Date: 3/2/17 12:05 pm
From: Bob Thomas <rathomas...>
Subject: Re: [LABIRD-L] FW: [LABIRD-L] LALIT: Do bird feeders increase nest predation?
What is the latest on feeding bluejays and its relationship to nest
predation? Any empirical studies?

On Thu, Mar 2, 2017 at 11:56 AM, Philip C Stouffer <pstouffer...>

> Hi all,
> There have been a couple of recent papers on feeders in Ornithological
> Applications (=Condor).
> This one is just out. The upshot is that when supplemental food attracts
> crows (not sure exactly how that works- it can't be a direct effect) it is
> bad for robin nest survival. Cardinals, on the other hand, don't seem to
> be affected.
> -
> open access On that Ibis paper, I'd be hesitant to accept that predation on
> quail eggs in artificial nests reflects reality except perhaps in a loose
> qualitative way.
> Back to the Red-headed Woodpecker thread, my impression is that the
> increase in Cooper's Hawks in LA is as Van described, a mostly
> urban/suburban phenomenon. Are Red-headed Woodpeckers declining in these
> settings? In my neighborhood in BR they are around (as are increasing
> coops). Is there anything in particular about rhwo that makes them
> vulnerable to coops? When I first got to LA I was impressed by rhwo
> drilling into creosote-coated poles. Maybe that habit of perching on poles
> (more than red-bellied, for instance) makes them easy prey?
> Good birding/feeding,
> Phil
> -----Original Message-----
> From: Bulletin Board for Dissemination of Information on Louisiana Birds
> [mailto:<LABIRD-L...>] On Behalf Of Bill Vermillion
> Sent: Thursday, March 02, 2017 9:37 AM
> To: <LABIRD-L...>
> Subject: [LABIRD-L] LALIT: Do bird feeders increase nest predation?
> Hi all,
> I was sent a 2016 paper from the journal Ibis this past week which
> documents research in the United Kingdom investigating whether bird feeding
> increases risk of nest predation for birds nesting in relatively close
> proximity to bird feeders. Researchers deployed filled and un-filled
> feeders and deployed artificial nests with Japanese quail eggs. Predation
> of these artificial nests by Magpies, Gray Squirrels, and European Jays was
> significantly higher adjacent to filled feeders.
> Here's the citation and abstract:
> Hanmer, H.J., R.L. Thomas, and M.D.E. Fellows. 2016. Provision of
> supplementary food for wild birds may increase the risk of local nest
> predation. Ibis 159:158-167.
> Abstract: In countries such as the UK, USA and Australia, approximately
> half of all households provide supplementary food for wild birds, making
> this the public’s most common form of active engagement with nature.
> Year-round supplementary feeding is currently encouraged by major
> conservation charities in the UK as it is thought to be of benefit to bird
> conservation. However, little is understood about how the provision of
> supplementary food affects the behaviour and ecology of target and
> non-target species. Given the scale of supplementary feeding, any negative
> effects may have important implications for conservation. Potential nest
> predators are abundant in urban areas and some species frequently visit
> supplementary feeding stations. We assess whether providing supplementary
> food affects the likelihood of nest predation in the vicinity of the
> feeder, by acting as a point attractant for potential nest predators. We
> provided feeding stations (empty, peanut feeder, peanut feeder with guard
> to exclude potential nest predators) in an area of suburban parkland in the
> UK and monitored the predation rate of eggs placed in arti- ficial nests
> located at distances that replicated the size of typical suburban gardens.
> Nest predators (Magpies Pica pica, Grey Squirrels Sciurus carolinensis)
> were frequent visitors to filled feeders, and predation caused by Magpies,
> European Jays Garrulus glandarius and Grey Squirrels was significantly
> higher when nests were adjacent to filled feeders. The presence of a feeder
> guard did not significantly reduce nest predation. As supplementary feeding
> is becoming increasingly common during the breeding season in suburban
> habitats, we suggest that providing point attractants to nest predators at
> this time may have previously unconsidered consequences for the breeding
> success of urban birds.
> Thanks,
> Bill V

*Robert A. Thomas, Ph.D., Professor & Director*
Loyola Distinguished Scholar Chair in Environmental Communication
Center for Environmental Communication
School of Mass Communication
Environmental Program Faculty
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