Raccoon (Procyon lotor)
Movement and Activity
Movement rates did not differ between sexes (P = 0.323) or across seasons (P = 0.520) during diurnal periods. Concerning movement rates during crepuscular and nocturnal periods, we detected interactions between period and season (P = 0.003). Movement rates differed between sexes (P <0.001) and across season/period combinations (P = 0.015). Male raccoons moved at greater rates (351.9 m/hr) than females (282.9 m/hr). Movement rates were greatest during parturition-young rearing within crepuscular periods (380.4 m/hr). Final analyses of raccoon activity on TWMA are being completed. However, preliminary findings suggest that raccoons were most active during crepuscular and nocturnal periods. Overall, raccoons were least active during fall-winter.
Movement rates differed moderately between sexes (P = 0.090). Movement rates differed across seasons (P = 0.002) with greatest movement during parturition-young rearing and fall-winter. Similarly, movement rates differed across periods (P <0.001) with greatest movement rates occurring during nocturnal and crepuscular periods relative to diurnal periods.
We detected interactions between season and period to affect percentage activity (P <0.001). Mean percentage activity did not differ between sexes (P = 0.869). Mean percentage activity differed across season/period combinations (P <0.001) with raccoons displaying greatest activity during crepuscular periods in parturition-young rearing (96%) and nocturnal periods of parturition-young rearing (96%).
SummaryRaccoons on TWMA and GP exhibited differential movement rates across biological seasons and within day periods. Raccoons are generally considered to use a promiscuous or polygynous mating system. Adult male raccoons may expand movements during breeding periods and are often most active during breeding periods. Hence, males would be expected to increase movements during breeding-gestation, presumably to increase potential mating opportunities. Although male movement rates were generally greater than females, raccoons on both areas exhibited the lowest movement rate during breeding-gestation and greatest movement rates during parturition-young rearing. We suggest that seasonal resource availability and habitat quality influenced seasonal raccoon movement rates.
Raccoons are opportunistic omnivorous foragers, hence they are able to efficiently obtain a multitude of prey items. As opportunists, raccoons are adept at exploiting temporally and spatially variable food resources and often concentrate their activities in areas abundant in these resources. Raccoons readily consume fleshy fruits, particularly blackberries and dewberries, during spring and summer. Although clearcuts were predominately distributed across both study areas, they were separated by stands > 15 years-old of equal sizes as per timber harvest procedures implemented by the US Forest Service and GP. This likely resulted in raccoons being required to move considerable distances between quality foraging habitats during parturition-young rearing.
Generally, habitat patch quality increases when food resources are abundant. Optimal foraging models predict that as movement distances increase, larger prey are likely to be favored as the range of prey sizes providing a positive energy gain decreases. Additionally, the more active the search behavior used, the higher the energetic cost. However, raccoons, being primarily crepuscular and nocturnal foragers, may be energy maximizers. For animals that have a fixed amount of time to forage, fitness increases with increasing amounts of energy obtained. Hence, raccoons may effectively balance energy losses through rapid movements and searching patterns during parturition-young rearing, when locating a high quality patch likely provides greatest net energy gain. Additionally, when resources are abundant, but widely distributed, raccoons should abandon patches of decreasing quality to quickly search for other high quality patches. These factors perhaps increased movements during parturition-young rearing and fall-winter, the latter season being recognized as a period of decreased resource availability for raccoons. During both seasons, habitat quality may vary drastically within finite patches, hence raccoons may be forced to search habitats more quickly to locate patches providing the greatest energy gain.