California Spotted Owls are faring well in forests burned by the 2013 Rim Fire, the largest forest fire in recent history in the Sierra Nevada. A new paper in the scientific journal The Condor: Ornithological Applications documents nearly all (92%) of the historical Spotted Owl territories within the area burned by the Rim Fire were occupied in 2014, including sites where fire killed most of the large trees surrounding the owls’ nests and roosts. “The Rim Fire was particularly large and burned so many known territories that we had an excellent opportunity to see how the owls responded to this major disturbance event,” says Derek Lee of the non-profit research organization Wild Nature Institute and the study’s primary author. The U.S. Forest Service has assumed fire-killed forests are no longer Spotted Owl habitat and is currently logging the burned public forests, including occupied Spotted Owl territories, in spite of the decades of science showing logging, not fire, is the greatest threat to this quiet sentinel of forest ecosystems. In their study, the Institute’s scientists recommended that forest managers avoid logging burned Spotted Owls sites, even in large areas of fire-killed trees. Fire does not have the same negative impact on owls as logging, because owls have evolved over millennia with wildfire as a natural disturbance and can still find foraging habitat in burned areas if they are not logged. “Spotted Owls like lots of big old trees, whether those trees are alive or fire-killed, and they can find prey in shrubby areas regenerating after fire,” Lee notes. “Fire is not a threat to Spotted Owls, but logging is.” Forest fire leaves behind many dead standing trees for the owls to perch on and listen for their rodent prey. The rodents are likely eating the seeds and leaves of shrubs that are numerous in burned areas. Scientists call these heavily burned forests that have not been logged after fire “complex early seral” or “snag forests.” Such forests support a unique community of flora and fauna that depend upon the nutrient-rich post-fire conditions, including standing dead trees (snags), and fallen logs as habitat. Wild Nature Institute’s scientists analyzed field data forms and survey maps from U.S. Forest Service biologists, who searched for Spotted Owls one year after the Rim Fire at all 45 historical owl territories that were burned. They also investigated how the amount of high-severity fire surrounding owl locations affected occupancy probability. An average of 37%, and up to 100%, of the forested area around owl locations burned at high severity, yet no decrease in occupancy was evident for sites with Spotted Owl pairs, no matter how much burned at high severity. “Many people thought that the owls would have abandoned these sites in droves because the fire was so massive,” explains the study’s co-author Monica Bond. “Forest Service spokespeople had characterized the area as nuked, a moonscape, but then the agency’s own biologists detected owls at almost every territory.” The iconic California Spotted Owl is a species of conservation concern because it prefers older conifer forests for nesting, roosting, and foraging. The nocturnal bird of prey has long been at the center of debates over commercial logging on public lands, which impacted the owl’s forest habitat for more than a century and led to population declines. Some wildlife and forest managers point to forest fire as the most serious current threat to the species while ignoring logging—but recent studies have found California Spotted Owls usually remain in burned territories and forage on rodents in forests blackened by high-intensity fire. The Rim Fire study adds to the growing body of evidence that forest fire is not a major threat to Spotted Owls and actually produces many ecosystem benefits, including a unique pulse of biologically rich, complex young forests that are becoming increasingly threatened due to post-fire “salvage” logging.
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On our recent survey for giraffe in the Tarangire Ecosystem, we came across a stunning, nearly white giraffe calf. This giraffe was not albino, but leucistic. Leucism is when some or all pigment cells (that make color) fail to develop during differentiation, so part or all of the body surface lacks cells capable of making pigment. One way to tell the difference between albino and leucistic animals is that albino individuals lack melanin everywhere, including in the eyes, so the resulting eye color is red from the underlying blood vessels.
For the bird fans out there, enjoy some recent photos from Tarangire and Lake Manyara national parks. Oliver's Camp, run by Asilia, is a beautiful tented camp deep inside Tarangire National Park. Oliver's Camp is now selling our tri-lingual children's book about wildlife migration (The Amazing Migration of Lucky the Wildebeest) and our "I Stuck My Neck Out for Giraffe" t-shirts. Many thanks to Justin and Jackie, the wonderful managers of Oliver's Camp, for their support and enthusiasm for giraffe research and conservation! We urge folks coming to Tanzania to consider staying at Oliver's Camp for a true experience of wild nature.
We were fortunate to have an up-close-and-personal experience with a pair of cheetahs in Tarangire National Park. The pair was sharing an early morning meal of a dik-dik, purring so loudly we could hear them from 10 meters away! Cheetahs are only occasionally seen in our study area, so spotting one (or two) is always a treat. Richard Estes calls this sleek and graceful cat a “felid version of a greyhound,” specialized for speed. They have an unusual social system for carnivores, whereby males hold small territories and females and non-territorial males roam across large areas. Outside the Serengeti Ecosystem, cheetahs are rare indeed. Even in the Serengeti, scientists estimate only about 210-280 individuals, and a total of 1,180 cheetahs occur in all of Tanzania (10% of the global population). This beautiful creature, the fastest land animal in the world, is facing in increasing risk of extinction in the wild due to habitat loss and capture for the captive animal trade (from the newly published A Field Guide to the Larger Mammals of Tanzania, Foley et al. 2014). Enjoy a short video of this playful pair and be inspired to help protect this extraordinary yet fragile animal. By Amanda Schupak, CBS News, January 16, 2015
http://www.cbsnews.com/news/mass-animal-deaths-on-the-rise-worldwide/ Thousands of birds fall from the sky. Millions of fish wash up on the shore. Honey bee populations decimated. Bats overtaken by a deadly fungus. Piglets die in droves from a mysterious disease. It was tragic stories such as these that prompted a group of researchers from the University of San Diego, UC Berkeley and Yale to embark on a broad review of all the reports of large animal die-offs in the scientific literature since the middle of the last century. They turned up 727 such papers documenting "mass mortality events" (MME) of 2,407 global populations of mammals, birds, fish, reptiles, amphibians and marine invertebrates -- like the thousands of starfish that perished in North America in 2014. Their analyses, published this week in the Proceedings of the National Academy of Sciences, revealed that not only are these events becoming more frequent, they're also increasing in magnitude, with the number of fatalities higher for birds, fish and marine invertebrates. Thirty-five events completely or nearly wiped out an entire population. Over the last 70-plus years -- between 1940 and 2012, when the researchers ended their data collection -- there has been about one more MME per year. "Going from one event to 70 each year is a substantial increase, especially given the increased magnitudes of MMEs for some of these organisms," said Adam Siepielski, University of San Diego assistant professor of biology and the study's co-lead author. The cumulative death toll reaches into the billions. The number one cause was disease, which was responsible for 26 percent of the mass killings, followed -- no big surprise -- by human activity, mostly traceable to environmental contamination. Toxic algal blooms, like the one that has plagued Lake Erie in recent years, have also emerged as a leading killer. "Mass die-offs result from both natural and human-driven causes," said study coauthor Samuel Fey, a Yale researcher who studies how extreme temperatures can affect biological populations. And even accounting for the possibility of reporting bias -- that is, an increase of attention that can potentially skew numbers to look artificially more impressive -- he and the team believe that their results are robust. That said, as much as anything, their findings show how important it is to get the reporting right. "Determining whether or not the upswing in the occurrence of MMEs is a real phenomenon or simply a result of increased awareness remains a critical challenge that needs to be addressed," they wrote. "Such results, combined with lack of studies measuring MMEs using population-level data, highlights the need for an improved program for monitoring MMEs." Kent Redford, a conservation consultant and former director of the Wildlife Conservation Society Institute who was not involved in the study, agreed. "Rare and dramatic events capture the human attention and imagination," he told CBS News. "This paper makes the important case for the need to document the dramatic death of large numbers of animals. Understanding the factors that structure animal communities requires knowledge of how and why animals die and more importantly, understanding how and why human actions shape the 'unnatural' deaths of animals is a prerequisite to knowing how to ameliorate such deaths." But while headline-grabbing stories -- like the deaths of a third of the nation's honey bees due to colony collapse disorder, or white-nose syndrome, which has killed 6 million bats in the U.S. since 2007 (neither was included in the PNAS paper) -- deserve close study and widespread alarm, they don't show the whole picture. "We must not let the rare dramatic events distract us from focusing on the smaller but constant erosion of animal communities that is taking place worldwide as a result of human action," said Redford. "Over the long term, these less-interesting and less note-worthy mortality factors are undoubtedly more important to study and to stop." The Masai giraffe is Tanzania's national animal and much loved, but the subspecies is in serious trouble. An article recently published in Ujumbe Magazine by Wild Nature Institute's Monica Bond explains why giraffe are so special, what threatens them, and how Tanzanians and people around the world can help.
http://www.kcet.org/news/redefine/rewild/birds-1/citing-declines-groups-want-california-spotted-owl-protected.html
by Chris Clarke Logging has seriously hurt the California spotted owl, say two wildlife groups who want the bird protected under the Endangered Species Act. In a petition filed Wednesday with the U.S. Fish and Wildlife Service, the Wild Nature Institute and Earth Island Institute's John Muir Project are asking that the rare owl be listed as either Threatened or Endangered under the Act. The groups say that while the owl (Strix occidentalis occidentalis) is doing okay on protected forest lands, forests where logging is allowed have seen decline in owl numbers for at least two decades. That, say the petitioners, is partly because both the intact forests where the owls nest, and the patchworks of burned forests where they often hunt, have been subject to timber harvests that don't take the health of the owl into account, say the groups. Logging has seriously hurt the California spotted owl, say two wildlife groups who want the bird protected under the Endangered Species Act. In a petition filed Wednesday with the U.S. Fish and Wildlife Service, the Wild Nature Institute and Earth Island Institute's John Muir Project are asking that the rare owl be listed as either Threatened or Endangered under the Act. The groups say that while the owl (Strix occidentalis occidentalis) is doing okay on protected forest lands, forests where logging is allowed have seen decline in owl numbers for at least two decades. That, say the petitioners, is partly because both the intact forests where the owls nest, and the patchworks of burned forests where they often hunt, have been subject to timber harvests that don't take the health of the owl into account, say the groups. Story Continues Below The California spotted owl is the only spotted owl subspecies not protected under the Endangered Species Act. The Northern and Mexican subspecies were listed as Threatened under the Act in 1990 and 1993, respectively, with the former then becoming the focus of pitched battles over the logging of its habitat in the Pacific Northwest. Wednesday's petition describes five recent studies that indicate that logging in Californian forests has caused steep declines in the spotted owl population there, while forests where commercial logging is prohibited show no such declines. Competition from the related barred owls is another factor in the spotted owls' decline. The larger barred owls drive spotted owls off their territories and can even kill them. According to the petition, spotted owls seem to hold their own better when their old-growth forest territory is left intact. Logging-related fragmentation of that habitat, however, seems to give barred owls an advantage. In recent years, an increase in large wildfires has led to ramped-up logging of burned forests in California under the rubric of "salvage logging" and fire prevention. Logging in green, unburned forests has continued as well. Listing the owl would allow USFWS to designate Critical Habitat for the birds, which would force the Forest Service to take the welfare of the spotted owl into account when approving timber harvest plans on federal land. "Forest fire is not the threat people think it is, yet logging on public lands in the name of reducing fire to save owls is rampant, and is having a devastating effect on this species," said Wild Nature Institute's Monica Bond, a spotted owl biologist and co-author of the Petition. "It is estimated that there are less than 1,200 California Spotted Owl pairs remaining today, after having lost over a quarter of their population in the last two decades," explained ecologist Dr. Chad Hanson of the John Muir Project. "Their populations continue to decline. Under any formulation of conservation biology the time to list this species is now." About the Author Chris Clarke is a natural history writer and environmental journalist currently at work on a book about the Joshua tree. He lives in Joshua Tree. |
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