Birds, Bees, and “Natural Areas”
May 21, 2013 4 Comments
One of the concerns we have with the way our wild lands are being managed is the disrespect for habitat. Many of those who support these actions – felling ‘non-native’ eucalyptus trees, removal of trees that are dead or dying even if they’re not hazardous, stripping away ivy and understory vegetation – don’t actually realize the impacts on the wildlife that call those habitats home. (All the photographs here are courtesy wildlife photographer Janet Kessler.)
EUCALYPTUS IS IMPORTANT AS HABITAT
Eucalyptus trees are hugely important as habitat trees. They provide cover and nest sites for birds as large as Great Blue Herons and Double-Crested Cormorants and hawks and Great Horned Owls – and as small as Pygmy Nuthatches.
[Edited to Add: For more pictures of heron and cormorant nests – and the story that goes with them – please see the latest article on the Coyote Yipps blog. ]
Their branches and trunks provide a hunting ground for small birds like kinglets and Brown Creepers.
Since they flower in winter when few other food sources are available, they provide nectar for insects – and the birds that feed on the nectar, the insects, or both. Honeybees in particular depend on winter-flowering eucalyptus. Cavities provide nesting spot for some birds – and even bees, like Glen Canyon’s last remaining bee hive tree.
DEAD TREES ARE IMPORTANT
Dead or dying trees – of every species – are valuable habitat, for two reasons. They’re more likely to have cavities that are suitable for nesting (and are easier to excavate for woodpeckers and other cavity-building species). They also have bugs that come to feast on the decaying wood, and that’s bird-food.
Unfortunately, the San Francisco Recreation and Parks Department – and now UCSF in its management of Sutro Forest – looks to remove ‘snags’ and dying trees. They’ve been removed in Glen Canyon Park, and in Golden Gate Park, and this fall, massive removals could start in Sutro Forest.
If that happens, it will have a negative impact on all the woodpeckers and cavity-nesting species of birds and even bats. It’s extremely important to leave these ‘in-decline’ trees as habitat, unless they are actually hazards.
THE VALUE OF IVY AND THICKETS
Smaller birds and animals in particular need the cover provided by ivy and understory plants to hide from predators – and to nest.
Here’s a picture of a tiny Bewick’s Wren outside its Glen Canyon nest, taken in 2012. The tree it’s nesting in is so ivy-covered you can’t actually see it. The nest is completely hidden.
Here’s the same tree this year. The ivy is gone, the understory mowed down. Is the wren coming back? Not too likely.