As we mentioned in our earlier blogs, we are banding at a new site this spring, Powderhorn Ranch in Calhoun County, Texas. The 17,000 acre property was only acquired for conservation last year. In fact, Powderhorn Ranch was the largest conservation investment in Texas history!
Powderhorn Ranch is about 17 miles across Matagorda Bay from our Mad Island site but it takes an hour and a half to drive there around the Bay. The old ranch house where we are staying is in the King Ranch style with a screened sleeping patio that wraps around. It is right on the coast and is very scenic but it's also pretty rustic. One hot day last week, a western diamondback rattlesnake decided to come in and rest on the cool tile floor. Now we keep the doors closed!
There is extensive wooded live oak forests habitat at Powderhorn Ranch. It should be good habitat for high densities of northward migrants to rest and refuel after crossing the Gulf of Mexico. We don't really know what to expect, though, because we are some of the first biologists to get to spend any significant amount of time out there. We have nets in the two primary woody habitat types here—taller and older live oak stands and adjacent lower scrubby oak habitat.
Both Powderhorn Ranch and Mad Island were pretty slow through mid-April. The most common migrants caught at Powderhorn were black-and-white, hooded, and Kentucky warblers, Louisiana waterthrush and ruby-throated hummingbirds. The strong south winds mean that migrants could be flying right over us and stopping further inland. Or are they later this year—who knows? We haven't had our usual catbird bomb yet. There are some days when we can catch hundreds of gray catbirds in one day (in addition to everything else)! This past week was still pretty slow until April 18th when we started catching lots of new species (although not in great numbers). Both sites had 60-70 birds before we had to close for rain. The birds caught the next day (about 40) likely stayed over at the site when it started raining (based on recaptures of banded birds and timing of captures).
The painted buntings, always a show stopper, have returned and many more thrush species are passing through. The Texas Ornithological Society was at Powderhorn yesterday and they saw cerulean warblers, a species we have not captured yet. The Mad Island site caught one this year, none in 2014, two in 2013, and three in 2012. So far, the capture numbers and species at Powderhorn and Mad Island seem to be quite similar—we are busy and slow on the same days and often catch new species on within a couple days. Interesting! It will be exciting to compare the data at the end of the season.
One cool thing about spring migration is that we are also here as the wintering birds leave and the breeding birds arrive. So far, there are many breeding northern cardinals and white-eyed vireos but surprisingly little else. It will be interesting to see who shows up to breed at Powderhorn as the summer approaches.
This year we started measuring arthropod abundance around the nets at both sites. We expect abundance to be greater when there are fewer insectivorous migrants at the sites and to increase as the spring progresses. It will also be interesting to see if arthropods abundance differs between Mad Island and Powderhorn. So far there have been more caterpillars at Powderhorn (a bird favorite!). We have also been surprised to find so many small snails in the Mad Island samples. We are also measuring refueling rates at Mad Island to see if migrants replenish fat stores more slowly on days when high densities of migrants stopover at the site.
Let me introduce the three experienced bird biologists living out at Powderhorn and helping us to collect this important data. Our lead bander, Kristin Davis, has worked on bird research projects in California and Texas and plant research projects in the US, Puerto Rico, and Ecuador. Kristin is off to start her Master's research in Colorado this summer. Ruby Hammond just finished a Master's degree studying Kauai's forest birds. She has also worked on bird research in Alaska, Connecticut, Texas and New Mexico. Alisa Muniz just graduated from college last year but this is already her 6th bird research project. She has worked in New Hampshire, Montana, Illinois, Oregon and California. Kristin, Ruby, and Aliasa are enjoying all the wildlife and the peacefulness of this remote site (remember life before e-mail!?).
|Mad Island||Powderhorn Ranch|