Mad Island Banding
April 22, 2014 by Emily Cohen
Here they come!
Things picked up at the beginning of the week. It wasn't overwhelmingly busy (50 or so birds a day) but it was a nice change compared to the 10 to 30 birds we had been catching earlier in the season. Also this week, most of the wintering birds moved north and we started getting a greater diversity of migrants coming across the Gulf of Mexico.
Then on Saturday, things exploded! We could tell it was going to be busy as we drove out to the banding site in the morning. There were bright blue Indigo Buntings foraging in flocks and lone Scarlett and Summer Tanagers glowing from the tops of trees. We only opened a few nets initially because we didn't know what to expect and we didn't want to get overwhelmed. We gradually opened a few more nets but kept most closed.
Nevertheless, we ended up catching 260 individuals of over 27 species in one day! Sunday was still busy with over 160 birds captured. Today (Monday) felt slow although we still captured over 70 individuals of 31 species. In the last few days we caught our first Veery, Chestnut-sided Warbler, and Canada Warbler, Magnolia Warbler, Yellow Warbler and female Painted and Indigo Buntings (the males show up first). There are a few species that dominate our numbers, primarily Indigo Buntings and Gray Catbirds but Swainson's Thrush, Red-eyed Vireos, and Rose-breasted Grosbeaks are also quite abundant. This week we also captured quite a few Tennessee Warblers, Painted Buntings, Summer Tanagers, Scarlett Tanagers, Yellow-billed Cuckoos, Baltimore Orioles, Orchard Orioles, Wood Thrush, Kentucky Warblers, and Hooded Warblers.
We open nets each day around 7:30 in the morning. The birds we catch in the morning are most likely birds arrived the previous day and stayed at the site for another day. Most birds leave the night after arrival but maybe these individuals needed more time to refuel before continuing migration? Or maybe they assess the advancement of spring on the northern side of the Gulf of Mexico and sometimes decide to remain at a site before continuing to their breeding area?
We usually start to catch migrants arriving across the Gulf of Mexico between 11 a.m. and 2 p.m. They likely leave around dusk the previous night and fly all night and into the next day, depending on the direction and strength of the winds. Many of these newly arrived birds are very lean having burned all of their fat stores and some muscle mass. We check the amount of fat they are carrying as well as their muscle size. We also record age and sex and collect tissue samples (a tip of the toenail and one feather). Together with all of the information we collect about every individual, these samples are like a living library that we will safely bank to address the many unanswered questions about migrating birds.
It is so amazing to witness the numbers and diversity of migrants returning every spring. In between net runs we also watch the nearby sandbar and bay for shorebirds and waterfowl also heading north. We are so lucky to get to spend spring down here on the northern coast of the Gulf of Mexico!
It should continue to be busy over the next two weeks. We will update you again next week. In the meantime, check ebird if you want to keep up with the species that Sean and Tim are seeing down here on Clive Runnels Mad Island Marsh Preserve. Just search for "Matagorda, Texas" on the explore data page of ebird and you can find their most recent lists. → Link
Also, last week Jordan Rutter hosed another 175 middle and high school students at Mad Island! Lucky kids.
"One of the topics I've been sure to cover with the kids is the Galveston oil spill. This is a great way to talk about local conservation as well as human impacts on our environment. Galveston is about a two-hour drive from Mad Island but much closer directly via the inter-coastal canal. Many students were seeing the inter-coastal canal for the first time when they came to Mad Island. We discussed the consequences of oil spills, which are not uncommon in Texas. Many students raised the issue that Texas has a large seafood industry and that many people would suffer from the spill because they cannot make money from selling oysters, shrimp, fish, and more.
We also talked about the various consequences of the spill to the environment. For example, oysters are filter feeders and would not be able to do that important job anymore and birds would not be able to fly or regulate their body temperature. Now there are plans to expand the canal in order for even larger barges with the threat of erosion, habitat loss, and the potential for more oil spills. You could tell that this one-day field trip was just starting to scratch the surface of everything there is to share, discuss, and learn. For the past two weeks I've tried to use their questions to guide the conversations and the emphasis of the activities while always bringing it back to birds and the unique and vital role Texas plays in bird migration."
Birds captured: 1232
Species captured: 72
Species observed: 203
Ticks collected: 34