U.S. Fish and Wildlife Whooper Updates

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  • Thursday, March 07, 2013 8:52 AM | Anonymous member (Administrator)
    Wintering Whooping Crane Update, March 7, 2013
    Wade Harrell, U.S. Whooping Crane Recovery Coordinator

    A Dallas hunter entered a plea of guilty and was sentenced for killing a juvenile whooping crane. After contacting Texas Parks and Wildlife, the hunter told state game wardens he thought the whooping crane was a sandhill crane. Read the full news release here.

    Whooping Cranes on the Aransas National Wildlife Refuge:

    • We have preliminary lab results on the whooping crane carcass that refuge staff recovered on Feb. 7, 2013. Unfortunately, no conclusive cause of death could be determined given the advanced decomposition and scavenging of the carcass. Bacterial tests of bone marrow did not indicate an infection that would have led to death. West Nile virus testing is still underway.
    • It appears that some whooping cranes have started to migrate back north, which is several weeks earlier than normal. Perhaps this is not surprising given the unusually warm and dry winter that the southern plains have experienced.
    • The annual whooping crane festival hosted by the Port Aransas Chamber of Commerce was a success. Tour boats reported seeing a high of 49 whooping cranes along the shoreline of the intracoastal waterway on the Blackjack Unit of Aransas National Wildlife Refuge. Talks and tours were well attended and the weather was cooperative for the most part.
    From Texas Whooper Watch and other observers:
    • February 8: Bird watchers at Quivira National Wildlife Refuge in Kansas reported six whooping cranes on the refuge. Staff was not able to reconfirm the sighting however this record is 11 days earlier than any previous refuge migration record dating back to 1960. Prior to this, the earliest record was February 19, 2000.
    • February 10: Five whooping cranes were reported in Wharton County, north of El Campo. This group has been sighted regularly on private lands in this area throughout the winter.
    • February 17: A confirmed pair of whooping cranes was documented in Matagorda County on The Nature Conservancy’s Mad Island Marsh preserve. Whooping cranes have used this area in previous years but this is the first winter that birds have been documented throughout the winter season.
    • February 18: Ten whooping cranes were spotted at Granger Lake on the lake shoreline across from Friendship Park. This group consisted of two family groups with one juvenile each and four birds associating as pairs. * See the update below on the marked family group.
    • February 22:
      • Texas Whooper Watch received a report of four whooping cranes migrating with about 300 Sandhill cranes west of Vernon, TX.
      • Salt Plains National Wildlife Refuge in Oklahoma received a report of six whooping cranes near Kremlin, OK and 2 whooping cranes near Ringwood, OK.
    • February 24: The marked family group (two adults and one juvenile) from Granger Lake left arriving in North Texas that evening. They stayed through Feb. 28 and then moved to SW Oklahoma where they remained through March 2. They then moved on to Quivira National Wildlife Refuge in South Central KS, a traditional migration stopover site for whooping cranes, where they currently remain.
    • March 3: Bird watchers reported eight whooping cranes near North Platte, Nebraska. We are working to confirm this report.

    Can You Find the Whooping Cranes?
    Every winter when the whooping cranes arrive on the Texas coast, biologists fly aerial surveys to try and get an estimate of the endangered birds’ population. These flights are conducted in December when most of the whooping cranes are known to be on their wintering grounds. This is also a prime time for many other birds to be feeding in the marsh. When flying over whooping crane habitat, this is what biologists see. How many whooping cranes do you see? Click Here.


    Tracking the Whooping Cranes

    The Whooping Crane Tracking Partnership recently issued their biannual report. The following is a summary of the data captured from the 2012 breeding season through fall migration (approximately May through November).

    During the 2012-2013 season, the Whooping Crane Tracking Partnership gathered location data from 36 transmitters during the breeding season and data from 30 transmitters during fall migration. Prior to migration, six transmitters stopped providing data. With the help of the technology, the mortalities of two juveniles and two subadults were confirmed on the breeding grounds of Wood Buffalo National Park. The two other transmitters were confirmed to have broken antenna. The tracking technology also revealed that three cranes spent the summer months in south-central Saskatechewan and 29 marked birds completed the fall migration.

    The birds began their fall migration on September 7, 2012, and data indicates that all of the birds arrived on the Texas coast by November 27, 2012. It took the cranes an average of 46 days to make the migration with the migration time ranging from 21 to 67 days. The data shows whooping cranes used 261 different locations where they stopped and stayed for more than one night. Stopover locations occurred in every state and province in the Great Plains. Cranes spent the most time at staging sites in Saskatchewan and the Dakotas. The general migration corridor used was similar to past migrations and there were no mortalities detected during the migration.

    The GPS tracking devices are programmed to record four locations daily and provide both daytime and nighttime locations. Transmitters upload data approximately every 2.5 days allowing for monitoring survival. The technology allows biologists to learn which habitats are being used and where the birds stop during their migration – important information when prioritizing management decisions.

    Precipitation/Salinity:
    The refuge has not had any significant rainfall since February 7, when 1.66 inches were recorded. This extended dry period has continued to impact freshwater availability and salinity levels within whooping crane habitat on and around the Aransas Refuge. Over the past month, the salinity levels in San Antonio Bay have ranged between 21 and 30 ppt, well above optimal levels. Weather forecasts for this upcoming weekend include a chance for a significant rain event.

    Food Abundance:
    Refuge staff was able to complete a 541-acre prescribed burn last Wednesday along the east shoreline of the Blackjack peninsula, an important foraging area for whooping cranes. This brings the winter burn total to 8,770 acres. This will likely be our last prescribed burn for the winter.

    The refuge has secured a contractor to rework two freshwater wells on Matagorda Island in order to enhance freshwater resources available to whooping cranes. We expect that work to begin very soon.

  • Friday, February 15, 2013 8:51 AM | Anonymous member (Administrator)

    2012–2013 Winter Whooping Crane Survey:
    U.S. Fish and Wildlife Service personnel conducted 7 surveys of the primary wintering grounds during December 2012. These efforts resulted in the training of 2 new observers and further refinement of the new survey protocol.

    Preliminary analyses of the data indicated 257 (95% confidence interval (CI) = 178–362) whooping cranes inhabited the primary wintering grounds. Additional observations suggested that at least 22 whooping cranes were outside the primary wintering grounds during the survey period (see whooping cranes outside the primary survey area below). We estimated 105 (95% CI = 73–146) whooping crane pairs in the primary winter grounds and at least 33 (95% CI = 19–51) of those pairs arrived with at least one chick. We estimated the ratio of chicks to adults during the winter 2012–2013 was 14 chicks (95% CI = 9–21) to 100 adults. As our new observers gain experience and we work out methodological details, we anticipate precision in these estimates to increase.

    Examination of the 60-year trend in whooping crane abundance reveals a slow, incremental increase with occasional declines. Such increase has been the rule rather than large year-to-year fluctuation. We do not expect to see wide swings in population growth from one year to the next unless there is a catastrophic event, like a hail storm or chemical spill. During winter 2010–2011, the traditional technique resulted in an estimate of 283 whooping cranes on the wintering grounds. We estimated 254 (95% CI = 198–324) whooping cranes in the primary wintering grounds plus approximately 13 were thought to occur in other areas (i.e., Bayside, Markham, and Granger Lake) during winter 2011–2012. Modeling of the historical time-series of whooping crane abundances predicted 272 (95% CI = 253–298) whooping cranes for winter 2011–2012 and 273 (95% CI = 250–301) for winter 2012–2013.

    Measures of the uncertainty in our estimates are new to whooping crane monitoring. In the past, we did not include confidence intervals or other measures of precision because it was assumed that the traditional technique resulted in a complete count. The traditional technique assumed that 1) none of the birds were missed, 2) pairs consistently used a defined area throughout the winter, and 3) a single observer was able to see and account for every single bird over repeated survey effort. Previously, the traditional technique had no established protocol, there was not a survey area or flight pattern determined before each flight, and the observer flew wherever they thought birds might be seen. This made sense when the whooping crane population was small and occupied a relatively small geographic area. Now, we have a pre-established flight pattern that covers the primary wintering area, we used 2 observers on every flight, and accounted for missed birds. Because no statistical model was applied in the past, we had no way of knowing the uncertainty in our estimates. Now, with the application of a protocol-based survey design and statistical models, we can characterize our uncertainty and develop ways to reduce that uncertainty. A simple explanation of confidence intervals which are a measure of uncertainty can be found here.

    Every year we do this survey we will learn something new and different and apply it to the next season. Our knowledge and precision will grow and we will have more solid information that leads to better management decisions. We expect this process will take several seasons before the obvious and not-so-obvious factors can be incorporated into the survey protocol and statistical models. This is how science progresses. It is a very typical process and ultimately helps us make the best decisions for the whooping cranes.

    Whooping Cranes Outside the Primary Survey Area:
    It is important to note that in addition to the estimate of 257 whooping cranes within the primary survey area, approximately 6% to 11% of the whooping crane population can now be found outside the survey area. This is not because the primary survey area is smaller than what was surveyed in the past; in fact, it is larger. This use of “nontraditional” wintering areas is great news and we are trying to get a better understanding of the expansion and use of whooping crane habitat.

    As many have stated, in the long-run, having whooping cranes winter in a variety of places across a broader geographic range gives us greater confidence that a catastrophic event will not wipe out the population. For decades there has been genuine concern that one catastrophic event near the refuge could lead to the extinction of whooping cranes. This is such an important part of the ongoing recovery of whooping cranes and cannot be understated. Between Texas Whooper Watch and the increasing number of birds marked with satellite transmitters via the tracking study, we are in a much better position to document birds using areas outside the primary survey area.

    The tables below provide our best understanding of birds that were outside the primary survey areas during mid-December. These numbers are concurrent with our aerial surveys. Keep in mind some birds may have been missed. Also, we cannot ever be completely certain that the birds did not move between these locations and to/from the primary survey area while survey flights were being conducted.

    These are three different data sources that help document the proportion of the whooping crane population using areas outside of the primary wintering area during mid-December.

    Table 1: Texas Whooper Watch

    Birds documented outside of the survey area in mid-December via Texas Whooper Watch

    General Area Adults Chicks Total Notes:
    Granger Lake 6 2 8 Includes 1 marked bird.
    N. of El Campo 2 1 3 Includes 1 marked bird. One more pair was documented in the area but we do not have mid-December records.
    Total 8 3 11


    Table 2: Tracking Study
    Birds documented outside of the survey area on December 17th via the tracking study

    General Area Adults Chicks Total Notes:
    Mission Bay (secondary survey area) 1 1 Marked as chick.
    North Matagorda Island (secondary) 2 1 3 Marked chick.
    Holiday Beach (secondary) 2 1 3 Marked chick located on the edge of the primary survey area in early morning prior to the aerial survey & and in the secondary survey area twice in the afternoon.
    Total 5 2 7


    Table 3: U.S. fish and Wildlife Survey
    Birds documented in the whooping cranes' secondary areas on December 13th via aerial survey

    General Area Adults Chicks Total Notes:
    Powderhorn Lake (secondary survey area) 2 2 Pair located on Myrtle-Whitmire Foster Unit of refuge.
    Guadalupe Delta (secondary) 2 2 Two pairs, total of 4 birds, were seen during the Christmas bird count on the 20th.
    Total 4


    * The data and results presented in this report are preliminary and subject to revision. This information is distributed solely for the purpose of providing the most recent information from aerial surveys. This information does not represent and should not be construed to represent any U.S. Fish and Wildlife Service determination or policy.

    Last Updated: Feb 15, 2013
  • Thursday, February 07, 2013 7:05 AM | Anonymous member (Administrator)
    Wade Harrell, U.S. Whooping Crane Recovery Coordinator


    On the morning of Feb. 7, 2013, Aransas Refuge staff retrieved the remains of an adult whooping crane on Matagorda Island. The remains will be sent to a lab for analysis and those results will be shared with the public as soon as they are available.

    Surveys & Monitoring

    The data on the winter whooping crane population estimate is being processed. We are applying sound science to calculate this estimate and will share it with the public as soon as the estimate is complete.

    Whooping Cranes:
    On the Aransas National Wildlife Refuge:
    • A family group of whooping cranes has been seen using the refuge’s Heron Flats area. The newly renovated observation deck provides some excellent views of the birds, which have been seen relatively close (within a couple of hundred yards).
    • A pair of whooping cranes has an established territory that is visible from the Observation Tower.
    • Whooping cranes continue to be seen using the prescribed burn areas throughout the refuge.
    • When you visit the refuge keep your eyes to the sky as we have whooping cranes flying over the visitor center on occasion!

    From Texas Whooper Watch and other observers:
    • On Feb. 4, 10 whooping cranes were spotted at Granger Lake. The 10 birds were photographed, including in a field with a couple of hundred sandhill cranes. Previous reports confirmed eight birds.
    • One of the whooping cranes at Granger Lake is part of the tracking study and has a GPS leg band. Last year, the juvenile bird spent the entire winter at Granger Lake with its parents. Data collected from the bird’s GPS leg band documents that this year the bird migrated to Aransas Refuge arriving at the end of October and returning to Granger Lake in late January.
    • A confirmed pair of whooping cranes was documented in Matagorda County, the Mad Island Marsh, which is on the coast about 30 miles northeast of Aransas National Wildlife Refuge. We had 2 confirmed pairs in the area earlier this winter, but they were not spotted during late December through mid-January. Since these birds are not marked, we don’t know if they have moved around this winter or simply were overlooked for a period of time.

    Tracking the Whooping Cranes
    In 2009, biologists began putting radio telemetry bands on the Aransas-Wood Buffalo whooping crane population. The opportunity to mark the wild birds with Global Positioning System (GPS) technology represents the best opportunity to enhance understanding of the birds and assess the risks they face.

    The technology records bird’s locations and allows biologists to learn which habitats they are using, where they stop during their migration, and more. It captures data from the breeding sites at Wood Buffalo National Park, wintering sites along the Texas coast near and at Aransas National Wildlife Refuge, and stopover locations between. Near completion, the project calls for the tracking of up to 30 juvenile and 30 adult birds.

    The reasons for doing this project are to: 1) learn more about the whooping crane’s breeding, wintering, and migratory ecology, including threats to survival and population; 2) provide reliable scientific data to support decisions affecting conservation, management and recovery efforts; and 3) minimize the negative effects of research activities on the birds.

    The whooping cranes are primarily captured using leg snares, a common trapping technique used on larger birds. Capture teams consist of individuals experienced at handling cranes, including a licensed veterinarian. A veterinarian performs a health check on each crane, which includes a general external examination; blood collection to determine pathogen, toxin, and genetic screening; and fecal collections to check for parasites.

    The GPS band is attached as a leg band. The bands have solar panels that maximize the battery life giving them a potential lifespan of 3–5 years. The transmitters on the leg bands are programmed to record four GPS locations daily, including daytime and nighttime locations. This data collection schedule allows for detailed information on daytime and roosting sites and general flight paths. Transmitters upload new data approximately every two and a half days allowing researchers to monitor survival of the banded birds. As of this winter, 42 transmitters have been put on wild whooping cranes.

    Data collected during the winter of 2011 showed the birds used a variety of distinct areas while over-wintering in Texas, including coastal salt and brackish marsh, agricultural and ranching areas and the inland freshwater wetlands. GPS-marked cranes provided more than 11,000 locations. Approximately 65% of the recorded locations were within the boundaries of the Aransas National Wildlife Refuge and 22% were recorded on nearby, privately owned lands -- areas the whooping cranes have often used in the past. Nearly 13% of the locations were in areas not known to be frequented by whooping cranes previously.

    The 2012 data shows that total time spent migrating between wintering and summering areas ranged from 15 to 46 days and averaged 27 days. For comparison, researchers estimated the average migration time during spring 2011 to be 31 days. The study has documented the whooping cranes using 266 stopover locations -- areas where the birds stayed for one night or more during their migration -- in every state and province in the Great Plains region.

    Trapping efforts for the 2012 winter have been completed with researchers able to put tracking bands on 12 birds. While this technology is already proven to be extremely valuable, it will be several years before sufficient data from the individual birds can be collected and fully analyzed. It will take a considerable amount of time before the information gathered will reflect patterns of the population as a whole.

    This project is conducted by a partnership of agencies and organizations, which includes the Canadian Wildlife Service, Crane Trust, U.S. Fish and Wildlife Service, Platte River Recovery Implementation Program, and U.S. Geological Survey, with support from the Gulf Coast Bird Observatory, International Crane Foundation, and Parks Canada.

    Precipitation/Salinity:
    As this is being written, the refuge is getting much-needed rainfall. As of Feb. 6, the salinity levels in San Antonio Bay are currently 24 ppt.

    Food Abundance:
    The current winter prescribed burn total is more than 8,000 acres. We have approximately 2,000 acres more planned for the winter. Our prescribed burning program is an important part of how we manage whooping crane habitat on the Aransas Refuge. We are seeing continued whooping crane use in the prescribed burned areas throughout the refuge. It opens up new habitat for the birds to forage in and provides food resources such as live oak acorns that would not typically be available. The satellite tracking study is providing insight into how the whooping cranes use the recently burned areas.

  • Thursday, January 24, 2013 7:06 AM | Anonymous member (Administrator)
    Wade Harrell, U.S. Whooping Crane Recovery Coordinator

    Surveys & Monitoring:
    We are still crunching the numbers on the winter whooping crane population estimate and hope to publish it within the next few weeks. We would rather report the best estimate the first time rather than have to revise it later. We understand how important the information is and will make it a priority to circulate the information as soon as it is completed.

    Reports from Outside the Survey Area:
    The following information is provided by observers who posted on Texas Parks and Wildlife Department’s Texas Whooper Watch website, as well information we have received.
    • There are still eight whooping cranes using the Granger Lake area, two family groups with a chick each and one pair without a chick. Whooper Watch observers have been able to photograph some of the birds using small stock ponds on private lands near the lake. One observer reported “I was out yesterday (Jan. 16) on my own at Granger and got to watch five whoopers together at a farmer's pond. A nearby family group "took over" the pond that a pair was dancing in. While the pair stayed close by, the group with a juvenile (no transmitter that I could see) began dancing, all of them, especially the juvenile, then bathed in the pond! They would squat and dip their bodies, then shake their feathers off. Then they would dip they heads under the water, then bring them up and shake their heads.”
    • Though it is infrequent, five whooping cranes (a family group and a pair) northwest of El Campo continue to be seen by local biologists and wardens.
    • An experienced birder reported a pair of whooping cranes using farm fields in conjunction with a larger group of sandhill cranes near the Loyola Beach area of Kleberg County. We are still gathering evidence to confirm the sighting but if you bird this area regularly, please keep an eye out and report any sightings to the Texas Whooper Watch.

    Count or Estimate?:
    Questions have come in regarding the difference between a “count” (or census) and an “estimate” (or survey). As it relates to whooping cranes, a census is an exact count where a survey is an estimate of the true number.

    From about 1950 to 2010, the Aransas National Wildlife Refuge staff attempted to conduct a census of the whooping crane population. The census would account for every individual bird in the population regardless of where they were found. This was possible because the population was small and stayed in a relatively small area.

    In wildlife biology, there are few cases where one can successfully complete a count/census of truly wild animals. This is mostly because, by nature, wildlife species move around in their environment. Also, they live in places where it might be easy to overlook them. Animals raised in zoos and released in the wild can be marked with transmitters or bands, which help biologists get an exact count. This is what has been done with the eastern migratory population of whooping cranes that are part of a reintroduction project.

    When the Aransas- Wood Buffalo whooping crane population was small and inhabited a limited area, it was reasonable to assume that most of the individual birds could be accounted for. Fortunately the whooping crane population has grown both in numbers and winter range over the past 20 years.
    What was originally a primary wintering range of the Blackjack Peninsula is today extended to encompass more than 30 miles of the Texas coast. Click here to see the survey map.

    In addition to the expanded range, we know the birds are moving in and out of the survey area. Data from the satellite tracking study shows the radio-marked birds move frequently, sometimes on a daily basis. We can no longer assume that we can properly account for every individual in the winter population because of the expanded range and increased population that moves around on the landscape.

    To make the transition from counting a few endangered species to surveying a growing population, the field of biology has developed methods for estimating the number of individuals in a population through the use of surveys within a given area. It is especially important the method be consistent and can be repeated. The basic survey method we use to estimate the wintering whooping crane population is Distance Sampling, a widely used technique that has been tested on many wildlife species in a variety of habitats.

    Knowing the whooping crane winter range is extensive and the birds move around, we are certain we will miss some of the individuals when conducting an aerial survey. To account for this, we use statistical models that extrapolate the “estimated” number of individuals in a survey area. We get an estimate of all of the whooping cranes in the survey based on the individual birds that are actually seen on the various flights. We conduct several flights using the exact same counting method every time -- consistent and repeatable.

    This type of statistical model typically produces an estimate of the true number of species with an associated confidence interval, i.e. we are 95% confident that the true population is between 220 and 270 individuals. In this case, the population estimate would be 245 individuals +/- 25.

    Several comments expressed concern that the first Distance Sampling estimate conducted last year had too large of a confidence interval to be able to detect change in the birds’ population. This year, our second time to apply the new survey methodology, we are working to narrow that confidence interval. We are doing this by flying more survey days, this is more data to include in the modeling to increase the precision. We are also continuing to refine the statistical model. Adding data and refining the model is a typical scientific process that will lead to increased statistical precision of our whooping crane population estimate.

    That said, the Aransas Wood-Buffalo population is made up of wild birds so there is always going to be some uncertainty when estimating the population. We are confident that the finalized survey protocol will be able to detect change in the birds’ population over time and will provide us the information needed to make critical management decisions.

    In human terms, a real life example can be found in the classroom where a teacher takes attendance to count students. She/he gets a count, an exact number. It is possible because each student is known and can be accounted for. That afternoon, the class attends a ceremony in the auditorium. Looking over the auditorium, the principal wants to gauge how many students are in attendance. How does she/he get an accurate accounting if students are coming and going? How can it possibly be known who didn’t attend school that day? The same principle applies to whooping cranes. It was possible to count the birds when there were less but the growing population and expanded range makes it hard to continue counting individual birds. Thankfully there are more whooping cranes and they are finding new habitats to winter, feed and raise their young.

    Satellite Tracking Study:
    The U.S. Geological Survey, International Crane Foundation, Gulf Coast Bird Observatory and other partners wrapped up this winter’s trapping season with a total of 12 whooping cranes marked with satellite transmitters. This important study has one more year of marking birds. Next winter, the team will come back to Texas to mark 10 more birds, which will wrap up the trapping portion of the study.

    Precipitation/Salinity:
    Since the last update, we have received 1.9 inches of rain. Most of this rain came on January 9, right after our last update. As is normal after a big rain event, we saw significant movement of cranes into the coastal marsh areas. They were undoubtedly taking advantage of the newly available freshwater and food. Salinity in San Antonio Bay dipped to less than 20 ppt for a couple days after the rain day but it has stayed between 22 and 27 ppt since then. We are hoping for another significant rain event to freshen up the coastal marsh and maintain optimal habitat conditions.

    Food Abundance:
    Refuge staff were able to complete a 1,095 acre prescribed burn last Thursday on the southern tip of the Blackjack peninsula, an important foraging area for whooping cranes. This brings the winter burn total to more than 8,000 acres. We have another 2,000 acres or so still planned for the winter. Our prescribed burning program is an important part of how we manage whooping crane habitat on the Aransas Refuge. It opens up new habitat for the birds to forage in and provides food resources such as live oak acorns that would not typically be available. The satellite tracking study is providing insight into how the whooping cranes use the recently burned areas.

    Questions?
    For general questions regarding the methodology, I would recommend taking another look at the December 18 Whooping Crane Update. The website also has extensive information about the survey methodology that can be found here.

  • Thursday, January 10, 2013 7:07 AM | Anonymous member (Administrator)
    Wade Harrell, U.S. Whooping Crane Recovery Coordinator


    Whooping Crane News:
    The tracking partnership continues to provide us new insight into whooping crane use of traditional coastal marsh areas. For example, we continue to note more extensive movement of family groups from the Blackjack peninsula to Matagorda/San Jose Islands during the winter season than previously documented.

    Items of note from Texas Whooper Watch and other observers of whooping cranes observed outside the winter survey area include the following (from LeeAnn Linam, TPWD):

    • Sightings since mid-December have indicated that only one family group and one pair remain at Granger Lake. The family group using the area includes one satellite radio marked bird, so we are able to monitor movements. However, LeeAnn reported that she has an unconfirmed sighting of another family group using farm fields nearby, so there still may be a total of 8 birds in the area. The Granger Lake manager recently observed some courtship behavior, including object tossing, and other observers have noted some dancing.


    •Local biologists, game wardens, and landowners continue to sight 5 whooping cranes (a family group and a pair) northwest of El Campo. One of these birds is a radio marked chick, and we have noted quite a bit of movement over the past several weeks. These cranes are using rice fields and flooded impoundments, along with numerous waterfowl and sandhill cranes.


    •Guadalupe Delta – Brent Ortego (TPWD) reports that the Guadalupe Delta Christmas Bird Count on December 20 detected at least two pairs of whoopers, one near River Road and one near the Barge Canal. We had previously noted a pair in the southern part of the Guadalupe Delta while flying our secondary survey areas. At this time, the Guadalupe Delta is not in our primary survey area, but we will continue to evaluate if the area is supporting enough overwintering cranes to warrant adding it to the primary survey area in future years.

    We are working to confirm several other reports of whooping cranes outside the normal coastal winter range, stay tuned!


    Surveys & Monitoring:
    As reported in the last update, we have completed aerial surveys for our peak winter abundance estimate. Our regional office Biological Inventory and Monitoring team is diligently working to analyze the data and we hope to be able to release a peak whooping crane estimate by the next update. The final draft protocol for our abundance estimates is close to completion, and it will be sent out for external peer review sometime in February.

    Satellite Tracking Study:
    The US Geological Survey, International Crane Foundation, Gulf Coast Bird Observatory and other partners have marked a total of twelve whooping cranes as of January 7th. The trapping team worked over this past weekend and early this week to mark 3 additional birds and hope to mark one more bird before finishing the winter field season the end of this week. Currently, over 40 marked birds in the flock are being tracked.

    Precipitation/Salinity:
    Relatively dry conditions persist around the Refuge, since the last update we have received about 2 inches of rain. We expect the low pressure system currently in place will increase our rainfall totals significantly and hopefully enhance coastal marsh conditions for the whooping cranes. The salinity level in San Antonio Bay was reported at 24 parts per thousand on January 9, and we expect that salinity will decline following the recent rains. NOAA reported this morning that the lower Guadalupe River will reach minor flood stage at Bloomington this weekend, which should give us a needed freshwater influx into San Antonio Bay.

    Food Abundance:
    Given the colder water temperatures (54F reported Jan. 9) and associated low tides we recently experienced, it appears that blue crabs and wolfberries are becoming less abundant in the marshes and whooping cranes are likely beginning to transition to increased use of other late-winter food sources. Refuge staff plan to prescribe burn a total of 8,000 -10,000 acres this winter to assist in providing food sources for the cranes. To date, 6,500 acres have been burned since October 2012.


  • Thursday, December 27, 2012 7:08 AM | Anonymous member (Administrator)
    Wade Harrell, U.S. Whooping Crane Recovery Coordinator


    Whooping Crane News:
    We have been seeing the whooping cranes moving about extensively within the coastal areas. It seem as though the birds may finally be settling in for the winter.

    From Texas Whooper Watch and other observers, the following has been reported on whooping cranes outside the winter survey area:
    • As of Dec. 17, five birds (one family group and one pair) have been spotted near Granger Lake near Austin, Texas. We are not sure if the three additional birds previously spotted have moved on.
    • Three birds have recently been sighted using private land north of El Campo.
    • In Matagorda County, participants in the annual Christmas Bird Count did not report seeing any whooping cranes using coastal marsh. The two pairs of birds using the area were last spotted on Dec. 10.

    Surveys & Monitoring:
    To date, we have completed seven survey flights (November 28, 29 and December 5, 12, 13, 14 and 17). This will conclude our aerial flight surveys used to estimate the number of cranes found on the primary areas of the wintering grounds. Over the next several weeks, we will be working to compile and analyze the data collected and expect to provide an estimate on the number of cranes by late January.

    The December 13 flight included fly-overs of the secondary survey areas (North Matagorda Island, Powderhorn Lake and Guadalupe Delta). Two pairs of cranes were seen using the coastal marsh in these areas.

    Satellite Tracking Study:
    The U.S. Geological Survey, International Crane Foundation, Gulf Coast Bird Observatory and other partners have marked a total of nine whooping cranes as of December 17. The trapping team plans to resume work the week of January 5 to finalize the winter trapping and marking efforts. Currently, nearly 40 marked birds in the flock are being tracked.

    Precipitation/Salinity:
    Relatively dry conditions persist around the refuge. Since the last update we have received less than 1/4 inch of rain. Long term forecasts are now calling for continued drier than normal winter conditions. Salinity levels for San Antonio Bay have ranged from 26 to 30 parts per thousand this past month.

    Food Abundance:
    Whooping cranes seem to now be focusing on blue crabs in the coastal marshes. A prescribed burn consisting of 4,520 acres was conducted on Matagorda Island on December 18 with immediate crane use.

  • Thursday, December 13, 2012 7:09 AM | Anonymous member (Administrator)
     
    Wade Harrell, U.S. Whooping Crane Recovery Coordinator


    Whooping Crane News:
    Nearly all of the radio-marked whooping cranes have migrated to their wintering grounds on the Texas coast. Visitors coming to the Aransas National Wildlife Refuge have a chance of seeing four adult whooping cranes that have been frequenting the observation tower. There are also several whooping cranes utilizing the Heron Flats area just south of Refuge Headquarters. The new observation deck at Heron Flats is now open for visitor use. Whooping cranes are being intermittently observed near Cavasso Creek, just off TX Hwy 35 North of Lamar. If you wish to view whooping cranes from a public highway, please use caution by making sure you are pulled completely off the highway and out of traffic flow. Keep in mind when viewing whooping cranes that they are sensitive to human disturbance and harassing them is a violation of federal law. Avoid approaching cranes and if they appear alarmed, increase your distance.
    With the help of Texas Whooper Watch and other observers, several family groups and individuals have been confirmed outside the winter survey area, including:

    • A confirmed report of two unmarked birds sighted near Quivira National Wildlife Refuge in Kansas on November 29th.
    • As of Dec. 1, a total of eight birds have been regularly spotted at Granger Lake east of the Austin area. Some of these birds are marked with satellite transmitters and we have confirmed that at least a portion of these birds are the same individuals that used this same area last year.
    • A total of five birds, a family group with one chick and one pair, have been seen utilizing private lands north of El Campo.
    • In Matagorda County, observers have noted two pairs of whooping cranes using coastal marsh.

    Continued observations of birds using habitat outside of the traditional wintering areas is an encouraging sign that whooping cranes are successfully exploiting resources and may be expanding their winter range. This would be a positive development for the continuing recovery of the wild flock. Expansion into new areas will provide additional security if a catastrophic event such as a late season hurricane were to impact the Aransas Refuge area. We will continue to monitor whooping cranes that are located outside of our regular aerial survey area.

    Surveys & Monitoring:
    We are conducting aerial surveys from Lamar to south of Port O’Conner as weather permits. Our survey goal is to fly at least five times before the end of December to obtain an accurate population estimate. To date, we have completed three flights (November 28th, 29th and December 5th ). We will provide a peak abundance estimate for our survey area once we have met our goal of at least five survey days. We are not able to capture 100% of the wintering flock within our aerial surveys. Our aerial survey focuses on the traditional high use areas on and around Aransas Refuge, but the continued expansion of the flock has resulted in birds spread out across a greater geographic area than we can effectively fly in a day. Hence, information on whooping crane locations from Texas Whooper Watch and other volunteer observers is invaluable In helping us document whooping crane use of areas outside of their traditional wintering grounds.

    There has been considerable public interest in the changes to wintering whooping crane surveys over the past year. Staff members from Aransas Refuge have flown low-level aerial surveys to estimate the number of whooping cranes in and around Aransas Refuge since 1950. This long-term data set is key in understanding the only remaining wild whooping crane population and is paramount in helping us make effective decisions regarding whooping crane conservation. In the past, an attempt was made to conduct a complete census, counting every bird. Recently, the Service has established a protocol for the aerial surveys to ensure that our surveys are conducted in a systematic way. This protocol is repeatable, allowing any trained biologist to produce a consistent and reliable population estimate within the survey area. We fly predetermined transects at an altitude of 200 feet within the traditional winter coastal areas with two observers each looking for whooping cranes up to 500 m to the side of a small, single engine airplane. Realizing that it is unlikely that we are detecting every crane in the survey area, we have begun implementing a widely-used technique called distance sampling. Distance sampling allows us to account for missed birds and estimate the total number of birds within the survey area. This technique also provides a mechanism for estimating statistical error and produces a confidence interval for the estimate (i.e. +/-). Our agency policy directs us to use the best available science, and clarify uncertainty in our monitoring efforts. We are continuing to work with partners to refine our methodology, ensuring it is as scientifically sound and reliable as possible.

    The US Geological Survey, International Crane Foundation and other partners are currently on Matagorda Island trapping, marking with satellite transmitters and releasing whooping cranes for an ongoing tracking study. Information from this study will provide us with valuable information on how whooping cranes utilize their entire range, from their nesting area around Wood Buffalo National Park, along the migratory corridor throughout the middle part of the US, and on their wintering grounds in Texas. This tracking effort also provides us estimates on whooping crane mortality throughout the range, an important piece of information for the recovery effort. As of December 10, six whooping cranes have been marked and released, with the winter 2012-2013 goal of marking 10 total birds. Currently around 35 marked birds in the flock that are being tracked.

    Precipitation/Salinity:
    Conditions on and around the Refuge have been drier than the long term forecast indicated, but the Refuge was fortunate to receive a total of 2” of rain from pre-frontal events in early December. Salinity levels for San Antonio Bay have ranged from 26 to 28 parts per thousand this past month. Recent rains should reduce salinity somewhat, which will help in maintaining blue crab abundance in the marsh.

    Food Abundance:
    Refuge staff continues to find whooping crane scat filled with wolfberry seeds. This year’s wolfberry crop on the refuge appears to be much improved from the previous few years. Tour boats have reported seeing whooping cranes regularly feeding on blue crabs in the marshes along the Refuge shoreline. Refuge staff plan to prescribe burn a total of 7,000 -10,000 acres this winter to assist in providing food sources for the cranes. To date, 1,657 acres have been burned since October.

    Refuge Update:
    We currently are developing plans to rehabilitate 2 existing water wells on Matagorda Island. This will provide consistent fresh water for whooping cranes to use during dry periods. The Friends of Aransas and Matagorda Island group has led the charge in raising funds for this effort and we are grateful for their assistance. We are also evaluating freshwater availability across the Refuge to ensure we are meeting the needs of whooping cranes and other wildlife. As mentioned earlier, the Heron Flats observation deck is now open for public use.

  • Thursday, November 29, 2012 10:36 AM | Anonymous member (Administrator)
    Whooping Cranes:
    The majority of the radio-marked whooping cranes have migrated to their wintering grounds on the Texas coast. There have also been sightings of cranes in Oklahoma. The survey season has begun and we hope to have preliminary estimates available for the next update. Visitors coming to the refuge have a chance of seeing four adult whooping cranes that have been frequenting the observation tower.

    Surveys & Monitoring:
    Refuge biologists conducted the first whooping crane aerial survey of the season November 28, 2012, and the second survey is being flown today. Data analysis is ongoing and several additional flights are scheduled to occur prior to December 17th. Based on the first flight, the cranes appear to be evenly distributed from Lamar to south of Port O’Connor and the marsh conditions look good.

    Thanks to the Texas Parks and Wildlife Department's Whooper Watch, the public has reported seeing several whooping cranes at Granger Lake near Austin, Texas, more than 150 miles north of the survey area. Additionally, whooping cranes have been seen in the uplands and utilizing the sand dunes of Matagorda Island, a behavior that is typical of sandhill cranes.

    Precipitation/Salinity:
    As of November 28th, the monthly precipitation levels for Aransas National Wildlife Refuge are 0.61 inches and salinity levels for San Antonio Bay are recorded as 29.4 parts per thousand. The National Oceanic and Atmospheric Administration is still predicting a wetter than average winter and spring for coastal Texas in 2013.  Because El Niño's development was abruptly halted, the agency has revised its prediction of the weather for the remainder of most of the country. 

    Food Abundance
    Refuge staff continue to find whooping crane scat filled with wolfberry seeds. This year’s wolfberry crop on the refuge has been abundant and is being utilized by the birds.

    Refuge Update:
    Whooping Crane Coordinator Dr. Wade Harrell will be heading up the aerial surveys this season. Wade is from Corpus Christi and has a B.S. in Wildlife and Rangeland Science from Texas A&M Kingsville. He earned both his M.S. and PhD from Oklahoma State University in Rangeland Ecology. He has served with the U.S. Fish & Wildlife Service as the Partners for Fish and Wildlife Program Coordinator for the Austin Ecological Services office since 2009 where he led a team of biologists in restoring and maintaining diverse wildlife habitats. Prior to coming to work for the Service, Wade was employed by The Nature Conservancy of Texas serving as the Coastal Prairies Project Director for six years.

    Sonny Perez is the new deputy refuge manager. Sonny comes most recently from the Laguna Atascosa National Wildlife Refuge in the lower Rio Grande Valley where he managed the 90,000-acre refuge known primarily for its recovery efforts on ocelots, a highly endangered wild cat. In addition, Sonny led the refuge’s efforts on Kemp’s Ridley sea turtle recovery efforts, as well as managed a large public use program, habitat restoration work, oil and gas issues, land acquisition and more. He graduated from Texas A&M Kingsville and is originally from Falfurrias.

    Refuge Manager Dan Alonso reached 25 years of service and has decided to retire. His plans are to remain in the area where he will continue to be involved in whooping crane issues. Brad Strobel, refuge biologist, accepted a position closer to his family in Wisconsin. His new position will be with the Necedah National Wildlife Refuge, the refuge that hosts the Eastern migratory flock of whooping cranes each summer for nesting. We wish Dan and Brad the best of luck and thank them for their service to the Aransas National Wildlife Refuge.
  • Friday, November 09, 2012 7:10 AM | Anonymous member (Administrator)
    Whooping Cranes: It is estimated that approximately 35% of the radio-marked whooping cranes have made it to their wintering grounds on the Texas coast. There have also been sightings of the cranes in Oklahoma.

    Salinity Levels: The salinity levels in San Antonio Bay were recorded at 26.6 parts per thousand today.

    Drought Conditions: The area is still unusually dry but the National Oceanic and Atmospheric Administration predicts south Texas will see a wetter than average winter and spring in 2013.

    Food Abundance: While conducting field work during the last few weeks, refuge biologists have come across a lot of whooping crane scat filled with wolfberry seeds. It appears this year’s wolfberry crop is still on schedule and seems to be strong.

    Inventory & Monitoring: Refuge staff began using traps to survey blue crabs in the marshes on the Blackjack peninsula this September. Blue crabs appear to be abundant in the marsh with many traps capturing more than 10 crabs per night.

    Freshwater Availability: To make certain freshwater is available to the whooping cranes when they arrive, refuge staff continue to work water well sites previously used by cranes on the Blackjack peninsula.

    Citizen Science: Texas Parks and Wildlife launched its Texas Whooper Watch Program. This is an opportunity for the public to report sightings of whooping cranes in Texas. This is very helpful in the collection of information regarding the birds’ migration and distribution. Please see the link below to learn more.

    Helpful Links:
    Texas Whooper Watch Program
    Whooping Crane Draft Revised International Recovery Plan (2006)
  • Thursday, October 25, 2012 7:10 AM | Anonymous member (Administrator)
    Whooping Cranes:
    -On October 23 the refuge biologist and manager saw one adult whooping crane feeding in the marshes on the Blackjack peninsula. The bird ate at least two prey items during the 3-5 minutes it was observed.
    -One GPS marked whooping crane arrived on the Texas coast on October 18 and has been using the marsh habitat extensively.
    -All other GPS marked whooping cranes are north of South Dakota awaiting favorable migration conditions. Biologists expect the cranes will take advantage of the strong north winds associated with seasonal cold fronts.

    Salinity Levels: The bay waters are fresher than they were at this time last fall and winter. The salinity levels in San Antonio Bay was recorded as 23.9 parts per thousand.

    Drought Conditions: To date, the refuge has received 25.6 inches of rain, which is a foot more than we had last winter at this time. The area is still unusually dry but the National Oceanic and Atmospheric Administration predicts south Texas will see a wetter than average winter and spring in 2013.

    Food Abundance: Wolfberry conditions in the marsh appear to be much better than this time last year. While conducting field work during the last few weeks, refuge biologists have noticed many flowering and budding wolfberry plants. Peak berry abundance typically occurs in November and December and the plants seem to be on schedule.

    Inventory & Monitoring: Refuge staff began using traps to survey blue crabs in the marshes on the Blackjack peninsula this September. Blue crabs appear to be abundant in the marsh with many traps capturing more than 10 crabs per night.

    Freshwater Availability: To make certain freshwater is available to the whooping cranes when they arrive, refuge staff have been working on water well sites previously used by cranes on the Blackjack peninsula to ensure they are in good working condition.

    Citizen Science: Texas Parks and Wildlife launched its Texas Whooper Watch Program. This is an opportunity for the public to report sightings of whooping cranes in Texas. This is very helpful in the collection of information regarding the birds’ migration and distribution. Please see the link above to learn more.
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