3.1 Spatial overlap and habitat suitability
Across Connecticut, the landscape was more suitable for eastern
cottontail than New England cottontail. We found New England cottontail
habitat suitability ranged from 0.00 to 0.83 and eastern cottontail
habitat suitability ranged from 0.00 to 0.97 (Figure 2). Models for both
species performed well, with an average AUC value of 0.92 (SD = 0.01)
for New England cottontail models and 0.84 (SD = 0.01) for eastern
cottontail models. In total, we found 48.22 ha were highly suitable for
New England cottontail (top 25% of suitability values) and 56,769.39 ha
were highly suitable for eastern cottontail (top 25% of suitability
values). The percentage of highly suitable New England cottontail
habitat overlapping with highly suitable eastern cottontail habitat was
100% and the percentage of highly suitable eastern cottontail habitat
overlapping with highly suitable New England cottontail habitat was
0.00%.
Both species’ habitat suitability was associated with the proximity to
and spatial pattern of young forest, shrubland, and understory
vegetation. The MSPA predictor had the largest contribution to both the
New England (28.34%) and eastern cottontail (27.18%) habitat
suitability models (Table 2). The MSPA categories most influential to
New England cottontail habitat suitability were core, core openings, and
perforations, while all MSPA categories had similar influence on eastern
cottontail habitat suitability except background (Figure 3). The land
cover most commonly comprising core openings was mixed forest, with
86.63% of the core openings land cover being mixed forest (Table S1).
Habitat suitability decreased with increasing distance from shrublands
and transitional to forest for both species. However, the contribution
of shrublands and transitional to forest differed between the two
species, where shrublands contributed more to the New England cottontail
model (13.99%) than the eastern cottontail model (2.58%) and
transitional to forest contributed more to the eastern cottontail model
(25.76%) than the New England cottontail model (9.64%). Understory
composition also contributed highly to the habitat suitability for both
species, with proximity to a mixed invasive understory contributing more
to the New England cottontail model (10.61%) than eastern cottontail
(1.28%) while proximity to a native understory species, greenbrier,
contributed more to the eastern cottontail model (9.10%) than New
England cottontail (6.37%). Distance to buildings also contributed
highly to both cottontail species’ habitat suitability, 14.38% for New
England cottontail and 18.10% for eastern cottontail. New England
cottontail habitat suitability was highest at least 250 m away from
buildings, while eastern cottontail habitat suitability remained high
across all distances to buildings (Figure 3, Table 2).