| Erinaceidae | Solenodontidae | Soricidae | Talpidae | Tenrecidae | |
Family: Erinaceidae (hedgehogs & gymnures)
Sources disagree about the number of species (17 - 20) and genera (7 - 9) in this family, but they are possibly the most similar of all extant mammals to the very earliest placental mammals. They are found throughout Africa, Eurasia, south-eastern Asia. Identifying features include their dental formula (i2-3/3, c1/1, pm3-4/2-4, m3/3 = 36 - 44), complete zygomatic arch, eyes and ears of moderate size, and plantigrade foot posture. In some species the anterior incisors are enlarged. The upper molars are quadritubercular, while the lower molars have well developed trigonids and talonid basins. Hedgehogs, but not gymnures, are covered with sharp spines. By rolling into a tight ball, many hedgehogs are able to protect vulnerable areas of the body from predators. Lacking spines, gymnures emit a foul odour when threatened.
Some gymnures are diurnal, others are nocturnal. All hedgehogs are nocturnal, resting during the day in a leaf nest or dry cavity. Some hedgehogs live in burrows, and generally dig their own. Several species, and typically Erinaceus europaeus, hibernate in the colder parts of their geographic range. The heartbeat of E.europaeus drops from its normal 188 beats per minute to 21 beats per minute during hibernation (Nowak 1991). All erinaceids feed on insects and other invertebrates. Gymnures also include some plant matter in their diet. Hedgehogs also consume a wide variety of foods, including carrion, roots and fruit. Although terrestrial, erinaceids are good climbers and can also swim. Echinosorex may be aquatic to some extent. Most have one or two breeding seasons a year, and a litter size of one to seven.
Erinaceus europaeus (European Common Hedgehog)
