Bobwhite quail roosting in woody cover were about twice as likely to survive in southern Indiana

Wildlife managers choose what to protect or restore partly by watching what animals prefer. That is a shaky guide, because an animal's preference for a habitat does not always show that the habitat improves its chances of surviving or reproducing ^[9]. The Oecologia study was built to test that gap. The team compared where birds chose to sleep with the habitat available around them ^[10], then asked which choices went with living longer. Birds with a stronger preference for woody cover were more likely to survive than birds roosting in less protected areas ^[11].

Survival is an outcome for each bird, so the denominator is the 169 birds. The 720 roosts work out to about 4.3 per bird on average ^[17]. The write-up does not report absolute survival rates, causes of death or how often birds chose poor sites, so "about twice as likely" ^[2] has no baseline attached.

The write-up says the birds are not always good at choosing ideal spots ^[13]. It also says they largely favored grasslands, regrowing burned or cleared ground, and areas near dense shrubs, briars and young trees ^[5]. In our reading, the poor choosers are the birds that slept away from thick cover. Justin Hill, the corresponding author and a postdoctoral researcher at UGA's Warnell School of Forestry and Natural Resources ^[16], defined the cover this way: "It's a patch of any woody-stem vegetation that's really kind of thick, nasty, difficult that you wouldn't want to walk into," Hill said ^[7].

The proposed mechanism is predation. Bobwhite live on the ground and escape in short bursts of flight, and dense vegetation gives refuge from hawks, foxes and other pursuers ^[12]. We think that is plausible. The comparison does not show what happens when a manager adds woody cover to a field. It is between birds that made different choices, and a bird that picks thick cover could differ from one that does not in ways the roost data do not capture.

Scale is the other limit. The tracking covered two fall and winter seasons in southern Indiana ^[1], and the paper's title confines its claim to the non-breeding season ^[3]. The 90% decline is a Georgia figure, which the state's Department of Natural Resources attributes, with a "likely", to the loss of open, shrubby landscapes ^[4]. In our view the result supports woody cover as a restoration target, though it does not size how much of that decline the target could recover.

Hill offered a field test for managers: "A person standing nearly anywhere in good quail habitat should be able to face in several directions, throw a softball and reach a patch of woody cover," Hill said ^[8].