Operative temperatures of five members of the deer family under different forest canopies during summer were estimated. Sky view factors and effective leaf area indices were obtained from hemispherical photography. These were combined with radiation regime, ambient air temperature, wind speed, and other relevant factors to obtain operative temperature. Upper critical temperatures were significantly related to operative temperature in the open (r2 = 0.65; p < 0.05). To assess the thermal cover value of different canopy closures, simultaneous operative-temperature values as a function of canopy closure were estimated by simulation. Operative temperature decreased sharply with increasing crown closure up to about 30% crown closure, and then more gradually. Crown-closure values providing thermal cover under different ambient temperatures are summarized for the five deer taxa. Crown-closure classes as commonly depicted on forest cover maps correctly rank the effectiveness in providing summer thermal cover (r2 = 0.91; p < 0.05).

Mike W. Demarchi and Fred L. Bunnell 1995. Forest cover selection and activity of cow moose in summer. Acta Theriologica 40: 23-36.Although thermal cover receives attention from managers, variations in data regarding its use by ungulates hinders development of effective cover guidelines. We examined patterns of habitat selection and activity of radio-collared cow moose Alces alces Linnaeus, 1758 to determine if these 2 parameters were influenced by ambient thermal environment. Cow moose used sites with relatively denser forest canopies when conditions of heat stress existed in open areas. Use of open areas did not change with ambient temperature; some sites classed as open on forest cover maps, however, had willow canopies capable of providing thermal cover. An increase in the use of open sites from 11.00 to 24.00 hr corresponded to a simultaneous decrease in the likelihood of thermal stress in such areas; predator-avoidance was deemed unlikely to explain observed behaviour. Moose decreased activity and distance traveled between successive locations during hot periods. Summer thermal cover is a selected, manageable component of moose habitat in southern British

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Populations of California sea lions Zalophus californianus and Steller sea lions Eumetopias jubatus in much of the eastern North Pacific Ocean have experienced significant growth since being protected in the early 1970s (by the US Marine Mammal Protection Act and Canada's Fisheries Act) from commercial harvests and fisheries-related culls. However, there remains substantial and unexplained variance in the annual number of sea lions using a major winter haulout at the entrance to the Salish Sea. We used linear regression on principal components to show maximum annual sea lion counts, adjusted for population growth, varied as a function of herring biomass and not local sea surface temperatures or precipitation. Results suggest that Race Rocks, British Columbia, Canada, is used as a stopover for an increasing number of sea lions approaching southern Vancouver Island to feed during the nonbreeding season. Reports of resource-driven movements of sea lions are not new, but this is the first study to use a multidecade data set to show resource-driven movements can underlie long-term patterns of population growth. Finally, we found an unexplained change in the seasonal use of Race Rocks affecting both species. Arrival at Race Rocks has occurred in late summer since 1965, but up to 1979 departure had occurred the following spring; since as late as 1997, departure has occurred mid winter. This study highlights the complexities of enacting conservation plans for species with latitudinal distributions and undergoing long-term population change.KEY WORDS: Pacific herring · Race Rocks · Sea surface temperature · Strait of Georgia · Pinniped · Juan de Fuca Strait · Vancouver Island Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 467: [253][254][255][256][257][258][259][260][261][262] 2012 efforts because its position in Juan de Fuca Strait makes it a gateway for thousands of marine mammals and billions of Pacific herring Clupea pallasii and salmon returning to the Salish Sea each year (Bigg 1988a,b, Jeffries et al. 2000 Fig. 1).Seasonal movement of both species of sea lions is influenced in part by the availability of prey fish, as has been documented in Alaska, Washington and California for salmonids, Pacific herring and eulachon Thaleichthys pacificus (Gearin et al. 1986, Lowry et al. 1991, Weise & Harvey 1999, Womble 2005). Scat analyses suggest Pacific herring is one of the most important prey for Steller sea lions in British Columbia, as is Pacific hake Merluccius productus off the coast of Oregon (reviewed in Bredeson et al. 2006). Ano malies in oceanic conditions, such as increased sea surface temperature (SST) or decreased productivity, are shown to correlate with California sea lion distribution and foraging behaviour (Weise et al. 2006, Bargu et al. 2010) and may have played important roles in the decline in the number of Steller sea lions in southern California (Bartho lo mew & Boolootian 1960). Similarly, although we suspect seasonal sea lion distribution...