We can sample marbled murrelet numbers by using standard transect methodology; however, I have some very serious reservations about our ability to convert these data into a population estimate. This is not an unusual assessment for Alaskan seabirds in general, but I think it is particularly apropos to this species.
We are still able only to guess at where the marbled murrelet nests and we have not a clue as to what sort of nesting strategy they pursue. I am not prepared to accept, on the basis of one North American record (Binford et al. 1975), that tree nesting is its habit throughout its range. What has been proved is that the marbled murrelet nests in trees and not, as these authors would have us believe, that it does not nest on the ground. It has become rather fashionable to ignore the Chichagof Island record (a ground nest), but it has not been discredited. The color of the Chichagof egg differs from that of the Big Basin egg, but does agree with the one taken from an oviduct by Cantwell (Gabrielson and Lincoln 1959). My own experience leads me to believe that tree nesting, if it occurs, is not the common habit of marbled murrelets nesting in the Prince William Sound region.
After many hours of observing marbled murrelets over a period of several years, I am intrigued by a number of things. These birds, as often as not, appear to be clustered in "pairs" as they feed. This occurs even at what should be the height of the breeding season. On several occasions I have noted a very pronounced evening flight of these birds from gathering areas on the water up into the surrounding mountains at sunset. This has moved me to wonder if their nesting strategy includes incubating at night but less than full-time attendance on days when the eggs can be warmed by the sun. We know that periodic egg-neglect is an aspect of storm-petrel behavior (Pefaur 1974). Is this behavior also possible on a more regular basis in an alcid? If so, it would certainly help explain why nests are hard to find.
It is apparent that more needs to be known about the population dynamics and life history of the marbled murrelet before we can make a proper estimate of its abundance. In spite of the fragmentary record, I conclude that the marbled murrelet probably enjoys the same relative abundance and distribution that it did at the beginning of the century.
Kittlitz's Murrelet (Brachyramphus brevirostris)
The Kittlitz's murrelet is not as abundant as the marbled murrelet, but locally it is sometimes found in large numbers. FWS surveys conducted during July-August 1972 provide an estimate of 57,000 murrelets of this species in Prince William Sound. Almost a fifth of these were concentrated in Unakwik Inlet above Unakwik Reef. Even more interesting, about 2,500 of these birds were concentrated in one loose flock.
In addition to Unakwik Inlet, Kittlitz's murrelets concentrate in College Fjord in Prince William Sound and in the waters fronting the Bering-Malaspina ice-fields (Isleib and Kessel 1973). Common as they are in these waters, this species is supposed to be even more abundant at Glacier Bay. The common feature of these waters is the amount of ice that can be found below their tributary glaciers.
The Kittlitz's murrelet is apparently distributed from LeConte Bay, east of Petersburg, Alaska, north to Point Barrow and west across the Aleutians to Attu, where Murie collected a pair (Gabrielson and Lincoln 1959). I once flushed a murrelet from an area of tread and riser topography near the top of the highest point on Kiska Island in heavy cloud cover, and although I could not see this bird well, I thought it to be of this species. From the range description in Gabrielson and Lincoln (1959) and Udvardy's (1963) range map, it is apparent that the distribution of this species is rather patchy, but I suspect that for the more mountainous part of its range this is more apparent than accurate. The record is too fragmentary to allow an assessment of any change in status during the historical period.
Ancient Murrelet (Synthliboramphus antiquus)
Chase Littlejohn (Bendire 1895) spent the spring and summer of 1894 collecting eggs on islands south of the Alaska Peninsula. He has left us a detailed record of what he saw but not where he saw it. Bent (1963) stated flatly that the site of his collecting was Sanak Island and this has common acceptance. Several things in his account point to a site which was a small island with several peers close by, but this could not have been Sanak. It could have been an island in the Sanak Island group or it could equally well have been somewhere in the Sandman Reefs. Unfortunately, because of this the record is clouded. There has never been anything approaching a survey of the southern half of the Sandman Reefs. We do not know what breeding colonies are there.