Natural History and Environmental History
of the
Great Blue Heron
at
Newport Bay, Orange County

Young Heron Life History
and
Adult Heron Life History

by
Robert "Roy" Jan van de Hoek
Field Biologist, Vertebrate Zoologist, Invertebrate Zoologist, Botanist, Ecologist, Archaeologist, & Geographer
Director of Research and Restoration for Wetlands Action Network
P.O. Box 1145, Malibu, CA 90265 - (818) 222-7456 2003

Introduction
Newport Bay is a very large estuary with seemingly abundant resources for the Great Blue Heron. So why is their such a small population of Great Blue Heron. And why do only 10 pairs (20 adults) breed in Newport Bay, while the rest of Orange County has about 100 pairs. It seems odd that only 10% of the known breeding of Great Blue Heron is at the largest estuary complex of Orange County. It follows therefore, that only about 10% of the young Blue Herons of Orange County are raised at Newport Bay. What are the biogeographical implications and ecological reasons for this phenomenon of low nesting numbers in Newport Bay? And correspondingly, why do no Egrets, neither the Great Egret or Snowy Egret nest at Newport Bay? The biogeography of nesting Egrets is common at other wetlands in Orange County but none at Newport Bay, which seems odd. And lastly, for comparison, why do no Black-crowned Night Heron nest at Newport Bay? They nest elsewhere in Orange County but not at Newport is another mystery. Also, no Green Heron are known to nest at Newport Bay? Could it be that Newport Bay is not good habitat for the Herons and Egrets at Newport Bay? What can be done to attract more kinds of Herons and Egrets to nest at Newport Bay. And interestingly, no White-tailed Kite, American Osprey, or Bald Eagle nest at Newport Bay, which again seems very odd from a biogeography and ecology perpective.

Material and Methods
Research methods utilized the literature and personal communication to track the history of the last 12 years of the biogeography of the Great Blue Heron at Newport Bay. In 2002 and 2003, I began to conduct field observations on the behavior and local movements of the Great Blue Heron in Newport Bay. This field research is an outgrowth and extension of my field research into the biogeography of the Great Blue Heron at the Ballona wetlands and Marina del Rey, which has been ongoing since 1997.

The environmental history of Harbor Island is important to understand in terms of why the Great Blue Heron nested there for five consecutive years of 1989 to 1993. Originally Harbor Island was a salt marsh island that was close to sea level. On high tides the island disappeared but on low tides it rose out of the water. It appears likely that it supported both eelgrass and cordgrass. Harbor Island may have been habitat for the Light-footed Clapper Rail and its prey item, fiddler crabs, prior to its alteration.

In 1927, a dredge placed mud taken from a deeper channel onto the tidal island, which destroyed the eelgrass and cordgrass vegetation. According to Duncan Gleason: "The firm of Sparks and McClellan received a contract in 1927 to deepend the water around a marshy spot near the mainland. They built a small suction dredger christened Little Aggie and the sand that it discharged was leveled off to form Harbor Island. A fringe of trim yachts in their slips circles the thickly built up community and arched bridge leads to the outside world." I mapped Harbor Island to be approximately 1,300 feet long by about 400 feet wide. In essence, Harbor Island is roughly 1/4 mile long and 0.1 mile wide.

Research on the internet web revealed that Harbor Island has only 31 homes. One particular home is on 1/2 acre with 11 rooms and 18,000 square feet. The home has a selling price of $24,000,000.00. There is 302 feet of deep-water shoreline for this one home, that is described as a "waterfront oasis" and "Harbor Island Haven." The realtor report states that this home has more "linear feet on the bay than any other private home in Newport!" It appears that the great size of the property and also that so few homes are on the island, creates an open atmosphere with just the right amount of vegetation with a tall pine tree, that the Great Blue Heron, 10 adult females and 10 adult males find it suitable to nest on the island.

Results
The Breeding Bird Atlas of Orange County supplied a table of the status of nesting of Great Blue Heron in Newport Bay. That data seems to have been compiled, at least in part, from Pete Bloom in his report of 1992 as follows:

Year ... Number of Nesting Pairs
1988 ... 0 nest, however there may have been one nest there already
1989 ... 1 nest recorded so not likely that they were there in previous years.
1990 ... 10 nests recorded [20 adult Herons]
1991 ... 10 nests
[20 adult Herons] 1992 ... 10 nests
[20 adult Herons] 1993 ... 10 nests
[20 adult Herons] 1994 ... Trees pruned heavily, nests fall to the ground, no new nesting
2003 ... No evidence of nesting by Robert van de Hoek

Gallagher (1997) reported that they nested on Harbor Island. Harbor Island is located in the central part of lower Newport Bay. This part of Newport Bay does not belong to the Upper Newport Bay Ecological Reserve. The Reserve is managed by the California Department of Fish and Game. Although, the Heron rookery on Harbor Island is not in the Reserve, the nesting Herons still fall under the jurisdiction of the Department of Fish and Game and the U.S. Fish and Wildlife Service.

Gallagher (1997) reported that Pine trees were used. Further research will indicate what species of pine tree and the height of the pine tree(s). Evidence for nesting inclination will also be calculated by estimating if there is not shrubbery under the tree canopy. Also the first branch will be measured in feet to see how high above the ground the nest is located.

Discussion
Preliminary results indicate that only about ten pairs of Great Blue Heron nest in Newport Bay. The factors involved are human impact both by an un-natural high number of raccoons, opossums, cats, and Red Fox, which prevent the Great Blue Heron from consideration of nesting on the ground on islands in Newport Bay. Herons have been known to nest on the ground on islands in a marsh. The Audubon Society in Marin County and the California Academy of Sciences at Golden Gate Park place metal plates that girdle trees so that small mammal predators such as the raccoon and opossum cannot rob the heron nests of eggs. The impact of Crows and Gull species are a threat to consider and would be more prevalent in an urban area such ast Newport Bay. There are tactics that can be used to discourage Crows from visiting and stealing young herons, either as eggs or chicks.

Lastly, Henry David Thoreau stated that he believed the Great Blue Heron was worthy of American citizenship. If so, then the Great Blue Heron nesting on a small exclusive island in Newport Bay adjacent ot an $24,000,000.00 homes, for economic purposes, is worth $24 million in its tree that it nests in and these large birds are therefore practically priceless. Of course, we birdwatchers and nature lovers knew long ago about the great beauty and majesty of a Great Blue Heron, and either consciously or unconsciously we have said to ourselves inwardly in our mind, at least, that the Great Blue Heron is priceless.

References Cited
Bloom, Peter H. 1992. Orange County Great Blue Heron Research Project. September 1991 - June 1992. Unpublished Report prepared by Western Foundation of Vertebrate Zoology for The Irvine Company. 6pp.

Gallagher, Sylvia. 1997. Atlas of Breeding Birds of Orange County. 264p.

Gleason, Duncan. 1958. The Islands and Ports of California. 201p.

Hamilton, Robert and Douglas Willick. 1996. The Birds of Orange County. Sea and Sage Audubon. 150p.

van de Hoek, Robert. 2001. Great Blue Heron. Report submitted to the California Coastal Commission and California Department of Fish and Game. 71p.

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