Use of chemical tracers in assessing the diet and foraging regions of eastern North Pacific killer whales

Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers—stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles—were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n = 84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.

Use of chemical tracers in assessing the diet and foraging regions of eastern North Pacific killer whales

Top predators in the marine environment integrate chemical signals acquired from their prey that reflect both the species consumed and the regions from which the prey were taken. These chemical tracers—stable isotope ratios of carbon and nitrogen; persistent organic pollutant (POP) concentrations, patterns and ratios; and fatty acid profiles—were measured in blubber biopsy samples from North Pacific killer whales (Orcinus orca) (n = 84) and were used to provide further insight into their diet, particularly for the offshore group, about which little dietary information is available. The offshore killer whales were shown to consume prey species that were distinctly different from those of sympatric resident and transient killer whales. In addition, it was confirmed that the offshores forage as far south as California. Thus, these results provide evidence that the offshores belong to a third killer whale ecotype. Resident killer whale populations showed a gradient in stable isotope profiles from west (central Aleutians) to east (Gulf of Alaska) that, in part, can be attributed to a shift from off-shelf to continental shelf-based prey. Finally, stable isotope ratio results, supported by field observations, showed that the diet in spring and summer of eastern Aleutian Island transient killer whales is apparently not composed exclusively of Steller sea lions.

The Specific Status of the Narrow-Skulled Vole (Subgenus Stenocranius Kashchenko) in North America

On morphological and zoogeographical grounds, discussed in the present paper, it is concluded that the narrow-skulled vole in North America, previously designated Microtus (Stenocranius) miurus Osgood, is conspecific with the Eurasian M. (Stenocranius) gregalis Pallas. Fourteen subspecies in Eurasia and 5 in North America are now recognized, but it is probable that the number in Eurasia will be reduced through future investigation. The Eurasian subspecies of this vole comprise two major groups, of which one occupies the tundra zone and the other occurs across central Asia below latitude 60° N; their geographic ranges are largely separate but evidently become confluent in northeastern Siberia. The members of the northern group of Eurasian subspecies and the North American forms are closely related; the present distribution of the latter indicates post-glacial dispersal from the Amphiberingian Refugium. It is believed that the tundra-inhabiting voles in Eurasia likewise survived the Pleistocene glaciations in northern refugia, while the members of the southern group of subspecies probably represent populations that survived south of the limits of the continental glaciers. The ranges of the two Eurasian groups probably have become confluent during post-glacial time in northeastern Siberia as a result of the southward spread of the northern forms. At least, the subspecies having the intervening range closely resembles members of the northern group. Some of the ecological and ethological characteristics of these voles are briefly discussed. The chromosome number of one of the North American subspecies of narrow-skulled vole was determined to be 54; this is the first time that the chromosomes of a member of the subgenus Stenocranius have been investigated. A karyogram has been included. German abstract: Auf morphologischen und tiergeographischen Grundlagen, die in dieser Arbeit besprochen wurden, ist festgestellt worden, daß die schmalschädlige Wiihlmaus in Nordamerika, friiher Microtus (Stenocranius) miurus Osgood bezeichnet, mit der palaearktischen Art M. (Stenocranius) gregalis Pallas identisch ist. Zur Zeit gelten 14 Unterarten in Eurasien und 5 in Nordamerika als unterscheidbar; vermutlich aber wird die Zahl der palaearktischen Unterarten durch eingehendere Untersuchungen künftig vermindert werden. Auf Grund ihrer Verbreitung bilden die palaearktischen Unterarten zwei beinahe vollständig getrennte Gruppen. Die Wühlmäuse der nördlichen Gruppe bewohnen die Tundrazone, während die Vertreter der zweiten Gruppe über Mittelasien südlicher als 60° N.B. verbreitet sind. Die Verbreitungsgebiete der zwei Gruppen verbinden sich anscheinend. Die nordamerikanischen schmalschädligen Wühlmäuse sind mit den in der Tundrazone vorkommenden palaearktischen Formen nahe verwandt; sie haben sich wahrscheinlich während der Postglazialzeit aus dem Amphiberingschen Refugium verbreitet. Möglicherweise überlebten die tundrabewohnenden Wühlmäuse Eurasiens die Eiszeit ebenfalls in vereinzelten Refugien in Nordostsibirien, während die Formen der südlichen Gruppe sie jenseits der Grenzen des Festlandsgletschers überlebten. Wahrscheinlich wurden die zwei Verbreitungsgebiete dieser Art in Eurasien erst während der Postglazialzeit durch das Vordringen der nordischen Formen verbunden, da eine nähere Verwandtschaft zwischen den nördlichen und der dazwischenliegenden Unterart besteht. Einige ökologische und ethologische Eigentümlichkeiten dieser Wühlmäuse werden kurz besprochen. Es wurde festgestellt, daß eine der nordamerikanischen Unterarten der schmalschädligen Wühlmaus 54 Chromosomen hat; sie ist der einzige Vertreter der Untergattung Stenocranius, dessen Chromosomen untersucht worden sind.

Review of issues concerning the use of reproductive inhibitors, with particular emphasis on resolving human-wildlife conflicts in North America

This manuscript provides an overview of past wildlife contraception efforts and discusses the current state of research. Two fertility control agents, an avian reproductive inhibitor containing the active ingredient nicarbazin and an immunocontraceptive vaccine, have received regulatory approval with the Environmental Protection Agency and are commercially available in the USA. OvoControl G Contraceptive Bait for Canada Geese and Ovo Control for pigeons are delivered as oral baits. An injectable immunocontraceptive vaccine (GonaCon Immunocontraceptive Vaccine) was registered with the Environmental Protection Agency for use in female white-tailed deer in September 2009. An injectable product (GonaCon Immunocontraceptive Vaccine) is registered for use in female white-tailed deer. Both products are labeled for use in urban/suburban areas where these species are overabundant. Several other compounds are currently being tested for use in wildlife in the USA, Europe, Australia and New Zealand that could have promise in the future. The development and use of reproductive inhibitors for resolving human–wildlife conflicts will depend on a number of factors, including meeting the requirements of regulatory agencies for use in the environment and on the biological and economical feasibility of their use. Use will also be dependent on health and safety issues and on public acceptance of the techniques.

Airport Bird Threat in North America from Large Flocking Birds (geese) (as Viewed by an Engine Manufacturer)--Part 1

In worldwide aviation operations, bird collisions with aircraft and ingestions into engine inlets present safety hazards and financial loss through equipment damage, loss of service and disruption to operations. The problem is encountered by all types of aircraft, both military and commercial. Modern aircraft engines have achieved a high level of reliability while manufacturers and users continually strive to further improve the safety record. A major safety concern today includes common-cause events which involve significant power loss on more than one engine. These are externally-inflicted occurrences, with the most frequent being encounters with flocks of birds. Most frequently these encounters occur during flight operations in the area on or near airports, near the ground instead of at cruise altitude conditions. This paper focuses on the increasing threat to aircraft and engines posed by the recorded growth in geese populations in North America. Service data show that goose strikes are increasing, especially in North America, consistent with the growing resident geese populations estimated by the United States Department of Agriculture (USDA). Airport managers, along with the governmental authorities, need to develop a strategy to address this large flocking bird issue. This paper also presents statistics on the overall status of the bird threat for birds of all sizes in North America relative to other geographic regions. Overall, the data shows that Canada and the USA have had marked improvements in controlling the threat from damaging birds - except for the increase in geese strikes. To reduce bird ingestion hazards, more aggressive corrective measures are needed in international air transport to reduce the chances of serious incidents or accidents from bird ingestion encounters. Air transport authorities must continue to take preventative and avoidance actions to counter the threat of birdstrikes to aircraft. The primary objective of this paper is to increase awareness of, and focus attention on, the safety hazards presented by large flocking birds such as geese. In the worst case, multiple engine power loss due to large bird ingestion could result in an off-airport forced landing accident. Hopefully, such awareness will prompt governmental regulatory agencies to address the hazards associated with growing populations of geese in North America.

SCWDS BRIEFS: Volume 21, Number 3 (October 2005)

H5N1 Influenza Virus in Wild Birds: A Fact Sheet Highly Pathogenic Avian Influenza Virus H5N1 and Wild Birds What are avian influenza viruses? What is a Highly Pathogenic Avian Influenza virus? What is “Bird Flu” and what is “HPAI H5N1”? What do we know about avian influenza viruses in wild birds? Do we have HPAI H5N1 in North America? Is there currently a public health risk associated with HPAI H5N1 in wild birds? Is there a domestic animal health risk associated with HPAI in wild birds? What is the possibility of HPAI H5N1 entering North America via migratory wild birds? What is the possibility of this virus being maintained in wild bird populations? Do we have surveillance for HPAI H5N1 in the United States? Additional information on HPAI can be found at these websites: The recognized geographic and species distribution of chronic wasting disease (CWD) has expanded since early September 2005 to include Hampshire County in the eastern panhandle of West Virginia National Fish and Wildlife Health Initiative Guiding Principles Eastern Equine Encephalitis (EEE) virus was isolated from seven white-tailed deer in southwestern Michigan during September 2005 During the past summer, more than 500 head of livestock in North Dakota and South Dakota were lost to one of the largest recorded anthrax outbreaks in U.S. history. Most of the losses were in cattle, but horses, bison, and farm-reared elk also were affected. Dr. John Fischer, Director of SCWDS, has received this year’s Special Recognition Award from the International Association of Fish and Wildlife Agencies (IAFWA). Dr. William Randolph Davidson is retiring in November 2005.

Distribution and Specificity of Helminths in Microtine Rodents: Evolutionary Implications

The taxonomic status of anoplocephaline cestodes of microtine rodents has been reviewed. Of the genus Andrya Railliet, 1883, five species are considered valid: A. macrocephala Douthitt, 1915; A. primordialis Douthitt, 1915; A. montana Kirshenblat, 1941 ; A. arctica Rausch, 1952; A. bairdi Schad, 1954. Of the genus Paranoplocephala Luehe, 1910, six species are regarded as valid: P. omphalodes (Hermann, 1783); P. blanchardi (Moniez, 1891); P. infrequens (Douthitt, 1915); P. variabilis (Douthitt, 1915); P. lemmi Rausch, 1952; P. neofibrinus Rausch, 1952. Andrya caucasica Kirshenblat, 1938, and A. bialowizensis Soltys, 1949, are regarded as synonyms of A. macrocephala. Paranoplocephala brevis Kirshenblat, 1938, is regarded as a synonym of P. infrequens. Three species, A. macrocephala, P. omphalodes, and P. infrequens, are holarctic in distribution, occurring mainly in species of Microtus. The uniformity of microtine rodents as hosts for various helminths has been discussed. It is concluded that Dicrostonyx is the most isolated genus from this standpoint, having two nematodes which have not been recorded from members of other genera, and harboring few helminths in common with others. This agrees with Hinton's conclusions, based on morphological characters of Dicrostonyx. From the present concept of Pleistocene glaciations, it is concluded that P. omphalodes and P. infrequens reached the St. Matthew Islands, in Bering Sea, as parasites of a vole from which Microtus abbreviatus has evolved. It appears that this vole arrived on these islands before North America was invaded, in the late Pleistocene, by the palearctic M. oeconomus and Clethrionomys rutilus,/i>. The present known distribution of P. omphalodes in North America corresponds about to that of M. oeconomus on the continent.

Intraspecific Comparison of Population Structure, Genetic Diversity, and Dispersal Among Three Subspecies of Townsend’s Big-Eared Bats, Corynorhinus townsendii townsendii, C. t. pallescens, and the Endangered C. t. birginianus

Townsend’s big-eared bat, Corynorhinus townsendii, is distributed broadly across western North America and in two isolated, endangered populations in central and eastern United States. There are five subspecies of C. townsendii; C. t. pallescens, C. t. australis, C. t. townsendii, C. t. ingens, and C. t. virginianus with varying degrees of concern over the conservation status of each. The aim of this study was to use mitochondrial and microsatellite DNA data to examine genetic diversity, population differentiation, and dispersal of three C. townsendii subspecies. C. t. virginianus is found in isolated populations in the eastern United States and was listed as endangered under the Endangered Species Act in 1979. Concern also exists about declining populations of two western subspecies, C. t. pallescens and C. t. townsendii. Using a comparative approach, estimates of the genetic diversity within populations of the endangered subspecies, C. t. virginianus, were found to be significantly lower than within populations of the two western subspecies. Further, both classes of molecular markers revealed significant differentiation among regional populations of C. t. virginianus with most genetic diversity distributed among populations. Genetic diversity was not significantly different between C. t. townsendii and C. t. pallescens. Some populations of C. t. townsendii are not genetically differentiated from populations of C. t. pallescens in areas of sympatry. For the western subspecies gene flow appears to occur primarily through male dispersal. Finally, geographic regions representing significantly differentiated and genetically unique populations of C. townsendii virginianus are recognized as distinct evolutionary significant units.

Cystic Echinococcosis in the Arctic and Sub-Arctic

The northern biotype of Echinococcus granulosus occurs throughout the holarctic zones of tundra and taiga, from eastern Fennoscandia to the Bering Strait in Eurasia and in North America from arctic Alaska approximately to the northern border of the United States. The cycle of the cestode is complex in taiga at lower latitudes, because of the greater diversity of potential hosts. In the Arctic and Subarctic, however, four patterns of predator/prey relationships may be discerned. Two natural cycles involve the wolf and wild reindeer and the wolf and elk (moose), respectively. Where deer of the two species coexist, both are prey of the wolf; the interactions of the wolf and elk are here described on the basis of long-term observations made on Isle Royale (in Lake Superior near the southern limit of taiga), where only the wolf and elk serve as hosts for E. granulosus. A synanthropic cycle involving herding-dogs and domesticated reindeer caused hyperendemicity of cystic echinococcosis in arctic Eurasia, mainly in northeastern Siberia. The 4th pattern, a semi-synanthropic cycle, formerly existed in Alaska, wherein sled-dogs of the indigenous hunters became infected by consuming the lungs of wild reindeer. The sequence of changes in life-style inherent in the process of acculturation affected the occurrence of cystic echinococcosis among nomadic Iñupiat in arctic Alaska. When those people became sedentary, the environs of their early villages soon became severely contaminated by feces of dogs, and cases of cystic echinococcosis occurred. Compared to cystic echinococcosis caused by E. granulosus adapted to synanthropic hosts (dog and domestic ungulates), the infection produced by the northern biotype is relatively benign. 0fearly all diagnosed cases of cystic echinococcosis (> 300 in Alaska have occurred in indigenous people; only one fatality has been recorded (in a non-indigenous person). After sled-dogs were replaced by machines, cases have become rare in Alaska. A similar effect has been observed in Fennoscandia, in the Saami and domesticated reindeer. Recent records indicate tbat the prcvalence of cystic echinococcosis is increasing in Russia, suggesting that dogs are used there in herding.