Redwood Heron

 

Modern illustration provided by the Museum of Novasola in leu of contemporary illustrations, made in the Reichwald style. Click image to enlarge.

Redwood Heron, Ardefallax sylvestris WS 45-50 cm, Family: Ardeidae

 

IUCN Conservation Status: Critically Endangered (CR)

 

Description:    

Small, stout heron with thick neck and a relatively short and sturdy bill. Mostly brown, upperparts are dark with lighter spotting in the wings and undersides are tan to cream with dark streaking. Head is darker with a pale throat, and neck is boldly patterned with red and dark striping. Legs are short and greenish, as is the skin around the eyes and bill. Wings broad and rounded. No sexual dimorphism, but juveniles have yellow eyes with dark and light streaking covering most of the body, face, and neck.

Voice:

Mostly silent, but will occasionally emit deep croaks and hoots, often described as sounding owl-like or frog-like, while on nest or communicating with mates. May squawk and hiss when disturbed.

Range and Habitat:    

Old-growth specialists, Redwood Herons are dependent on large tracts of undisturbed, old-growth rainforest, especially damp, dark, and densely-foliated forests. As the name implies, Redwood Herons prefer mid-elevation stands of large, mature island redwoods, but they will also use forests dominated by cedars, spruce, and coopers-fir. They are usually found in moist drainages. Extremely rare, all wild Redwood Herons live in a handful of small populations whose summer ranges are localized to pockets of montane forests along the western slopes of the Angelics and the Great Shadow Lake basin. Birds which breed near the lake migrate to winter in the southern Angelics.

Discussion:      

The Redwood Heron is an extremely unique and fascinating endemic bird about which relatively little is known, due mostly to its rarity. Thought to have always been uncommon, Redwood Herons are now critically endangered, possibly the most endangered bird on Novasola and one of the most endangered birds in all of North America. Their populations have crashed in the past two centuries following heavy deforestation. The heron relies exclusively on mature, old-growth redwood and cedar forests which at one time covered much of Novasola’s western slopes but have been targeted by loggers ever since the island’s colonization by Europeans. Severe logging has cleared or destroyed over 80 percent of old-growth redwood forests on the island. Redwood Herons were at their lowest numbers in the 1930s and were so rare they were presumed extinct; the last confirmed sighting of a Redwood Heron occurred in 1927, and the species was not observed again until 1954. This was followed by a string of sightings in the 1960s and now, thanks to stronger protections and conservation actions, the current total population estimate for Redwood Herons is around 800-900 individuals. Still an alarmingly low number, it is at least a marked improvement. It is worth noting, however, that these population estimates may be unreliable, as the birds’ elusive nature makes studying them and estimating their numbers difficult. Redwood Herons became somewhat of a cultural icon to some and an object of controversy to others during the 1980s and 90s as environmentalists and conservationists fought with the logging industry to protect the heron’s habitat of large treed forests, a Novasolan campaign of the famed “Timber Wars” enveloping the Pacific Northwest at the time.

Redwood Herons are unlike most other herons in many ways, especially in their habitat use and needs. Redwood Herons are less tied to bodies of water that most herons; though they will forage along forested streams and ponds, they also spend much time foraging away from water along the forest floor, albeit mostly in damp, mossy basins. They eat beetles, earthworms, snails and slugs, small mammals, salamanders and frogs, fish, and crustaceans like crayfish. Strangely, the herons will also forage in the canopy: the only heron known to do so. Famously, Island Redwoods create entire ecosystems within their canopy, with numerous species of epiphytic plants and fungi and canopy-specialist invertebrates and vertebrates. Every year scientists discover new species of mosses, insects, snails, slugs, and even the occasional salamander, frog, or rodent which spends the bulk of, if not the entirety of, its lifespan within a redwood canopy. Older redwoods often develop entire communities in their branches, as well as cracks and hollows which fill with water. These pools act as miniature ponds which sustain these communities. Redwood Herons, it seems, heavily utilize these canopy environments: they nest in the canopy and forage there as well, hunting the animals there. A recent study of Redwood Heron diet found that a high proportion, as much as 50 percent, of their diets consist of canopy-specialist species like snails and slugs, voles, and salamanders. More strangely, the same study documented multiple instances of herons “farming” food in the canopy. Researchers observed Redwood Herons take small fish or tadpoles from streams or ponds and fly to a redwood with a flooded hollow or branch-pool to deposit the prey alive, presumably to stock the pool with prey for later. This sort of behavior has been observed in a few other heron species, but the Redwood Heron’s use of old-growth forest canopies is unique: no other species has ever been recorded transporting aquatic prey animals from streams to place them in treetops. Granted, this sort of behavior is only possible due to the Island Redwood’s unique growth habits. That study estimated that this “stocking” behavior is common in herons inhabiting redwood forests. Herons in other forest types, like Coopers-fir or spruce dominated forests, have fewer chances to stock because the canopies have fewer pools and epiphytes, and thus these birds are likely to forage entirely on the ground. The true extent of this stocking behavior is unknown, but there are a number of species of amphibians unique to Novasolan canopies that some scientists now think may have evolved in part because of continuous and frequent transplantations to the canopy from the forest floor by herons. 

Redwood Herons are mostly nocturnal, or at the very least crepuscular. Their large eyes have adapted to better see in the dark, and many of their prey species are most active at night. They also inhabit isolated pockets of undisturbed forest and avoid human development and activity, rarely being seen within twenty miles of well-trafficked roads. Their nocturnality, range, rarity, and dependence on dense foliage and tall upper canopies all conspire to make observing and studying the heron extremely challenging, and as a result very little is known about them. Certainly one of the stranger endemic Novasolan birds, the Redwood Heron has confused scientists since its discovery. Its placement in heron taxonomy is controversial and debated, but they may be closely related to Asian night herons in the genus Gorsachius. Fossils of herons found in Siberia appear similar to Redwood Herons and may represent an ancestral species.     

Not much is known about Redwood Heron breeding habits. They prefer to nest in large cavities like hollows in large trees and snags, or they will build stick nests when no cavities are available. Few nests have been found and fewer still have been studied. One study found that herons nested only in large, mature conifers, while another from ten years later found herons building nests in smaller understory trees like madrone, dogwood, and yew. Nothing has been published on chick rearing behaviors, incubation, or clutch sizes, but anecdotal reports suggest both parents incubate and raise an average of two or three chicks. Chicks mature within a year and then disperse to new territories. Redwood Heron territory size is unknown, but some pairs have been observed permanently remaining within a five square mile study site. Some birds are known to migrate, while others do not, and migratory individuals seem to have extremely high site fidelity, always returning to the same forest patch, and usually the same nest tree. It is theorized this high site-fidelity has contributed to their declines, because it decreases their ability to recover from clear-cutting or forest fires. Their nests are often depredated by weasels and martens.

In a modern landscape dominated by increasing development, habitat loss and fragmentation, and climate change, Redwood Herons are still supremely imperiled. Few stands of old-growth rainforest remain undisturbed on Novasola, and those that do may become increasingly inhospitable due to droughts and fires. There is hope, though, as more resources are being allocated to heron conservation. Conservationists are constantly pushing for more protections, and numerous organizations, public and private, are actively engaged in habitat restoration efforts and awareness campaigns while scientists race to learn as much as they can in the hopes of better understanding such a bizarre and unique bird.

Oddly, if Richard Reichwald was ever aware of the existence of the Redwood Heron, he did not express it. Nowhere did he note any encounters with the bird, either during the Novasola Research Corps expeditions or in his years exploring the island afterwards. He did not include it in his Native Birds of Novasola, and seemed never to have heard stories of it. The species wasn't described for science until 1919 by Robert Ridgeway. However, the first known written records of the bird date back to 1843, and indigenous cultures obviously knew of its existence. Reichwald may have referenced the bird unknowingly in an article he wrote for the magazine Forest & Stream in which he dismissed, or “debunked” a number of Native American mythic creatures some believed to truly exist on Novasola. In a paragraph about the thunderbird he mentions another large bird that spends time in the treetops and sounds like a frog.

“… but no such creatures have yet been found in the territory. The same can be said of the mighty Thunderbird, a ubiquitous Indian creation, said to soar over the vast skies of much of the country. Novasola, it seems, is barren of thunderbirds in much the same as the rest of the country, or at least barren to the annals of science. Indians inhabiting the Georgian foothills tell stories of numerous fantastic avian beasts including not just the aforementioned Thunderbird, but also fierce owl-men, flying whales, and feathered frogs which croak from high in the trees and shy away from sunlight. But until those mountains can be thoroughly surveyed, these creatures must still be relegated to fable.” – Richard Reichwald, “Creatures of Novasolan Indian Folklore”, Forest & Stream, 1919