Five-year eastern monarch butterfly (Danaus plexippus ) roadkill MaxEnt Models and roadkill hotspot kernel density estimation for 2016-2020

Combined 2016-2020 five-year monarch roadkill MaxEnt models were developed for the monarch fall migratory Texas Central Funnel. Monarch roadkill density data from all years were categorized as hotspots using criteria of 2016 thinned data, and kernel density estimate (KDE) intensities for roadkill presence were mapped for the Texas Central and Coastal monarch migratory funnels. The timing of Texas monarch roadkill hotspot occurrences was compiled from various sources. Five-year MaxEnt roadkill models clearly indicate higher monarch roadkill in the southwest Texas portion of the Central Funnel, aligning well with previous roadkill models and observed roadkill hotspots. Major monarch roadkill hotspots were in southwest Texas were associated with creeks and draws, especially along IH-10 from Sonora to Sheffield. The five known live monarch roadkill hotspot observations occurred from 12-23 October, which generally aligns with peak monarch weekly migration mapped using KDE intensity. Potential direct mitigation for monarch roadkill in the Texas Central Funnel should include identified creeks and draws associated with past hotspots, and be implemented from 12-25 October. Previous fall 2018 reports of roadkill hotspots in the Texas Coastal Funnel are all associated with causeways. The only known live observations of high monarch roadkill in the Coastal funnel are from 26 October and 3 November on the Lavaca Bay Causeway at Point Comfort, where roosts have been noted for nine years from 23 October to 10 November. Potential direct mitigation in the Texas Coastal Funnel should focus on causeways from Point Comfort to Corpus Christi during 25 October to 15 November.