Gharial Merganser
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| Male |
 |
| Female |
Gharial
Merganser, Mergus gavialis L 50-60 cm, WS 65-70 cm, W 800-1400
g, Family: Anatidae
IUCN Conservation Status:
Vulnerable
(VU)
Description:
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| Field Guide Reference |
Voice:
Generally
silent. Females emit hoarse croaking calls when communicating to chicks and
both sexes squawk when disturbed. Males with make raspy, cat-like meow
calls during courtship.
Range and Habitat:
Found
throughout Novasola on freshwater bodies, especially rivers. They are common in
forested ecosystems, and far less common in the interior prairie. They prefer moving
water like rivers and streams surrounded by trees, but will also use lakes,
ponds, and marshes. They may appear away from forests occasionally, especially
in rivers with tall banks and many cavities. Though they generally avoid
saltwater, they may uncommonly be found in brackish water, estuaries, and
protected coastal bays.
Discussion:
Common
to waterways across Novasola, Gharial Mergansers have been called many names
based on the number of features that distinguish it from other native ducks. Names
like Emerald Duck and Black Merganser refer to the male’s dark, iridescent
green plumage, as does the name Cayuga Merganser, in reference to an all-green
breed of domestic duck. Shaghead refers to the wild, unkempt-looking crests.
Sawbill and Redspike were used by early white pioneers and refer to the bird’s
thin, serrated beak. The Cishtaklun name for the bird is Aglayaq, and
the Juliquit name is Kaax. The name Gharial Merganser is a reference to
the bill as well, specifically the large, rounded knob at the tip, as gharials
are a type of crocodilian native to India known for its long and narrow snout
tipped with a prominent, bulbous protuberance.
Like
other members of Mergus, the Gharial Merganser is primarily piscivorous,
meaning it eats fish. Mergansers forage by diving underwater and chasing small
fish. Mergansers can swim remarkably fast, up to 10 miles per hour, and are
surprisingly agile. They can remain underwater for three minutes, though
usually spend no more than 30 seconds. They use their serrated beak, or
“sawbill”, to keep hold on slippery and squirming prey. Though less common,
mergansers will also eat amphibians, crustaceans, mollusks, and other aquatic
invertebrates. Gharial Mergansers may forage in groups and hunt cooperatively,
corralling fish to shallow water or pools where they are easier to catch. When
not diving, they sit low on the water surface much like loons or cormorants,
and typically swim downstream or with the current, travelling back upstream
while hunting underwater. When on still water bodies like lakes, Gharial
Mergansers typically stay closer to shore, and groups might corral fish from
deeper water to the shallow edges.
Gharial
Mergansers are mostly found on water bodies that are surrounded by forests or
other woody cover, or with tall banks, especially in the spring and summer.
This is because they are cavity nesters and most often build their nests in
large tree hollows or bankside underground burrows. Though not common now, it
was a commonly-held belief in the 20th century that the Gharial
Merganser’s oversized bill knob evolved as an adaptation for burrow digging. They
may compete with other birds for nest holes, especially Long-crested Ducks,
though Long-crested Ducks are less common on moving water. Mergansers will
sometimes travel significant distances from water to their nests, up to 15
kilometers. Outside the breeding season, Mergansers may be found on larger
water bodies or farther from forest cover. During courtship in the spring,
males will chase each other from groups of females before pairing with one
female to build the nest. Females lay anywhere between five to 30 eggs, after
which the male departs and plays no further part in rearing offspring. After
hatching, chicks will leave the nest far before they can fly and will follow
the mother to water on foot. The farthest known distance from a nest to a water
source was recorded at 15 kilometers. Because most females nest in tree
cavities, chicks must leap from the nest, sometimes up to 50 feet to the
ground. Female mergansers are social and will usually be found in groups where
all females take part in protecting and caring for the communal chicks. They
will also readily “adopt” other female’s chicks and orphaned chicks. It is not
uncommon to see female Gharial Mergansers with 40-50 chicks. Males may join
these female groups but are more likely to form bachelor groups.
Like
many other endemic species, Gharial Mergansers have suffered sever population
declines since European settlement of Novasola. Though always prized for meat
and ornamental feathers by indigenous groups, settlers hunted mergansers on a
scale that caused population crashes across the island, especially west of the
Paramounts. Males in particular were sought after by plume hunters, who sold
their iridescent feathers first for specialty fly-fishing lures and then for
early 20th century fashion. Thankfully, Gharial Merganser
populations have rebounded thanks in large part to conservation efforts,
including hunting bans and nest box campaigns which helped create artificial
nest structures to combat habitat loss due to logging. Now, Gharial Mergansers
have a healthy population in most parts of the island and are open to, albeit
restricted, hunting.
Though
generally uncommon in the early 20th century, Gharial Mergansers, or
“Cayuga Mergansers” to Richard Reichwald, were a fairly common sight for the
Novasola Research Corps during the 1902 and 1903 expeditions, due to the Corps’
reliance on rivers for travel. As a result, Reichwald’s observations were some
of the best first-hand accounts of mergansers until their populations began to
recover in the 1940s.
“This
stretch of river abounds with the Cayuga Fish Duck. Just now, as I write, a
group fishes along the opposite bank. Two drakes lead the group, a deep oil-black,
gleaming at odd times even beneath the overcast sky, followed by several hens with
warm cinnamon heads. Their manner is one of constant vigilance; never do all
birds dive at once, and each resurfacing is accompanied by a quick survey of
the banks. This is the closest I’ve managed to approach the mergansers without
them disturbed to flight.” – Expedition log, May 5, 1902
“The
Merganser is no dabbler; it vanishes entirely below the water’s surface when
hunting, reappearing upstream after 30 seconds or more. They are excessively
greedy birds, and would, it seems, by their choice completely depopulate a
river of its fish in one go. Mergansers are always foraging and I have counted
ducks swallowing scores of fish in one morning. They also seem to forget their
own limitations when presented with prize fish, which they will chase even if
there is no possibility of fitting the fish down their throat. I recall once a
hen pursued a trout of considerable size, the chase carrying both beneath the
riffles until only rings upon the surface betrayed their path. When at last she
surfaced, empty-billed, she shook herself once and resumed the hunt without
ceremony, as if such contests were routine and beneath notice.
…
Of
all waterfowl in the Fastwaters, none appear so ill-suited to the table as the
merganser. The flesh bears strongly of fish, a fact known well enough to the
trappers who rarely trouble themselves with pursuit of the bird for meat. They
are however targeted by fishermen as pests and competition and prized by
hunters for the drake’s valuable plumage.” – Native Birds of Novasola,
1912