3. PROTOCOL

This section reviews the recommended survey methods and provides protocols for the inventory of harlequins, kingfishers, and dippers. Recommendations for the use of the survey, a discussion of the method including a list of advantages and disadvantages, and specific protocols are included in each section. Survey techniques for dippers and kingfishers are similar for most seasons. For harlequins there are significant differences between breeding season and nonbreeding season survey methods. The following methods are intended for various census intensities and geographical and seasonal coverage.

Table 1. Recommended survey types for riverine birds in the breeding and nonbreeding seasons and the level of survey intensity.

	Survey Type	Species	Level of Intensity
Breeding Season
	Aerial (Helicopter)	Harlequin Duck	PN, RA, AA
	River Shoreline	Harlequin Duck Belted Kingfisher American Dipper	PN, RA
	Mark/recapture	Harlequin Duck Belted Kingfisher American Dipper	AA
	Territory length	American Dipper	AA, (RA)
Nonbreeding Seasons
	Aerial (Fixed-wing)	Harlequin Duck	PN
	Marine Boat Offshore Island	Harlequin Duck	PN, RA, AA
	Land-based shoreline	Harlequin Duck	PN, RA
	Mark/recapture	Harlequin Duck American Dipper	AA
	River Shoreline	American Dipper	PN
	Territory length	American Dipper	AA, (RA)

* PN = presence/not detected (possible); RA = relative abundance; AA = absolute abundance

3.1 Sampling Standards

The goal of any survey design is to obtain precise and accurate estimates. An estimate with a relatively low standard error is said to be precise. In some cases, precision can be improved by increasing sample size, standardizing methods and maintaining constant observers. An estimate that is free of systemic errors is said to be accurate. Unlike random errors, systemic errors tend to bias results in one direction i.e., either under-estimate or over-estimate. These errors are usually intrinsic to the method and are not reduced by increasing sample size. For example, aerial surveys constantly underestimate numbers. It is important to be aware of the source of errors and biases in any method so that they can be addressed and kept to a minimum.

3.1.1 Scheduling of the Survey

Scheduling of surveys is the most critical component of inventory planning. Unfortunately, because of different breeding chronologies and behaviours, riverine birds may not be efficiently surveyed at the same time. For example, Cassirer and Groves (1994) suggest that surveys must be conducted specifically for harlequins. In addition, the methods used to census breeding, wintering, and migrant populations may differ substantially.

3.1.2 Time of Year

Appropriate dates for surveys of breeding and wintering populations must be considered during the planning phase. Because the chronology of the annual cycle for riverine birds varies between species it may not be possible to efficiently survey all three species during the same time periods.

Surveys for harlequins on rivers should focus on the window around pre and/or post-laying and incubation periods, which varies with latitude and elevation, but is roughly May and August. Male dippers sing most intensively during April, so are most detectable then, but nests can be found most easily later in the spring, during the nestling period, when both parents are making regular feeding trips to the nest.

3.1.3 Time of Day

Variation in activity levels and behaviour throughout the day often causes changes in the detectability of birds, which may result in a time-of-day effect that biases the results of counts (Shields 1977; Rollfinke and Yahner 1990). Dippers are most active in mornings and late afternoons, but males sing all day long (Kingery 1996). Coastal wintering harlequins swim offshore and spend the night in rafted flocks, and may feed more actively during early morning and early evening. Kingfishers are active during daylight hours but feeding activity is least during mid day (Hamas 1994).

3.1.4 Tidal Cycle

The timing of counts of moulting and wintering harlequins in relation to the tidal cycle can cause wide variation in the numbers reported. During low tide, more reef habitat is available and birds can be more difficult to count as they are sparsely distributed in contrast to high tide when harlequins will be concentrated in less habitat and are easier to detect and count. Alpha-numeric colour bands are often easier to see during higher tidal amplitudes.