Mother Birds Know Best -- Even Before Birth

(Mar. 27, 2010) — Mother birds communicate with their developing chicks before they even hatch by leaving them messages in the egg, new research by a team from the Department of Zoology, University of Cambridge, has found.

By changing conditions within the egg, canary mothers leave a message for their developing chicks about the life they will face after birth. In response, nestlings adjust the development of their begging behaviour.

If chicks get a message that they will be reared by generous parents then they beg more vigorously for food after hatching. But chicks that are destined to be raised by meaner parents end up being much less demanding.

By attending to messages in the egg, nestlings gain weight more rapidly because they match their demands to the parents' supply of food, and can avoid either begging too little or wasting effort on unrewarded begging.

The Cambridge team made the discovery using fostering experiments, exchanging eggs between canaries' nests so that the chicks grew up in an environment that they were not expecting.

"This work changes our understanding of the pre-natal environment in birds," says Dr Rebecca Kilner of the University of Cambridge, who led the research.

"We've known for about twenty years that maternal substances in the egg can influence how chicks develop, but the common assumption is that they are a means by which mothers manipulate their offspring in a way that suits the mother more than the chick.

"What we've shown is the reverse: these substances are actually there to suit the chick. If we muck up the message in the egg experimentally, it is the chick that is penalised directly rather than the mother."

What it's like to be a Florida python hunter

Greg Graziani thinks Burmese pythons are "fascinating animals" that shouldn't be in the wilds of South Florida.


"They're beautiful animals," Graziani said of the non-poisonous snakes that can grow to 14 feet or longer. "If I could take them all to Southeast Asia, I would, but I can't foot that bill."

Graziani is one of about 15 people who have been issued licenses to capture or kill the giant constrictors in Florida. The National Park Service - which administers the Everglades National Park and Big Cypress National Preserve, both near Miami, wants the non-native reptiles eradicated from its lands. So do the Florida Fish and Wildlife Commission and the South Florida Water Management District.

From left, Greg Graziani (licensed to kill or capture pythons in South Florida), Florida Fish and Wildlife (FWC)Commissioner Ron Bergeron, Shawn Heflick (another permit holder), and FWC Chairman Rodney Barreto.Photo by Patricia C. Behnke/Courtesy of Florida Fish and Wildlife Commission

Biologists fear that the giant snakes will decimate native animals, including protected species of wading birds. [Read conservation biologist Stuart Pimm's blog post: Pythons in Florida Everglades: Is the Snake Invasion Only Beginning?]

"I hate that we have to euthanize them, but they don't belong there, and what are we going to do?" Graziani said.

The Burmese python's native habitat includes China, India, Thailand, Vietnam, and Nepal. But they've also become a favorite of American snake collectors, especially in South Florida, where the climate is similar to Southeast Asia.

Graziani made weekly trips during last summer from his home in Venus, Florida to hunt pythons. He caught "three or four" during these trips, and plans to resume hunting them this year.

The best time to hunt the pythons is between 11 p.m. and 4 a.m. during a moonless night, but Graziani doesn't plunge into the thick vegetation seeking the snakes. The cold-blooded animals are attracted to the warmth of roads that have baked in the sun all day, he said.

"They're ambush predators," Graziani said. "Night time is when they're going to move. The worst time to hunt is during a full moon. There are no reptiles or frogs on roads during the full moon. I assume that's because they know all other predators are out there because they can see so well."

Shawn Helfick, a licensed python-hunter, measures a Burmese python.Photo by Patricia C. Behnke/Courtesy of Florida Fish and Wildlife Commission

Graziani doesn't carry a lot of equipment with him during a hunt, but he has equipped his truck with high-powered spotlights. And there's no special technique for capturing the pythons. When he sees one, he simply grabs it by the tail and waits for it to start striking at him.

"I let it strike five to seven times," he said. "Each strike became more labored. I wait for it to tire itself out."

When the snake tires, Graziani grabs it behind the head and puts it into a large, lockable plastic container. He was bitten once by an eight-and-a-half foot python that his son captured. He said the bite wasn't especially painful, but one of the python's small, needlelike teeth did break off in one of his knuckles.

"We expect a defensive bite. It wants to hit you and get away," Graziani said. "When that happens, it's like 80 or 100 hypodermic needles puncturing your flesh and coming out."

Graziani said the bite healed without becoming infected.

Burmese python caught in Everglades National Park. More than 1,200 Burmese pythons have been found in the Florida Everglades.Photo courtesy NPS

Graziani euthanizes the snakes captured on Florida Fish and Wildlife lands by severing the brain from the spinal cord. Snakes that are taken on National Park Service lands are turned over to the Park Service, which euthanizes them.



George Horne, deputy executive director of the South Florida Water Management District in West Palm Beach, said that more than 1,200 pythons have been found in a relatively small area in the Florida Everglades. And there's been a dramatic increase in the number of pythons found in the past year, Horne said.

Some of the pythons were released into the wild by people who became disenchanted with their pets, Graziani said. But most of them escaped into the wilds when powerful Hurricane Andrew tore into Homestead--just south of Miami--in 1992, he said. At least 1,000 pythons escaped when the hurricane destroyed a dealer's containment area near Homestead, he said.

Estimates of the number of pythons in South Florida vary widely, from a few thousand to as many as 150,000. Graziani thinks the number probably is between 3,000 and 5,000.

Horne said the snake-hunting permits were first issued about three years ago as part of the South Florida Water Management District's effort to restore the Florida Everglades.

"One of the key things with the Everglades restoration, one of the measures of success, was that we had to be able to increase the bird population," Horne said. The increasing python population could make it impossible for the bird population to increase, he said.

"We could have pristine water quality, and it could be lifeless except for these large predators," Horne said.

Willie Drye is the author of "Storm of the Century: The Labor Day Hurricane of 1935," published by National Geographic, and a regular contributor to National Geographic News. He has also written for the Toronto Globe and Mail, the Washington Post, the Tampa Tribune and the Orlando Sentinel.

Drye is a graduate of the University of North Carolina at Chapel Hill. Visit his blog: "Drye Goods."

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Key Largo gets some wood rats back

Seven Key Largo wood rats -- from a kinder, gentler rodent strain than the one humans abhor -- were released into their only known home.

This is one of seven Key Largo wood rats taken to Crocodile Lake National Wildlife Refuge. LOWRY PARK ZOO/TAMPA

Photo By CURTIS MORGAN
The seven pioneers spent the week preparing for their upcoming ordeal in North Key Largo, sampling berries and other local fare, redecorating homes with sticks, leaves and whatever else they got their little paws on, and generally getting used to life outside a cage at Disney World.

On Tuesday, scientists lifted protective enclosures to release captive-bred Key Largo wood rats into Crocodile Lake National Wildlife Refuge -- the first test of a restocking experiment that might represent the last and best hope for an obscure rodent that ranks among Florida's rarest species.

So far, so good. Feral cats and Burmese pythons didn't immediately swallow any, and the lab rats -- products of a breeding program run by the U.S. Fish and Wildlife Service, Tampa's Lowry Park Zoo and Disney's Animal Kingdom -- showed some of the skills and instincts they'll need to survive.

For one, they've lived up to another name they sometimes go by: pack rat. They've busily added to nests -- distinctive mounds cobbled with everything from sticks to dung to the random bottle cap -- that were vacated by other members of their vanishing population.

``They've piled so much stuff over the nests it's incredible,'' said Sandra Sneckenberger, a Wildlife Service biologist.

The Service started the breeding program in 2002 as a last-resort attempt to reverse the population decline in the rat's only known home, the tangled hardwood hammocks of the largest island in the Florida Keys chain. The estimated population has dwindled to no more than 300 -- down dramatically from about 6,500 before 1984, when the rat was added to the federal endangered species list.

Though they are rats, they are a different genus than the nasty, biting carriers of disease reviled by humans, said Christy Alligood, a research specialist at Disney's Animal Kingdom. The wood rat arises from a kinder, gentler rodent strain and wants nothing to do with homes or buildings. In nature and size, they're more akin to mice -- small at just four to nine inches, docile and shy.

Though handling the seven was kept to a minimum to help acclimate them to the wild, biologists and breeding teams grew attached enough to name them, Sneckenberger said. ``They are very charismatic creatures.''

The first group of seven -- Tweak, Ralph, Roxy, Frieda, Rosie, Fern, and Garfunkle -- will be followed by seven others later this month. The rats, fitted with tiny radio collars, will be tracked for 60 days. If they survive, the hope is they'll breed.

It's not something they do all that frequently in the wild, which might partially account for the species' decline. Unlike prolific urban rats, wood rats breed only two to three times a year, producing about two ``pups'' each time, Alligood said. Otherwise, they tend to be solitary homebodies.

Getting them together in captivity proved one of the major challenges for the eight-year breeding program, she said. If they weren't in the mood, they might even attack each other. Researchers and technicians at the Animal Kingdom's Conservation Station learned to recognize the signs of a ``receptive'' wood rat, including a tell-tale, high-pitched raspy chirp.

Development, the most prevalent threat to wildlife in Florida, certainly played a role in reducing the rat's prime habitat, but its most recent rapid decline, starting around 1995, happened with much of its remaining habitat under state and federal protection.

The dire drop remains somewhat of a puzzle to scientists.

Tracking the lab rats also might help sort out threats, including diseases associated with a round-worm found in raccoon feces, as well as Key Largo's problematic population of feral cats and Burmese pythons.

Rat remains have been found in the guts ofat least two captured snakes.

Those birds aren't crazy, they're drunk

February 20, 2010: The cold snap has brought an usual effect to part of Florida: drunken birds. They are flying into car windshields and house doors, and making messes on vehicles, according to floridatoday.com.

Florida Today talked with some experts and learned that the birds are getting inebriated on berries left fermenting on the vine. When it gets really cold, plants stop sending nutrients to limbs, leaving the berries to rot).

Dane Culbert of the University of Florida’s extension service said he has seen hundreds of orange-breasted robins congregating in his yard in the past two weeks. “They were coming through, and it’s like, ‘Where’s Alfred Hitchcock?’ ”

"So the next time you are sitting at the police station and performing your breath analyzer test for the third time, be sure to announce that you had consumed several drunken "Robins" for dinner and you are suffering from a severe contact drunk from the birds". ~ Jim (also be sure to have a few Robin feathers to shove in your mouth just prior to the arresting officer approaching your vehicle...it may add more weight to your absurd claim)