Navigating urban environments: Red Squirrel Sciurus vulgaris ecology in Irish cities

With increasing global urbanisation, urban ecology has become an essential aspect of native species conservation. The Eurasian red squirrel (Sciurus vulgaris), typically found in rural woodlands, can also thrive in urban parks and green spaces if there is sufficient tree cover., Maintaining connectivity between suitable habitats is crucial to prevent population isolation and link established populations. This project investigated the suitability of urban habitats for red squirrels. The initial study was conducted in Galway City, an urban area in western Ireland where invasive grey squirrels (Sciurus carolinensis) are absent. Using non-invasive monitoring techniques, including hair tube surveys, trail camera surveys, and a citizen science survey, we determined the distribution of red squirrels across Galway's urban centre. Red squirrels were found to be established in three woodlands in Galway's urban centre, with transient red squirrels from these populations observed in surrounding green urban areas. Notably, they were absent from other seemingly suitable woodlands in the city. Red squirrels preferred broadleaf habitats in summer due to greater food availability but were detected less frequently with hair tubes in that habitat during spring. Squirrels observed in green spaces surrounding woodlands exploited anthropogenic food sources, including bird feeders, a behaviour linked to higher population densities in other urban areas. The population demographics of one of the identified red squirrel populations in a fragmented woodland in Galway were examined through live trapping. Radio tracking techniques were employed to examine the habitat usage of individuals in Menlo. Mean population densities were estimated at 0.63 squirrels per hectare using the Lincoln Index in a 23.8-hectare broadleaf woodland. Mean body weight of the squirrels was 268.6g, which is lower than typical values from Britain and Ireland. The weight of male squirrels exhibited greater stability over the course of the study compared to females, which demonstrated more pronounced fluctuations. Low fecundity was attributed to lower body weight, resulting in fewer second litters.

Publisher

University of Galway

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International

cbn

Collections

University of Galway Theses (PhD Theses)