Parallel Telemetry Study: Long-billed Dowitchers in San Francisco
Over time the region neighboring the San Francisco Bay estuary has become highly urbanized, and recent developments and diking of baylands have put stress on the Long-billed Dowitchers species. The San Francisco Bay estuary is one of the most important wintering areas for the Long-billed Dowitchers on the Pacific Flyway (where migratory birds travel to follow food sources or head to breeding grounds) of North America. In 2000 from November to December, John Y. Takekawa, Nils Warnock, Greg M. Martinelli, A. Keith Miles, and Danika C. Tsao decided to create the first radio-marking study of Long-billed Dowitchers to examine their use of baylands. They captured 33 Long-billed Dowitchers by rocket netting around the North Bay area of San Francisco. Once the shorebirds were captured, each bird got its own identification number and their age, week, and mass were recorded. They used radio telemetry to examine the Long-billed Dowitchers’ wintering movements and home range by gluing the transmitters on the Dowitchers’ lower backs as well as putting leg bands on them. They tracked the shorebirds one low tide and one high tide each day, and any day the locations were collected on successive tides, mean movements were estimated for each bird by averaging the distance between consecutive low and high tide locations.
After data was collected from the radio telemetry study, Black-necked Stilts and Western Sandpipers (other shorebird species in the estuary) were used to compare space use of baylands. Through these comparisons it was determined that the Long-billed Dowitchers have a more selective use of high-tide habitats. Also with the lack of movement within the Stilts and the Sandpipers to different subregions of the bay, the study shows strong site fidelity for shorebirds in the estuary. After comparing and collecting data on the Long-billed Dowitchers, research shows that their strong site fidelity is highly impacted and makes them more vulnerable to the highly urbanized estuary and any in widespread changes in the composition of the bayland wetlands of the San Francisco Bay estuary may greatly alter the amount of Long-billed Dowitchers. Radio collaring the Long-billed Dowitchers helped come to these conclusions and without them it would have increased the difficulty of tracking the Long-billed Dowitchers’ locations during each tide.
Though this telemetry study is a large-scale version of Lovett's Box Turtle study, parallels were drawn between the study of the San Francisco Bay estuary and Lovett's study of Box Turtles, besides the apparent similarity that they were both radio telemetry studies. To begin the study of Box Turtles, each group was assigned a turtle from a given habitat. The group was to measure, weigh, and determine the sex of the turtle. The same procedure occurred in the study of the San Francisco Bay estuary. One bird would be caught, its species would be determined, and its age would be determined. Both the box turtles and the Long-billed Dowitchers received radio transmitters. For the birds, the transmitters were glued onto their lower back, as opposed to the transmitters being taped and Velcro-ed on to the shell of the box turtle. Both the turtles and birds were released into their original capture area. For both studies, the home ranges of the box turtles and the Long-billed Dowitchers were examined. One of the main differences between the two studies includes that within the San Francisco Bay estuary study, the mean distances between the location of the bird one day and another day were calculated in order to determine how the bird was moving from area to area. Despite this difference, the box turtle study and the San Francisco Bay estuary study are very similar.
This article informed us not only on future ideas for a Box Turtle study, but also interesting facts about Long-billed Dowitchers and other shorebirds. Throughout the process, it was determined that the average distance a bird moves during a specific time frame, such as tidal movements, can be useful in determining future locations and migratory patterns. It is interesting to learn that different methods of patterns researchers use to track movement and it would be very fascinating to see a Box Turtle study done at Lovett with a set pattern of when to check the turtles' movements. An example of this would be having to go whenever it rains. Another method is comparing similar animals within the Lovett community with the Box Turtles we are studying to help improve results and limit generalizations based off of one animal, since some animals can be more selective than others. In the study the Long-billed Dowitchers were more selective than the Western Sandpipers when considering their use of high tide habitats. We also learned the environmental effects on estuaries and shorebirds due to urbanization. For instance, diking and development are harming baylands, but to fix it conservationists transformed a lot of the diked baylands to tidal salt marshes, causing a loss of habitat for the waterbirds to migrate to in the Winter. A fact that was the most surprising about Long-billed Dowitchers is that although their home range size is highly variable, usually ranging from 21.9km² to 239km², most birds, no matter their body mass, only use a very small section in the center of their home range. This article was very interesting and very informative for the rest of our Box Turtle study.
After data was collected from the radio telemetry study, Black-necked Stilts and Western Sandpipers (other shorebird species in the estuary) were used to compare space use of baylands. Through these comparisons it was determined that the Long-billed Dowitchers have a more selective use of high-tide habitats. Also with the lack of movement within the Stilts and the Sandpipers to different subregions of the bay, the study shows strong site fidelity for shorebirds in the estuary. After comparing and collecting data on the Long-billed Dowitchers, research shows that their strong site fidelity is highly impacted and makes them more vulnerable to the highly urbanized estuary and any in widespread changes in the composition of the bayland wetlands of the San Francisco Bay estuary may greatly alter the amount of Long-billed Dowitchers. Radio collaring the Long-billed Dowitchers helped come to these conclusions and without them it would have increased the difficulty of tracking the Long-billed Dowitchers’ locations during each tide.
Though this telemetry study is a large-scale version of Lovett's Box Turtle study, parallels were drawn between the study of the San Francisco Bay estuary and Lovett's study of Box Turtles, besides the apparent similarity that they were both radio telemetry studies. To begin the study of Box Turtles, each group was assigned a turtle from a given habitat. The group was to measure, weigh, and determine the sex of the turtle. The same procedure occurred in the study of the San Francisco Bay estuary. One bird would be caught, its species would be determined, and its age would be determined. Both the box turtles and the Long-billed Dowitchers received radio transmitters. For the birds, the transmitters were glued onto their lower back, as opposed to the transmitters being taped and Velcro-ed on to the shell of the box turtle. Both the turtles and birds were released into their original capture area. For both studies, the home ranges of the box turtles and the Long-billed Dowitchers were examined. One of the main differences between the two studies includes that within the San Francisco Bay estuary study, the mean distances between the location of the bird one day and another day were calculated in order to determine how the bird was moving from area to area. Despite this difference, the box turtle study and the San Francisco Bay estuary study are very similar.
This article informed us not only on future ideas for a Box Turtle study, but also interesting facts about Long-billed Dowitchers and other shorebirds. Throughout the process, it was determined that the average distance a bird moves during a specific time frame, such as tidal movements, can be useful in determining future locations and migratory patterns. It is interesting to learn that different methods of patterns researchers use to track movement and it would be very fascinating to see a Box Turtle study done at Lovett with a set pattern of when to check the turtles' movements. An example of this would be having to go whenever it rains. Another method is comparing similar animals within the Lovett community with the Box Turtles we are studying to help improve results and limit generalizations based off of one animal, since some animals can be more selective than others. In the study the Long-billed Dowitchers were more selective than the Western Sandpipers when considering their use of high tide habitats. We also learned the environmental effects on estuaries and shorebirds due to urbanization. For instance, diking and development are harming baylands, but to fix it conservationists transformed a lot of the diked baylands to tidal salt marshes, causing a loss of habitat for the waterbirds to migrate to in the Winter. A fact that was the most surprising about Long-billed Dowitchers is that although their home range size is highly variable, usually ranging from 21.9km² to 239km², most birds, no matter their body mass, only use a very small section in the center of their home range. This article was very interesting and very informative for the rest of our Box Turtle study.