EFFECT OF CHEMICAL COATING OVER SEEDS OF THREE SPECIES IN THE CONSUMPTION OF RED-BELLIED SQUIRRELS

Abstract

One factor limiting the success of aerial dispersal of seeds for reforestation is consumption by wildlife. It has been proposed that coating seeds with chemicals, or pelleting, will repel potential consumers. To determine the effect of pelleting on consumption by Red-bellied Squirrels (Sciurus aureogaster), tests were carried out in the Coyoacan Nursery in Mexico City. Coated seeds of three tree species (Pinus ayacahuite, P. cembroides and Enterolobium cyclocarpum) were offered in paired tests. Coating consisted of three treatments per species, including an aversive conditioning (LiCl), a fungicide (dicarboximide), an insecticide (lambda cyalotrine) and a preservative (BzNa). When a squirrel was found it was exposed to two seeds, one with coating and one without it. This was repeated with 100 squirrels. Data were analyzed with the McNemar test to determine if frequencies of pelleted seed consumption and without pelletizing were equal. There was no significant difference in the consumption of P. ayacahuite and P.cembroides. No seed of E. cyclocarpum, was consumed. Squirrels showed two behavioral patterns: they opened the hard seed coat to consume the embryo or buried the seeds they could not open. This precludes the effect of coating, since removal of the seed coat did not have the expected aversive effect. Therefore, seed pelleting of the evaluated forest species did not avoid damage by squirrels.