Jenness Enterprises
Wildlife and Forestry Tools for ArcGIS Pro — Tool Reference
jennessent.com
Tool Reference › Home Range › LoCoH Parameter Explorer

LoCoH Parameter Explorer

Home Range · interactive window · by Jeff Jenness
Works at every ArcGIS Pro license level
Learn more About LoCoH home-range analysis covers the method behind these curves — local hulls, cumulative isopleths, and the leveling-off logic this window automates. Home-range estimation is also a wildlife module of Jeff's GIS training course, with videos and lab exercises using these tools.

Summary

An interactive window that runs the Getz et al. (2007) leveling-off analysis for choosing a LoCoH parameter: pick a point feature class, choose the Standard (k), Adaptive (a) or Fixed Sphere (r) method, and the window sweeps the parameter across a sequence of values, building the local hulls at every value and charting the areas of the 50%, 75% and 95% isopleths against it. A dashed line marks the starting value the method's authors recommend — a rule of thumb computed from your own data (k = √n for the Standard method, for example) that gives the search a sensible first anchor. Where the curves climb, holes are filling; where they flatten, the estimate is stable; where they jump, hulls have begun to bridge a real gap. Run it before committing to a parameter in the LoCoH tools; this tool may help you choose an appropriate LoCoH sizing parameter value. Export the chart (PNG/SVG), the sweep table (CSV), or place the chart on a layout.

Why sweep the parameter?

Every LoCoH variant has one governing parameter, and the choice matters more than any other decision in the analysis: too small fragments the range with spurious holes, too large inflates it toward the minimum convex polygon. The LoCoH literature's advice is empirical — build hull sets across a range of values and watch how the isopleth areas respond (Getz et al. 2007; Lyons et al. 2013) — which is exactly the tedious, repetitive work a tool should absorb. This window does the whole procedure in one click, on the very data you are about to analyze, with the layer's selection honored — so a season of multi-animal telemetry can be swept one animal at a time by selecting each animal's locations.

The LoCoH Parameter Explorer window after a 25-step Fixed Sphere sweep: the layer picker, method radio buttons, Steps box and Run Sweep button along the top, the blue help button and Close at the right, and the three-curve chart filling the pane with a dashed heuristic line at 724 meters
The Explorer after a Fixed Sphere sweep of the two-individual Oak Creek dataset — with Steps raised from 12 to 25 for smoother, more trustworthy curves. Export buttons and the online-help button ride along the window edges.

Reading the curves

Each curve tracks one isopleth — the cumulative-hull polygon that first encloses 50%, 75% or 95% of the locations — and the horizontal axis is the swept parameter. Three behaviors carry the meaning:

Climbing — as the parameter grows, hulls widen and spurious holes fill; the isopleth areas rise quickly. Flattening — when the artifacts are gone, adding more neighbors changes little; a plateau is the signature of a stable estimate, and the value at its start is the minimum spurious hole covering. Jumping — a sudden step up means the hulls just bridged a genuine gap: a hole or bay the animal truly avoided has been swallowed. Treat the value just before a jump as a ceiling.

No prior estimate of the true home-range area is needed — the judgment reads the shape of the curves plus your own knowledge of which gaps are real. And it is honest to say the judgment is a skill: as Getz et al. (2007) put it, “only experience with the method, however, will reveal appropriate methods for deciding when this leveling off has been achieved.” This window exists to make that experience cheap to acquire.

The three sweeps, one dataset

The charts below sweep the same data — the two-individual Oak Creek dataset from the Concave Hull page, 43 locations in two clusters with a gap between them — through all three methods. The gap dominates every chart, and finding it in each is good practice in reading sweeps.

A sweep chart for the Standard k method: three curves for the 50, 75 and 95 percent isopleths rising with k from 3 to 43, a dashed heuristic line at k equals 7, a steep jump in the 95 percent curve between k of 8 and 16, and the 75 percent curve leaping at the far right to meet the 95 percent curve
Standard (k). Through k ≈ 8 the areas stay small — every hull is confined within one individual's cluster. Between k = 8 and 16 the 95% curve leaps from about 13 to 43 km²: hulls have begun to span the gap between the two individuals, and the climb never levels off again. The heuristic k₁ = √43 ≈ 7 sits just below the jump — the largest k that still respects the two-cluster structure. (At the far right, even the 75% curve leaps to join the 95% at the full MCP.)
A sweep chart for the Adaptive a method: the three isopleth-area curves flat at small budgets, then climbing steadily from about 2,000 meters onward with no upper plateau, the dashed heuristic line at the far right at the maximum pairwise distance
Adaptive (a). A clean shelf up to a budget of about 1,700 m — within-cluster hulls, stable areas — then a long climb as bigger budgets start buying neighbors across the gap, with no second plateau before a₁ (the maximum pairwise distance, the heuristic's deliberately generous starting point). The shelf is the honest zone: on this dataset an a near 1,200–1,700 m keeps each individual's structure.
A sweep chart for the Fixed Sphere r method: flat curves up to about 700 meters, a steep knee between roughly 800 and 3,000 meters, and a clear upper plateau beyond 3,000 meters where the 95 percent curve flattens near 26 square kilometers; the dashed heuristic line sits at 724 meters
Fixed Sphere (r). The clearest two-plateau story: a lower shelf out to about 700 m (within-cluster spheres), a steep knee as radii from roughly 800 to 3,000 m progressively bridge the gap, and an upper plateau past 3,000 m where everything reachable has been swallowed and the isopleths approach the MCP. Both plateaus are “level” — but only the lower one respects the animals. The heuristic r₁ = 724 m lands right at the shelf's edge, just before the knee.

The common lesson: when a curve jumps, ask what geography just got bridged. On this dataset every jump is the gap between the two individuals — a warning that no single parameter honestly describes both animals at once. The remedies are the ones the charts suggest: keep the parameter below the jump, or better, sweep and analyze each animal separately (select one animal's locations and re-run; the selection is honored).

From sweep to home ranges

The payoff comes when the curves send you back to the LoCoH tools with actual numbers. The Fixed Sphere sweep above picked out two good plateaus: one right at the heuristic, r = 724 m, and a second at about r = 3,750 m, where the gaps had finished filling in. So we ran the LoCoH (Fixed Sphere) tool twice, once at each radius — and now we can choose between two defensible home-range estimates, each answering its own question. Possibly the 724 m version serves to identify the core areas, while the 3,750 m version is more the general home range.

The LoCoH Fixed Sphere geoprocessing pane with the radius specified as 724 meters, beside aerial imagery where the cumulative hulls form many small tight polygons hugging each knot of the two individuals' locations
Fixed Sphere LoCoH at the lower plateau, r = 724 m: the hulls hug each knot of locations tightly, splitting the range into small heavily-used patches — a natural candidate for the core areas.
The same geoprocessing pane with the radius specified as 3,750 meters, beside aerial imagery where the hulls have merged into two large smooth polygons, one around each individual's cluster of locations
The same tool at the upper plateau, r = 3,750 m: two clean polygons, one per individual — more the general home range. Both radii came straight off the sweep chart, and both estimates are defensible because the chart shows each one sitting on a plateau rather than a slope.

A tour of the window

Pick the point features, choose the method, optionally adjust Steps (how many parameter values to try, 4–40; more steps draw smoother curves and take proportionally longer), and click Run Sweep. A progress bar tracks the hull building, and Cancel stops a long sweep. The sweep values are spaced logarithmically from very tight to each method's natural ceiling — k up to n, a up to the maximum pairwise distance, r to several times the heuristic — with the heuristic value itself always included, so the dashed line always touches a computed point. Geographic (latitude–longitude) points are handled in a data-centered equal-area projection, and areas are always square kilometers.

The Home Range Tools gallery open on the ribbon, with the LoCoH Parameter Explorer button, in the Local Convex Hulls row, outlined in blue
Where to find it: LoCoH Parameter Explorer is in the Local Convex Hulls row of the Home Range Tools gallery, in the Home Range group of the Wildlife and Forestry tab.

Save Graph... exports the chart as a 300-dpi PNG or scalable SVG; Export CSV... writes the sweep table (parameter value and the three isopleth areas per row); Add to Layout places the chart on a layout as native, individually editable graphic elements — the active layout when one is open, otherwise you pick from the project's layouts. The blue ? opens this page.

Recommended citation

Jenness, J. 2026. LoCoH Parameter Explorer. Wildlife and Forestry Tools add-in for ArcGIS Pro, v. 1.99 (September 2026). Jenness Enterprises. Available at: https://github.com/JeffJenness/Wildlife_Tools.

Credits and references

By Jeff Jenness, Jenness Enterprises (www.jennessent.com). The leveling-off analysis follows Getz et al. (2007); the isopleth-area-curve procedure follows the T-LoCoH practice of Lyons, Turner and Getz (2013).

Licensing information

Works at every ArcGIS Pro license level (Basic, Standard, Advanced). No extension licenses are required.