Surveys of style morph frequencies in 163 populations of the eastern North American, clonal, tritylous aquatic, Decodon verticillatus suggested a wide range of clonal diversity among populations.
Based on the model of Whittingham et al. (1992, Am. Nat., 139, 1115-1125), it is predicted that males in many monogamous species of birds will not decrease their level of parental care until their confidence of paternity is very low...
We present the first experiment to assess band color effects in a natural bird population. 38 territorial male red-winged blackbirds (Agelaius phoeniceus) were randomly assigned to 1 of 2 banding treatments. They received either all red bands (to...
We demonstrate that degree of parasitism by larval water mites (Arrenurus spp.) was associated with reduced condition of males and with lowered fecundity of young females of the damselfly, Enallagma ebrium (Hagen) (Odonata: Coenagrionidae). We also demonstrate that degree of...
Tree swallows engage in extra-pair copulations, creating an opportunity for sperm competition. The aim of this study was to determine whether the pattern of within-pair copulation was consistent with the use of frequent copulation by the male to assure paternity.
In resource-defence mating systems we intuitively expect that the most competitive males should win the best resources so that, in territorial species, male quality and territory quality will be highly correlated. In the "polygyny threshold model" (PTM) of mate choice...
The role of courtship behaviour in ethological isolation was studied by analysing courtship sequences between different crosses of pumpkinseed (Lepomis gibbosus), bluegill (L. macrochirus), and their hybrid sunfish. Crosses were established in large laboratory tanks, under an artificially advanced photoperiod...
The dogbane tiger moth (Cycnia tenera Hübner; Arctiidae) responds to ultrasonic, artificial bat echolocation signals by emitting stereotyped trains of high‐frequency, rapidly repeated clicks. By comparing this response in intact and headless moths, the role of protocerebral auditory inter‐neurones...
The Yellow Warbler (Dendroica petechia) is frequently parasitized by the Brown-headed Cowbird (Molothrus ater) resulting in reduction of nest success at parasitized nests (Schrantz 1943, McGeen 1972). There are several avenues open to a Yellow Warbler once a...
Injection of male bullheads (Ameiurus nebulosus) with estradiol induced the production of a major serum phosphoprotein of molecular weight 145 000. This protein was immunoprecipitable by antisera raised against lipovitellin from bullhead eggs and was absent from the...
Ages determined by counts of apparent annuli on scales, sagittae, vertebrae, pectoral fin ray and dorsal fin spine cross sections of largemouth bass from northern populations, which are older and slower growing fish than in the southern parts of its...
Male sunfishes build nests and provide care for eggs spawned therein. It is shown here that small non-nesting male pumpkinseed and bluegill will intrude during conspecific spawnings, to fertilize eggs. Such behaviour cuckolds the males which care for the brood.
The purpose of this paper is to compare and contrast the morphology and ecology of these two species of mice that have evolved in and now inhabit areas with widely different climatic characteristics. Data for P. Leucopus were taken from...
Movements of island populations of deer mice were studied by smoked paper tracking supplemented by live trapping. Some mice tracked regularly, others rarely. Some stations were tracked much more than others. The number of track records per night varied greatly...
