True Power Loss Reduction by Enhanced Tree Squirrel Search, Enhanced Salp Swarm, and Swim Bladder Operation-Based Shark Optimization Algorithms

In this chapter, enhanced tree squirrel search optimization algorithm (ETSS), enhanced salp swarm algorithm (ESS), and swim bladder operation-based shark algorithm (SBS) have been applied to solve the power loss reduction problem. Enhanced tree squirrel search optimization algorithm (ETSS) utilizes the jumping exploration method and progressive exploration technique—both possess winter search strategy—in order to preserve the population diversity and to perk up the convergence speed. A new-fangled winter exploration strategy is implemented in the jumping exploration technique. In enhanced salp swarm algorithm (ESS) an inertia weight ω∈ [0, 1] is applied, which picks up the pace of convergence during the period of exploration. Then swim bladder operation-based shark algorithm (SBS) is proposed to solve the problem. Based on contracting and expanding actions of the swim bladder in shark, SBS algorithm has been modelled.

Gross anatomical features and osteometric variables of the scapula of the african tree squirrel (Funisciurus anerythrus), house (Rattus Rattus) and wistar rats

This study comparatively investigated gross features and osteometric variables in scapula of three rodents: tree squirrel (Funisciurus anerythrus ), house (Rattus Rattus ) and Wistar rats. A total of thirty three animals (11 per rodent species) were used for the study. The rodents were anaesthetized using ketamine and xylazine combination (80 mg/kg: 10 mg/kg body weight), sacrificed and processed for scapular bone extraction by burying method. Grossly, the scapular bones are flattened in all the rodents and have various shapes; semicircular in squirrel and roughly triangular in both Rattus rattus and Wistar rats. The scapula of the squirrel bears a hook-like acromion process and a distinct subscapular spine. Osteometric variables; scapular width and length of scapular neck are significantly reduced (p<0.05) in the squirrel relative to other rodents. While the length of glenoid and diameter of infra spinatous fossa in Rattus rattus as well as the scapular spine length in squirrel respectively show marked increase when compared to other rodents. Keywords: Funisciurus anerythrus, Rattus rattus , Wistar, scapula, morphology, osteometry, comparative

Comparison of cranial and body morphology of tree squirrels (Helioscurius rufobranchium) in selected locations of rainforest in Nigeria

This study examined the differences in cranial morphology of tree squirrel species (Heliosciuru srufobranchium) from four different locations in rainforest part of Nigeria. Locally fabricated live traps made of wire-mesh and steel were used to capture the squirrels. Trapped tree squirrels were immediately transferred to the laboratory in cages, where they were euthanized by placement in a bell-jar containing chloroform-soaked cotton wool. Individuals from two locations (33 from Ile Ife and 49 from Emure Ekiti) were then preliminarily identified to the generic level, using an identification key. Eighty-two (82) skulls were prepared from them, using Long Island Natural History Museum Guide. The sexes of the specimens were determined by visual inspection of the external genitalia. Twenty-seven (27) cranial and six (6) external body parameters were measured using digital Vernier caliper. One-way analysis of variance at p<0.05 was used to determine the difference in measured body parameters and Principal Component Analysis was used to differentiate the measured skull parameters. The results showed that the body parameters; head body length, tail length, tail body length, ear length, hind foot length and body weight measured were slightly different from one location to another. Also, the cranial measurements showed some similarities and differences between the two locations (Ile Ife and Emure Ekiti). In conclusion, the cranial measurements of the tree squirrels from the two locations (Ile Ife and Emure Ekiti) showed slight differences despite the fact that the tree squirrels are from the same genus (H. rufobranchium). Keywords: Heliosciurus rufobranchium; rainforest; tree squirrel; cranial; morphometric

Heliosciurus rufobrachium (Rodentia: Sciuridae)

Heliosciurus rufobrachium (Waterhouse, 1842), one of six species of Heliosciurus, is a sciurid commonly called red-legged sun squirrel. It is a medium-sized diurnally adapted tree squirrel occurring at ground-level to upper heights of the canopy of mature forests. It ranges from the west coast of Africa to Garissa County, Kenya. Adapted to an arboreal life, its frugivorous diet makes it a seed disperser for forest plants. In portions of West Africa, it serves as a source of bushmeat and it is a reservoir for human monkey-pox virus and Trypanosoma brucei, which causes African sleeping sickness. H. rufobrachium is listed as “Least Concern” by the International Union for Conservation of Nature and Natural Resources.

Geographical variation in Eurasian red squirrel (Sciurus vulgaris L., 1758) mandibles and the issue of subspecies-level organization: a failure of history?

Sciurus vulgaris is a widespread, highly polytypic tree squirrel species, under which a large number of subspecies have been described. This study tests the robustness of the current subspecific classification by using geometric morphometrics to quantify morphological variation in mandible shape, along with canonical variates analysis to test hypotheses of morphological distinctiveness. Patterns of mandible allometry were examined in eight out of 16 currently recognized subspecies. The significance of the discriminate functions was tested statistically, and the iterative jackknife procedure was applied to evaluate stability of the subspecies-specific discriminant functions. Applying criteria that focus on shape diagnosability, rather than mean group differences, indicates that most regional subspecific groupings show intergradations and continuity in mandible shape and size and that allometric effects on mandible shape are negligible. Evidence of a distinct subspecies confined to the Iberian Peninsula (Sciurus vulgaris infuscatus) and a discrete group originating from an extinct, 19th century population in Dorset, UK were identified based on these mandibular data. All other regional subspecific groupings were not diagnosably different. These results suggest that most red squirrel subspecies might represent non-diagnosable morphological variants whose taxonomic validity seems doubtful. More generally, our results highlight the importance of applying objective, quantitative and reproducible criteria to the issue of subspecies delimitation.