113th CBC West Indies/Bermuda Regional Summary

By Robert L. Norton

With the addition of three more count areas in Cuba, the region’s total species tally improved substantially. New counts at Vinales, Bermejas, and Salinas-Zapata increased the current number of West Indian circles to 20 representing eight countries and yielding 570 party-hours or over 23 days of counting birds. Getting to 30 days would be a terrific and achievable goal for the region. The total number of international participants including those in multiple counts was 454.  Fajardo, Puerto Rico led the way with 62 observers (Table 1). The highest number of species for a circle went to Cabo Rojo, Puerto Rico with 134. Congratulations to all for an outstanding year.

* average number of species for Antillean counts

Long standing counts such as Bermuda and St John, US Virgin Islands extended their periods of record to 30 plus years. Cabo Rojo and St Croix just celebrated 40 years, a scientifically valuable achievement. Contributions such as this could help shed light on the effects of environmental change on resident and native birds alike. For example, the 30-year records of occurrence of common migrants may indicate fluctuations driven by environmental effects during breeding and/or nonbreeding seasons (Figures 1 & 2).

The data review engines provided by National Audubon Society through the Christmas Bird Count website provide an exciting avenue to explore spatial/temporal relationships of many species.  Below are few examples of relative abundance of migrants or residents compared over three decades period on the Puerto Rico Bank.  An interesting question might be “what happened to waterfowl species abundance during the decade 1990-2000?” Can this apparent depression hold up with other species or islands in the region? There is too little space in this column to tease this out, but compilers and participants throughout the region now have an opportunity to work on these problems with the tools provided by National Audubon well into the future. To add a twist to the sage rule, if you want to enjoy a forest now, you should have planted trees 20 years ago. If you don’t have a data set now, start today.

Figure 1. Relative abundance of resident and migrant waterfowl in the US Virgin Islands (1975-2012).

Figure 2. Relative abundance of Bananaquit at Puerto Rico and US Virgin Islands (1975-2012)