Comparison of Pellet-Group and Radio Triangulation Methods for Assessing Deer Habitat Use

1988 ◽  
Vol 52 (3) ◽  
pp. 524 ◽  
Author(s):  
Eric R. Loft ◽  
John G. Kie
Keyword(s):  
Rangifer ◽  
2009 ◽  
Vol 27 (2) ◽  
pp. 121 ◽  
Author(s):  
Anna Skarin

Habitat selection theory predicts that herbivores should select for or against different factors at different spatial scales. For instance, quantity of forage is expected to be a strong factor influencing habitat choice at large scales, while forage quality may be important at finer scales. However, during summer, herbivores such as reindeer (Rangifer tarandus tarandus) can be limited in their grazing time by insect harassment, and do not always have the possibility to select for high quality forage. Human disturbances from hikers, etc., can also have a limiting effect on the possibility for reindeer to graze in high quality foraging habitats. Reindeer habitat selection at the landscape level was investigated through faecal pellet-group counts during the summers of 2002 and 2003 in two reindeer herding districts in Sweden. Resource utilization functions (RUFs) were developed using multiple linear regressions, where the pellet densities were related to vegetation types, topographic features, distances to tourist resorts, and distances to hiking trails. Validations of the models were performed through cross-validation correlations. Results show that high altitudes with high quality forage were important habitats. Areas that offer both snow patches and fresh forage plants for the reindeer were used in relation to their availability. The reindeer also seemed able to habituate to human intervention to a certain extent. The predictive capabilities of the RUF models were high and pellet-group counts seemed well suited to study how abiotic factors affect the habitat use at large temporal and spatial scales Abstract in Swedish / Sammanfattning: Renens användning av sommarbetesområdet, uppskattat med spillningsinventeringar Hierarkiskt habitatval innebär att djur väljer för och emot olika faktorer beroende på den rumsliga skalan. Mängden bete kan t ex spela stor roll för en växtätares habitatval på en stor skala medan kvalitén på betet kan ha större betydelse på en mindre skala. För renar (Rangifer tarandus tarandus), kan betestiden och möjligheten att hitta bra bete sommartid begränsas både på stor och liten skala pga. störningar från insekter och mänsklig aktivitet. Här studerades renarnas val av betesområde på landskapsnivå med hjälp av spillningsinventering under somrarna 2002 och 2003 i två samebyar i Sverige. Spillningstätheten för respektive område och år undersöktes statistiskt med hjälp av multipel linjär regression eller sk ”resource utilisation functions” (RUF). Där relaterades spillningstätheten till vegetationstyp, olika topografiska faktorer, avstånd till vandringsleder, stugplatser och fjällstationer. Resultaten visade att områden högt upp i terrängen med hög beteskvalitet var attraktiva. Vegetationstypen moderat snölega som anses ha hög beteskvalitet användes av renarna i relation till dess förekomst. Däremot verkade renarna undvika områden kring välbesökta fjällstugor och fjällstationer medan de däremot t o m föredrog områden nära vandringsleder. Det kan bero på att vandringslederna går genom attraktiva vegetationstyper. RUF-modellerna hade en hög prediktiv förmåga vilket visar att spillningsinventeringar är användbara när man önskar studera hur djuren använder ett betesområde i relation till olika faktorer på en relativt stor rumslig och temporal skala.


1999 ◽  
Vol 14 (4) ◽  
pp. 177-182 ◽  
Author(s):  
Mark L. Secord ◽  
Peter E. Zager ◽  
Daniel H. Pletscher

Abstract Relatively little is known about the response of white-tailed deer (Odocoileus virginianus) to forest management practices currently used in northern Idaho. We used pellet group surveys and radiotelemetry to assess the influence of season, clearcut age, and clearcut size on deer use in the Priest Lake watershed of northern Idaho. Deer use of 14 clearcuts ranging from 1 to 25 yr in age and 4.05 to 14.75 ha in size was investigated. No association between pellet group density and clearcut size or age was found. Both pellet group and telemetry data, however, indicated seasonal shifts in white-tailed deer habitat use patterns. Deer displayed strong avoidance of nonforested sites during winter and concentrated on low elevation winter ranges characterized by dense overstories. With the advent of warm weather and reduced snow depths, nonforested sites received increasing use. Clearcut use peaked during early spring and declined with the onset of summer as deer migrated to higher elevations. Spring use of clearcuts was significantly higher than summer use on all sites sampled. Spring pellet group densities averaged 1.52 groups/plot, whereas summer densities averaged 0.50 groups/plot. In the Priest Lake drainage, cutting units should be restricted to less critical sites adjacent to wintering areas. Clearcuts within winter habitats will further fragment existing forested stands and will be at the expense of critical thermal cover. In other regions, vegetation structure and composition should not be the only criteria used to evaluate the influence of clearcutting on white-tailed deer habitat use. West. J. Appl. For. 14(4):177-182.


Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 47 ◽  
Author(s):  
Anna Skarin

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 (Rangifer tarandus). During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. 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’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus) tidigare. I området kring Ammarnäs genomfördes under åren 2001- 2005 ett fältexperiment för att uppskatta nedbrytningshastigheten av renspillning. Under tre somrar lades totalt 382 renspillningar ut i hägn i tre olika typer av habitat (fjällhed, fjällbjörkskog och granskog). Det visade sig att nedbrytningshastigheten var långsammast på fjällheden, där spillningshögarna fortfarande var kvar efter fyra år. Den exponentiella nedbrytningshastigheten beräknades till -0.027 högar/vecka om nedbrytningen antas ske under barmarksperioden. I skogshägnen gick nedbrytningen snabbare och alla högar var borta inom två år. Vid spillningsinventeringar på kalfjällsområdet eller områden med liknande marktyp, där syftet är att studera djurens habitatval över en längre tid rekommenderas att använda den så kallade ”faecal accumulation rate”-metoden, där man inventerar orensade ytor. Det ger en generell bild av hur djuren använt området under en längre period, eftersom nedbrytningen av spillning är långsam i sådana habitat.


2016 ◽  
Vol 544 ◽  
pp. 197-211 ◽  
Author(s):  
A Chin ◽  
MR Heupel ◽  
CA Simpfendorfer ◽  
AJ Tobin

2019 ◽  
Vol 609 ◽  
pp. 239-256 ◽  
Author(s):  
TL Silva ◽  
G Fay ◽  
TA Mooney ◽  
J Robbins ◽  
MT Weinrich ◽  
...  

2020 ◽  
Vol 642 ◽  
pp. 227-240
Author(s):  
L Lodi ◽  
R Tardin ◽  
G Maricato

Most studies of cetacean habitat use do not consider the influence of anthropogenic activities. We investigated the influence of environmental and anthropogenic variables on habitat use by humpback Megaptera novaeangliae and Bryde’s whales Balaenoptera brydei off the coast of the Brazilian city of Rio de Janeiro. Although there are 2 marine protected areas (MPAs) in this area, few data are available on cetacean habitat use or on the overlap of different cetacean species within these MPAs. Our aim was to evaluate the effectiveness of the MPAs and propose a buffer zone to better protect the biodiversity of the study area. We conducted systematic surveys and developed spatial eigenvector generalized linear models to characterize habitat use by the species in the study area. Habitat use by humpback whales was influenced only by depth, whereas for Bryde’s whales there was the additional influence of anthropogenic variables. For Bryde’s whales, which use the area for feeding, sea surface temperature and the distance to anchorages had a major influence on habitat use. We also showed that neither of the MPAs in the study area adequately protects the hotspots of either whale species. Most of the humpback whale grid cells with high sighting predictions were located within 2 km of the MPAs, while areas of high sighting prediction of Bryde’s whales were located up to 5 km from the MPAs, closer to beaches. Our findings provide important insights for the delimitation of protected areas and zoning of the MPAs.


2020 ◽  
Vol 639 ◽  
pp. 169-183
Author(s):  
P Matich ◽  
BA Strickland ◽  
MR Heithaus

Chronic environmental change threatens biodiversity, but acute disturbance events present more rapid and immediate threats. In 2010, a cold snap across south Florida had wide-ranging impacts, including negative effects on recreational fisheries, agriculture, and ecological communities. Here, we use acoustic telemetry and historical longline monitoring to assess the long-term implications of this event on juvenile bull sharks Carcharhinus leucas in the Florida Everglades. Despite the loss of virtually all individuals (ca. 90%) within the Shark River Estuary during the cold snap, the catch per unit effort (CPUE) of age 0 sharks on longlines recovered through recruitment within 6-8 mo of the event. Acoustic telemetry revealed that habitat use patterns of age 0-2 sharks reached an equilibrium in 4-6 yr. In contrast, the CPUE and habitat use of age 3 sharks required 5-7 yr to resemble pre-cold snap patterns. Environmental conditions and predation risk returned to previous levels within 1 yr of the cold snap, but abundances of some prey species remained depressed for several years. Reduced prey availability may have altered the profitability of some microhabitats after the cold snap, leading to more rapid ontogenetic shifts to marine waters among sharks for several years. Accelerated ontogenetic shifts coupled with inter-individual behavioral variability of bull sharks likely led to a slower recovery rate than predicted based on overall shark CPUE. While intrinsic variation driven by stochasticity in dynamic ecosystems may increase the resistance of species to chronic and acute disturbance, it may also increase recovery time in filling the diversity of niches occupied prior to disturbance if resistive capacity is exceeded.


Sign in / Sign up

Export Citation Format

Share Document