Posts Tagged: raptor
UC Davis Biodiversity Museum Day: See 'Bird's Eye View' at the Raptor Center
Last year during the 12th annual UC Davis Biodiversity Museum Day, visitors to the California...
This is the newly installed mural, "Bird's Eye View," which visitors to the California Raptor Center, UC Davis campus, can see during the UC Davis Biodiversity Museum Day on Saturday, Feb. 10. (Photo by Diane Ullman, UC Davis distinguished professor of entomology and artist)
Plans Progressing for March 6th UC Davis Biodiversity Museum Day
Plans are progressing for the 11th annual UC Davis Biodiversity Museum Day, set from 11 a.m. to 3...
The 2022 UC Davis Biodiversity Museum Day will feature 11 museums or collections, represented on this bus graphic by Ivana Li, UC Davis biology lab manager. (The Marine Invertebrate collection will not be represented but a sea cucumber hitched a ride anyway).
In this image, taken at the 2020 UC Davis Biodiversity Museum Day, doctoral students Christopher Pagan (front) and Corwin Parker (back) chat with visitors. (Photo by Kathy Keatley Garvey)
The UC Davis Bee Haven will be open for tours at noon and 2 p.m. on Sunday, March 6, during UC Davis Biodiversity Museum Day. Visitors can expect to see honey bees pollinating the huge almond tree near the entrance. (Photo by Kathy Keatley Garvey)
The Bohart Museum's tarantulas are crowd-pleasers. (Photo by Kathy Keatley Garvey)
Mark Your Calendar: Fifth Annual Biodiversity Museum Day Set Saturday, Feb. 13
DAVIS--The University of California, Davis will celebrate its fifth annual Biodiversity Museum Day...
Bohart Museum associate and entomologist Jeff Smith (in back, at left) talks about the Lepitoptera section that he curates. (Photo by Kathy Keatley Garvey)
Bohart Museum associate Robbin Thorp (center), distinguished emeritus professor of entomology, with visitors at a Biodiversity Museum Day at the Bohart Museum. At right (foreground) is UC Davis entomology undergraduate student and Bohart volunteer Wade Spencer. (Photo by Kathy Keatley Garvey)
The Häagen-Dazs Honey Bee Haven will be a part of the Biodiversity Museum Day this year. The bee sculpture is the work of Davis artist Donna Billick, who co-founded and co-directed the UC Davis Art/ Science Fusion Program with professor/entomologist Diane Ullman. (Photo by Kathy Keatley Garvey)
Exotic mange found in California golden eagles
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.
Do California spotted owls prefer to nest near forest edges? SNAMP scientists say no.
Adult and juvenile California spotted owl
During a Sierra Nevada Adaptive Management Project (SNAMP) public meeting, a participant brought up the idea that California spotted owls preferred to nest near forest edges to be closer to foraging habitat and their prey. Principal investigator for the SNAMP Owl Team, Dr. Rocky Gutierrez, charged research fellow Casey Phillips and SNAMP Owl Team project leader Doug Tempel to research this question at SNAMP study sites in the Tahoe and Eldorado National Forests to see if this was true.
Owl researchers used field data that consisted of current vegetation maps derived from aerial photos and owl nest site location data gathered during their annual surveys. One nest tree site within a forest stand was randomly selected from each owl territory and one comparison location within those stands was randomly selected by a computer program. The distances between these two locations, relative to the nearest edge of the forest stand, were then compared statistically. A forest edge could be either a hard edge, such as an adjacent clear-cut; or a soft edge, such as a young, mixed-conifer forest. Elevation at each nest site was also considered because owls living at higher elevations prey on flying squirrels that typically inhabit forests with greater canopy cover. So, one might expect owl nest sites to be further from forest edges at higher elevations.
Researchers found no evidence that owls chose nest sites closer to forest edges than one would expect by chance, even though an edge location might bring them closer to a prey source. Results also showed that owls nested further from hard edges than expected. These results were consistent regardless of the elevation at a nest site.
It is possible that some timber harvest may have occurred after owls used a particular nest site, and before the vegetation maps were made. This scenario would have only lessened the distance to the nearest edge at these sites. This would also apply to the randomly selected points. Therefore, habitat alteration should not have affected the findings. Researchers speculate that limited availability of suitable nest trees within the stand may be as important of a determinant in the location of a nest site as any physical characteristics associated with its location.
Banded female California spotted owl
Where owls choose to nest has implications for forest managers and their management plans. This research suggests that creating forest edges would not enhance owl nest site choices and that other factors would likely influence owl nest site selection, such as the availability of large trees appropriate for nesting (i.e., those with cavities, broken tops, and mistletoe broom).
Information for this article comes from the following: Phillips, C.E., D.J. Tempel, and R.J. Gutierrez. 2010. Do California spotted owls select nest trees close to forest edges? Journal of Raptor Research 44:311-314.