were significantly related in both adults and subadults.

Seasonal variation in habitat use in sympatric Afrotropical semi-aquatic snakes, Grayia smythii and Afronatrix anoscopus (Colubridae)

Identifying habitat shifts by snakes and determining the potential causes of such shifts are important to understanding snake ecology and evolution (Gibbons and Semlitsch, 1987). Habitat shifts between seasons have been demonstrated for a number of species, in both temperate (e.g., Reinert, 1984) and tropical regions (e.g., Shine and Lambeck, 1985). Seasonal shifts in habitat use are most likely in regions with ephemeral habitats or in regions where the climatic variability between seasons is high. Considering that many zones in southern Nigeria are characterized by a mosaic of aquatic habitats (ponds, lakes, lagoons, rivers, creeks, marshes), and that several of these habitats are strongly seasonal (i.e. they are flooded during the wet months and almost dry during the dry months; see climatic data in fig. 1), it is likely that habitat use of some species may exhibit seasonal variation in response to pronounced seasonality. This may be especially true for the aquatic species, which are often found in temporary ponds or in water basins subjected to strong seasonal variations in waterdepth (Luiselli and Akani, 2002a, b).

Diet of the semi‐aquatic snake, Afronatrix anoscopus (Colubridae) in southern Nigeria

Abstract A total of 332 specimens (59 subadults, 131 males and 142 females) of the semiaquatic colubrid Afronatrix anoscopus were collected in southern Nigeria to study their dietary preferences. The adult male to female sex‐ratio (0.92) was not significantly different from equivalence, with female body length being greater than that of males. A total of 60.2 % of the subadults, 39% of the males, and 43.2% of the females had identifiable food items in their stomachs. The diet of all categories (subadults, males and females) consisted of amphibians and fish, with a predominance of anuran tadpoles and the frog Silurana tropicalis. Subadults took significantly more anuran tadpoles than adults of both sexes, but fewer fish than adults of both sexes.

The leopard (Panthera pardus) in southeastern Nigeria: Status, ecological correlates of occurrence, and conservation implications

Abstract The status and the ecological correlates of occurrence of the leopard (Panthera pardus Linnaeus, 1758) from rainforests of southeastern Nigeria are presented in this paper. A total of 47 randomly selected forest patches with at least some patches of primary vegetation were examined, and eight different environmental variables were recorded from each study site. Canonical Analysis and Principal Component Analysis were used to assess which variables were positively correlated with the presence of the leopards, which proved extremely rare over the whole study region. In fact, the presence of the leopard was ascertained only in two sites (4.25% of the total number of surveyed areas), whereas it was a possibility in four other sites (8.5% of the total number of surveyed areas). Scats and tracks were found in only one of the former localities, whereas the skull of a recently killed adult specimen was seen in the other of the two sites. The various environmental parameters include total wooded surface (...

Body Size and Altitude Partitioning of the Hares Lepus Europaeus and L. Corsicanus Living in Sympatry and Allopatry in Italy

Abstract We present morphological and ecological data on hares of the genus Lepus living on the Italian peninsula and Sicily. During 16 years, we analysed specimens shot by hunters with respect to their habitat choice and distribution. Our morphometric data confirmed the existence of two different but closely related species, i.e. Lepus europaeus present in central and northern Italy and Lepus corsicanus endemic to central and southern Italy and Sicily. The distribution of the two hare species overlaps in a wide area of central Italy, tentatively estimated to be > 200 km. In terms of altitude, L. europaeus and L. corsicanus do not differ significantly when they live in allopatry. However, when they coexist in sympatry, L. corsicanus occurs at altitudes significantly higher than L. europaeus. L. europaeus inhabits significantly higher altitudes when it lives in allopatry than when it lives in sympatry, and L. corsicanus inhabits significantly higher altitudes when it lives in sympatry than when it lives in allopatry.

Distribution and habitat of otters (Aonyx capensis and Lutra maculicollis) in southern Nigeria

Abstract We report new data on the distribution and habitat of two otter species, Aonyx capensis and Lutra maculicollis, from southern Nigeria. Although preliminary, our investigations suggest that these two species may use the available habitat differently. Lutra maculicollis appears more linked to freshwater streams and Aonyx capensis is mainly restricted to brackish water streams (with mangrove vegetation along the banks) and, more occasionally, to transitional habitats between freshwater and brackish‐water environments. The possible reasons explaining habitat partitioning are discussed.