Great Blue Herons Are Nesting Along the Fox River Right Now!

heron pic 1 (1)
A few nests of the Great Blue Heron rookery on the Fox River at the Kane/Kendall County line are visible from Route 25. Note the the small group of Double-crested Cormorants perched on the one tree also.

I frequently like to take drives along the Fox River where roads closely parallel the riverbank.  One such road that I particularly like to take during this time of year (spring) is IL Route 25 from Aurora south to Oswego.  This route passes by some great fishing areas, the sites of several water willow stands. These were planted by Friends of the Fox River in conjunction with the Illinois Smallmouth Alliance and the Illinois Department of Natural Resources.

Also included were Violet Patch Park, which is the site of the memorial to “The Fox” (Jim Phillips), and a Great Blue Heron rookery on some islands just north of the US Route 30 bridge at the Kane/Kendall County line.

herom pic 2
A few Great Blue Heron adults stand on their nest in a Fox River rookery. March, 2021.

Starting in late March and continuing through April into early May, pairs of Great Blue Herons can be seen tending their nests improbably high in the branches of the trees on these Fox River islands.  It’s kind of a startling sight to see these large, long-legged wading birds (they can be up to 4.5 feet tall with a 6.5 foot wingspan) standing on their stick nests so high in their precarious locations in the crowns of these trees! 

As startling as the sight is, it’s certainly another welcome sign of spring.  While a few hearty Great Blue Herons overwinter in the Fox Valley, most migrate south for the winter and return to the Fox River in the spring, when the river ice clears and the fish and amphibians that they feed on become more accessible.  They also return at this time of year to nest in rookeries (large groups of nests) located throughout the Fox Valley and other areas of northern Illinois. 

heron pic 3
A wider view of the Great Blue Heron rookery in the Fox River along IL Route 25 just north of US Route 30. March 2021.

The nests in the rookery on the islands at the Kane/Kendall County line have been in place for years.  The herons return to these nests year after year.  The male Great Blue Herons return to the nests first and attempt to lure passing females to the nests they occupy.  The herons are monogamous during each breeding season but generally select new mates each year. 

Once the birds pair up, the females lay 2 to 6 pale-bluish eggs that are from 2.5 to 3“ long.  The eggs hatch after 27 to 29 days with both the females and males sharing incubating duties.  The chicks are ready to fledge about two months after hatching.  If the young birds live to fledge (typically only two or three from each nest do), they can live to be nearly 25 years old!

heron pic
A lone Great Blue Heron, perhaps a male trying to woo a mate, perches on a nest in the rookery along Route 25 at the Kane/Kendall County line. March 31, 2023.
heron pic 4
A pair of Great Blue Herons on a nest in the rookery on March 31, 2023. Note the interesting pose of the one on the left with its beak pointing straight up!

Great Blue Herons are very interesting to observe throughout the year and are fairly common sights in our Fox River Valley.  They are very stealthy hunters who move very slowly and patiently in search of an unfortunate fish or frog (or even mouse or gopher) with lightning quickness and their dagger-like bills.  Their almost prehistoric “croaks” are a familiar sound to visitors along the river.

If you find yourself in the Aurora/Montgomery/Oswego area and would like to see an interesting sight, take a drive along Route 25 and keep your eyes peeled!  The heron rookery provides quite a sight to see!  As long as you’re there, continue a couple of miles further south to Violet Patch Park and visit the memorial to one of the original watershed warriors, Jim Phillips (aka “The Fox”).  It’s an idyllic sight along the river, fitting for a memorial to a man who dedicated his life to protecting it.

Until next month, enjoy the warming weather and all the natural wonders of spring along our beautiful Fox River!

fox memorial 1
A wide view of the memorial to Jim Phillips also known as “The Fox” at Violet Patch Park along IL Route 25 in Oswego, Illinois. The Fox River flows past in the background.
fox memoril 2
A closer view of The Fox memorial. The three plaques tell the story of Jim Phillips and the Fox River. The rock in front of the plaques shows “The Fox” trademark signature that he used to identify his environmental protection exploits.

All pictures by Tom Schrader.