Assiniboine Park Zoo

Winnipeg, Canada

Assiniboine Park Zoo

Winnipeg, Canada
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Morin P.A.,Southwest Fisheries Science Center | Parsons K.M.,National Oceanic and Atmospheric Administration | Archer F.I.,Southwest Fisheries Science Center | Avila-Arcos M.C.,Copenhagen University | And 21 more authors.
Molecular Ecology | Year: 2015

Global climate change during the Late Pleistocene periodically encroached and then released habitat during the glacial cycles, causing range expansions and contractions in some species. These dynamics have played a major role in geographic radiations, diversification and speciation. We investigate these dynamics in the most widely distributed of marine mammals, the killer whale (Orcinus orca), using a global data set of over 450 samples. This marine top predator inhabits coastal and pelagic ecosystems ranging from the ice edge to the tropics, often exhibiting ecological, behavioural and morphological variation suggestive of local adaptation accompanied by reproductive isolation. Results suggest a rapid global radiation occurred over the last 350 000 years. Based on habitat models, we estimated there was only a 15% global contraction of core suitable habitat during the last glacial maximum, and the resources appeared to sustain a constant global effective female population size throughout the Late Pleistocene. Reconstruction of the ancestral phylogeography highlighted the high mobility of this species, identifying 22 strongly supported long-range dispersal events including interoceanic and interhemispheric movement. Despite this propensity for geographic dispersal, the increased sampling of this study uncovered very few potential examples of ancestral dispersal among ecotypes. Concordance of nuclear and mitochondrial data further confirms genetic cohesiveness, with little or no current gene flow among sympatric ecotypes. Taken as a whole, our data suggest that the glacial cycles influenced local populations in different ways, with no clear global pattern, but with secondary contact among lineages following long-range dispersal as a potential mechanism driving ecological diversification. © 2015 John Wiley & Sons Ltd.


PubMed | University of Winnipeg, Assiniboine Park Zoo, Copenhagen University, Gulf and 9 more.
Type: Journal Article | Journal: Molecular ecology | Year: 2015

Global climate change during the Late Pleistocene periodically encroached and then released habitat during the glacial cycles, causing range expansions and contractions in some species. These dynamics have played a major role in geographic radiations, diversification and speciation. We investigate these dynamics in the most widely distributed of marine mammals, the killer whale (Orcinus orca), using a global data set of over 450 samples. This marine top predator inhabits coastal and pelagic ecosystems ranging from the ice edge to the tropics, often exhibiting ecological, behavioural and morphological variation suggestive of local adaptation accompanied by reproductive isolation. Results suggest a rapid global radiation occurred over the last 350000years. Based on habitat models, we estimated there was only a 15% global contraction of core suitable habitat during the last glacial maximum, and the resources appeared to sustain a constant global effective female population size throughout the Late Pleistocene. Reconstruction of the ancestral phylogeography highlighted the high mobility of this species, identifying 22 strongly supported long-range dispersal events including interoceanic and interhemispheric movement. Despite this propensity for geographic dispersal, the increased sampling of this study uncovered very few potential examples of ancestral dispersal among ecotypes. Concordance of nuclear and mitochondrial data further confirms genetic cohesiveness, with little or no current gene flow among sympatric ecotypes. Taken as a whole, our data suggest that the glacial cycles influenced local populations in different ways, with no clear global pattern, but with secondary contact among lineages following long-range dispersal as a potential mechanism driving ecological diversification.


News Article | August 22, 2016
Site: news.yahoo.com

This July 2016 photo provided by Explore.org shows the view of a beluga whale from a webcam gathered in the Churchill River in the Hudson Bay in Manitoba, Canada. Canadian researchers are turning to the internet to learn about the social behavior of thousands of beluga whales that migrate to Hudson Bay every year. (Explore.org via AP) HELENA, Mont. (AP) — The underwater webcam attached to Hayley Shephard's boat captures what at first appear to be green glowing orbs as she motors through an estuary in remote Canada. Then the orbs come into focus, revealing some of the more than 3,000 beluga whales that gather near that western part of Hudson Bay each summer. The white whales, which resemble oversized dolphins, nuzzle and clown for the camera. They feel the lens with their teeth and blow bubbles at it. Sometimes they swim upside down for a better view. That's what Stephen Petersen, head of conservation and research for Winnipeg's Assiniboine Park Zoo, and his wife, biologist Meg Hainstock, are looking for. Only when the whales turn upside down can the researchers determine their sex, which they need as they study the animals' social structure and behavior. The webcam's viewers across the globe are helping, too. Its creators — Bozeman, Montana-based Polar Bears International and Explore.org, a project of the Annenberg Foundation — included a "snapshot" feature that allows viewers to take still shots of the feed. Petersen and Hainstock hope the result will be a trove of photographs of individual whales that will help them catalog the population as they try to answer questions about the animals' behavior. For example, why do certain whales of a similar age and sex consistently gather at certain times or locations? What function do Hudson Bay's estuaries serve for these animals? Do beluga whales have a matriarchal social structure? Do certain whale groups' low numbers have a long-term effect on the rest of the population, such as the case with the population in Alaska's Cook Inlet, which is struggling as compared to the healthy Hudson Bay population? "As far as I know, there's no other investigation of beluga from under the water on this scale," Petersen said. "A lot of the stuff that's been done before is from observers on top of the water. It doesn't really give us a good sense — belugas don't spend a lot of time on top of the water." Explore.org and Polar Bears International have used similar crowdsourcing technology to monitor polar bears' annual migration in Hudson Bay. Researchers hope years of viewers taking snapshots will provide them with images that can help assess the bears' health and reproductive rates. Other scientists are increasingly using crowdsourcing to raise money for research or perform tasks that would be too costly or time-consuming to be performed by a team of researchers. One of the most well-known projects is by the SETI Institute in Mountain View, California, whose software has been downloaded by millions of users and allows researchers to use the data-processing power of those computers in the institute's search for alien life in space. "In general, there is a growing interest in using citizen science projects to raise awareness and support scientific research," said Krista Wright, executive director of Polar Bears International. For the beluga whale project, Petersen said viewers are instructed on how to identify males from females, and are then asked to take snapshots when the whales flip over and their sex is in view of the camera. The photographs are tagged male or female and uploaded to a database that will help identify individual whales and their locations. Operators switched on the cameras July 15 and have since averaged about 2,500 viewers a day, according to Explore.org spokesman Mike Gasbara. The researchers hope that after this season ends in August, they will have a catalog of individual whales that can be tracked in subsequent years, along with the locations where different groups are gathering to find if any patterns emerge. Understanding the beluga whales is important because their ecosystem soon may be altered with the effects of climate change, Gasbara said. Less Arctic ice could bring threats to the beluga in the form of killer whales and increased boat traffic and pollution, he said. "I think because we're right at the beginning of this, any information that we get on social structure is going to be informative for other locations," Petersen said. Back on the surface in Canada's Hudson Bay, ghostlike humps emerge as more whales are drawn to Shepherd's 10-foot inflatable boat. She pilots the vessel slowly around the estuary for four hours a day over the short northern summer, sometimes narrating her observations to web viewers. "It's important to know that we ultimately are visitors and we are in their territory," Shepherd said. "Them approaching the boat, following the boat — it's all their doing. We don't need to run up to them and ride along." Occasionally, one of the whales will slap the water with its tail and soak her. "Sometimes I feel like they've adopted me into their pod," Shephard said.


Pomerleau C.,University of Quebec at Rimouski | Pomerleau C.,Canadian Department of Fisheries and Oceans | Lesage V.,Maurice Lamontagne Institute | Ferguson S.H.,Canadian Department of Fisheries and Oceans | And 3 more authors.
Marine Ecology Progress Series | Year: 2012

The eastern Canada-West Greenland (EC-WG) bowhead whale Balaena mysticetus population is slowly recovering from the intensive commercial whaling of the 18th and 20th centuries. However, climate change, through effects on ice conditions and prey availability, is one of several threats that might affect bowhead whale recovery. In this study, we exploited the variability observed in isotopic signatures of prey assemblages across the eastern Arctic to examine variability in diet among bowhead whales (n = 202) and identify their potential foraging areas. We compared δ13C and δ15N isotope ratios of biopsied skin samples with those of potential zooplankton prey species collected across the Canadian eastern Arctic, and calculated the proportional contributions of various sources (zooplankton) to the diet of bowhead whales using a Bayesian stable isotope mixing model. A cluster analysis indicated some variability in isotopic composition among groups of individuals, but not between males and females or age classes. The isotopic model discounted Davis Strait and Disko Bay as potential foraging areas for bowhead whales, at least in spring and summer. Lancaster Sound, Baffin Bay and the Gulf of Boothia were the 3 main areas likely used for summer feeding, where bowhead whales fed primarily on large Arctic calanoid copepods (Calanus hyperboreus, C. glacialis, Metridia longa, and Paraeuchaeta spp.), mysids and euphausiids. While some inter-individual variability in diet was observed, the strong dependence of this endemic Arctic species on Arctic zooplankton may make them vulnerable to the predicted latitudinal shift in prey species composition caused by ongoing warming. © Inter-Research and Fisheries and Oceans Canada 2012.


Watt C.A.,University of Manitoba | Petersen S.D.,Assiniboine Park Zoo | Ferguson S.H.,University of Manitoba | Ferguson S.H.,University of Winnipeg
Polar Biology | Year: 2015

Narwhals (Monodon monoceros) are an entirely arctic odontocete, living in upwards of 95 % pack ice and complete darkness over the winter. As a result of the harsh conditions in which they live, there are few studies of their social structure; however, it has been hypothesized that narwhals display a matrilineal social structure where pods are centered on the mother. A fortuitous opportunity arose to study social structure when an ice entrapment event near the community of Pond Inlet, Nunavut, Canada captured many females and their offspring. Using genetic analyses and fatty acids as a dietary marker, we investigated whether individuals that are closely related forage together, which would support a matrilineally driven social structure where females teach their young foraging strategies, and/or travel and forage together. We found no evidence that genetic relatedness was correlated with the fatty acid biomarkers, which provides some evidence against a matrilineal social structure. The possibility of narwhals displaying a fission–fusion societal structure is discussed, but further observational and experimental techniques are needed to support or refute this hypothesis. © 2015, Springer-Verlag Berlin Heidelberg.


Waterman J.M.,University of Manitoba | Macklin G.F.,University of Manitoba | Enright C.,Assiniboine Park Zoo
Canadian Journal of Zoology | Year: 2014

Sex-biased parasitism is found in many species, but the skew to one sex or the other varies and is most likely due to differences in host and parasite behaviour and the intensity of sexual selection. We examined sex-biased parasitism in Richardson's ground squirrels (Urocitellus richardsonii (Sabine, 1822)) and hypothesized that males would be more heavily parasitized than females, as they are larger, have larger home ranges, and display high aggression and fighting during the short mating season, suggesting that they may trade off investment in immunity for higher investment in reproduction. Squirrels were caught during the mating season and examined for endoparasites and ectoparasites. Body mass, condition, and immune measures were recorded. Males had higher nematode prevalence and abundance, whereas females had higher flea prevalence. Males also had lower lymphocytes than females, as well as higher neutrophil to lymphocyte ratios. Females had higher eosinophils and they were in poorer body condition than males. The higher endoparasite loads in males suggests that they may be trading off immunity, whereas higher flea prevalence in females may be due to differences in sociality between the sexes. Our study demonstrates the importance of examining multiple parasite types to understand the factors influencing sex-biased parasitism.


Hare J.F.,University of Manitoba | Ryan C.P.,University of Manitoba | Enright C.,Assiniboine Park Zoo | Gardiner L.E.,University of Manitoba | And 3 more authors.
Current Zoology | Year: 2014

We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites (FGMs) from captive male and female Richardson's ground squirrels Urocitellus richardsonii. Blood samples were drawn to explore the correlation between plasma cortisol and FGM concentrations. We also injected groups of squirrels with normal saline (CTL; control), adre-nocorticotropic hormone (ACTH; stimulating adrenal activity), or dexamethasone (DEX; suppressing adrenal activity). Potential correlations between stress and behaviour were explored through quantification of fecal pellet production and the intervention necessary to elicit defecation, as well as the behaviour of subjects in the context of handling. Changes in plasma cortisol concentration between capture (baseline), and following handling (stress-induced) were also quantified for free-living squirrels. While glucocorticoid concentrations recovered from feces during our captive-animal study were not well correlated with plasma cortisol concentrations, and uncorrelated with defecation or behaviour, FGM concentrations did reflect the activation of the hypothalamic-pituitary-adrenal (HPA) axis. FGM concentrations increased significantly during initial captivity, but declined to baseline level as individuals acclimated to the novel environment. Injection of subjects with ACTH increased FGMs above baseline, confirming activation of the HPA axis. Plasma cortisol concentrations increased significantly with induced stress, indicating that capture and handling activated the glucocorticoid stress response even among previously handled, free-living subjects. Our findings validate a non-invasive tool that will afford new insight into the physiological processes underlying social, reproductive and antipredator behaviour of Richardson's ground squirrels. © 2014 Current Zoology.


Ryan C.P.,University of Manitoba | Ryan C.P.,Northwestern University | Anderson W.G.,University of Manitoba | Berkvens C.N.,Assiniboine Park Zoo | Hare J.F.,University of Manitoba
PLoS ONE | Year: 2014

The adaptive manipulation of offspring sex and number has been of considerable interest to ecologists and evolutionary biologists. The physiological mechanisms that translate maternal condition and environmental cues into adaptive responses in offspring sex and number, however, remain obscure. In mammals, research into the mechanisms responsible for adaptive sex allocation has focused on two major endocrine axes: the hypothalamic pituitary adrenal (HPA) axis and glucocorticoids, and the hypothalamic pituitary gonadal (HPG) axis and sex steroids, particularly testosterone. While stress-induced activation of the HPA axis provides an intuitive model for sex ratio and litter size adjustment, plasma glucocorticoids exist in both bound and free fractions, and may be acting indirectly, for example by affecting plasma glucose levels. Furthermore, in female mammals, activation of the HPA axis stimulates the secretion of adrenal testosterone in addition to glucocorticoids (GCs). To begin to untangle these physiological mechanisms influencing offspring sex and number, we simultaneously examined fecal glucocorticoid metabolites, free and bound plasma cortisol, free testosterone, and plasma glucose concentration during both gestation and lactation in a free-living rodent (Urocitellus richardsonii). We also collected data on offspring sex and litter size from focal females and from a larger study population. Consistent with previous work in this population, we found evidence for a trade-off between offspring sex and number, as well as positive and negative correlations between glucocorticoids and sex ratio and litter size, respectively, during gestation (but not lactation). We also observed a negative relationship between testosterone and litter size during gestation (but not lactation), but no effect of glucose on either sex ratio or litter size. Our findings highlight the importance of binding proteins, cross-talk between endocrine systems, and temporal windows in the regulation of trade-offs in offspring sex and number. Copyright: © 2014 Varanda et al.


PubMed | Assiniboine Park Zoo and University of Manitoba
Type: Journal Article | Journal: PloS one | Year: 2014

The adaptive manipulation of offspring sex and number has been of considerable interest to ecologists and evolutionary biologists. The physiological mechanisms that translate maternal condition and environmental cues into adaptive responses in offspring sex and number, however, remain obscure. In mammals, research into the mechanisms responsible for adaptive sex allocation has focused on two major endocrine axes: the hypothalamic pituitary adrenal (HPA) axis and glucocorticoids, and the hypothalamic pituitary gonadal (HPG) axis and sex steroids, particularly testosterone. While stress-induced activation of the HPA axis provides an intuitive model for sex ratio and litter size adjustment, plasma glucocorticoids exist in both bound and free fractions, and may be acting indirectly, for example by affecting plasma glucose levels. Furthermore, in female mammals, activation of the HPA axis stimulates the secretion of adrenal testosterone in addition to glucocorticoids (GCs). To begin to untangle these physiological mechanisms influencing offspring sex and number, we simultaneously examined fecal glucocorticoid metabolites, free and bound plasma cortisol, free testosterone, and plasma glucose concentration during both gestation and lactation in a free-living rodent (Urocitellus richardsonii). We also collected data on offspring sex and litter size from focal females and from a larger study population. Consistent with previous work in this population, we found evidence for a trade-off between offspring sex and number, as well as positive and negative correlations between glucocorticoids and sex ratio and litter size, respectively, during gestation (but not lactation). We also observed a negative relationship between testosterone and litter size during gestation (but not lactation), but no effect of glucose on either sex ratio or litter size. Our findings highlight the importance of binding proteins, cross-talk between endocrine systems, and temporal windows in the regulation of trade-offs in offspring sex and number.


News Article | October 23, 2015
Site: www.reuters.com

Klondike, a female polar bear, was euthanized after weeks of worsening medical conditions that included mobility problems and infections, officials said. "There was no significant improvement in her condition, and given her advanced age and poor prognosis, zoo staff decided that the best decision would be to humanely euthanize her," Philadelphia Zoo said in a statement posted on Facebook. Klondike exceeded the typical lifespan for her species, which in captivity lives to about 30 years and generally no longer than 20 years in the wild, according to the Pittsburgh Zoo. The zoo's Coldilocks, also 34, has become the country's new oldest polar bear. Both bears arrived at the zoo in October 1981, the year after they were born in different parts of New York state. The world record-holding oldest polar bear, named Debby, died at age 42 seven years ago at Canada's Assiniboine Park Zoo. Polar bears, which can stand as high as 11 feet (3.35 meters) tall and weigh as much as 1,400 pounds (635 kg), use floating sea ice as platforms for hunting, mating and traveling vast distances in the Arctic. They were listed as threatened under the U.S. Endangered Species Act in 2008 due to disappearing sea ice, becoming the first animals granted such protection because of conditions tied to global climate change.

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