Please Visit Us at Stow Lake

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**Click to View The Live Heron Cam**

(Note: The Heron Cam is not turned on because there are no Active Nests on Heron Island. The herons have moved to another island nearby.)


Activities for Home and in the Classroom:

History of the Stow Lake Colony:

We have put together some fun and educational activities that you will enjoy. These engaging activities will teach you more about the great blue heron, its habitat, physiological struture, predators, etc.  . . . Learn More

Nancy DeStefanis, Executive Director of San Francisco Nature Education, discovered the first nesting pair in San Francisco’s Golden Gate Park, in June, 1993. . . Learn More



* Keep our Heron cam streaming

Nancy's Blog: August 12, 2015

On August 5, 2015, the last chick in the nest departed. The total of chicks fledged at Stow Lake since 1993 is now 167!

An interesting note: when I first spotted the chicks in mid June, I thought I saw three chicks. After a few days, there were only two so I thought I was mistaken. However, Photographer Frank Marino kindly sent me photos confirming there were three chicks on June 17th but only two in photographs taken on June 20th and afterwards. Hard to say what happened to the youngest chick. See photo below.

For more information on the Stow Lake Great Blue Heron Colony, please see our Heron Chronology under Programs on our website. More photos coming in our September Newsletter.

Photo courtesy: Frank Marino

Nancy's Blog: July 25, 2015

This morning, our last day of Summer Heron Watch, the oldest chick flew out of the nest! The chick left about 10:30am and did not return while we were there.

The second chick jumped up in the nest as we departed at noon. I would expect this chick to fledge sometime in the next week or so. The parents will keep feeding the chicks until they depart for good.

After that, all the herons go their own way. They may stay in the park or in the City.

About two weeks ago, I saw one of the fledglings from Heron Island standing in its' old nest!

If you have any comments, feel free to email me at info@sfnature.org

Photo - copyright Nancy DeStefanis 2015


Nancy's Blog: July 10, 2015

The parent heron flew in and fed the two chicks around 5:45pm. After regurgitating into the nest, the adult flew off.

The chicks appear to be at least six weeks old.

SF Nature Education volunteers will be at Stow Lake on Saturdays July 11, 18 and 25 from 10-noon showing the chicks with spotting scopes. Please come by for this free program. See the map below for location of the nest and spotting scopes.

Photo - copyright Nancy DeStefanis 2015


Nancy's Blog: June 22, 2015

I decided to check on the two nests (#5 and #6) which we had spotted in early May located on a Monterey Pine tree on the small island near the Waterfall.

This is the first time in the history of Stow Lake that great blue herons have nested on this island.

Lo and behold two chicks emerged from deep down in nest #6. The chicks could be about three to four weeks old. This nest is located at the top of the tree. One parent flew in yesterday to feed them then left again-leaving the two chicks alone. See my attached photo.

The other nest - #5, is located lower down the tree and has been occupied steadily by two adult herons. Sometimes one of the adults sits down in the nest. One adult has been delivering sticks to the nest regularly.

There is no indication of any chicks. It is getting very late for this pair to start a family because the adults start their breeding season in January. Most likely this nest will not be successful.

If all goes well in nest #6, the chicks should fledge in mid to late August. Stay tuned. Please see our June Newsletter on our home page for more information and photos.

Photo - copyright Nancy DeStefanis 2015


Nancy's Blog: June 5, 2015

We haven't seen any of the three chicks in nest no. 1 on Heron Island since May 29th. This means that the three chicks hatched much earlier that we had originally believed-at least one month earlier around March 1st. All three fledged at the end of May- three months after hatching.

Because we cannot see into the bottom of the nest, we were completely fooled and thought we saw the first chick on March 29th.

But we're delighted that nest no.1 was successful. The adult male in this nest (Tongue Guy) is the same male that successfully built a new nest last May which resulted in three chicks as well.

Nest no. 2 appears to be abandoned. The other two nests (no. 3 & 4) on the island were abandoned in early May. At the same time, we saw two new nests on the island by the Waterfall.

Since then one nest has been abandoned (#5) and #6 is still occupied with lots of twig presentations taking place.

We will continue to monitor this nest but it would appear unlikely that it will succeed because it is getting very late in the season and the parents would have to stay into September for the chicks to fledge. The herons usually begin again in January. We will keep you posted.

For the latest photos of the heron nests, please click on the June Newsletter on the home page.

In closing, I would like to share an email we received recently:

"Thank for the Nature Walk last Saturday. We had a great time and appreciated talking to your volunteers, who did a wonderful job.
I really want to thank you for the live cam.
I go out every day to see what's going on.
It is so nice to stay connected, even when you can't be there in person!

The only way to top the cam...
Get the cam in the nest...... Or does that bring up Heron privacy issues?
Just kidding, the cam you have is GREAT!

Craig Kelso Pleasanton, CA

Stay tuned.


Nancy's Blog: May 17, 2015

Our last tours at Stow Lake to observe the great blue herons were pretty exciting.

The three chicks in Nest no. 1 on Heron Island by the Boathouse have been jumping out of the nest and branch hopping all week. The chicks are about seven to eight weeks old and should be hopping farther and farther from the nest during the next two weeks.

The pair in nest no. 2, also on Heron Island, continues to engage in twig presentations.

Meanwhile, at the island by the waterfall, the occupants at nest no. 6 continue to sit on their nest. This new nest is very small and we couldn't see a heron in it when we first arrived to set up our scopes. After awhile, the heron stood up to our delight, banishing any idea that the nest was abandoned.

We are also observing a red tail hawk nest hidden on Strawberry Island. Two chicks are fed regularly by their parents- who forage for squirrels, rock pigeons etc. The parents very tenderly feed their chicks' beak to beak- carefully tearing up their prey for the chicks to digest easily.

Stay tuned.


Nancy's Blog: May 10, 2015

There has been quite a lot of activity at Stow Lake this past week.

The three chicks in Nest no. 1 on Heron Island are now branch hopping but still staying close to home. I discovered the chicks in nests 2 and 4 which means the adults that formerly occupied these nests have departed and abandoned these nests. The chicks always return to nest no. 1 at night and also for feedings. They are all full size now that they have reached the six-week mark.

We had two new nests on the island by the Waterfall these past two weeks (nests #5 & #6), which probably explains where the two pair from Heron Island flew. Now there is only one nest- #6- occupied but a heron is now sitting and there are lots of twig presentations going on.

Meanwhile, back in Nest no. 2 on Heron Island, it appears that this pair has started over. We are seeing lots of twig presentations.

The chicks should fledge at around twelve weeks- sometime at the end of June.

If all goes well and we have chicks at the other two nests, they would hatch around the end of May. We shall see.

While observing the new nests on the island by the Waterfall on May 2nd, our intern Fiona observed a Red Tail Hawk swoop down and carry away a gosling. The hawk then flew to a nearby tree and ate it. Nature in action.

Our last Heron Watch program is Saturday, May 16th. The adult tour starts at 10:15 and ends at noon. The family walks starts and ends at the same time. Both tours visit all the nests.

Hope to see you!


Nancy's Blog: April 26, 2015

During yesterday's Heron Watch tour, it became clear that the three chicks in nest no. 1 had reached the four-week mark. The parents only flew in to feed them; otherwise the chicks were left alone in the nest to bill duel, stretch their wings and hunker down to rest when necessary.

When a parent did fly in to feed them, you could hear the chicks' begging squawks all over Stow Lake! 

The other three nests are still incubating.

The BIG NEWS of the day was the arrival of two pair of great blue herons on a small island by the Waterfall at Stow Lake. When I discovered them two days ago, they were engaged in all sorts of courtship behavior- mutual preening, twig presentations etc.

The new nests are quite small; the great blue herons have never nested on this island before. If all goes well, we could have chicks in these nests at the end of May.

Stay tuned. Questions- write: info@sfnature.org


Nancy's Blog: April 17, 2015

The chicks in nest no. 1 are now about three weeks old. One parent remains at the nest while the other parent forages for fish, gophers etc. to feed them.

You can see the marked difference in size as you observe the chicks on the Heron Cam. The oldest is quite a bit taller than the second chick and much taller than the third chick. The difference is size is very apparent when they are standing in the nest.

The chicks are very observant of goings on around them: watching parents trade places at nest no. 3 - just to the right of nest no. 1 and also keeping an eye peeled for the parents in nest no. 2 (to the left of them).

This morning the female at nest no. 1 left for short periods of time and brought back branches to place in the nest. This activity is unusual as the parents generally stop all twig presentations and branch gathering once the chicks arrive.

I am keeping watch on nests no. 2, 3 and 4 and have nothing new to report at this time.

Visit us at Stow Lake and see the action up close and personal. Also stay tuned and please donate now and keep our Heron Cam streaming!

Questions- write: info@sfnature.org


Nancy's Blog: April 9, 2015

The three chicks in Nest no. 1 are growing by leaps and bounds. Checking our mail bag, Ann from upstate New York asks how often the parents feed them.

According to Helen Pratt, a field ornithologist who studied the herons and egrets for thirty years at Audubon Canyon Ranch in Stinson Beach, CA, the chicks at age 10 days or less generally get fed every two hours.

Unlike egret chicks who are fed bill to bill by their parent, the heron parent regurgitates the food into the bottom of the nest. The food they present to newly hatched chicks tends to be softer and more predigested than the food they give to older chicks.

Herons feed their young soon after arriving back in the nest from feeding forays. For small chicks, the parents are able to offer several meals without going out to forage again. Later on when chicks are a bit older, four feedings during the day was most common.

How do we know who 'Dad' is in nest no. 1? He is identifiable because of a tongue injury which caused his tongue to protrude like a pencil below his beak. We have seen 'Dad' on top during mating. We also call him Tongue Guy.

I am pleased to report that our Heron Cam is the only one in California. Stay tuned.

Questions- write: info@sfnature.org


Nancy's Blog: April 2, 2015

We now have three chicks in nest no. 1!  All three emerged from this very deep nest in the last five days. The two oldest chicks have already started bill dueling!

In the next week or so, you should be able to see all the chicks regularly and always at feeding time-when the other parent flies in to feed them. At feeding time, the parent regurgitates all the food into the bottom of the nest which results in quite a feeding frenzy among the chicks.

Because great blue herons lay their eggs asynchronously (every other day), you should be able to see a significant difference in the size of the chicks at this time. If there were a food shortage- then the oldest chicks would have an advantage by intimidating the youngest at feeding time and therefore survive.

If all goes well, the eggs in Nest no. 2 would be the next to hatch.  On the Heron Cam, this nest is located to the left of nest no. 1. The herons in this nest are constantly stretching.

The herons in Nests no. 3 and 4 started two weeks later than the herons in nest #1. I estimate that we may see chicks around the third and fourth weeks in April.

Questions- write: info@sfnature.org Stay tuned.


Nancy's Blog: March 25, 2015

I checked out all four nests from the various vantage points at Stow Lake and on top of Strawberry Island today. Watching the Heron Cam also helps me ascertain when the chicks might hatch.

I believe that the eggs should hatch any day now in Giant nest no. 1 in the center.  The parent has been standing more than sitting which is a good indication that the eggs have probably hatched.  At the latest, I would bet we have chicks in this nest by Easter. The herons here started sitting around Feb. 28. Once they lay the eggs, it takes about 30 days for the eggs to hatch. 

The eggs in nest no. 2 ( a few feet to the left of nest no. 1) should hatch by Opening Day of Heron Watch, April 11th if not sooner.  The herons in this nest started sitting a few days later than the herons in nest no.1.

Nest no. 3 was occupied around March 7th. This nest is a few feet to the lower right of nest no. 1. The herons in nest no. 4 constructed their new nest on March 14th. This nest faces the other side of the island and is hidden behind foliage in the Heron Cam.

Nests no. 1, 2, and 3 were all pre-existing nests before they were occupied this year. Most times, the herons come in and choose pre-existing nests. But they always conduct twig presentations to strengthen the pair bond.

Finally, there has been a lot of activity in the early morning and at dusk. Frequently, unattached herons will come too close to nesting herons and all hell will break loose with the nesting herons chasing the interloper all over the lake.

Stay tuned.


Nancy's Blog: March 18, 2015

Since I wrote on March 10th, I have discovered another nest on Heron Island bringing our total number of nests to four!

The first three nests are in plain view on the Heron Cam.  Because the fourth nest faces the other side of Heron Island, you can only see the occupants when they fly in and out or when they stand on top of the canopy at the far right.

We are hoping for chicks in early April. Once the herons actually lay their eggs, it takes about thirty days for the eggs to hatch. Based on when the herons started sitting in nest no. 1, the giant nest in the middle, I estimate April 5th.

The male in nest no. 1 has been at Stow Lake for around six years. We know him because he has a tongue injury, which causes his tongue to protrude from his beak like a pencil.  This injury does not prevent him from mating and raising a brood. Please check our April Newsletter to see photos of him at the nest- we call him Tongue Guy.

If you have questions, please send them to info@sfnature.org Space permitting, I will try to answer them.


Nancy's Blog: March 10, 2015

Our new, improved Heron Cam is LIVE! The Cam is located at Stow Lake in Golden Gate Park, San Francisco, California. At this time, I believe our Heron Cam is the only one in the USA trained on active nesting great blue herons.

We are observing three great blue heron nests- most of the activity can best be seen from the opposite side of the Boathouse from where we have traditionally set-up spotting scopes during the Saturday Heron Watch program.

Nest no. 1 (a huge nest) in the center has a pair of great blue herons taking turns incubating the eggs.  We expect chicks to hatch by the beginning of April.

Nest no. 2 is located just a few feet to the left of nest no. 1 on a lower branch. This nest is located under some foliage and can be difficult to see.

Nest No. 3 is located on the lower right of nest no. 1.  This pair of herons moved in on Sat. March 7th and began constant twig presentations and other courtship displays. On March 9th, I observed a heron sitting on the nest. Today, a pair of herons are standing in the nest. This pair of herons settled in on March 7th and are engaged in continuous courtship rituals, like neck stretches and greetings. One of the herons has been sitting since March 9th.

If all goes well, we will have chicks to show the public when our on-site program-Heron Watch- opens on April 11th. Hope to see you there if you live in the Bay Area.  Please donate now and keep our Heron Cam  streaming.

San Francisco Nature Education wishes to thank:

ERM Foundation, SF Recreation and Parks, and Stow Lake Boathouse. Special thanks to Phil Ginsburg, General Manager SF Recreation and Parks Dept., Mike Smylie, Regional Commercial Director, NA ERM and Alan Hopkins, former President Golden Gate Audubon Society and Dave Simpson, Manager, Stow Lake Boathouse.