How should large-scale population dynamics be assessed?

ERDC TN-DOER-E17

September 2004

Recommend standardized habitat categories and subsequent descriptions to provide

consistency among regions and/or Districts.

Include habitat data (e.g. water levels at USGS gauges, estimates of sandbar habitat avail-

ability, reduction of island "bridging" with the mainland, nest elevations in relation to water

flows) as part of the monitoring database.

Measures of vegetative cover (basic habitat/foraging conditions), nest locations, and stan-

dardized habitat types (e.g., lake, reservoir, river).

How should large-scale population dynamics be assessed?

Can survival (particularly juvenile survival) be measured for population modeling?

What can we learn about dispersal from ongoing genetics studies? Current genetics stud-

ies should be fully supported as they may provide information critical to a comprehensive moni-

toring effort.

How can we investigate connections among breeding populations of ILTs?

Would a banding program help answer questions about survival, dispersal, and popula-

tion connectivity?

Monitoring-related Research Needs for the ILT (Eileen Kirsch, USGS): This discus-

sion focused on identifying specific research needs for improving understanding of ILT popula-

tion status and basic ecology. Basic research efforts should be tied to issues needed to be

resolved concerning establishment of a standardized monitoring protocol. Goals need to focus on

general abundance and distribution of the ILT population, productivity increases or declines

(relationship with habitat quality), and population sustainability.

With these goals in mind, the following questions were proposed:

How do we obtain reliable data?

What is the spatial extent of the monitoring effort?

What is the temporal schedule of survey efforts: every year, every 3 to 5 years?

How many surveys per year?

How do we obtain sufficient funding and personnel?

Additional research topics on abundance, distribution, and productivity were presented and dis-

cussed that are relevant to development of a monitoring protocol as well as understanding ILT

life history:

The influence of "floaters" in the population (distribution).

The relationship between river flood stage/flow, sandbar area, and ILT population size in

a given locality (distribution).

How are movements among breeding areas related to hydrology? (distribution).

How important are areas not currently covered by monitoring efforts? (abundance).