MDOsprey,

The regular eBird users among you may have noticed a change in the last few
days. The checklists you are presented with from your home birding area will
have changed. Below I offer some explanation (and give a small plea for
help).

The news is that I have now generated 23 new filters (one per MD county)
that have individual values for each month of the year; this was a total of
102,120 individual decisions (~370 taxa including subspecies and hybrids x
23 counties x 12 months) so if you find errors, that is my excuse (that and
the fact that I haven't birded MD in almost a decade!). Bob Ringler already
pointed out several errors to me (Ruby-crowned Kinglet, Eastern Towhee, and
Black-capped Chickadee being the three worst--these are now fixed). 

In the end, the data entry checklists you see should now be a reasonable
list for your county in a given month. For example, while a Howard County
submission for May used to show Piping Plover, now it only shows expected
species for Howard County in May. Likewise, Black-capped Chickadee sightings
in western Maryland no longer require confirmation (but a Carolina Chickadee
would). 

YOU CAN HELP: As you use eBird, please pay attention to what species seem to
be missing from the checklists on the data entry page. Also please pay
attention to species that appear but are truly rare in the county and would
be better masked under the "rare species"
button. Feel free to contact me with any recommended changes--these filters
are constantly being refined.

For more explanation about how eBird filters work, read on or check out the
following story at eBird:
http://ebird.org/content/ebird/news/Data_Quality.html.

The data entry page checklists that you see in eBird are generated from
automatic filters that define what is a reasonable number of every state
species to encounter on a given day's birding in a given month. Thus
Tropical Kingbird and Ross's Gull are set at zero for all months, but
Eastern Towhee might be at 25 for January and Red-winged Blackbird might be
at 10,000 for January or 150 for June, when they are not flocking. 

These filters serve several purposes:

1) All species with a value >0 appear on the main checklist; all species
with a '0' can be seen by clicking the blue "rare species" button at the top
of the list. Additional species, subspecies, hybrids, and spuhs can be added
to your daily list--like if you are the first to identify Maryland's first
(overdue) Sharp-tailed Sandpiper at Hart-Miller Island or if you routinely
identify all your Orange-crowned Warblers to subspecies--"Orange-crowned
Warbler (celata)" on the eBird list.
 
2) All species with a zero for a given month appear on the eBird Google
gadget (a real-time Rare Bird Alert based on eBird reports) and on Jack
Siler's brand new and VERY COOL map showing eBird rarities
(http://birdingonthe.net/gmaps/eBirdMap.html).

3) All reports with a value higher than the filter limit ask the user for
confirmation to make sure it is not a typo or a case where the user did not
understand that Black-capped Chickadees are limited to Maryland's three
western counties or that Boat-tailed Grackles do not occur away from
Maryland saltmarshes. (These two errors are very frequent among novice eBird
users).

4) All reports that are confirmed by the user and have a count entered that
is higher than the acceptable filter limit are reviewed by our expert
Maryland reviewers: Tyler Bell and Paul Woodward (and sometimes me). Tyler
and Paul may follow up with an email requesting more information on a rarity
report, or they may recognize that 15 American White Pelicans at Blackwater
are not unusual in recent years or that everybody and their mother (well,
not me :-( )and saw the Say's Phoebe near Hughes Hollow last September and
accept those reports without question.

We are proud of this data quality process and have found it very very
successful. Any comments are welcome..contact me at  

Best,

Marshall Iliff
-- 

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Marshall J. Iliff
West Roxbury, MA
miliff AT aol.com
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eBird/AKN Project Leader
Cornell Lab of Ornithology
159 Sapsucker Woods Rd.
Ithaca, NY 14850
http://www.ebird.org
http://www.avianknowledge.net
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