The reason I was drawn to it was that the bird's cycles are continuous and so the circle expresses this better than a time-line. It is also hemispheric neutral in that time-lines start in January and finish in December and so for Southern birds their breeding season, for example, might cross the December and January year boundary and so, for those birds you would not see a continuous line but a line in two segments
Jan Feb Mar Apr ... Oct Nov Dec
nesting ------- -------
It is also similar to the situation awareness visuals I have seen  and very much like.
Learning how to read this visual is not difficult and so a short audio training might be used. For example, this NPR story  is about the movie High Noon's title song and how its elements were repeated in the movie's score. Towards the end of the story there is a short segment of the score featured with overlaid commentary. It is a stunningly informative information presentation. At least to this musical klutz.
 "Visual Correlation for Situational Awareness" http://www.sci.utah.edu/publications/yarden05/VisAware.pdf
 "High Noon"
- Principle Engineer, Engineering Team, Providence, RI, USA, Narragansett Project, AlphaDog Project, BetaBand Project, Stewie Project, Java Specialty, Concurrency Specialty, User Interface Specialty, Data Model Specialty, Interface Specialty, Gardening Interest, Cooking Interest, Parenting Interest, Board Game Interest, Automata Interest, etc...
My instant message client user interface would then allow me to view staff by any set of tags. Either a small faceted search or a two-level hierarchy. Selecting an account name would start or join a conversation. Selecting a tag would start or join a conference.
When I worked at Ingenta I installed an instant message server and gave everyone in the company an account. I also automatically created everyone's "buddy lists". The buddy list contained everyone's account (in one list ordered by first name), it was fixed (no adding or removing accounts), and was updated with every staffing change.
The server was a great success -- over time. Even the COO logged in each day. Over the course of my work day in Providence, RI (US) I would see the Providence staff's full work cycle of starting their day, going to lunch and coming back, and ending their day. For the Oxford and Bath (UK) staff their day had already begun and so I would mostly see them return from lunch and end their day. For the lone California developer I saw him start his work day just before I headed out for lunch.
And it wasn't just me that saw this but everyone because everyone had the same buddy list.
Read Geoffrey Bilder's posting, "Backchannel" , about his experience at Ingenta.
Now replace location with team member names and you have a much better presence indicator.
While buying my morning Cafe Tobe from Coffee Exchange I picked up a post card for a new exhibit of Thomas Sgouros's paintings. His work is atmospheric and stunningly large. If you every get to see his work do so. The Gallery Agniel has some images of this work.
Looking for an interesting image to use here I discovered this information visual  about the molting, breeding, and migration periods of the Calliope Hummingbird. I have heard about the Cornell bird encyclopedia  but this is the first time I have seen content from it. I would like to see more; perhaps my library has access to it.
I wonder, do they let you overlay several birds year so you can compare the comings and goings of the population?
 http://content.ornith.cornell.edu/ UEWebApp/images/ calliope-hummer-fig-4_6.gif
Even if you are not looking for such a portal it is worth reading about Launchpad's features. I especially like the Blueprints and their rough dependency tracking.