Conservation and Management

Effects Of Human Activity

Forest clearing for agriculture can increase forest edge, preferred habitat for chickadees. Feeders enhance chickadee survival (Desrochers et al. 1988, Brittingham and Temple 1988). Overzealous forest management can reduce or eliminate natural nest sites. Where natural sites are rare, nest boxes may be accepted, especially if partially filled with sawdust. Boxes having holes 1.13–1.25 inches (2.86–3.18 cm in diameter) are best, as these eliminate larger competitors such as House Sparrows (Passer domesticus).

Chickadees living in mature forests and regenerating forests in British Columbia differ in a number of ways. First, regenerating habitat appears to be poor-quality habitat with reduced breeding success and more frequent nest abandonment (Fort and Otter 2004a). This effect is greater in years with atypical weather (Otter et al. 2007b). Territorial intrusions occur more frequently than in mature forest, suggesting either territory defense is reduced or territories contain insufficient resources (Fort and Otter 2004b). Fewer neighbors can be heard singing at dawn in disturbed habitat, indicating that communication networks may be compromised (Hansen et al. 2005). Second, differences that are often detectable between high and low-ranking birds are not evident in regenerating forests. Song rate at dawn is lower in high-ranking males, reducing the reliability of the signal (van Oort et al. 2006). Third, low-ranking individuals fare disproportionably poorly in regenerating forests. Low-ranking individuals feed nestlings at lower rates in poor habitat (van Oort et al. 2007) and have lower nesting success (Fort and Otter 2004a) than high-ranking individuals. This difference is not evident in mature forests.

Forest fragmentation had no affect on chickadee body condition in winter across different levels of forest cover (Turcotte and Desrochers 2008) but did increase risk taking behavior (Turcotte and Desrochers 2003). Chickadees prefer to move through continuous forest and avoid crossing gaps. Forest fragmentation can constrain movements (Bélisle and Desrochers 2002). For a detailed review of the effects of forest fragmentation on Parid behavior see Desrochers and Bélisle (2007).

In Colorado, Chickadee abundance was negatively related to distance to houses in a suburban environment, suggesting they are a human-sensitive species (Odell and Knight 2001). Chickadees were significantly more abundant in undeveloped compared to both high and low density (of homes) developed landscapes. In Washington, urban development also had a negative effect on chickadee abundance (Donnelley and Marzluff 2006). Chickadees can breed successfully (though at lower densities) in suburban landscapes where natural snags are available (Blewett and Marzluff 2005), and winter survivorship is similar between suburban and food supplemented forest habitat in Pennsylvania (Egan and Brittingham 1994).

Little apparent affect of diflubenzuron application (for gypsy moth infestations) on body fat level or diet composition (Sample et al. 1993,Whitmore et al. 1993). Declining forest health due to acid rain also has little effect on breeding success (Mahony et al. 1997). PCB contamination results in abnormal song structure but does not influence song output (DeLeon and Dhondt 2008).

Habitat models for the Northeast predict that climate change will result in negative changes in incidence and habitat occupancy of Black-capped Chickadees (Rodenhouse et al. 2008). Habitat change models for the Willamette Basin in Oregon predict a decrease in population size from projections for 2050 (Schumaker et al. 2004).