1. Wide of large pink birds taking flight in the Mad Island Nature Conservancy
2. Bird perched on rock
3. Wide of Mad Island sign
4. Mid of bird expert making bird calls
5. Close of Bird expert Richard Kostecke making and listening to bird calls
6. SOUNDBITE: (English) Richard Kostecke, Bird expert, Mad Island Nature Conservancy:
"The big news this year in Texas was the weather and fire. So, we had actually a one-year drought of record, so it's the worst drought, single-year drought that Texas has seen. We've also had historic wild fires, spanning across the state."
7. Wide of waterway
8. Wide of low water mark seen on rock
9. SOUNDBITE: (English) Richard Kostecke, Bird expert, Mad Island Nature Conservancy:
"So some of the things we're seeing particularly with birds, is there is either direct loss of habitat, so you don't have wetlands available for some of these species any more. Habitat quality and condition is just poor. The vegetation didn't do well this year, it didn't put out buds, it didn't flower, it didn't put out seed or fruit, so a lot of those food sources are lower than they might be."
10. Wide of muddy water
11. Wide of sparse grass in water
12. SOUNDBITE: (English) Richard Kostecke, Bird expert, Mad Island Nature Conservancy:
"So we're seeing smaller numbers of many birds that we typically expect more of, but it's also causing some displacement. The birds have to find suitable habitats, so they're moving around different places."
Mad Island, Texas - December 2011, Exact date unknown
13. Wide of whooping cranes
14. Mid of cranes
Mad Island, Texas - 16 February 2012
15. SOUNDBITE: (English) Richard Kostecke, Bird expert, Mad Island Nature Conservancy:
"They also have some whooping cranes that are wintering as far north as Nebraska, which is very unusual. And there is a whole bunch of cranes, roughly about a third of the known population that have not yet been accounted for."
16. Wide of small white bird
17. SOUNDBITE: (English) Richard Kostecke, Bird expert, Mad Island Nature Conservancy:
"We have some ducks that have gone unusually far south. So there is the country of Belize apparently had a bunch of new records of different species of waterfowl that they've never seen before."
Mad Island, Texas - December 2011, Exact date unknown
From whooping cranes spending their entire winter in Canada to ducks flying farther south than normal, scientists in Texas have noticed some strange trends in bird migrations of late.
They believe flocks are becoming more desperate for food and habitat, which have become scarce because of the state's stubborn drought.
The unusually mild winter in the Northeast and Midwest has even persuaded some birds they could stay put, fly shorter distances or turn back north earlier than normal.
The list is disturbing.
Endangered whooping cranes flew 2,500 miles (4,000 kilometres) from Canada to Texas, where they usually spend the whole winter.
They pecked around a little before turning around and flying back.
In Nebraska, other cranes never left.
Some ducks just kept flying south, all the way to Belize in Central America.
A snowy owl was spotted near Dallas, only the sixth time that's ever happened.
Migratory birds often use the winter months to rest, eat and gain energy for the long journey back to their nesting grounds, so biologists can only guess at the effects of this season's peculiar movements.
"The big news this year in Texas was the weather and fire," said Richard Kostecke, a bird expert and associate director of Conservation, Research and Planning at the Nature Conservancy in Texas.
"We had actually a one-year drought of record, so it's the worst drought, single-year drought that Texas has seen. We've also had historic wild fires, spanning across the state."
At the Nature Conservancy's Mad Island preserve alone, wetlands have been depleted from 1,100 acres (445 hectares) to a mere 200 acres (81 hectares).
Kostecke says the weather has adversely affected vegetation that many types of birds rely on.
"The vegetation didn't do well this year, it didn't put out buds, it didn't flower, it didn't put out seed or fruit, so a lot of those food sources are lower than they might be," said Kostecke.
In a typical winter, the Texas Gulf Coast is packed with tens of thousands of birds - songbirds, waterfowl, catbirds, gnatcatchers, warblers and other migrants.
But this year, an annual count done just before Christmas found the population had dropped steeply.
The number of water-dwelling birds was down significantly.
Geese, for example, were 61 percent below their 19-year average.
A mid-winter population survey revealed that overall numbers were down about three percent compared with last year.
Surveys show inland species are on the move, too.
The disruption in natural migration comes with risks, even for the birds who survive into the spring.
Birds that switch migratory paths may be fine for a couple years, but they could die later if they follow the same path only to find that their destination has become much warmer or colder than expected.
One of the biggest concerns is for the whooping crane.
There are only about 300 of these majestic, five-foot (1.5 metres) birds left in the wild.
This endangered flock, which scientists and the federal government have been working to revitalise for decades, flies every year from its nesting grounds in Wood Buffalo National Park in Canada to the Texas Gulf Coast.
In 2009, the year of the last major drought, an estimated 23 birds died, probably because they were unable to find enough of the high-protein blue crabs and wolf berries to eat in Texas.
Scientists were concerned the same thing could happen again.
But the first census found many of the birds weren't even on the coast.
Only about two-thirds of the cranes were spotted.
One family, or about a half-dozen cranes, reached the Gulf, then turned around to spend the winter at Granger Lake about 225 miles (360 kilometres) north.
A few others were seen in unusually mild Nebraska. The rest are missing.
Scientists plan to monitor the bird population to study the long-term consequences of this season's migratory patterns.
Experts in Belize are sharing notes with counterparts in Texas, who are talking to other specialists in the northern United States and Canada.