DOI: 10.5061/dryad.hmgqnk9h3
title: Transect and plot data from: Fruit trees drive small-scale movement of elephants in Kibale National Park, Uganda

description: Understanding what motivates animal spatial behavior
 requires discerning the relationship between animals and
 the landscape in which they move. Many studies have focused on
 large scale trends that drive migrations and movement across broad
 landscapes, but few studies have focused on drivers of local movement
 within smaller areas based on fine–scale landscape
 heterogeneity. This is especially true for African elephants
 (Loxodonta africana), whose movements in relation
 to landscape
 variables have frequently been
 studied across vast areas, but infrequently on
 a small scale.  We report on
 how the local distribution of an important resource—fruit
 trees—shapes elephant movement patterns
 in Kibale National Park,
 Uganda. We hypothesized that the spatial location of
 elephant trails, and especially intersections in the network of trails,
 would be heavily associated with fruit trees, with trail density being
 higher in areas with greater fruit availability. Elephant trails
 and nearby fruit trees were mapped within a 64-km2 area within
 the interior of the Park. Trail and fruit tree sampling
 were conducted along sixteen evenly spaced one-km control transects and
 compared to 28.6 km of elephant trails arrayed throughout the
 park. Fruit tree basal area was higher along trails and at trail
 intersections. Trail density was also positively correlated with fruit
 tree density. Fruit trees may thus serve as a determinant of
 small-scale elephant movement and could be used to predict patterns of
 elephant spatial behavior across forested habitat, which has potential
 implications for elephant management in the area.  
description: Elephant trail data: We divided the 64
 km2 study area into two-kilometer grid cells, resulting in
 sixteen squares (grid cells) of 4 km2 area which were each labeled by a
 letter. One elephant trail was mapped within each grid cell. Trails were
 followed for a minimum of one kilometer and a maximum of two kilometers.
 Each trail was divided into 200m segments, which are indicated by
 "Transect.Label" in the data.  Along these trails, we recorded
 all trees of the study species &gt;20cm DBH that lay within 10m
 of either side of the trail with approximate GPS location recorded in UTM.
 Trees that were greater than 20cm, but too small to be considered mature
 were removed in post processing. Vegetation was classified according to
 Wing & Buss (1970).  Basal area was calculated in post
 processing. Control transect data:
 Control transects followed the method of “path of least
 resistance transects” (sensu Blake & Inkamba-Nkulu, 2004). These
 transects allow for minor deviations (40 degrees) around obstructions from
 the desired path (Blake & Inkamba-Nkulu, 2004).  All trees of the
 study species &gt;20 cm DBH (Table 1) within 10m of either side of the
 transect were recorded.  Each transect was divided into 200m segments,
 which are indicated by "Transect.Label" in the data.  Along
 these transects, we recorded all trees of the study species &gt;20cm
 DBH that lay within 10m of either side of the transect with approximate
 GPS location recorded in UTM. Trees that were greater than 20cm, but too
 small to be considered mature were removed in post processing. Vegetation
 was classified according to Wing & Buss (1970).  Basal area was
 calculated in post processing. Paired plot
 data: In each location (intersection and control
 site) we recorded all trees of the study species &gt;10 cm DBH within
 a circular 400 m2 plot (11.3m radius). The minimum DBH was lowered to 10cm
 to gain a better understanding of the abundance of smaller trees. Trail
 intersections were identified along the trails previously
 mapped above. Trail intersections were only sampled within forest and
 woodland land cover. A maximum of one intersection per 200-m trail segment
 was sampled. Intersections were chosen by sampling the first major trail
 intersection crossed within that segment. Sample plots were located at
 the center of the intersection, as judged by eye. Paired
 controls to each trail intersection plot were placed 50m away in
 the direction most orthogonal from the trails at the intersection. Control
 plots may have been crossed by elephant trails. If the location of the
 control plot was deemed to contain the intersection of elephant trails
 with greater use or number of intersecting trails than in the recorded
 elephant trail plot, we returned to the initial trail intersection and
 measured 50m in the opposite direction to record an alternative control
 plot.  The dataset includes trees from both the trail
 intersection and control plots which are distinguished by the
 "Plot.Type" column.  Plot number indicates which pair the tree
 belongs to within the grid cell.  UTM coordinates were taken from the
 center of the plot and do not accurately represent the location of
 specific trees.  Trees that were greater than 10cm, but too small to be
 considered mature were removed in post processing. Basal area was
 calculated in post processing.
description: Any blank rows with only a plot and grid label indicate that
 there were no trees meeting our requirements in that plot.