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The science
Seed shadow. A cassowary swallows fruit whole; seeds spend a random gut-passage time T (here Gamma-distributed, shape k, mean set by the slider) inside the bird, which keeps walking. Where the seed is dropped is the bird's displacement after T.
Movement. The bird is a persistent random walker: speed v (walking speed x fraction of time on the move) and a heading that diffuses with persistence time tau, so the velocity autocorrelation is v² e-t/tau. The mean-square displacement is <r²> = 2 v² tau [T - tau (1 - e-T/tau)]: ballistic (r = vT) for short T, diffusive (r² = 2 v² tau T) for long T. Averaging over the Gamma gut time gives 2 v² tau [T̄ - tau (1 - (1 + T̄/(k tau))-k)].
Janzen-Connell. Seedlings near the parent suffer more from host-specific pests and pathogens. Survival is modelled as S(r) = 1 - m e-r/L (m = extra mortality at the trunk, L = length scale). Recruitment density = seed density x S(r); because seed density per hectare falls with distance, the peak of recruitment is where those two curves cross over.
Honest simplifications. Walking speed, activity fraction, persistence time, gut time distribution, m and L are illustrative typical values, not measurements (spot-check against the literature before quoting). One bird, one parent tree, flat homogeneous forest, no territory edges, no home-range return, no secondary dispersal by rodents or beetles, no seed germination effect of gut passage. The 3D scene is a diorama: tree and bird are drawn about 8x larger than the map scale so they stay visible.
Independent educational model of a cassowary (Casuarius) in tropical rainforest; assets modelled in Blender.