Emerging Issue Summary
SPECIES OF INTEREST – MIGRATORY BIRDS

Highlights:

  • Habitat use/selection is incompletely known for most migratory birds on the North Slope. A more complete understanding of migratory bird use of arctic habitats, including offshore habitats, is needed to identify appropriate mitigation measures in areas of oil and gas development and to more accurately predict the potential impacts of climate change and land management decisions. The lack of data on rare species (existing species in low numbers) is a major concern, given their significant influence on management decisions.
  • Understanding population status and trends is also critically important. Inter-annual and seasonal data are necessary to describe the natural range and variation in population dynamics parameters for target species.
  • An oil spill into Arctic waters could be devastating to migratory birds, particularly if it occurs during a key life cycle event (e.g., molting). A spill occurring in the Outer Continental Shelf (OCS) during a period of broken ice could be problematic in that the oil could be concentrated at the water surface in open leads, directly impacting resting birds. As these leads close or shift, oil could be forced down into water column, thus impacting prey or the ability of these birds to forage successfully. An onshore spill into a water body could also affect birds in key life cycles such as described above.
  • Limited information is available about migratory corridors and wintering areas for many bird species using the North Slope. Understanding impacts in areas farther south and cumulatively will be important for making management decisions on the North Slope.
Bird
Red-necked phalarope (Brad Winn)


Overview and Management Relevance:

The seasonal distribution and abundance of migratory birds using Alaska’s Arctic habitats is dependent on the amount of high quality, intact and undisturbed habitat for breeding, rearing and molting. With climate change and the expansion of industrial activity on the North Slope, we can expect changes in the availability and distribution of seasonal habitats used by migratory bird populations. Changes in habitat availability and use may result in changes in population dynamics parameters including initial productivity and causes and rates of mortality for both juvenile and adult birds. For example, development of the area near Teshekpuk Lake will require an understanding of molting goose responses to industrial activities, including overflights and the construction of infrastructure. The time required to establish meaningful pre-development information should not be underestimated. In many cases, data will have to be collected for ten years or more to acquire a reasonable understanding of natural variation in seasonal bird habitat use, productivity, and population trends. Populations may already be impacted by climate change, but we cannot yet discern these impacts.

Understanding population status and trends is also critical in determining if mitigation efforts are effective, and to identify the level of risk that a population can tolerate and be sustainable. Understanding natural variation in population status is also necessary for determining what levels of change in populations can be detected using standard accepted methods for monitoring population status and trends. Although habitat use is understood on a coarse level for many species, further research is needed to understand the use of estuarine areas by species such as long tailed ducks, red phalaropes, red-throated loons, and others. Finally, birds that use the North Slope in summer may be impacted by anthropogenic stressors in transit to/from and within their winter habitats. Therefore, it is also important to understand the threats to birds across their entire migration routes, including storms, contaminants, loss of habitat, and predators.

In addition to these broad concerns, the NSSI Senior Staff Committee provided the STAP with specific questions relevant to migratory birds. STAP responses to these individual questions follow below.

  1. Are current breeding bird surveys sufficient to meet management needs in a changing environment?

    A waterbird breeding population survey conducted annually by the USFWS provides an index of trend and numbers of breeding pairs for roughly one-third of the bird species and their distribution along the Arctic Coastal Plain. These surveys are conducted only once in the summer and do not specifically estimate population size nor determine trends in abundance. Their design works best for species with more uniform distributions, but is less well suited for species with more clumped distributions, such as brant and lesser snow geese. While these surveys do show the distribution of breeding pairs, they do not capture complete information about habitat use and trends. Habitat use data are critical for understanding climate change impacts. New studies need to reconcile differences in scale between the way data are collected and the way they are applied. For example, waterbird surveys are generally broad-scale aerial counts, while industry often conducts site-specific aerial monitoring.

    An important step in establishing a well-designed breeding bird monitoring program is to begin by compiling existing data, with an eye towards data collected for industry (which may be poorly incorporated into the public knowledgebase) within the broader bird survey database.

    Other considerations in designing an adequate migratory bird monitoring program include:

    • Collecting data before, during, and after construction. Studies should be designed to address both short-term and long-term changes associated with industrial activities. In addition, broader scale experimental designs are needed to identify trends driven by factors such as climate change.
    • Aerial surveys need to be ground truthed. There is currently little long-term consistent ground monitoring on the North Slope at a regional scale. This is especially needed on barrier islands and other key habitats. Ground surveys would allow estimates of productivity to provide data on population status and trends. Also, surveys need to be expanded into the late spring and early fall to understand the importance of Alaskan waters for birds migrating through to the Canadian High Arctic
    • To allow for the improved design of monitoring studies, managers should identify the degree of change that is important; for example, a study intended to detect a 10 percent change in the number of birds occupying a particular area would have a different design than a study intended to detect a 30 percent change in the same area.
    • Monitoring needs to be further expanded beyond waterfowl surveys to include other migratory species; current breeding surveys consider approximately one-third of the North Slope bird species. Unmanaged species are not typically treated as being of concern until they near a critical threshold, and then it is difficult to know what is normal or sustainable. To make investments in such an expanded effort most efficient, it will be necessary to develop lists of species of potential management concern and/or to identify appropriate ‘sentinel’ or focal species.
    • Other issues besides oil and gas development, including issues related to subsistence and sport hunting, should be considered.

  2. Are there likely to be shifts in species composition and how will this affect subsistence use patterns?

    Shifts are already occurring as a result of industrial activity and possibly climate change. Ravens, gulls, foxes and other predators appear to be concentrating around infrastructure and villages, and in turn may be affecting some bird species on a local scale. Recent studies on the role of these predators on tundra nesting birds were not able to discern an adverse impact. Long-term monitoring plots and ongoing monitoring of bird species is important for interpreting dynamics of change. It is also important to understand subsistence use patterns to capture social implications (cultural importance, nutrition and economics), including public perception of industrial impacts (e.g., Nuiqsut). Species important to subsistence include white fronted geese, king eiders, common eiders, Canada geese, snow geese, black brant and others.

  3. Is there sufficient data on rare species to credibly advise whether a specific management action is/isn’t needed?

    In some cases the answer is no. However, in some areas over 10 years of data on ESA-listed or proposed species (Steller’s and spectacled eiders, yellow-billed loons) have been collected prior to infrastructure development. Site-specific monitoring is always appropriate and necessary to understand habitat use in proposed development areas before infrastructure development or other management activities that may alter habitat are undertaken. Rare species (existing species in low numbers) need to be the focus of specific surveys at the appropriate spatial and temporal scale. Lack of data on rare species is a major concern, given their significant influence on management decisions. However, managers with limited resources will need to prioritize data collection on rare and common (but important) species.

  4. Are any species headed toward ESA listing? If so, which ones and how may their listing affect management?

    Potentially, yes. The listing of yellow-billed loons as a threatened or endangered species under the ESA was recently found to be warranted by the USFWS, but precluded by other higher priority listing actions. Other species whose populations may be of concern include dunlin, ruddy turnstones, other loon species, and long tailed ducks. The STAP’s listing of these species is not intended to reflect any specific knowledge of their suitability for ESA listing, but simply to provide the requested heads-up on which species may bear watching. Indeed, other species may face significant threats and subsequent ESA listing as habitat and other conditions continue to change.

  5. How might water use patterns (e.g., lake pumping versus recharge) affect waterfowl habitat quantity and quality?

    This is an important question related to both industry and climate change. Impoundment research and water withdrawal studies related to fish also need to be expanded to consider migratory birds. To understand the cumulative effects, improved understanding of the amount of water needed to sustain key habitats is needed, including the balance between inputs and losses. Issues behind this question are closely linked with other emerging issues, including hydrology and lake drying emerging issues. Waterfowl may be useful as a biological indicator (or ‘sentinel’) species, but habitat selection data and site specific data before and after water withdrawal will improve knowledge of impacts. It would be useful to review existing data on recharge, water quality, and water quantity and overlay these with species use data. Industry datasets may be helpful to this data mining effort in support of modeling efforts to improve impact projections

  6. Is more robust subsistence harvest data needed, what kind, which species, how will it be used?

    Legalization of spring and summer harvests resulted in some studies to address migratory bird harvest, which provide estimates of take for commonly harvested species. However, data are sparse for rare and endangered species. The Alaska Migratory Bird Management Council (AMBCC) has a subcouncil on Subsistence Harvest Documentation that advises on collection of subsistence data. There is concern over the accuracy of data on subsistence users’ recollection of seasonal take when these data collections occur only periodically. These data are sufficient for detecting change in subsistence use of common species, but better data are needed for rare species.

  7. Will the nature of ice edges as locations of food gathering and/or resting places change, and what will be the effect of this change on species’ bioenergetics?

    Conditions have already changed, especially since the extreme sea ice late summer minima of 2007 and 2008. The Pacific Arctic has shifted to a ‘new state’ with regard to sea ice. Most of the multi-year ice is gone, with the remaining first-year ice easily moved and shifted by wind. Predictions are now for a summer/autumn ice-free Arctic by 2040, with increased inter-annual variability. Understanding the impacts of changing conditions along the ice edge requires information on both bird energetics and how birds use the ice edge, neither of which is well understood. There is some dietary information for Bering Sea populations, but not for the Chukchi and Beaufort Seas (with the possible exception of guillemots). Species that use ice edges and warrant further study include eiders (all), ivory gulls (potential candidate species) and Ross gulls, long-tailed ducks, and black guillemots.

  8. What changes may be in store for ice leads as habitat and what may be the effect of any changes in oil spill risks on the likely function/value of ice leads?

    Springtime lead systems remain a key feature to winter/spring conditions offshore of the North Slope as migratory birds seek open water for resting and feeding. An oil spill will make a lead unsuitable habitat if it reaches the lead. Oil on the surface of an open lead will directly impact resting waterfowl, and as ice leads open and close, oil can be forced down into the water column, impacting bird food sources. However, the extent to which migratory birds use leads or lead edges for more than a staging ground is not well documented for most species.
    Data needs include:

    • Physical data on leads should be linked to bird studies, especially energetics;
    • Compile existing data (e.g., from long-term studies in Chukchi Sea) and develop better characterizations of the benthos, and of gaps in our knowledge of benthos, to describe important feeding areas;
    • Collect productivity data that account for interactions between warming on the one hand and sub-ice and open water productivity on the other hand

  9. How & where will oil spill risks to birds (from rig operation, loading/transport, pipelines) be altered if additional energy development occurs?

    Oil and other fluid spills can occur in association with all aspects of exploration, development, and production. Smaller spills associated with construction and minor spillage from ships associated with energy development can potentially impact smaller numbers of birds. Much larger numbers of birds could be impacted from pipeline leaks, and especially from catastrophic failure of pipelines, especially if offshore or onshore near waterbodies frequented by waterbirds. Major spills associated with serious shipping accidents could also impact large numbers of birds. Lastly, although the likelihood of loss of control at the wellhead (a blowout) is extremely small, if quantities of oil in the water associated with loss of control at the wellhead are high and difficult to control, it could impact a large number of birds.

  10. Will an increase in energy infrastructure (OCS oil/gas rigs, wind energy structures) increase bird strikes?

    An increase in energy infrastructure will lead to an increased number of bird strikes. Power lines seem to be especially problematic, but birds are also known to collide with offshore and coastal infrastructure. Some information on bird strikes is currently collected (USFWS, discreet industrial studies), but data are not organized in a way that allows a definitive understanding of bird strikes and are not intended to answer questions of population level impacts. It is recognized that current techniques are not sufficient to accurately quantify bird strikes, as predators could remove a carcass before it can be counted. At best, only qualitative analyses, which are likely under-reporting, are being used to assess bird strike frequency. In addition to developing techniques or technologies to assist with quantifying the impacts the number of bird strikes, there is a need to further develop technologies to mitigate bird strikes (e.g., lighting and paint/color, diverters, flagging).

  11. How will any changes in migratory waterfowl numbers or distribution alter risks to aircraft from bird strikes?

    Increases in migratory waterfowl will clearly increase the risk of aircraft strikes, as will an increase in flights. To understand how to mitigate this impact, habitat use, locations of strikes, and timing of bird activity (diurnally and seasonally) needs to be better understood. Understanding how to manage waste and site infrastructure is also needed to discourage congregation.

Recommendations:

  1. Site-specific monitoring needs to be implemented well in advance of industrial activity. Information needed to understand productivity, recruitment, longevity and survival rates should be collected for a sufficient time to establish pre-development conditions. Once infrastructure construction/installation begins, data on disturbance should be collected in a way that allows quantification of impacts to populations as well as thresholds of disturbance/tolerance. This is not possible for all bird species. Monitoring programs should initially focus on the minimum number of species for which we can adequately collect data, with a priority on those birds with high potential for listing under the Endangered Species Act or of those of other conservation concern (such as species important for subsistence use).
  2. Collection of subsistence use data, especially for rare or uncommon species, may not be adequate for some purposes. To the extent that co-management councils and others are not adequately addressing this issue, additional effort should be made to improve collection of subsistence use data,
  3. Because of the broad range of impacts migratory birds face across their migration routes, quantifying these impacts is critical. For example, climate, weather and habitat quality across the migration route may impact individual and population responses to conditions in the Arctic.
  4. Changes in Arctic climate and habitat quality will also impact migration success. Conceptual models that describe key drivers and processes are needed to develop hypotheses that direct research designs to detect and interpret impacts. To assess each of these impacts and their relative risk, it is recommended that a database is designed and filled for key species with key variables derived from the conceptual models. From this effort, it should then be possible to identify data gaps; including monitoring needs for rare species, and determine how to fill these gaps. This process will lead to development of conceptual models.
  5. Understanding the risks from oil spills to onshore and offshore populations needs to be improved through monitoring and appropriate experimentation prior to development, and this understanding should be re-evaluated as development proceeds. Monitoring programs need to be designed so that significant oil spill impacts can be quantified and to guide oil spill impact mitigation.

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