Studying scavenge hunting animals remaining worldwide

Date:

August 4, 2015

Source:

Plataforma SINC

Summary:

Human activities such as livestock farming, fishing or hunting yearly waste tons of food into natural ecosystems. A large part of this anthropogenic food is provided as carrion and subsidizes a wide range of vertebrate species. Scientists have described for the first time the general structure of scavenger communities worldwide, which consist mainly of birds (66%) and mammals (34%).

Read on ..

Hyenas, jackals feast at vulture restaurants

24 September 2014 Last updated at 12:18

By Jonathan WebbScience reporter, BBC News

"Restaurants" of dead meat set up for endangered vultures also attract an undesirable clientele of hyenas and jackals, according to a six-year study.

The research consisted of repeated "scat surveys" (dung counts) at two nearby sites in South Africa.

There was a surge in numbers of both the cheeky mammals, specifically at the site with extra food, which went back down again when the restaurants closed.

The scientists have recommended a new strategy to help boost vulture numbers.

The birds have been in decline worldwide for a number of reasons.

Specifically, the researchers suggest using fences to exclude the unwanted, earthbound customers, and dishing up the extra meat for the vultures in random locations instead of re-stocking a regular carrion pantry.

Continued ...

Great White Sharks Scavenging On Dead Whales

Apr. 10, 2013 — Many terrestrial animals are frequently observed scavenging on other animals- whether it is a hyena stealing a lion kill in the Serengeti or a buzzard swooping down on a dead animal. However, documenting this sort of activity in the oceans is especially difficult, and often overlooked in marine food web studies.

In a new study published in PLOS ONE titled, "White sharks (Carcharodon carcharias) scavenging on whales and its potential role in further shaping the ecology of an apex predator," Captain Chris Fallows from Apex Expeditions collaborated with University of Miami (UM) scientists Dr. Neil Hammerschlag and Austin Gallagher, to explore the behaviors of Great white sharks scavenging on dead whales in South Africa. The team documented as many as 40 different sharks scavenging on a carcass over the course of a single day, revealing unique social interactions among sharks.

The study summarized observations based on four scavenging events opportunistically observed over a 10 year period. In each multi-day observation, the team recorded daily evidence of social, aggregative and feeding behaviors observed in the waters off South Africa. They suggest that although the occurrence of coming upon a whale carcass may be sporadic, the shark populations are likely prepared to scavenge on them, and may even rely on their scavenging activities to supplement their regular feeding activities.

"Although rarely seen, we suspect that as white sharks mature, scavenging on whales becomes more prevalent and significant to these species than previously thought," said Hammerschlag, who is director of the R.J. Dunlap Marine Conservation Program at UM.

Continued:  http://www.sciencedaily.com/releases/2013/04/130410141530.htm

Lead poisoning ‘epidemic' plagues California condors

THE endangered California condor faces an "epidemic" of lead poisoning from scavenging carcasses contaminated by lead bullets despite years of costly conservation efforts.

The rare birds were reduced to a population of just 22 in 1982, and have since recovered to number about 400, with half of those still in captivity, said the study in the Proceedings of the National Academy of Sciences.

About five million dollars are spent per year on programs to boost the birds' population through captive breeding and release programs. But if those efforts were to cease, the birds would likely die off again, said the study.

Lead poisoning remains a critical danger, and efforts to limit the use of lead bullets by hunters in California in the past few years have not cut down on the number of chronic poisoning cases, researchers said.

"We will never have a self-sustaining wild condor population if we don't solve this problem," said first author Myra Finkelstein, a research toxicologist at the University of California Santa Cruz.

"Currently, California condors are tagged and monitored, trapped twice a year for blood tests, and when necessary treated for lead poisoning in veterinary hospitals, and they still die from lead poisoning on a regular basis."

Each year, nearly a third of condor blood samples showed serious lead exposure and 20 percent of free-flying condors in California are found to have blood lead levels that require treatment, according to the researchers.

Without chelation therapy to remove lead from the blood, birds can suffer paralysis, stiff joints and lose their ability to fly. At high levels, lead poisoning can kill.

The effects of chronic sublethal lead poisoning on the central nervous system are unknown and deserve further study, the authors said.

Continued:  http://www.heraldsun.com.au/news/breaking-news/lead-poisoning-epidemic-plagues-california-condors/story-e6frf7jx-1226408501659

Hyenas Give Up Scavenging For Lent

Humans aren't the only ones who give up certain foods for Lent. In the 55 days before Easter in Ethiopia, hyenas are forced to turn from scavenging to hunting to make up for Christians' fasting traditions.

Members of the Orthodox Tewahedo Church give up meat and dairy during the Lent period in Ethiopia. Now, a new study of hyena droppings finds that local hyenas, deprived of butcher scraps during this time period, supplement their diets by hunting donkeys for food instead.

Spotted hyenas are adept hunters, capable of bringing down prey such as zebras, wildebeests and even young rhinoceroses. But these pack hunters are also adaptable: They scavenge freely, devouring everything from dead birds and mammals to garbage and dung.

"Hyenas can eat almost any organic matter, even putrid carrion and anthrax-infected carcasses," study researcher Gidey Yirga of Mekelle University in Ethiopia said in a statement. "They are capable of eating and digesting all parts of their prey except hair and hooves. Bones are digested so completely that only the inorganic components are excreted in the hyena's droppings."

Read on:  http://www.livescience.com/19490-hyenas-scavenging-lent.html