Scratch that last post

Yesterday,Monday 4/19, about 5 nests were visibly occupied, some by one bird some by two.

Now I am wondering if female birds were flying off the nest because the eggs had not been laid. Or if the laying birds hunker down in the nest in such a manner that they can't be seen.

At least: construction can't begin this season (is my understanding of "the rules," whatever they are. Laws? I'll tell the biological powers that be.

With any luck, people will post here pertinent observations, particularly sightings of eagles or other raptors. Send then as comments.

New nest site?

The old nests aren't being used anymore, however there still seem to be herons in the area. See Carolyn's comment on the last post.

The new nesting location, if there is one, is presumably not accessible to me. So my part in spreading the word about the birds appears to have ended. Also, I'm not sure that publicizing the new nest location would be in the best interest of the herons.

I'd love to hear from others about this. There was a glitch in my picking up the comments, but I'll try to stay on top of them now. Is anyone else interested in posting their observations?

Gone

Though I saw many herons sitting on the nests earlier this month, for the past week they've been gone, presumably due to eagle predation. Jenna, who lives in the house next to the heronry (she painted the beautiful "keep out" sign now standing at the end of the road) says she has seen eagles sitting on a log in the ravine, eating something.

Also, there's a yellow city sign now posted at the end of the road, a notice of the subdivision for the six townhouses.

If the herons are gone, there's no point to the website. I haven't put the signs up this year.

Herons return

On Sunday 3/28 at about 4 pm, 43 herons were seen circling in the air, and subsequently landed in some fir trees along Rogers street, just north of the food co-op. This is one block from where the (approximately) 18 nests were constructed last year.

Yesterday (3/29) two birds per nest were seen perched in the five nests that can be seen from the road that traverses the rookery. I haven't previously seen these nests in use this year. Last year the birds that nested here were subject to harassment from eagles, such that no birds successfully fledged (I don't think).

As noted here, the developer of the townhomes that are to be built on Dickinson has renewed his permit, though no building activity has commenced yet.

Return?

Jean, who lives on Woodard Ave, reports that she was leaving the co-op on March 1 and saw 30 herons in the sky. They settled in trees at the end of Bowman Avenue, a few blocks from the location where they've nested in previous years.

Breeding season has commenced

According to the literature, the heron breeding season begins in mid-February. Amy Buckler, the city planner, reports that the developer has renewed his land use application since the original approval expired. The development still calls for 6 townhomes to be built on the site that has been cleared directly east of the rookery.

The status of the land the rookery actually sits on is unclear. It is still owned by an out-of-state owner, according to the county records (which Amy Buckler says are often need to be updated.) No for sale sign is posted there. Yet the fact that the developer considered expending the number of townhomes by utilizing this site suggests that it is up for grabs.

I posted the site plan for the town homes at right, with the other maps. If you click on it, it will enlarge.

Disturbance

Gretchen-the-biologist sent me a bulletin on herons a while ago. It's not for posting, because it was only a draft document ("Survey protocol for measuring reproductive productivity at Pacific GBH breeding colonies"), but I think it's okay for me to post this excerpt, because it is pertinent:

Colony response should be tested and recorded using Data Sheet #3 (Colony Disturbance Summary). The various responses by birds are as follows (record all responses that occur):

No response. Birds ignore the observer. They may stare and subsequently look elsewhere, as other activities occur in the colony.

Stare. Birds view is fixed on the observer. This is particularly noticed when birds peer over the nest at an observer in the colony.

Chortle or cluck. The first sign that birds are disturbed is a low nasal “cluck” (Vennesland 2000), or "chortle" (Moul 1990). This activity may be continuous or start and stop as movement of the researcher occurs.

Stand. Incubating birds rise off the nest, or move around in the nest.

Off nest. Birds leave the nest, but stay on a branch nearby.

Scream. After chortling, the next progression in vocal alarm is screaming. This is a very loud vocalization and usually occurs with, or immediately prior to, flushing. Researchers must never cause this disturbance as it shows extreme stress (such as during a successful predator attack).

Flush/Return. Birds fly away, typically as individuals, circle and return to the nest. Researchers must never cause this disturbance, as it can lead directly to colony abandonment.

Flush/Leave. Birds fly away as a group and do not return until observer leaves the colony. Researchers must never cause this disturbance, as it is likely to cause colony abandonment.

I'm not sure how researchers are to execute this test. When the leaves come down it'll be interesting to get the nest count.