Environmental factors influence nest excavation by foxes
*Subscription may be required
Predation rates of freshwater turtle nests can vary markedly, suggesting that in addition to different suites of predators present, environmental factors (e.g. vegetation characteristics, distance to water/clearing and rainfall) also influence survival of turtle nests. Understanding the influence of environmental factors on nest success can aid turtle conservation through successful management of nesting habitat. This study simultaneously investigated the effect of multiple factors on artificial nest survivorship at a site where oblong turtles Chelodina colliei were present. Over a 12-month period, we monitored the fate of 580 artificial nests installed as 145 nest-sets, each having one of four treatments: (1) two chicken eggs (E) buried and the ground sprayed with water from a turtle pond (S) (E+S+), (2) two chicken eggs (E+S-), (3) nest sprayed (E-S+) and (4) hole dug and refilled (E-S-). Seven environmental factors were recorded for each site and nests. Nests were monitored for 2 months after installation, by which time, 46% of the nests had been excavated. Depredation rate was affected by both the presence of eggs (P<0.001) and being sprayed with turtle pond water (P=0.005); but we found that even 38% of empty nests (holes simply dug and refilled) were excavated. Nest excavation was more likely for more obvious nests located in areas with more sparse vegetation (P<0.05) closer to the shoreline (P<0.01). Excavation rates were highest immediately after installation, but continued for the duration of the monitoring period. The introduced red fox Vulpes vulpes was identified as the only predator observed on cameras for a subset of 60 nest-sets. In conclusion, foxes use both visual and olfactory cues to locate nests, and environmental conditions at the nest site significantly influence the fate of the nests.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||School of Veterinary and Life Sciences|
|Copyright:||© 2014 The Zoological Society of London.|
|Item Control Page|