Watching out for Wildlife: Safety Corridors and Sensitive species

Often when we think about sensitive species, we think about those determined to be threatened or endangered due to loss of critical habitat or other human related activities. However, many common species are afforded the same protections as species in decline due to other factors such as time of year. In the vegetation and fuels management world we regularly encounter these restrictions during breeding bird season, roughly from March to September each year. During this time period, we take great lengths to protect against disturbing nesting birds so that their offspring have the best chance for survival. In order to implement projects in the Spring, CLERC biologists survey project areas for nesting birds prior to any chain saws running on the ground. It was during one of these surveys that we discovered a hotbed of bird activity

Before work done - images captured by Fire and Forestry Project Coordinator Grant Coleman

After work is done - images captured by Fire and Forestry Project Coordinator Grant Coleman

The Greenlaw Forest Health Project covers roughly 66 acres of land in the Loch Lomond region of Lake County. The project area has experienced significant large tree die off, and has excessive ground fuels that have taken over without competition from a prominent overstory. Much of the project can be seen from the southern end of Harrington Flat Rd, which serves as a primary evacuation route for the community living in that area in the event of a wildfire. In fact, one of the primary goals of this project is to harden this evacuation route by eliminating the vegetation that crowd the roadside, most notably the large stands of highly flammable manzanita.

Adult Coopers Hawk

Before work began, we performed the routine nesting bird surveys. In total, the surveys took around 4 days to complete, and  on the second day we made a discovery that would surprise us all. We found not one, not two, but three Cooper’s hawk fledglings! The birds were immediately noticeable by their call, raspy juvenile voices echoing throughout the forest as they communicated their locations to their parents. 

A typical survey consists of walking a treatment unit and looking for obvious signs of occupation by a nesting bird. Signs could be anything from obvious nest structures, tree cavities, or even whitewash around a roosting site. From these observations we can typically glean information on the habitat quality for most species in the area. In conjunction with habitat features, we also take note of species that are present in the area. This is done by recording what birds we see, but more importantly what birds we hear while out surveying. By adding these observations to our data, we can infer the potential impacts the treatments could have on species present regardless of nesting status. 

During this particular survey, we heard the juvenile birds long before we saw them. Once we located the birds, it was obvious that they were all recently fledged as they were practicing their flying skills clumsily flapping between neighboring trees. Immature birds can be distinguished from adults due to their overall brown appearance, brown-streaky markings on their chests, and their bright yellow eyes. Once they mature, adult birds will lose their brown coloration for slate gray wings, reddish-barred chests, and reddish-brown eyes. A distinctive visual characteristic for these birds across most age groups are their long rounded tails with a wide white terminal band.

While Cooper’s hawks are not all that uncommon, finding such a high concentration of birds in a single area speaks to the richness of the habitat that they are located in. These young birds will spend time with their parents learning how to fly and hunt for food before they are old enough to search out new territories. During this developmental period, it is important that we as stewards of the land do not perform any actions that may negatively impact them. Raptors such as these typically prey on small birds, rodents, and the occasional reptile. They are quite adept at flying through forest stands due to their small wing span and overall stature compared to other birds of prey. In fact, these birds are forest hunting specialists and use dense tree cover and foliage to conceal themselves as they hunt for prey. In order to protect their foraging habitat we created a buffer around their nest using flagging so our contractor would know to stay out. (see map)

So, how can a project geared towards removing vegetation ultimately benefit species such as the Cooper’s hawk? By eliminating roadside fuels, we reduce the probability of a common ignition source for many devastating wildfires - cars. By securing the roadway as an evacuation route for human inhabitants, we are also preventing human caused fires from traveling into wildlife habitat.