Ruffed Grouse and Winter
The state bird of Pennsylvania, ruffed grouse is a clever little game bird that’s very well adapted to winter. Ruffed grouse is non-migratory, and even sleeps in self-made snow tunnels when conditions permit. Insulating feathers thicken around its nostrils, and around its legs, as fall temperatures drop.
Most interesting, however, are the pectinations that appear – Professor Julian Avery, Penn State, photographed a ruffed grouse foot “in its winter ‘form’:”
Pectinations - Ruffed Grouse's Winter Feet
“During fall, they grow these pectinations, or comb-like structures, on the outsides of their toes. These modified scales help them tread on snow like a snowshoe does, and will fall off when spring arrives. Adaptations like these enable species to exist in all manner of crazy environments, and they also make a powerful argument for the conservation of biodiversity. Imagine the time and trial by selection it took to reach this solution, that not only helps them find scarce resources, but that is also in sync with the seasons.”
— Julian D. Avery
Pectinate: having narrow parallel projections or divisions suggestive of the teeth of a comb
The pectinations on the winter foot of a ruffed grouse is an extension of the scales, made of cartilage, and not feathers.
Snow Roosting: the Grouse Dive Bombs to Bed
Other adaptations include “snow roosting.” When the snow is deep enough, and loose enough, a ruffed grouse will perch on a branch, choose its spot, and propel itself into the ground. Widening its tunnel by waddling and winging a bit further, the grouse spends its night burning fewer calories and protected from wintry outside air and wind chill. This snow-tunnel strategy also helps hide him from its bevy of predators: goshawks, great horned owls, fox, and fishers. Ruffed grouse are infamous for bursting explosively forth from these snow dens, another way to startle and evade predators, and hikers. Learn more:
Bonasa umbellus
Order: Upland Game Birds – Galliformes (incl. turkeys, grouse, chickens, quails, and pheasants)
Family: Upland Game Birds – Phasianidae (heavy, ground-dwelling birds)
Species: Ruffed Grouse – Bonasa umbellus
Mating ritual: drumming – a rapid beating of wings by the male
A group of grouse is a: covey
Conservation of Ruffed Grouse
Though currently designated a species of “least concern,” ruffed grouse populations have declined steadily for over three decades, primarily due to:
Habitat loss
Ruffed grouse particularly need early successional forest – the phase between field and saplings. Grouse and woodcock were among those species that benefitted from the clear-cutting of Pennsylvanian forests in the 1800s, nesting in the downed treetops and grasses. Ruffed grouse also needs mature forest – for winter shelter and forage.
Climate change
As a species especially adapted to deep winter conditions, ruffed grouse is losing its evolutionary edge as our winters warm. Poor or icy snow cover renders grouse more susceptible to energy depletion, predation, and freezing.
West Nile Virus
This mosquito-transmitted disease is reducing grouse numbers – and the Pennsylvania Game Commission has been tracking its “very high mortality” impact on our local population since its appearance in the early 2000s. Warmer weather and stagnant water benefit mosquitos – save a grouse, eliminate standing water on your property. Read more about West Nile in ruffed grouse:
https://ruffedgrousesociety.org/the-scientific-impact-of-west-nile-on-ruffed-grouse.
