Posts Tagged Feeding

Feeding ducks ‘human food’ leads to health problems


By Chirsty Hart-Harris
Twitter: @ChristyTDR

Posted Jun. 2, 2014 @ 12:02 pm

Coldwater, Mich.

COLDWATER — Every year during the summer months, Waterworks park is filled with families enjoying the sun, company and the many ducks that frequent the park’s river. The best part is feeding the ducks. Although it is done with good intentions, feeding the duck bread and human food products can cause their organs to become engorged and fatty, which in turn can cause them to suffer from heart disease, liver problems and other health complications.

According to Duck rescue network, a informational organization specializing in duck rescues, “When wild ducks are fed human food (especially bread or crackers) their Bread also has very few nutrients, and can get compacted in a bird’s crop. Many rehabilitators see “bread-impacted crop” in sick and distressed park ducks.”

Bread is very low in protein and contains additives that wildfowl are not able to digest properly. Ducklings require vital nutrients during their crucial first weeks. If they are fed bread, they can experience splay leg, angel wing, slipped tendons and other growing defects.

Waterfowl at artificial feeding sites are often found to suffer from poor nutrition. In a natural setting they will seek out a variety of nutritious foods such as aquatic plants, natural grains, and invertebrates.

Sophia DiPietro, Biologist and Wildlife Rescuer at All Species Kinship in Battle Creek Mich., said, “There are healthier ways to feed wildlife without causing the harmful impacts of bread feeding. The most helpful time to feed birds is during winter-time when food sources are scarce.”

DiPietro suggests feeding them cracked corn, non-medicated poultry scratch and greens such as turnips or dandelion greens ripped into small pieces.

Feeding the ducks at the parks can be a fun experience for children especially. It can also cause issues to arise between the ducks and humans. As most frequenters of Waterworks park have witnessed, competition for each bread crumb is extremely high. Ducks may also become unnaturally aggressive towards each other and to humans. Some ducks, usually the younger ones, are unable to compete for the food and never learn to forage naturally.

Feeding the ducks also has the potential to creates an unnaturally high population of waterfowl and diseases can flourish in overcrowded and unsanitary conditions.

In addition, attracting ducks teaches them not to fear humans. This can be a problem as some “rehabilitators often see ducks purposefully chased by dogs and children, with injuries from dog bites or thrown rocks – or – all too often run over by cars,” said DRN.

DNR suggests substituting bread with “cheerios, grapes cut in half, a thawed bag of frozen peas or corn, or kale, romaine or other leafy greens (not iceberg lettuce).”

DiPietro said, “Say no to bread and yes to greens and grains instead.”


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Tourists Are Giving Endangered Iguanas Diarrhea And High Cholesterol

From Scientific American at

Hop on over to the photo-sharing site Flickr and you’ll find dozens of photos and videos of people eagerly feeding grapes to hungry iguanas on the beaches of the Bahamas. It looks like great fun and the iguanas obviously go crazy for the fruit, which is usually fed to the lizards on the ends of long sticks. There’s just one problem with this activity: the food is making the iguanas sick. Health conditions arising from the grapes and other foods that iguanas do not normally eat in the wild include diarrhea, high blood sugar and cholesterol as well as lowered levels of potassium and a high level of parasitic infections. All of these problems “could have deleterious effects on long-term fitness and population stability,” according to Charles Knapp, director of conservation and research at Chicago’s John G. Shedd Aquarium and the lead author of a new study of the iguanas published last week in Conservation Physiology.

iguana grapes Bahamian rock iguanas (Cyclura cychlura) live on the islands of Andros and Exuma and several small nearby cays in the island chain. Although not technically endangered, they are considered vulnerable to extinction, with a total wild population of fewer than 5,000 individuals. That count covers the entire species, which also includes three subspecies, two of which are endangered and one of which is critically endangered.

As Knapp and his fellow researchers wrote in the paper, the feeding of wildlife is “an increasingly popular yet under-studied tourism-related activity” that is often sanctioned and encouraged for both marine and terrestrial animals. Sometimes that is beneficial, providing the animals with access to low-stress nutrition and humans with a positive conservation experience. Other times, however, feeding wildlife can cause problems, especially if it includes items from outside of their native diets. Consequences can include nutritional imbalances, obesity or behavior changes that have harmful long-term effects.

Knapp and his team wanted to find out if the hundreds of weekly tourists visiting iguana habitats were having a positive or negative effect on the animals’ health. They traveled to the islands in 2010 and 2012 and examined iguanas that interact with tourists as well as those in more isolated locations. They found that both groups of iguanas appeared the same externally but the tourist-fed iguanas—especially the more aggressive males—showed signs of nutritional imbalance. Many had diarrhea, all of them carried parasites and their blood showed abnormal levels of calcium, glucose, potassium and uric acid. The tourist-fed males also had aberrant amounts of cholesterol, copper, magnesium and other nutrients. The paper links the high-sugar, low-potassium levels to the grapes, Ground beef and other animal proteins could be causing the high cholesterol and uric acid levels found in the iguanas. (The iguanas are normally herbivorous.)

Tourists aren’t the primary threat to Bahamian rock iguanas, however. The species faces habitat loss due to construction, dangerous feral animals such as goats, collection for pet trade and illegal hunting. (They’re the only iguana species still caught for food.) Those threats aren’t going away anytime soon.

In a press release Knapp said that it’s unrealistic to expect tourists to stop feeding the iguanas. “Instead,” he suggested, “wildlife managers could approach manufacturers of pelleted iguana foods and request specially formulated food to mitigate the impact of unhealthy food. Tour operators could offer or sell such pellets to their clients, which would provide a more nutritionally balanced diet and reduce non-selective ingestion of sand on wet fruit.” Done right, the authors suggest, tourism could actually benefit the iguanas and give them the nutrition and safety they need in order to boost their populations. That’s a worthy goal we’re sure the iguanas can get behind, even if it means fewer grapes.

Photo: Iguana reaching for grapes by Chris Dixon via Flickr. Used under Creative Commons license

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A Whale Of A Time

My family and I have just returned from a fantastic trip to the Philippines. While the scuba diving was superb everyone’s highlight was the 30 minutes we spent swimming with whale sharks. Whale sharks are the world’s largest fish. They can grow up to 40 feet long and weigh as much as 20 tons. Despite these impressive statistics they pose no danger to humans, being filter feeders that consume things like plankton, krill and fish eggs.

The small town of Oslob, on the island of Cebu, is where our amazing interaction took place ( Whale sharks used to be regarded as pests, and were even killed by locals, as their presence interfered with their fishing activities. This has now changed with these massive fish pumping significant ecotourism dollars into the local economy. However, in order to ensure that the steady stream of tourists has something to snorkel with, the locals have begun feeding krill to the whale sharks. At this point the activity is regulated so that feeding and swimming only occur between 6 am and midday.

Ordinarily I am completely against the feeding of wildlife but, in this case, I might have to make an exception. One criticism that has been levelled at the activity is that it changes the whale shark’s behaviour inducing them to stay for the free food, instead of foraging far and wide, as they normally would. Up to 50 whale sharks have been identified by local researchers, but there were only three swimming about while we were there. A whale shark consumes between 0.5 and 3.0% of its bodyweight every two to three days. An adult whale shark needs to eat about 400 kg to fill its massive stomach ( The ones we interacted with were possibly half grown, which still translates into 200 kg of food. I cannot see it being economically viable or physically possible to tip this much krill down their throats, which means that the whale sharks still need to forage to satiate themselves, and possibly come in for a free feed when they feel like a top up. The fact that the water was not boiling with whale sharks would seem to bear this out.

Unlike the junk food that is put out in bird feeders whale sharks are at least fed a natural diet, so there should hopefully not be any nutritional issues.

A recent Australian study found that tourism had no negative effects on the whale sharks’ behaviour ( Admittedly these whale sharks were not being fed.

However, if the alternative to feeding and ecotourism is spearing, then it is difficult not to endorse the current activities which, at the moment, appear to be reasonably well regulated. When I say we interacted with the whale sharks this is not strictly true as they appeared to completely ignore us, swimming where they wanted, and doing what they wanted when they wanted, as is your prerogative when you weigh several tons.

The locals’ view of whale sharks has certainly changed since this tourism venture began in December 2011. This is probably motivated more by self-interest than any inherent concern for the whale sharks or their conservation. It has certainly become very trendy for zoos in particular to promote their animal encounters as a way of encouraging conservation. An interaction with a whale shark (or koala, or gorilla, or seal) will make people more likely to care about their conservation, or so the rhetoric goes. But does it? Is there any real evidence to support the statement that animal interactions foster greater conservation outcomes? Or are the people who seek animal interactions more likely to join conservation organisations, donate money and plant trees anyway? I suspect the latter is more likely to be the case.

The fact that we are prepared to spend a considerable amount of money to swim with a large fish (or cuddle a koala, or see a gorilla, or kiss a seal) shows how isolated from the natural world we have become, and how we still see nature as entertainment, instead of a vital part of our existence. Not that I am any different because I got just as much of a buzz from my up close and personal experience as everyone else did.

Dr. F. Bunny

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