Imp Ibex Mann
Total Page:16
File Type:pdf, Size:1020Kb
ALPINE MARMOT (Marmota marmota, L.) Mann C. S.*, Macchi E.**, Janeau G.* *I.R.G.M. - Faune Sauvage, I.N.R.A. - BP 27, 31326 Castanet-Tolosan Cedex (France) **Dipartimento di Produzioni Animali, Facoltà di Medicina Veterinaria, Via Nizza 52, 10126 Torino (Italy) IBEX J.M.E. 1:17-30 1 Systematic Status Class: Mammals Sub-family: Sciurinae Order: Rodents Genus: Marmota Family: Sciuridae Species: marmota French: Marmotte; German: Murmeltier (n); Italian: Marmotta; Spanish: Marmota. Species belonging to the genus Marmota (according to Nowak & Paradiso, 1983: 11 species): M. monax, M. flaviventris, M. caligata: North-América M. olympus*, M. vancouverensis*, M. broweri*: North-América (* Species belonging to the “caligata group” in Ellerman 1940, M. broweri as M. caligata broweri) M. caudata, M. menzbieri: Asia M. camtschatica: Asia (belonging to the “caligata group” in Ellerman, 1940); M. bobak: Europe + Asia M. marmota: Europe 2. Origins and distribution but also in America and Europe (migration 2.1 Origins: Asia → America → Europe) all of which com- The first rodents - During the Paleocene municated quite freely in that period (Russell, (some 60 million years ago), in Asia, a group of 1968). mammals appeared with a novel masticatory The first American and European rodents apparatus that enabled them to gnaw (with belonged to the family Paramyidae (Wood, strong incisors) and chew (with cheek teeth), 1962): Paramys atavus appeared in North gnaw and chew... in quick succession. From American forests in the late Paleocene/early this fossil group of mammals known as the Eocene (Chaline & Mein, 1979; Vianey-Liaud, mixodonts (Mixodentia = Anagalida) and to 1985) and Paramys sp. in Europe as early as the which for instance the chinese Heomys orienta- Lower Eocene (Hartenberger, 1989). They lis belonged, two “sibling orders” both deserve special mention here as the pre- (Hartenberger, 1977) branched out: the sent dental pattern of Marmota is exactly the rodents and the lagomorphs. same as that of these very ancient rodents! According to current knowledge, rodents first (Hartenberger, 1992 pers. comm.) appeared in China during the Paleocene, some At the beginning of the Lower Eocene, Europe 56 million years ago (see fig.1) (Li Chuan and North America were finally completely Kuei, 1977; Mein, 1992). They radiated separated by the Atlantic. The land-area of outwards extremely fast since true rodents Europe was at that time an island separated already exis-ted at the start of the Lower from Asia by a shallow sea and for 15 million Eocene (-55 M Y) not only in Asia (Cocomys) years original fauna developed there. However, IBEX J.M.E. 1:1993 17 Mann C. S., Macchi E. & G. Janeau Monograph events were to change drastically. probably the birthplace of the Marmotini The T.E.E. and the “Grande Coupure” - The which date back to the lower Miocene with end of the Eocene, about 35 million years ago Miospermophilus (Black, 1963; Mein, op. cit.) (recent datings give 34 MYA), was marked by and subsequently radiated both in America and worldwide climatic changes (the Terminal in Eurasia (Chaline & Mein, op. cit.). Eocene Event) and deep tectonic movements The genus Marmota also appeared in America, which led to the disappearance of the sea in during the Pliocene (Black, op. cit.), and then Eastern Europe. The combination of these cli- migrated along with the horse across the frozen matic and tectonic events in Europe led to Bering Straits to Eurasia at the end of the what palaeontologists call the “Grande Tertiary/beginning of the Quaternary (Mein, Coupure”, i.e. a tremendous modification of op. cit.). the fauna in the early Oligocene. Broadly, cli- Marmots reached Europe around 250,000 years matic changes caused most species of that ago, before or during the Riss *** glaciation. period to die out* (Hartenberger, 1983), inclu- During the Würm period (a series of successive ding rodents**, and the end of Europe’s isola- glacial phases interrupted by warmer episodes) tion meant that external species (mostly from marmots in Europe lived in the lowlands Asia) were free to occupy the newly abando- during the colder phases and sought refuge in ned ecological niches (ibid.). the mountains during the warmer ones. The This was a major step in the history of rodents split between Marmota bobak and Marmota as almost all of the old European Eocene bran- marmota started at that time by an alternation ches disappeared and the first members of the of contact (in the lowlands during the glacial modern families, especially the Sciuridae, took phases) and isolation (in the mountains during over from them. the interglacials) of populations (Chaline, 1972). The split became final after the ultima- Appearance and development of the te retreat of the Pleistocene ice about 10,000 Sciuridae... - They appeared as early as the years ago when Marmota marmota sought per- Lower Oligocene both in North America manent refuge in the mountains. (Protosciurus) and in Europe (Palaeosciurus, Vianey-Liaud, op. cit.) and have evolved consi- derably since (flying, arboreal and terrestrial * even complete groups were wiped out, such as the European primates (Mein op cit.). forms), especially as regards the American ** except for the Gliridae (Hartenberger pers. comm. 1992) ground squirrels (Mein, op. cit.). *** fossils of Marmota from the Riss period in Europe ...up to the marmots - North America is (Chaline, 1972; Mein, op cit.) Fig. 1 - Major steps during the Tertiary and the Quaternary in the evolution leading to Marmota marmota 18 IBEX J.M.E. 1:1993 Monograph Mann C. S., Macchi E. & G. Janeau 2.2 Distribution - Marmota marmota was wide- there in Europe (e.g. Roumania, Ramousse, op. spread after the Würm period: from Central cit.). Europe (Carpathians) to the Pyrenees, inclu- ding the Apennines and the Dinar Alps in the 3. Tracks south. But its distribution then considerably The presence of marmots is best recognised by receded during the Quaternary under the pres- their call: alarm call upon the approach of a sure of climate and other events. walker, repeated calls at dawn or towards the At the present time, marmots are found (Fig. end of the day. Burrows are more easily spotted 2) in the Carpathians, Tatras mountains inclu- by the debris in front of them than by the ope- Fig. 2 - Distribution of Marmota marmota ded (Huber, 1978), in the Pyrenees, in the nings themselves: this debris is conspicuous Alps, in part of the Apennines and in some from a great distance as it remains bare and is other locations (see below). only colonised by vegetation if the hole is sel- In many of these areas however, the species dom or never used. In the summer, these two was (re)introduced both to establish new clues (call and debris) give a reliable indication nuclei or for restocking already existing popula- of the presence of marmots from a distance, tions. and with a little patience will help in spotting Such operations have been carried out: in the the animals themselves. Pyrenees since 1948 both on the French and The latrines (a shallow hole in the ground, Spanish sides (Couturier, 1964; Herrero, 1978; often beneath a block) can be found if you Nebel, 1992), in the French Alps, Jura, Vosges have a good sense of smell or after careful and Massif Central (e.g. Magnani, 1992; exploration and it is then possible to tell Ramousse, 1992), in the Swiss Jura (Neet, whether the faeces are recent. 1992), in the Tosco-Emiliano Appennines and From July to early August paths such as those Italian Alps (Ferri et al., 1988; Chiesura that run from burrow to burrow are quite con- Corona, 1992; Panseri, 1992) and here and spicuous and show up the routes most com- IBEX J.M.E. 1:1993 19 Mann C. S., Macchi E. & G. Janeau Monograph monly taken by the animals. - The retina is totally devoid of rods and the- When the winter turns into spring (end of refore unsuitable for night vision. It is also April to May) and if the snow cover is even devoid of a fovea, giving the animal a visual and deep enough the often dirt-stained burrow acuity “certainly better than that of other openings are visible from quite a distance. rodents, whilst not as good as that of humans” Footprints can also be found in the snow but (Rochon-Duvigneaud, 1955). The field of are quickly spoilt by the repeated passages of vision is very wide both sideways and upwards, the animals and even more by the sun. because of the location of the eyes mainly. 4. Physical Features Size, weight and gait - The marmot is a stubby 5. Ecology and Ethology animal with short ears, a stout body and hardly 5.1 Preferred habitat - The marmot is rare in any neck, a morphology adapted to the life of a the mountain belt and in the forested subalpi- burrower. An adult (head + body) measures ne belt, it is mainly an inhabitant of the subal- roughly 50-60 cm in length, and its tail is rou- pine and alpine meadows. The highest local ghly 15 cm long. Body weight varies tremen- densities are found in scree with large to dously with the season because of hibernation medium sized blocks long since stabilized and (see § 7). As a rough guide, the weight of an totally or partially overgrown with vegetation. average adult is around 5 kg (or more) in The most populated parts of the grassland are September and drops to 2.5 kg (or less) in those where blocks are present both on the sur- April just after hibernation. face and underground. The marmot also lives Its walking gait is slightly rolling and its run by the edge of the forest but is not a true forest has been well described by Hainard (1988): dweller.