Clever grebes always ready to duck for cover
Ms Risely said migratory animals were notoriously hard for ecologists to track and test for infections.
“With the rate of zoonotic diseases – pathogens that jump from animal hosts to humans on the rise, migratory animals have been under increasing scrutiny and suspicion of aiding the spread of avian influenza viruses (bird flu), Lyme THE Australasian grebe is one of our more interesting waterbirds.
There are usually a couple of pairs on Balyang Sanctuary, on the ponds in Eastern Park and at Jerringot on the Belmont Common.
During the spring they build floating nests from an accumulation of waterweeds anchored to a reed or sedge growing in the water.
When the eggs are laid they are dull white, and as incubation progresses — it takes about three weeks — the eggs become stained to a dark brown.
The young are well-developed when they hatch, and within a day or two they are swimming with their parents.
They will often be seen hitching a ride on the adult’s back.
Grebes are smaller than any of the common “waterhens”, dumpy little birds with scarcely any vestige of a tail.
You rarely see them fly, for at the first sign of danger they simply dive and swim underwater to a more distant part of the wetland. disease, and even ebola,” she said. “Billions of animals fly, swim and walk around the globe every year on their seasonal migrations, but there is in fact surprisingly little direct evidence that these animals are frequently spreading pathogens long distances.”
Ms Risely and her co-authors Professor Marcel Klaassen and Dr Bethany Hoye
If harassed, they seem to vanish, staying submerged with only their beaks and eyes above the surface, often hidden by a floating plant.
One of their more interesting features is the way they vanish from a wetland, for they seem so unwilling to fly.
Yet at times they turn up one morning on a pond where they were not to be seen on the previous day.
Obviously they fly during the night when predators such combed through as many relevant studies as they could looking for overarching patterns to discern whether infected migrants can still migrate successfully.
“We found infected migrants tended to be in poorer condition, didn’t travel as far, migrated later and had lower chances of surviving,” Prof Klaassen said. as falcons are asleep. They are not the only birds that do this for many of the other waterbirds and shorebirds also travel at night. Predators are not the only hazard, of course, and the birds are occasionally attracted to strong lights and shiny factory roofs.
The new net fence at Curlewis may also see casualties for it would be virtually invisible to night-flying birds. Wildlife information and questions can be sent to ppescott@gmail.com