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Texas: A Wintering Duck Destination

Texas: A Wintering Duck Destination

Migration and Population Shifts

 

Article by Nate Skinner

Photos by Larry Ditto

 

The Texas Gulf Coast has provided waterfowl hunters with plentiful and diverse hunting opportunities for decades. Composed of both public and private lands, it encompasses a variety of habitat types and is a key destination for wintering North American waterfowl species.

Swarms of ducks over our coastal bays, marshes and prairies have long been a standard sight during the fall and winter months. Over time, though, the ducks’ distribution across coastal terrains has shifted. There has also been a change in the number of birds wintering along the coast within certain, specific species.

If coastal waterfowl hunters could only pick one duck to represent Texas bays, undoubtedly it would be the Redhead. It has been estimated that 80 percent of the continent’s population of Redheads annually winters along the Texas coast, specifically the Lower Laguna Madre. According to TPWD Waterfowl Program Leader Kevin Kraai, this number has even been higher at times.

“In recent years, we have been seeing a shift in wintering populations of Redheads farther south,” Kraai said. “We are seeing more birds moving into Mexico.”

Kraai attributed the southern shift in Redhead migrations to human disturbance.

“We have not seen a concerning reduction in resources in regard to food and habitat for Redheads along the lower Texas coast,” he said. “The seagrasses that these ducks rely on continue to thrive. There’s always a concern towards the availability of freshwater on the landscape along the coast, but the years in which we have seen an absence of Redheads in our bay systems have not coincided with a drought, so freshwater wasn’t the issue.”

Kraai said that the term “human disturbance” doesn’t refer solely to hunting pressure, but all forms of pressure on our bay systems. In addition to hunting, it includes fishing pressure and boat traffic.

“It’s very clear, that Redheads are becoming very intolerant of the human activity taking place across our bays,” Kraai said. “It’s becoming harder and harder for them to find areas where they can rest and raft up on these bodies of water.”

He continued, “Flying requires a lot of energy, and if they are having to spend most of their days flying to avoid boats and other forms of human activity, then they will eventually become motivated to leave, because staying put would be detrimental to their health.”

Kraai said that some years have been better than others for wintering Redhead populations, and that some bay systems tend to have better years than others in regard to Redheads.

“Overall, Redheads are becoming fickler with their wintering habits,” he said. “There were significant up and down swings in the number of Redheads wintering along the Texas coast from 2017-2020.”

Kraai said Redheads seem to be using more and more areas that have sanctuary-like qualities, especially during daytime hours.

“These are areas off the beaten bath, in places that even specialized vessels like air boats struggle to reach,” he said. “They are likely feeding at night when there are fewer people on the water bothering them.”

The Scaup is another diver duck species, like the Redhead, that is highly prevalent along the Texas coast. To many hunters’ dismay, this season’s bag limit on Scaup has been reduced to one bird per person. Kraai said that this regulation change is a result of the data from the breeding survey that was conducted in May 2019, which showed a significant decrease in Scaup.

“To be honest, we are not quite sure why Scaup were unsuccessful during the spring of 2019, so we are working to investigate this issue,” Kraai said. “Scaup are not necessarily prairie pot hole type ducks, although good proportions of them do nest in prairie pot hole habitats.”

He continued, “The majority of Scaup nest in the boreal forest, and there are current hypotheses being investigated about stresses and changes happening in that region. There are also a lot of hypotheses about food availability during their migration, specifically their northward migration back to the boreal forest prior to production. We are overturning every rock to try to find a solution to the problem.”

According to TPWD midwinter survey data, there were 442,475 Scaup along the Texas coast during the winter of 2019, prior to their unsuccessful reproduction season. In the winter of 2020, survey data showed there to be only 89,081 Scaup wintering on the Texas coast.

One diver duck that has been sort of a conundrum for waterfowl biologists is the Canvasback. Kraai said that Canvasbacks may be the most stable duck in North America, as far as their population is concerned.

“Their population stays fairly consistent year after year,” he said.

Despite what some folks may think, Canvasbacks are not a big fan of saltwater and are not seen in huge numbers along the coast. Kraai said that the habitats they are primarily looking for tend to have freshwater with plenty of submerged aquatic vegetation. Freshwater marshes just inland of the coastline with these features do attract some Canvasbacks.

Canvasback wintering populations on the coast tend to fluctuate, unlike their overall population. In 2018, TPWD midwinter survey data revealed that only 2,384 Canvasbacks were wintering along the Texas coast. In 2019 this stat was 101,087 birds, and in 2020 it dropped down to 10,521 birds.

The Bufflehead is a coastal duck with fairly stable population numbers according to Kraai. They typically fly in small flocks and are very common along our bay systems. Kraai said Buffleheads are particularly important to our coastal waterfowl hunters because often they are the duck that allows bay hunters to fill their daily bag limit due to the regulations on other species.

Besides diver ducks, the Texas coast sees significant influxes of dabbling ducks during the fall and winter months. One species that is expected to have a tremendously healthy migration towards our coastal prairies, marshes and bays this year is the Blue-winged Teal.

“The coast has seen a huge increase in the amount of Blue-winged Teal wintering across the landscape in recent years,” Kraai said. “One important thing to note about blue-wings is their change in migration over the past five years or so, in that they have become season long residents for hunters to take advantage of.

“We used to see waves of them during September and October, and then they would be gone during the regular hunting season, having migrated even further south. That is not the case anymore.”

Kraai said that milder winters have been keeping Blue-winged Teal around the Texas coast throughout the hunting season’s entirety.

“Like any other migratory bird, blue-wings are only going to migrate as far south as they have to, and this fact has been a blessing for us here in the Lone Star State,” Kraai said. “Blue-winged Teal populations have literally exploded over the last two decades and the northward shift in their wintering grounds has been extremely welcome.”

TPWD midwinter data shows that the number of Blue-winged Teal wintering on the Texas coast jumped from under 20,000 birds in 2017 to more than 68,000 birds in 2020.

Like Blue-winged Teal, Kraai said that Green-winged Teal are thriving along Texas coastal

“Green-winged Teal populations have rebounded to their long-term average in recent years and are fairly stable,” Kraai said. “They are plentiful across the coastal region of the state, and they are a part of a coastal waterfowl hunter’s bread and butter.”

A dabbling duck species that has become more of a resident bird along the Texas coast, is the Mottled Duck. Kraai said that Mottled Duck numbers have been declining for quite some time.

“We are watching our Mottled Ducks very carefully,” he said. “There is a ton of research and monitoring taking place right now, all in the name of the Mottled Duck.”

The waterfowl banding operation in Texas focuses solely on the Mottled Duck.

“Data from this operation helps us learn about harvest rates and survival rates on these birds,” Kraai said. “Operational banding began in 1997 in Texas. For the first 8-10 years we were banding about 2,000 birds a year. We are lucky to get our hands on 300-400 Mottled Ducks nowadays.”

Kraai said that although Mottled Duck populations show declines over the long term, they have been relatively stable in Texas over the past decade.

“Survival rates on banded Mottled Ducks seem to be stable to increasing, while harvest rates are declining,” Kraai said.

One noteworthy dabbling duck that is becoming more and more prevalent on the Texas coast each year is the Northern Shoveler. Kraai compared Shovelers to Blue-winged Teal in that they are thriving along coastal areas each fall and winter. In fact, he said that a Shoveler is more closely related to a Blue-winged Teal than a blue-wing is related to a Green-winged Teal, as far as genetics are concerned.

“Just like Blue-winged Teal, Northern Shovelers have become a staple duck along the Texas Gulf coast,” Kraai said. “At one time many waterfowl hunters were apt to turn their noses up at Shovelers, but in recent years it seems more hunters are beginning to appreciate their abundance and availability.”

Kraai said shoveler populations are just a couple of years removed from all-time record highs.

“The Northern Shoveler has been in the top three harvested species of ducks in Texas for a number of years now,” Kraai said. “They are an extremely important duck in Texas, and they could quite possibly be considered the savior of Texas Gulf coast duck hunting.

The Northern Pintail is also a well-known symbol of Texas coastal duck hunting, and Kraai said he expects pintail numbers to continue to increase along the coast this winter.

“Pintails had excellent conditions along their breeding grounds in the Dakotas the last two breeding seasons,” Kraai said.

Wintering numbers for Pintails along the Texas coast jumped from 82,066 birds in 2018 to 296,422 birds in 2020, according to TPWD midwinter survey data.

Despite the fact that Pintails have had prime breeding conditions in recent springs, their continental population still remains well below historical averages. The majority of Central Flyway Pintails winter on the Texas coast. Kraai said the females tend to depart wintering areas in a relatively lean body condition, which is quite different from Pintails that are wintering in other regions.

“This may be due to a low-quality diet in wintering areas, or possibly because the birds in other regions have different spring migration strategies,” Kraai said. “Currently, there is a lot of uncertainty about how winter ecology and spring migration strategies impact reproduction on the breeding grounds. This is important to understand because these scenarios present very different management implications.”

Texas Parks and Wildlife has partnered with the Caesar Kleberg Wildlife Research Institute at Texas A&M University–Kingsville, U.S. Fish and Wildlife Service, Ducks Unlimited, New Mexico Game and Fish, U.S. Geological Survey, and the Louisiana Department of Wildlife and Fisheries to investigate both winter ecology and spring migration strategies of Pintails wintering in different regions across North America.

According to Kraai, the research’s goals include the following: investigating the habitat use and behavioral activities of Pintails wintering in Texas; comparing the spring migration strategies of Pintails within and among wintering areas in North America; investigating the links between migration strategies and reproductive success; assessing the contribution of endogenous nutrients to reproduction for different regions and different migration strategies; and identifying critical stopover areas for Pintails migrating from different wintering areas.

“Pintails were captured in several wintering locations during the fall and winter from 2019-2020,” Kraai said. “These locations included the Texas coast, Texas Panhandle, New Mexico, Arizona, central California and the Louisiana coast. To date, 148 females have been outfitted with hybrid GPS-ACC tracking devices; 52 of which came from the Texas coast.”

Kraai said these tracking devices provide location information every 60 minutes and reveal almost continuous behavioral data, such as whether the birds are feeding, walking, resting or flying. This information will help better quantify their habitat use information during the winter, as well as aid TPWD in understanding their migration strategies during the spring. Two more field seasons of this study are planned for 2021 and 2022.

Freshwater is key to all ducks wintering along the Texas Gulf coast. Kraai said that every species at some point or another must visit freshwater at least once a day.

“Where available freshwater sources lie, their proximity to coastal bays and marshes significantly affects the distribution of ducks along the Texas coast each year,” Kraai said. “TPWD and its partners with the Gulf Coast Joint Venture have conducted research to map out where freshwater resources are located in relation to saltwater habitat features, such as sea grasses, that our coastal ducks rely on. This is something that’s been a real priority to us.”

Kraai said that luckily, Texas has not been losing a lot of freshwater availability just inland of the coast, except for a few locations.

“Obviously, freshwater availability is cyclical to some degree as some years are wetter or drier than others,” he said.

Although things are continually shifting along the Texas coast in regard to waterfowl, good habitat health in that region is still essential for a plethora of duck species. As we adapt and try to overcome these changes, one thing is for sure—collective efforts from all Texans are necessary to preserve our coastal waterfowl wintering grounds.



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