Spatially Explicit Modeling of Community Occupancy using Markov Random Field Models with Imperfect Observation: Mesocarnivores in Apostle Islands National Lakeshore

Abstract

We hereby developed a Markov random field based spatial-explicit community occupancy model that accounts for spatial auto-correlation and interspecific interactions in occupancy simultaneously while also account for interspecific interaction in detection. Simulation results showed the new model can distinguish different mechanisms. We applied this new model to camera trap data of Fisher(Pekania pennanti)-Marten(Martes americana) and Coyote(Canis latrans)-Fox(Vulpes vulpes) system in Apostle Island National Lakeshore. Results showed the observed partition pattern between marten and fisher may be better explained by a flipped mainland-island source-sink pattern rather than competition, while we detected some evidence that on top of the mainland-island source-sink pattern, there was a positive association between fox and coyote than deserve further study.

Comparative biogeography of volant and nonvolant mammals in a temperate island archipelago

“…Furthermore, Allen et al (2019) found that marten presence on an island was determined by human avoidance and direct competition with larger carnivores (i.e., fisher) to a lesser degree, possibly explaining why martens were more likely to colonize islands further from the mainland. However, Shen et al (2021) found partitioning between martens and fishers to be mostly explained by their opposing source-sink dynamics, rather than direct competition. While more research is needed, island isolation likely has a more positive effect on the presence of sensitive species like marten than other carnivores, where more isolated islands provide refuge from mainland stressors (Allen et al, 2019;Shen et al, 2021;Smith et al, 2021).…”

“…However, Shen et al (2021) found partitioning between martens and fishers to be mostly explained by their opposing source-sink dynamics, rather than direct competition. While more research is needed, island isolation likely has a more positive effect on the presence of sensitive species like marten than other carnivores, where more isolated islands provide refuge from mainland stressors (Allen et al, 2019;Shen et al, 2021;Smith et al, 2021).…”

“…Therefore, large mammal diversity would more likely be regulated by island isolation, where an island's diversity is dependent on its proximity to the mainland or other islands for continual colonization, consistent with the equilibrium theory of biogeography (Sax & Gaines, 2011). However, Smith et al (2021) and Shen et al (2021) independently detected reversed source-sink dynamics for American marten (Martes americana) at the Apostle Islands, where the archipelago acts as metapopulation and source population, with individuals dispersing more often from the islands to the mainland. Smith et al (2021) suggested this reversed dynamic could be a result of more complex forest habitat on the islands provided partly by Canada yew being able to flourish in isolation from mainland disturbances (i.e., deer herbivory).…”

Random Fields in Physics, Biology and Data Science

“…Other applications of random fields in biology include demography and selection to study weakly deleterious genetic variants in complex demographic environments [111] and for species clustering [112], in population genetics. MRFs have also been applied to understand species distribution patterns and endemism and to unveil [113] interactions between cooccurring species in processes governing community assembly [114]; as well as for spatially explicit community occupancy [115] in ecology.…”