During my time here at Hawk Ridge, I've had a few people ask what the point is of collecting all these data. What is being done with the numbers of birds we record? What are we learning about hawks and other birds from these numbers?
The answer is: these data have taught us a lot about bird populations, survivorship, and ecology, and they will continue to be a valuable resource in the future. Let me try to answer a few questions that I get asked a lot.
1. What data do you collect? Every hour, we count the number of raptors of each species that fly by the hawk watch. They get entered onto a data sheet that looks like this:
The numbers are broken down by hour, by species, and sometimes by age and sex, for species for which it's possible to tell. For example, Northern Harriers (NH) have distinct immature, adult male, and adult female plumages, so usually we can age and sex them. But the data sheet also includes a row for Unknown Northern Harrier (NH Unk.), in case a bird is so distant that we can't tell its age or sex.
At the hawk watch, we also collect data on non-raptors, like songbirds, waterfowl, etc. that fly by the hawk watch in the morning. We collect this data in much the same way, hourly on a data sheet with each species listed separately.
At the banding station, there are opportunities to collect even more detailed data. Hawk Ridge has banding programs for songbirds, raptors, and owls. After putting a band on each bird, the banders "process" the bird: they collect data on its species, its age and sex, its weight, and the length of its wing. The unique number on each bird's band also gives us the opportunity to collect more data: if the bird is re-sighted or recaptured at a different station, we might be able to find out how far it migrated or how old it lived to be.
2. What happens to the data that you collect?
The raptor data that we collect gets entered into a website called HawkCount, which is run by HMANA, the Hawk Migration Association of North America. Here's the October month summary for Hawk Ridge, and you can use the toolbar on the left to see summaries for other months and other years, as well as more detailed daily summaries (which break down the counts by hour). HawkCount does not include details on sex and age of the raptors; that data is kept by Karl Bardon, our count director, on the theory that it's better to collect as much data as we can; if birds are consistently ageable or sexable in flight, it seems silly not to record what we see.
The non-raptor numbers are kept and summarized by our head counter, Karl Bardon. You can read Karl's summary of the non-raptor data in this paper, published in The Loon in 2012.
The bird banding data are reported to the USGS Bird Banding Laboratory, which keeps records of birds banded dating back to 1960.
3. Are there other sites around the country that monitor hawk migration?
Absolutely! There are over 200 hawk watch sites across North America. You can find a complete list on the HMANA website, here, and explore data for each site. Together, the North American hawk watches are helping to give scientists a more comprehensive knowledge of hawk migration patterns.
4. What is the ultimate use of these data?
Collecting data at the hawk watch is satisfying because I know that we're contributing to something bigger. Lots of scientists have drawn on hawk migration data from Hawk Ridge and other hawk watch sites for their research. Here are some examples:
This post has been pretty light on photos. Sorry about that! Here's a Long-eared Owl to make up for the lack. I got to watch this bird get banded and released last week at the owl banding station.
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Welcome to Hawk Ridge
A Massive Migration
A Happy Birdthday
Photos from the Week
Visiting the Banding Station
A Watched Kettle Never Streams
Food, Part 1
The Big Picture
Last Weeks at the Ridge
Belize, Part 1
How to Look at Birds, A Guide (or: Belize, Part 2)
All Creatures Great and Small
Kids and Language, Again
More Photos from France
Food, Part 2
Building Nests in California
Please Do Not Pet the Woodpecker
Condors and Creatures in Big Sur
A Day at Hastings
I am a high school graduate taking a gap year before college. I’m interested in birds, biology, and the natural world, as well as history, foreign languages, writing, and reading.