Posts Tagged: mites
Two adult golden eagles that were recovered in California between July and August 2013 were infested by a mite with morphologic features similar to those of Micnemidocoptes derooi, a species of mite seen only once, in an African palm swift in West Africa more than 40 years ago.
Both eagles had substantial feather loss and scabbing on the head, neck, and legs and near the cloaca. One of the raptors was found grounded and so ill the animal was euthanized. The other was live-trapped, rehabilitated, and eventually returned to the wild. (She underwent 8 months of recovery and rehabilitation at the California Raptor Center, a program of the UC Davis School of Veterinary Medicine. Read her story here.)
A third golden eagle, found in December the previous year in the same region as the others, was likely also infected by the Micnemidocoptes–like mite, according to the report. The bird had been struck by a car and died of its injuries.
In their report, the authors note that while wild raptors can sometimes become infested with mites, such debilitating mange in otherwise healthy animals is highly atypical.
“The severity and diffuse distribution of skin lesions of these eagles suggest a possible serious, unique outbreak,” they wrote.
Additional golden eagles with suspicious feather loss have been spotted in California and Nevada since August 2013.
Feather loss impacts an eagle's ability to maintain normal body temperature and may limit the animal's ability to obtain food, making it weak and susceptible to trauma. Severe mite infestation is unusual in birds, especially adult birds. No such infestation among golden eagles has been previously reported.
“It's all very strange,” Dr. Hawkins admitted. “It's not something that's been identified by any researchers that we're aware of at that point. This may be closely related to M derooi but has not been previously described.”
As for how this potentially novel species of mite arrived in the United States and is spreading, they are also mysteries. The entire life cycle of M derooi is reported to be spent on its host, so theoretically, transmission would require direct contact between birds. Dr. Hawkins supposes the mites could be passed along through an infested bird's nest, although additional research is needed in this and other areas involving this mite.
In the meantime, the California Department of Fish and Wildlife is asking residents to report golden eagles or other large birds with severe feather loss. Dr. Hawkins has written a paper on the clinical treatment of eagles with mange, which is expected to be published in the near future.
The article, “Knemidocoptic mange in wild golden eagles, California, USA,” is also available online.
This article originally appeared in JAVMA News by Scott Nolen.
"Does colony collapse disorder (CCD) still exist?"
Eric Mussen, UC Cooperative Extension specialist in the Department of Entomology and Nematology at UC Davis says "yes."
But the winter losses are being attributed to many other causes. "Less than 10 percent of the losses are now attributed to CCD," Mussen points out.
CCD surfaced in the fall of 2006 when beekeepers starting seeing their colonies decimated. They'd open the hive, only to find the queen, the brood and the food stores. The adult workers? Gone.
"CCD still exists and it appears as though in cases where multiple other stresses combine to severely weaken the bees, then viruses can overwhelm the immune system and the bees fly away and die," Mussen says. "We do not know what causes apparently-sick bees to fly from the hive, and we still have a difficult time describing how all the bees could become affected so swiftly."
"As colony losses mounted, the beekeepers had to spend even more time monitoring the conditions of their colonies. They noted things that might be done to prevent some problems that seemed to be starting. So, we are better at preventing the losses, but the percentage for about 25 percent of our beekeepers is still way too high."
Mussen says that "the other 75 percent of the beekeepers are doing relatively well (5-15 percent losses), so we have leveled off in national colony numbers. If the 25 percent can better determine what is going wrong, we should see improved data in the future."
Scientists attribute CCD to a combination of causes, including pests, pesticides, viruses, diseases, malnutrition, and stress. The No. 1 problem in the hives, they agree, is the varroa mite. Mussen writes about those topics - and others in his newsletter, from the UC Apiaries and "Bee Briefs." Both are available free on his website.
Mussen, who is retiring in June after 38 years of service, was recently named the recipient of the 2013-14 Distinguished Service Award, sponsored by the UC Division of Agriculture and Natural Resources.
Mussen devotes his research and extension activities toward the improvement of honey bee health and honey bee colony management practices. Mussen, who joined the UC Davis department in 1976, is known throughout the state, nation and world as “the honey bee guru” and “the pulse of the bee industry" and as "the go-to person" when consumers, scientists, researchers, students and the news media have questions about honey bees.
Extension apiculturist Eric Mussen in front of the apiary at the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. (Photo by Kathy Keatley Garvey)