[Odonata-l] Meadowhawks: two species in close proximity?
Joshua S. Rose
Thu, 19 Jun 2003 12:50:48 -0400 (EDT)
On Thu, 19 Jun 2003, Martin Reid wrote:
> Yesterday I found five or six S. ambiguum (no mature males) along one
> stretch of a wooded trail. Perched just about eighteen inches from one of
> them was another Sympetrum that I feel was a female vicinum; is it normal
> for two closely-related species of Sympetrum to occupy the same habitat and
> perch so closely?
I happen to have a couple of relevant articles cited in my in-progress
Michiels, N. K. and A. A. Dhondt 1987. Coexistence of three Sympetrum
species at Den Diel, Mol, Belgium (Anisoptera: Libellulidae).
Odonatologica 16(4): 347-360.
Rehfeldt, G. E., and H. Hadrys 1988. Interspecific competition in
sympatric Sympetrum sanguineum (Muller) and S. flaveolum (L.) (Anisoptera:
Libellulidae). Odonatologica 17(3): 213-225.
Watanabe, M., and M. Taguchi 1988. Community structure of coexisting
Sympetrum species in the central Japanese paddy fields in autumn
(Anisoptera: Libellulidae). Odonatologica 17(3): 249-262.
Short version is that Rehfeldt and Hadrys found their two species to
differ significantly in preferred perch height, while Watanabe and Taguchi
found differences in preferred amount of sunlight/shade, and both they and
Michiels and Dhondt noted differences in the time of day that species were
present at breeding habitat.
S. vicinum and S. ambiguum are the only two species we get here in the NC
Piedmont. We typically don't see them until October, when other species
start fading away. However, there have been two or three reports of
teneral S. vicinum emerging in the past couple of weeks, guess they hide
out for the summer...
Joshua S. Rose
Department of Biology (Zoology, R.I.P.)