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The critically endangered Sumatran tiger (Panthera tigris sumatrae Pocock, 1929) is generally known as a forest-dependent animal. With large-scale conversion of forests into plantations, however, it is crucial for restoration efforts to understand to what extent tigers use modified habitats. We investigated tiger-habitat relationships at 2 spatial scales: occupancy across the landscape and habitat use within the home range. Across major landcover types in central Sumatra, we conducted systematic detection, non-detection sign surveys in 47, 17×17 km grid cells. Within each cell, we surveyed 40, 1-km transects and recorded tiger detections and habitat variables in 100 m segments totaling 1,857 km surveyed. We found that tigers strongly preferred forest and used plantations of acacia and oilpalm, far less than their availability. Tiger probability of occupancy covaried positively and strongly with altitude, positively with forest area, and negatively with distance-to-forest centroids. At the fine scale, probability of habitat use by tigers across landcover types covaried positively and strongly with understory cover and altitude, and negatively and strongly with human settlement. Within forest areas, tigers strongly preferred sites that are farther from water bodies, higher in altitude, farther from edge, and closer to centroid of large forest block; and strongly preferred sites with thicker understory cover, lower level of disturbance, higher altitude, and steeper slope. These results indicate that to thrive, tigers depend on the existence of large contiguous forest blocks, and that with adjustments in plantation management, tigers could use mosaics of plantations (as additional roaming zones), riparian forests (as corridors) and smaller forest patches (as stepping stones), potentially maintaining a metapopulation structure in fragmented landscapes. This study highlights the importance of a multi-spatial scale analysis and provides crucial information relevant to restoring tigers and other wildlife in forest and plantation landscapes through improvement in habitat extent, quality, and connectivity.

B rid g e s, A .S ., V a u g h a n , M .R . & K le n z e n d o rf, S. 2004: S e a so n a l v a ria tio n in A m erican black bear Ursus americanus activity patterns: quantification via rem ote p h o to g ra ph y. -W ildl. B iol. 10: 277 -28 4. A c tiv ity p a tte rn p la stic ity m a y serve as an ev o lu tio n a ry ad ap ta tio n to op tim iz e fitness in an inco nstant environm ent, how e ver, quantifyin g patterns and dem o n strating v a ria tio n c a n be p ro b le m a tic . F o r A m e ric a n b la c k b e a rs Ursus ame ricanus, w a rine ss a nd h a b ita t in a c c e ss ib ility fu rth e r c o m p lic a te quantifica tio n. R adio telem etry has bee n the prim a ry te ch niq ue use d to ex a m in e activity, ho w ever, interpretation erro r and lim itation on num be rs o f anim als available to m on itor prevent extrapolation to unm a rke d o r untransm ittered m e m bers o f the popu lation. W e used re m o te c a m e ra s to qu an tify blac k b e a r activ ity patte rns and ex a m in e d d iffe re n c e s by se a so n, se x a n d re p ro d u c tiv e c la ss in th e A lle g h a ny M o u n ta in s o f w e ste rn V irg in ia , U S A . W e u se d 1,533 p ic tu re s o f b la c k bea rs ta k e n d u rin g 19 98 -20 02 fo r o u r an alyses. B la c k b e a rs ge n e ra lly w ere d iu rn a l in su m m e r a nd no cturna l in autum n w ith a vespe rtin e activity p ea k du rin g both seasons. B e ar-hound training seasons oc cu rred during S e p tem be r and m ay offer e x p la n a tio n fo r th e o b se rv e d sh ift to w a rd s n o c tu rn a l b eh a v io u r. W e fo u n d no su b s ta n tia l d iffe re n c e s in a c tiv ity p a tte rn s b e tw e e n se x a n d re p ro d u c tiv e cla sse s. U se o f re m o te c a m e ra s a llo w e d us to e ffic ie n tly sa m ple la rg e r n u m be rs o f in d iv id u a l a n im a ls a nd lik e ly o ffe re d a b e tte r a p p ro x im a tio n o f p o p u lation-level activity patterns than individual-level, telem etry-based m ethodologies.

Information on spatial and temporal variation in abundance is crucial for effective management of wildlife. Yet abundance estimates for the Critically Endangered Sumatran tiger Panthera tigris sumatrae are lacking from Riau, the province historically believed to hold the largest percentage of this subspecies. Recently, this area has had one of the highest global rates of deforestation. Using camera traps we investigated tiger abundance across peatland, flat lowland, and hilly lowland forest types in the province, and over time, in the newly established Tesso Nilo National Park, central Sumatra. We estimated densities using spatially explicit capture-recapture, calculated with DENSITY, and traditional capture-recapture models, calculated with CAPTURE. With spatially explicit capture-recapture the lowest tiger density (0.34 ± SE 0.24 per 100 km 2 ) was estimated in the hilly lowland forest of capture-recapture the spatially explicit capture-recapture approach resulted in estimates 50% lower. Estimates of tiger density from this study were lower than most previous estimates in other parts of Sumatra. High levels of human activity in the area appear to limit tigers. The results of this study, which covered areas and habitat types not previously surveyed, are important for overall population estimates across the island, provide insight into the response of carnivores to habitat loss, and are relevant to the interventions needed to save the tiger.