Hilltopping Insects

[Cris Guppy & Aud Fischer]

A wildlife biologist has mentioned to me that a home on the summit of a hill
outside Williams Lake (town), British Columbia has an unusually high density
of feeding nighthawks. Normally there is only one at a time feeding in an
area, this hill top regularly has half a dozen or more feeding at the same
time. It seems likely that they are feeding on twilight and early
night-feeding insects associated with the hilltop (not necassarily
"hilltopping" in the territorial sense). This indicates that hilltopping
insects may be important concentrations of food for birds, which may locally
include rare species.

-----Original Message-----
From: David Wagner <dwagner at uconnvm.uconn.edu>
To: leps-l at lists.yale.edu <leps-l at lists.yale.edu>
Date: December 21, 1999 6:55 AM
Subject: Hilltopping Insects


>I am preparing a report for the Massachusetts Chapter of The Nature
>Conservancy on the significance of a summit in southwestern Massachusetts
>that is the highest point in the entire region.  I figured it made sense to
>include a paragraph about the importance of hilltops as mating stations for
>insects, especially for those that might otherwise rarely encounter one
>another.  I reproduce my account below.  There is an ample literature for
>butterflies (?but not moths), but would love to have citations for other
>orders.  Can anyone help with references for non-pompilid Hymenoptera?  Are
>there some benchmark papers on the subject?
>
>Draft Text:  "The Importance of Hilltops
>
>By virtue of the fact that Mount Everett is the tallest peak, as well as
>the most defined summit in the region, it may have special significance as
>a mating station for many insects. The highest point on the horizon--being
>the most reliable topographic features in virtually any habitat--is used by
>many insects as a rendezvous site for courtship and mating (Shields 1967,
>Scott 1968, 1974, Thornhill and Alcock 1983, Britton 1995).  Scott noted
>(1968) that many rare butterflies, which otherwise might have difficulty
>locating one another, use summits of hills and mountains to initiate mating
>behaviors.  Invertebrates known to hilltop include butterflies (especially
>papilionids, pierids, nymphalids, lycaenids, and hesperiids), Hymenoptera
>(e.g., pompilids), and flies (e.g., cuterebridae, gastrophilids, oestrids
>and sarcophagids)(Scott, 1968, 1974, Thornhill and Alcock 1983, Tarrier
>1996, and Povolny and Znojil 1998).
>
>Because adults use vision to locate the highest point on the horizon, it
>makes sense that hilltopping behaviors would be poorly represented (if
>present at all) in the moths--the subjects of this study.  Future surveys
>should emphasize diurnal collections.  And because the most interesting
>organisms are apt to be rare, flight interception or malaise traps should
>be deployed at or very close to the summit."
>
>Any help would be appreciated.
>
>
>*************************
>David L. Wagner
>Ecology & Evolutionary Biology
>v. 860-486-2139; f. 860-486-6364
>dwagner at uconnvm.uconn.edu
>
>