Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3-6 years and long 9-12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.

Following an estimated 60% decline in population abundance in early 1993, recovery of the Pacific herring Clupea pallasii population of Prince William Sound, Alaska, USA, has been impaired by disease. Comprehensive epidemiological study from 1994 through 2002 validated an age-structured assessment (ASA) model of disease and population abundance; from 2003 to 2006, the impact of disease was modeled by analyzing only 2 lesions: ulcers and white foci in the heart. The ASA model identified increased natural mortality since 1993 that can be explained by (1) epidemics associated with ulcers (prevalence about 3%) and the North American strain of viral hemorrhagic septicemia virus (VHSV Type IVa; prevalence up to 14%) in 1994 and 1998 and (2) relatively high prevalence of the mesomycetozoean Ichthyophonus hoferi from 1994 through 2006, including epidemics with the greatest sample prevalence in 2001 (38%, by histopathology) and 2005 (51%, estimated histopathology prevalence). Fourteen other parasites occurred at prevalence >10%, but none were considered significant contributors to fish mortality. We predict that if natural mortality after 1994 had returned to background levels that best fit the model from 1980 to 1992 (0.25 yr -1 ), population biomass in 2006 would have been 3 times the best estimate, despite relatively poor recruitment since 1994. In conclusion, disease information can be used to explain and predict changes in populations that have confounded traditional fisheries assessment.KEY WORDS: Pacific herring · Clupea pallasii · Viral hemorrhagic septicemia virus · VHSV Type IVa · Ulcers · Ichthyophonus hoferi · Age-structured assessment model · Population-level response Resale or republication not permitted without written consent of the publisherDis Aquat Org 90: [1][2][3][4][5][6][7][8][9][10][11][12][13][14] 2010 are 3 to 5 yr old, live for about 12 yr, and weigh up to about 250 g. Mature fish spawn every year, but for reasons probably related to environmental conditions (Williams & Quinn 2000), strong year-classes recruit into the adult population only about once every 4 yr. The most accurate biomass estimates are made in early spring, when fish aggregations move to shallow waters to spawn. After spawning, fish disperse and do not reaggregate near spawning areas until late fall. Feeding is minimal during the winter (Foy & Norcross 2001).Four years after the March 1989 'Exxon Valdez' oil spill in Prince William Sound, about 60% of the Pacific herring population died during the winter of 1992/1993. Death was attributed to poor food availability in 1992, which resulted in poor fish condition the following winter (Pearson et al. 1999, Elston & Meyers 2009). The weakened fish had 2 types of lesions or pathogens that are commonly associated with population stress: (1) cutaneous ulcers and (2) the North American strain of viral hemorrhagic septicemia virus (VHSV Type IVa) (Meyers et al. 1994, Pearson et al. 1999, Carls et al. 2002). An alternative hypothesis attributes a greater proportion of th...

Projections related to future climate warming indicate the potential for an increase in the distribution and prevalence of blood parasites in northern regions. However, baseline data are lacking for resident avian host species in Alaska. Grouse and ptarmigan occupy a diverse range of habitat types throughout the northern hemisphere and are among the most well-known and important native game birds in North America. Information regarding the prevalence and diversity of haemosporidian parasites in tetraonid species is limited, with few recent studies and an almost complete lack of genetic data. To better understand the genetic diversity of haemosporidian parasites in Alaskan tetraonids and to determine current patterns of geographic range and host specificity, we used molecular methods to screen 459 tissue samples collected from grouse and ptarmigan species across multiple regions of Alaska for infection by Leucocytozoon, Haemoproteus, and Plasmodium blood parasites. Infections were detected in 342 individuals, with overall apparent prevalence of 53% for Leucocytozoon, 21% for Haemoproteus, and 9% for Plasmodium. Parasite prevalence varied by region, with different patterns observed between species groups (grouse versus ptarmigan). Leucocytozoon was more common in ptarmigan, whereas Haemoproteus was more common in grouse. We detected Plasmodium infections in grouse only. Analysis of haemosporidian mitochondrial DNA cytochrome b sequences revealed 23 unique parasite haplotypes, several of which were identical to lineages previously detected in other avian hosts. Phylogenetic analysis showed close relationships between haplotypes from our study and those identified in Alaskan waterfowl for Haemoproteus and Plasmodium parasites. In contrast, Leucocytozoon lineages were structured strongly by host family. Our results provide some of the first genetic data for haemosporidians in grouse and ptarmigan species, and provide an initial baseline on the prevalence and diversity of blood parasites in a group of northern host species.

The effects of hunting on wildlife populations vary dramatically, depending on the timing and magnitude of harvest, and population-specific states and vital rates. We examined the hypothesis that spatially and seasonally concentrated harvest decreases annual survival probabilities of willow ptarmigan (Lagopus lagopus). We estimated survival of radio-marked willow ptarmigan at 2 categories of sites: those where ptarmigan were easily accessible and heavily hunted and those that were remote and received little or no hunting pressure in Alaska, USA. We predicted that seasonal survival estimates during the willow ptarmigan hunting season would be lower in access corridors than at remote sites and that this would result in lower annual survival unless subsequent seasonal compensatory mortality occurred. Consistent with our prediction, annual survival was higher at remote sites (adult males: 0.50, 95% credible interval [CrI] = 0.42-0.57; adult females: 0.36, 95% CrI = 0.26-0.46; juveniles: 0.39, 95% CrI = 0.29-0.50) than at accessible sites (adult males: 0.36, 95% CrI = 0.26-0.46; adult females: 0.23, 95% CrI = 0.12-0.32; juveniles: 0.25, 95% CrI = 0.13-0.37) for all demographic groups. Concentrated harvest occurred in accessible sites during the hunting season (Aug-Mar). During the post-breeding season (Aug-Nov), when willow ptarmigan were near their breeding sites and the hunting season was open, survival was higher for those from remote sites than for those from accessible sites when accounting for demographic group (adult male, adult female, juvenile). In contrast, during winter (Dec-Mar), when willow ptarmigan had

Understanding the effects of harvest on wildlife populations is fundamental to theoretical wildlife science and applied wildlife management. Demographic compensation plays a key role in models of wildlife population dynamics and in developing harvest strategies. The degree and form of compensation in a given population depend on its particular ecological and life-history characteristics and the timing and magnitude of harvest. Consequently, substantial variation exists in compensatory potential among populations, and it cannot be assumed that a particular population is capable of compensating for harvest. This underscores the importance of population-specific assessments of responses to harvest.We examined the hypothesis that concentrated hunting pressure in road-accessible areas reduces subsequent breeding season densities of willow ptarmigan (Lagopus lagopus), in Alaska, USA, 2014-2015. We estimated breeding season densities of ptarmigan territories at sites within hunted access corridors and at remote sites with little or no hunting pressure. Estimated densities were substantially higher at remote sites (5.3-5.8 territories/km 2 ) than at accessible sites (1.8-3.7 territories/km 2 ). Two habitat-proxy covariates, distance to water and elevation (modeled as smoothed effects), exhibited strong associations with the density of ptarmigan territories. These results suggest a possible additive effect of spatially concentrated harvest on local breeding densities.