Mule deer mothers are in sync with their environment, with reproduction patterns that closely match the cycles of plant growth in their habitat. And new research using NASA satellite data shows that tracking vegetation from space can help wildlife managers predict when does will give birth to fawns.
Raising a fawn is no easy task - a doe needs a rich supply of vegetation for the late stages of pregnancy and for nursing. Mule deer birth rates peak shortly before the peak of annual plant growth, when food sources are increasing. Through a combination of satellite measurements and ground-based population counts, researchers can forecast the timing of fawning seasons based on vegetation.
"We had never tracked the deer population this way, and we had never been able to predict it with such precision," said David Stoner of Utah State University, lead author of a recent study. "We can estimate the start and peak of the season using satellite imagery, and then we can map and predict when the deer are giving birth in any given region."
Mule deer populations are closely monitored and counted by biologists and land managers, in part to determine population trends over time, which helps them set the proper number of hunting permits to issue. At the same time, remote sensing scientists have a space-based way to track when vegetation greens up and how productive it is compared to drought or wet years. the health of vegetation
. The tool is called the Normalized Difference Vegetation Index (NDVI), which is a measure of the "greenness" of the landscape. It measures how plants absorb and reflect light -- the more infrared light is reflected, the healthier the vegetation. So by measuring the greenness of the mule deer habitat, scientists were able to mark the beginning and peak of the plant growing season - and the fawning season.
To visualize the relationship between vegetation greenness and fawns, Stoner and his colleagues divided mule deer habitat that stretched from southern Idaho to central Arizona into three zones. They measured the NDVI for each day of the calendar year, using the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA's Terra and Aqua satellites.
They found that vegetation greenness in the northern latitudes peaks earlier than in the southern latitudes, according to Stoner. Since nutrient-dense food sources were available earlier in the year, there was more food available for mule deer mothers and babies at the time when they needed it most. That greenness is partly a result of a consistent stream of snowmelt moisture feeding the deep roots of mountain plants.
In southern latitudes, on the other hand, the plants are more dependent on rain from late summer monsoonal showers. This means vegetation quality peaks later in the year, after a brief drought that comes before the summer monsoons. As a result, does give birth later in the south than in the north.
"This kind of applied research is very important for making remote sensing data relevant to wildlife management efforts," said Jyoteshwar Nagol, a researcher at the University of Maryland. Deer have a huge economic impact in the United States, from hunting to crop damage to car accidents. As regional climates shift or droughts occur, deer distributions could change in response to changes in the timing of vegetation green-up.
For more information:
Earth Observatory Story:
Kate Ramsayer | EurekAlert!
Stagnation in the South Pacific Explains Natural CO2 Fluctuations
23.02.2018 | Carl von Ossietzky-Universität Oldenburg
First evidence of surprising ocean warming around Galápagos corals
22.02.2018 | University of Arizona
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy