Herons Forever News

Black River updates are posted weekly by Herons Forever’s volunteer photographer, Mike Hamilton. See his photos on his website http://home1.gte.net/mikeham, which he updates every weekend. If you would like to receive his daily emails, contact him at mikeham@verizon.net.

 

July 11, 2008, End of this Year’s Nesting Season

On July 9^th, we watched ten newly fledged herons exploring the shallows along the far edge of the Black River pond. They made tentative stabs at the water as they tried their luck hunting for small prey. We were surprised to hear no sounds of nestlings inside the colony. It meant that the young birds across the pond were the last great blue heron chicks of the 2008 season.

Just a week earlier, on July 2^nd, we had heard 30 to 45 chicks still in their nests. Their constant guk-guk-guk sounds should have meant that we would continue to see fledglings up through the end of July and perhaps into August.

What might have happened to the nestlings? We can only speculate. Perhaps someone set off fireworks close to the colony during the July 4^th holiday, which can startle the nestlings and cause them to fall from their nests. If they leave their nest before they are able to fly, their parents do not have the ability to feed them or protect them from predators. Perhaps less likely is that the resident bald eagle parents might have taken the nestlings to feed their recently fledged eaglet. If he was still in the nest, then this seems like a more likely scenario, but he is not.  

We also saw 23 fledglings that day (July 2). By now, those fledglings have staked out their locations where they will spend the winter. Our Fannini subspecies here in the Puget Sound region does not migrate. Instead, they disperse to nearby locations, including the Nisqually Delta, the Skagit Flats, and along the shores of Renton, Burien, and West Seattle. For more informations, see The Great Blue Heron.

Total number of fledglings

The total number of heron fledglings this year is approximately 30 to 40. We hoped it would be more, and it is possible that that the number is slightly higher, as some fledglings may  have stayed away from the main pond and used the back side of the forest as a result of the adults building deeper into the forest this year to put more distance between the nesting eagles and themselves. 

Hope for the long term viability of the colony

Despite the impact the eagles are having on the colony, we are encouraged by the heron’s new aggressiveness against their more-powerful adversary. A single heron is no match against a bald eagle, however, this year we saw the herons prevail again and again when they worked together as a tightly organized team to protect their young.

From our vantage point across the pond, we cheered the herons every time we witnessed an attempted attack that resulted in the eagles returning to their nest empty handed (or more accurately, empty taloned).

By April, a month after the adults began the nesting season, every nest was occupied and new ones were being built, bringing the total nest count to approximately 90 by the time the cottonwoods leafed out in mid-April. This tells us that the herons were fully committed to this location for raising their young despite the close proximity of the nesting eagles. Unfortunately, within six weeks, about half of the nests were empty after repeated eagle attacks on the heron's eggs and nestlings.

The most experienced herons often rally in this situation and remain to defend their territory while some younger birds leave to build new nests, establishing small satellite colonies nearby. The older birds have more experience protecting their nests and often have better success defending their chicks, according to researchers here and in British Columbia. The new colonies consisting of less experienced parents often fail to yield many if any fledglings.

The number of fledglings at Black River this year is similar to the 2007 count. This contrasts with previous years, when an average of approximately 330 chicks fledged from up to 140 nests, and the eagles nested 1,000 feet and many trees away. They had no line of sight visibility into the heron colony. This is very different from the current situation – the eagles are only 400 feet away and facing directly into the colony. 

Despite the heron’s losses over the past two years, this colony is doing better than many others in the region. We are hopeful that the relative success of our herons could bode well for its long term health. The overall eagle population has increased tremendously in the past 30 years, making it impossible for herons and other wildlife to find safe refuge from this top-of-the-food-chain predator.

We will continue to cheer the herons on as they fight back against their adversary, and welcome each and every young heron who survives their perilous eight weeks in the nest to make a first flight and join with the others to make her way in this corner of the world they call home.

 

Introduction to Herons Forever and the Black River Heron Colony

Herons Forever is a Puget Sound-based all-volunteer nonprofit organization. We are the only group dedicated solely to the protection of Renton’s Black River great blue heron colony, the largest in the tri-county region and one of the largest in Washington state. In 2006, the colony consisted of at least 121 active nests, and produced more than 300 fledglings. (fledgling: A young bird that has taken its first flight.)

Bird-lover and conservationist Suzanne Krom founded the organization in 1989 in order to protect the colony from the impacts of nearby development. She continues to lead the now-600 member organization as president. Thousands of people have helped make Herons Forever’s efforts successful by contributing their time and resources. (Click the About Us link in left margin.)

The colony is in Renton, just west of the intersection of SW 7th and Oaksdale SW, at a junction of the old Black River and Springbrook Creek. The P1 Pond was dredged in 1985, and the next spring six great blue herons built three nests overlooking the same pond they have continued to choose as their breeding location ever since. This year, 2007, marks their 22nd year at Black River. (Scroll for History of Black River.)

Our herons belong to a unique subspecies that does not exist anywhere else. The fannini heron does not migrate, which is the primary difference between these herons and all the others in the United States. Biologists are concerned about the long-term health of the fannini population as their numbers are declining at an estimated 6% per year. (Click The Great Blue Heron link in left margin to learn more.)

 

History of the Black River

The Black River Riparian Forest is named in memory of the river that used to flow through the area where the herons now nest.

The Black River ran out of the southern end of Lake Washington. It flowed south through Renton, and then veered west and merged with the Green River to form the Duwamish River.

In 1916, the lowering of Seattle's Lake Washington during the construction of the Lake Washington Ship Canal drained the Black River and caused it to dry up.

For more information and photos, click here.

 

Duwamish Tribe

The Duwamish tribe had a village located along the Black River for at least 1,400 years and perhaps for thousands of years. The Duwamish were still there in 1916 when the river dried up.

In the early 1990s, anthropologist Jim Chatters conducted an excavation near the Black River Riparian Forest. Over 100 boxes of Duwamish tribal artifacts are stored with the University of Washington's Burke Museum from that dig.

The Duwamish, including Chief Sealth (178?-1866), for whom Seattle is named, were among the signers of the Point Elliott treaty. The treaty guaranteed both fishing rights and reservations, neither of which the Duwamish have today. Recently the tribe submitted a request to the Federal government for  For more information, click here and here.