Physical Sciences and Mathematics Commons^™

Der Kormoran Phalacrocorax Carbo In Der Mongolei, Michael Stubbe, Lucie Marie Baltz, Davaa Lchagvasuren, Lukas Kratzsch, Lara-Sophie Dey, Annegret Stubbe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The Great Cormorant Phalacrocorax carbo is a wide spread breeding species in Mongolia with a progressive population trend. Observations of the Mongolian-German Biological Expeditions were analyzed and summarized with data from literature. About 1,500 young birds were ringed in 2016 and 2017. One important recovery was coming from the wintering area Mai Po Marshes Nature Reserve of Hong Kong. It is unclear if all Mongolian Cormorants are flying at the same route to their wintering region in South China. The main feeding fishes in Mongolia belong to endemic species of the genus Oreoleuciscus (Cyprinidae). Measurements of 113 eggs from Tolbo- …

Mist-Netting Of Forest-Dwelling Bats In The Lazovsky State Nature Reserve, Russian Far East, Kerstin Birlenbach

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Many bat species depend on a high value of healthy and undisturbed forests with a high ratio of roost sites in old tree stands. This investigation focused on the diversity, distribution and reproduction status of bats within the area of Lazovsky State Nature Reserve. The importance of an area for bats can be measured by the ratio of reproduction. The most important and sensitive time in a bats yearly circle is the time of hibernation in winter and the reproduction time of females. From the beginning of July to the end of August 2007, in total 139 bats of eight …

Surgical Sterilization Impacts On Behavior Of Coyote Pairs, Tyler Leary, Jeffrey T. Schultz, Julie K. Young

USDA Wildlife Services: Staff Publications

Coyotes (Canis latrans) involved in depredation of livestock, an act frequently resulting in human-wildlife conflict, often do so out of necessity for provisioning pups. Surgical sterilization methods such as vasectomy that preserve gonadal hormones have been successful in reducing depredation by free-ranging coyotes while allowing individuals to maintain territoriality and mate fidelity. However, use of these methods remain costly and ineffective for wide-scale use. Given the alternative proposal of using chemical sterilization techniques, we investigated whether the use of hormone-altering sterilization methods impacted behavior of captive coyote pairs (i.e., male-female pair bonds). Our objective was to evaluate behavior …

Measuring Adrenal And Reproductive Hormones In Hair From Southern Beaufort Sea Polar Bears (Ursus Maritimus), Marilize Van Der Walt, Lorin A. Neuman-Lee, Patricia A. Terletzky, Todd C. Atwood, Eric M. Gese, Susannah S. French

USDA Wildlife Services: Staff Publications

Polar bears (Ursus maritimus) use sea ice to access marine mammal prey. In Alaska’s Southern Beaufort Sea, the declining availability of sea ice habitat in summer and fall has reduced opportunities for polar bears to routinely hunt on the ice for seals, their primary prey. This reduced access to prey may result in physiological stress with subsequent potential consequences to reproductive function (physiological changes that accompany reproduction), which can be measured via reproductive hormones. Hormone concentrations in hair can be used as a minimally invasive alternative to serum concentrations, which must come from animal captures. Hair samples also …

Reproductive Trade-Offs In The Colorado Checkered Whiptail Lizard (Aspidoscelis Neotesselatus): An Examination Of The Relationship Between Clutch And Follicle Size, Hannah E. Caracalas, S. S. French, S. B. Hudson, B. M. Kluever, A. C. Webb, D. Eifler, A. J. Lehmicke, Lise M. Aubry

USDA Wildlife Services: Staff Publications

Life history theory predicts that there should be an inverse relationship between offspring size and number, because individuals cannot simultaneously maximize both when resources are limited. Although extensively studied in avian species, the occurrence and determinants of reproductive tradeoffs in oviparous reptiles are far less understood, particularly in parthenogenetic species. We studied this trade-off in the Colorado Checkered Whiptail, Aspidoscelis neotesselatus, a female-only parthenogenetic lizard. Using data previously collected in 2018 and 2019, we tested for clutch and egg size trade-offs and determined whether this relationship could be influenced by female size and aspects of physiological condition. Physiological condition …

Competing Reproductive And Physiological Investments In An All‑Female Lizard, The Colorado Checkered Whiptail, Lise M. Aubry, Spencer B. Hudson, Bryan M. Kluever, Alison C. Webb, Susannah S. French

USDA Wildlife Services: Staff Publications

Organisms in the wild have to allocate limited resources towards competing functions such as reproduction, growth, and self-maintenance. These competing investments create significant changes in physiological activity, and we still know little about the relationship between physiological activity and reproductive investment in natura. We investigated trade-offs between physiological activity and reproductive investment in the parthenogenetic Colorado checkered whiptail, Aspidoscelis neotesselata, across three different sites at the US Army Fort Carson Military Installation near Colorado Springs, CO, through-out the reproductive season in 2018 and 2019. We measured clutch size and reproductive activity and quantified plasma corticosterone (CORT), reactive oxygen metabolites (ROMs), …

Reproductive Characteristics Of Landlocked Fall Chinook Salmon From Lake Oahe, South Dakota, Kelsen L. Young, Michael E. Barnes, Jeremy L. Kientz

The Prairie Naturalist

Lake Oahe, South Dakota, USA, landlocked fall Chinook salmon (Oncorhynchus tshawytscha) reproductive characteristics were examined over a 27 year period, from 1988 to 2015. Mean total lengths of spawning females ranged from 665 mm (1995) to 812 mm (2015) with considerable year-to-year variation. Post-spawn female weights varied, ranging from 2.02 kg (2000) to 5.55 kg (2015), with an overall mean of 3.04 kg. Fecundity peaked at 4,555 eggs per female in 2003, which was just 3 years after a low of 2,011 eggs per female in 2000. Relative fecundity based on female weight was greatest at 1,211 eggs/kg …

Reproduction And Population Characteristics Of White-Tailed Jackrabbits In South Dakota, Charles Dieter, Dustin Schaible

Great Plains Research: A Journal of Natural and Social Sciences

We evaluated the reproductive biology of314 white-tailed jackrabbits (Lepus townsendii) in 44 counties throughout South Dakota from June 2004 to September 2005. We classified jackrabbits as juveniles or adults based on the closure of the proximal epiphysis of the humerus using X-ray analysis. We determined annual reproductive activity through fluctuations in measured weights of reproductive organs for both sexes. The 2005 breeding season started in late February and proceeded until mid-July, approximately 142 days, allowing for females to potentially produce 3.3 litters. We found four distinct breeding periods by the overlap of estimated conception and parturition dates. Mean …

Long-Term Ecology Of Asiatic Wild Ass (Equus H. Hemionus Pallas) In Central Asia, Annegret Stubbe, Michael Stubbe, Nyamsuren Batsaikhan, Ravčigijn Samjaa

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The main population of the nominate form Equus hemionus hemionus Pallas, 1775 occurs in the south-east Gobi desert of Mongolia. From 2003 to 2012 we studied the reproductive ecology and mortality of dschiggetajs or khulans (English also ‘hulan’). During these years, the rate of reproduction was variable, ranging from 6.4% to 23.0% depending on climate, feeding conditions, and fitness of the mares. Our research shows that there appears to be a relationship between minimum temperatures in June (main foaling time) and rate of successful reproduction. The primary cause of decline in the numerical density of the population of E. hemionus …

Paddlefish Egg Deposition In The Lower Yellowstone River, Montana And North Dakota, Shannon E. Miller, Dennis L. Scarnecchia, Steven R. Fain

The Prairie Naturalist

We used passive egg collectors during May, June, and July of2003 and 2004 in the lower 50 river kiiometers (rkm) of the Yellowstone River, eastern Montana and western North Dakota, to detect egg deposition by spawning paddle fish (Polyodon spathula). Sampling yielded 292 eggs (46 in 2003 and 246 in 2004). All egg collections in 2003 occurred on the descending limb of the spring hydrograph but 99% of egg collections in 2004 occurred before the spring hydrograph began to descend. Catch-per-unit-effort (CPUE) in 2004 was about four times that of 2003. A combination of river conditions, in addition …

Age Structure And Reproductive Activity Of The Blue Sucker In The Milk River, Missouri River Drainage, Montana, Julie Bednarski, Dennis L. Scarnecchia

The Prairie Naturalist

The life history and ecology of the blue sucker (Cycleptus elongatus) in the lower Milk River, Montana were investigated in 2002 and 2003. A total of 253 blue sucker was captured; 248 adult fish, three larval fish, and two age-0 juveniles. The ages (n = 102) of the adult blue sucker ranged from 10 to 37 years; maximum age greatly exceeded ages reported in other studies. Blue sucker in the Milk River population grew slower, matured later, and lived longer than fish at lower latitudes. Adult females of the blue sucker were longer and weighed more than …

Reproductive Development In The Sicklefin Chub In The Missouri And Lower Yellowstone Rivers, Douglas J. Dieterman, Eric Roberts, Patrick J. Braaten, David L. Galat

The Prairie Naturalist

We describe aspects of sicklefin chub (Macrhybopsis meeki) reproductive development from three study areas encompassing greater than 2,700 km of the Missouri and Lower Yellowstone rivers. The sicklefin chub was collected between late July and early October in 1996 and 1997. A total of 193 sicklefin chub was collected and examined for reproductive characteristics. Twenty-nine sicklefin chub were found to be reproductively mature females. Some sicklefin chub matured at age 2, but most matured at age 3 and all matured by age 4. Females first became mature at 70 to 79 mm total length (TL) in the Upper …

Reproductive Ecology Of Two Common Woody Species, Juniperus Sabina And Artemisia Santolinifolia, In Mountain Steppes Of Southern Mongolia, Katrin Ronnenberg

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The present study describes the reproductive ecology of the prostrate shrub Juniperus sabina and the dwarf shrub Artemisia santolinifolia in dry mountain steppes of southern Mongolia. Whereas stands of the juniper are located at the drought limit of the genus’ distributional range, the genus Artemisia is typical of central Asian drylands. Both species produce large numbers of reproductive organs. For Juniperus sabina, however, only 2.5% of the morphologically intact seeds were found to be viable. Correspondingly, neither seedlings nor saplings were found in the field, and recruitment by reseeding happens at most rarely under the present climatic conditions.

Instead, …

Zur Populationsökologie Und Raumnutzung Der Steppenwühlmaus Microtus Brandti (Radde, 1861) In Der Fortpflanzungsperiode, Ulrich Zöphel, N. Dawaa

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

During the growing season between 1988 and 1990 the population biology of Brandt’s vole (Microtus brandti) was observed in a population near Ulaanbaatar. Mark-recapture techniques (1,438 markings, 19,606 recaptures in total) and complementary methods were used. The density maximum was observed in July with 98 (1988); 169 (1989) and 94 (1990) individuals/ha and the population fluctuated by a factor of 7.4.

At the beginning of reproductive period the males disperse over a minimum distance of one female home range whereas the females do not migrate after winter. The typical mating system is promiscuity. Youngsters have been recorded from …

Das Arteninventar Der Avifauna Der Mongolei Während Einer Nord-Süd-Durchquerung 1997, Tobias Stenzel, Michael Stubbe, R. Samjaa, Annegret Stubbe, C. Dulamsuren

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Here we present a detailed report on bird biodiversity of ecosystems along a North-South transect through Mongolia in 1997whic h serves as a guideline for further research projects and training for students in all Mongolian vegetation zones from northern steppes to southern deserts.

Two hundred fifty-five bird species were observed between 21st of July and 10th of August 1997. The main study sites were located in the North the Selenge-Orchon-basin with meadows and dune woodlands 15 km southern from Suchbaatar, the Middle Gobi-Aimag with desert steppes and sajrs (covered with Ulmus pumila) and in the Bordzongijn-gobi in the South …

First Results Of Wild Ass Research In The South Gobi Aymag/Mongolia In 2003 And 2004, Annegret Stubbe, Michael Stubbe, N. Batsajchan, R. Samjaa, S. Doržderem

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The population of the Mongolian wild ass belongs to the nominate form Equus hemionus hemionus described by Pallas in 1775. This species is adapted to semidesert habitats in the Gobi region and is listed in the Red Book of Mongolia as well as on appendix I of the Washington Convention (CITES). Mapping of the northern border of the distributional range showed a remarkable decrease in size in comparison to the maps of Murzaev (1954) or Bannikov (1954). The pressure of civilization, settlements, motorization, and increasing numbers of domestic livestock in connection with the occupation of water resources and illegal hunting …