Monitoring

Allen's Hummingbird, young male

Population monitoring helps identify geographical areas that are integral to the survival and reproduction of hummingbirds and potential threats to their populations. Monitoring generates questions about hummingbird biology and ecology that research projects can then address, and helps develop more effective preservation plans by providing a way to evaluate the effectiveness of existing plans. At sites open to the public, we also fulfill our educational goals by informing the public about hummingbirds.

HMN's monitoring program generates knowledge about hummingbird diversity, abundance, productivity, and survivorship in a variety of habitats. It is a systematic banding study that employs additional counting techniques so we can learn more about hummingbird population dynamics.

HMN's Monitoring Goals are:

• Determine the best long-term monitoring sites: Monitoring sites are selected based on geographic factors such as elevation, longitude, and latitude, and vegetation types. Once every other week, we trap and band hummingbirds from late March through October. We also use other counting techniques to assess population sizes of hummingbirds. At the end of each year, results from sites are evaluated based upon levels of breeding activity, migration stopover use, and patterns of species occurrence and abundance. We use this information to determine which sites are the best contenders for long-term monitoring, and to see if new sites should be added and evaluated. This information will help define important areas for sustaining hummingbird diversity and abundance

• Sample so population trends can be detected: HMN's monitoring protocol allows us to estimate relative abundance. Work at each site follows the same protocol so data can be prepared.

HMN's Protocol

• Five commercial hummingbird feeders with a sugar solution of one part sugar to four parts water are maintained at each site while hummingbirds are present. At sites where the feeder number can not be controlled, the number of feeders in the area is recorded. Hummingbirds are trapped and banded once every two weeks from early March to late October. Trapping and banding begin within one half-hour of sunrise and continue for five hours, but is delayed if the temperature is below 38°F. We use two Hall traps that each cover one feeder. The other feeders are taken down and are not accessible to hummingbirds during the banding period.
• At the banding table, birds are identified, aged, and sexed in chronological order and are held no longer than 30 minutes. The bander determines how many birds that he/she can safely band within this time limit. When the number of birds waiting to be processed is reached, the bander requests the trappers to stop trapping. While they are not actively catching birds, they record the number of birds that enter the trap. They also record all birds that escaped while actively trapping.


Measuring the wing

• At the same time we capture and band individuals. We learn more about each species such as the age and sex ratios at different times of year that give us an idea of reproductive success of each species in each habitat, elevation, and region. We learn in greater detail about the timing of molt, of fat accumulation for migration, the transport of pollen of different species of plants that is necessary for the plants' survival, the faithfulness of birds to specific stopover sites in migration, and the longevity of the different species of hummingbirds.
• We examine the plumage colors, feather shapes and patterns, and measure each bird with great care to be sure that our specific age, and sex determinations are correct. In the process, we accumulate new information that will assist others to more accurately age and sex birds in the field and in the hand.
• Experimental Design/Statistical Analyses – The experimental design of the monitoring program is factorial with geographic and vegetation parameters as its factors. With this design, ANOVA, other parametric and non-parametric statistics can be used to evaluate the effects of these factors on hummingbird diversity patterns.
• Use information to assist in their protection and preservation.
• The Rufous Hummingbird migration information gathered during the 2005 monitoring season at HMN's California and Arizona sites, has guided the expansion of the Network in 2006.

HMN's community goals for monitoring include:

• Train and Use Citizen Scientists. Our monitoring program is ongoing and the most labor intensive project HMN conducts. At each monitoring site, a scientist or a citizen scientist is responsible for all activities at the site. People who train to be banders and to manage a monitoring site are considered citizen scientists. Their work includes strict adherence to the project’s protocol, safely banding hummingbirds, ensuring that the data are taken correctly and accurately, submitting reports and the banding data after each session, working with the site hosts, and managing the other volunteers needed to successfully complete a banding session. These high expectations are significant, but HMN’s volunteers continue to show strong commitment to the mission of HMN and the goals of its monitoring program.

• Partner with land managers. We work on land managed by federal, state, provincial, and local governmental agencies, by universities and non-profit organizations, and with many private landowners. We endeavor to work constructively with each manager/owner. Please see our Partners for more information. Now we are working in Arizona, California, British Columbia, and Sinaloa, Mexico, and soon Colorado. We will be expanding into new areas as personnel are trained to follow our standardized methodology and to submit and share their data.

• Increase public awareness and outreach. At our public sites, we inform visitors about the project, discuss the importance and interrelatedness of hummingbirds in the natural world, and teach visitors about hummingbird biology. Visitors often leave with a sense of wonder for hummingbirds.