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Tuesday, July 17, 2012

Are Hummingbird Numbers Down???

People have been emailing us reports of hummingbird population declines. Are your hummingbird numbers up or down and where do you live? Here are some recent comments we have gotten:


"It's now July 2012 and in Pittsburg, Kansas at this time of year ten or fifteen hummingbirds at one time might be buzzing at each other to be at the feeder on the south and others on the west side of our house. Now once in a while, I'll see one or two.  I mentioned this to a daughter in Rolla, Missouri.  She's noticed the same problem, and so has my daughter in Owensboro, Kentucky.  What's going on, we wonder.  Do you have any ideas??"

Not everyone is reporting hummer numbers as down, but some people we're hearing from are saying they see less hummers than usual. So what's going on? It's hard to know whether the reports we get accurately reflect a widespread population decline in hummingbirds, especially Ruby-throated Hummingbirds. Who is even keeping track of hummingbird numbers?

The Breeding Bird Survey, a long-time study that started in 1966, surveys nesting birds in May and June. Volunteers drive a 25 mile routs and stop every half mile for 3 minutes and record every bird seen or heard at that spot. This is most effective at picking up singing males. Birds that do not sit in one spot and sing (such as hummingbirds) may be under-reported in the BBS. You can look up population trends for any species on the Breeding Bird Survery website.

eBird is another source of bird population data. This recent website was begun in 2002 by Cornell and it allows people to send in their bird reports electronically. You can look up how many reports of each species have been seen in your area on their website. People have been sending in reports of hummingbirds. But this is not a long term scientific study, so it's hard to draw conclusions about overall poplulation trends. 

The Christmas Bird Count is a long running population survery of birds in December and January and you can look up which birds are found where on the website. Many hummingbirds leave the Untied States in the winter months. A few Ruby-throated Hummingbirds do overwinter in southern and Gulf Coast states.

Aside from these surveys, there seems little else in the way of widespread collection of hummingbird population data in spring and summer.

Why might some people be seeing less hummingbirds in their areas?


Here is speculation:

- There is lack of food at critical times such as when they first arrive from migration. If colder or hotter or more severe weather (due to global warming) affects the flowering of their nectar sources or insect populations (Ruby-throats do eat insects) when they need it, they may not survive.
- Or there could be more abundant food and flowers in the wild, so hummers do not come to feeders where they can be seen and counted by people.
- Or there could be higher mortality for Ruby-throated Hummingbirds in their wintering areas (Central and South America, and who is counting them there?) so less return each year.
- Or, there are other unknown factors (disease? severe weather extremes) impacting them that we do not know about.
- Or, their reproductive success rate, due to lack of food when the young are in the nest or other factors, is declining.

How can you help in the short term? Keep your hummingbird feeders clean and free of mold and bacteria, which can harm hummingbirds. That means cleaning your hummer feeders every 2 days in hot weather!! Plant hummingbird flowers that bloom at different times so there is ample wild nectar resources from early spring to fall. Help conserve land so hummingbirds continue to have places to nest.


Keep your hummingbird feeders full and clean for the rest of the summer. In August you may see more hummingbirds, and they may also come back to you next year. Hummer numbers are at peak in August as young of the year are out of the nest. There is also peak hummingbird migration through August and September and migrating hummingbirds may show up at your feeders.

12 comments:

Scott said...

I don't have a feeder in my yard, but I checked my eBird stats, and so far I've seen more hummingbirds since May here in FL than I saw all last year. Of course, that may have something to do with the fact that I found a park near home with Trumpet Vines.

Marilyn Kircus said...

Planting native plants in your yard for hummers and other pollinators - bees, butterflies, flies, is one of the most important things we can do. And adding tall trees, an understory, and water sources, will allow your yard to serve the needs of these important and beautiful creatures.

Gail Baker said...

Numbers of Broad-tailed Hummingbirds are definitely down in Colorado Springs - even before the fires. We've noticed an overall decline in other birds also. This is the first year we have not had any Western Tanagers or Yellow Warblers - and only one Bullocks Oriole; less Mt Chickadees but more Black-capped. Many more House Sparrows.

Gail Baker said...

Numbers of Broad-tailed Hummingbirds are definitely down in Colorado Springs - even before the fires. We've noticed an overall decline in other birds also. This is the first year we have not had any Western Tanagers or Yellow Warblers - and only one Bullocks Oriole; less Mt Chickadees but more Black-capped. Many more House Sparrows.

Scott said...

This summer has been good to me for seeing hummers in central FL. I've seen more since May than I did all last year. But, I suspect that has more to do with the fact that I found a park with lots of trumpet vines than it does with overall population numbers. Ebird data doesn't show the same rise that I've seen personally.

Pat ODonnell said...

On their wintering grounds in Costa Rica, other than reports to eBird, the only specific censusing for Ruby-throats that I know of is carried out by Bill Hilton. He has been organizing trips for some years now that band Ruby-throats in CR. It will be interesting to see if they note any difference in numbers. http://www.rubythroat.org/

I will spread the word in the local birding community in Costa Rica to keep an eye out for Ruby-throats next winter. They are a commonly encountered species in many areas on the Pacific slope so if they are fewer birds around, I think people will notice.

Scott Simmons said...
This comment has been removed by the author.
Anne McCormack said...

As far as I'm aware in my area--St. Louis MO--hummingbird numbers are about the same as usual this summer. I have plenty of hummer plants in my suburban garden. I'm interested to see what the data show in other areas.

Jeffrey said...

Very interesting. I've seen fewer hummers this year.

Anonymous said...

I put up my first hummer feeders this summer, had a hummer within an hour. Since then, it's been almost nonstop activity. I don't have any other years to compare to, but I almost can't imagine getting more hummers than what I have been getting. I've had to put a third feeder in the mornings and evenings to help with overflow during 'rush hour'. Location: Northwest Arkansas

Anonymous said...

I am in Michigan and the number of hummingbirds has definitely declined since last year. In May there were two straight days when the temperature did not get above 18 degrees F. The cold destroyed the peach and pear crop. The apple crop will be only 20% of a normal year. Would this cold spell kill the hummingbirds?

Anonymous said...

I am in Michigan and the number of hummingbirds has definitely declined since last year. In May there were two straight days when the temperature did not get above 18 degrees F. The cold destroyed the peach and pear crop. The apple crop will be only 20% of a normal year. Would this cold spell kill the hummingbirds?