TY - JOUR AU - Skarin, Anna PY - 2008/06/04 Y2 - 2024/03/29 TI - Decay rate of reindeer pellet-groups JF - Rangifer JA - Ran VL - 28 IS - 1 SE - Articles DO - 10.7557/2.28.1.151 UR - https://septentrio.uit.no/index.php/rangifer/article/view/151 SP - 47-52 AB - Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (<em>Rangifer tarandus</em>). During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarn&auml;s. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest) was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals&rsquo; general habitat use over several years. <p><em>Abstract in Swedish / Sammanfattning:</em><br />Nedbrytningshastighet av renspillning</p><p>Inom viltforskningen har spillningsinventeringar anv&auml;nts under flera &aring;rtionden f&ouml;r att uppskatta habitatval och populationst&auml;thet hos olika djurslag. F&ouml;r att kunna anv&auml;nda data fr&aring;n spillningsinventeringar kr&auml;vs ofta att man vet hur l&aring;ng tid det tar f&ouml;r spillningen att brytas ner. Nedbrytningshastigheten &auml;r olika beroende p&aring; marktyp och djurslag. Nedbrytningshastighet p&aring; spillning har studerats f&ouml;r bland annat olika typer av hjortdjur, men det har inte studerats p&aring; ren (<em>Rangifer tarandus</em>) tidigare. I omr&aring;det kring Ammarn&auml;s genomf&ouml;rdes under &aring;ren 2001- 2005 ett f&auml;ltexperiment f&ouml;r att uppskatta nedbrytningshastigheten av renspillning. Under tre somrar lades totalt 382 renspillningar ut i h&auml;gn i tre olika typer av habitat (fj&auml;llhed, fj&auml;llbj&ouml;rkskog och granskog). Det visade sig att nedbrytningshastigheten var l&aring;ngsammast p&aring; fj&auml;llheden, d&auml;r spillningsh&ouml;garna fortfarande var kvar efter fyra &aring;r. Den exponentiella nedbrytningshastigheten ber&auml;knades till -0.027 h&ouml;gar/vecka om nedbrytningen antas ske under barmarksperioden. I skogsh&auml;gnen gick nedbrytningen snabbare och alla h&ouml;gar var borta inom tv&aring; &aring;r. Vid spillningsinventeringar p&aring; kalfj&auml;llsomr&aring;det eller omr&aring;den med liknande marktyp, d&auml;r syftet &auml;r att studera djurens habitatval &ouml;ver en l&auml;ngre tid rekommenderas att anv&auml;nda den s&aring; kallade &rdquo;faecal accumulation rate&rdquo;-metoden, d&auml;r man inventerar orensade ytor. Det ger en generell bild av hur djuren anv&auml;nt omr&aring;det under en l&auml;ngre period, eftersom nedbrytningen av spillning &auml;r l&aring;ngsam i s&aring;dana habitat.</p> ER -