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A while ago I was asked to provide updates on the current Utah moose study, but since I've only been receiving them for a couple of months and it's been going on since January 2013, I needed to get a couple of annual reports (2013, 2014) to get up to date, which I did.
The reports are a bit long and have several charts, graphs and tables, and a bunch of scientific wording, so I'll have to take a few days to post both reports before posting the current updates. And I may have to do it in sections, please be patient and wait until both reports are complete before commenting. (If any of you want the original reports, please email me at [email protected]) Thanks, Lee (UWC)
First off, a bit of background on the project and the administrators:
The project is called "Determinants of Population Growth in Utah Moose" and was initiated by Joel Rupercht, a student of Utah State University as his masters project. He is assisted by his advisor, Dan MacNulty, Phd, Wildlife Ecology, USU faculty, Wildland Resources Dept., and by Kent Hersey, Big Game Project Leader, UDWR. There are other USU students also doing some of the groundwork. I don't know the financial details, but I think we can assume that USU is paying the majority of it through grants, though the DWR may be more involved than just paying Kent's salary. In any case, I think it'll be a worthwhile project if it helps us learn how to save and grow the moose population in Utah and elsewhere. In general, all species of moose in North America are suffering from decreasing numbers.
Here's the 2013 Report: (Edited by myself for clarity and easier reading.)
Introduction
Recent fluctuations in Utah's moose population prompted a collaborative study between the Utah Division of Wildlife Resources (UDWR) and Utah State University (USU) to investigate the demographic rates and population dynamics of the state's moose herds. Specifically, we seek to answer the following questions:
1) What are the sources of variation in moose population growth rates in Utah?
2) What are the demographic rates of two herds in Utah, and what is driving differences between them?
To answer the first question, researchers at USU will analyze a 50+ year time series of UDWR aerial moose counts to determine the effects of climate and weather patterns, moose density, hunter harvest, and plant phenology on moose population growth rate.
To answer the second question, UDWR deployed VHF radio collars on 120 moose in two study areas/management units: the North Slope of the Uinta Range and the Wasatch Mountains. Collared moose will be monitored between 2013 and 2016 to estimate the following demographic rates: pregnancy rates, calving and twinning rates, timing of calving, recruitment, and survival.
Our working hypothesis is that moose herds are currently at or above carrying capacity and are being regulated by density-dependent resource limitation.
Information from this study will help to set and achieve sound management objectives for the persistence Utah's moose herds.
Methods
Capture
120 female moose were captured in January and February 2013 by Quicksilver Air, Inc. However, one moose has never been detected and had no capture data recorded, so whether that collar was actually deployed is in question. Thus, the actual collared sample may have only been 119. One additional collar is believed to have slipped shortly after capture. There have been 17 mortalities since the time of capture, leaving a maximum of 102 collars currently on air.
During captures, each moose was fitted with a Sirtrack VHF radio collar, and a blood sample was obtained for nutritional condition and pregnancy assessment. In addition, the following measurements were recorded: neck circumference, hind foot length, metatarsus length, body length , and chest girth. On a subset of moose ([email protected]), a specialized crew was present to evaluate body condition using ultrasonography. For 43 of the moose with ultrasonographic measurements, an incisor was removed to determine age. Only a portion of the micronutrient results from blood samples were available at the time of writing but some preliminary results are present.
Telemetry Monitoring
Aerial telemetry monitoring took place every 1-3 months after initial captures, with monthly flights scheduled to continue for the duration of the study. A crew of 3 technicians monitored moose biweekly from the ground between 6 May 2013 and 20 August 2013. The ground crew attempted to detect signals from each moose every other week throughout the summer and conducted calving surveys to detect the presence of calves with radiocollared female moose throughout the summer months. If a mortality signal was detected, crews located the animal as soon as possible to try to determine cause of death. From each dead moose, we collected samples of internal organs for lab analysis if the carcass was in sufficient condition. We also took a sample of femur bone marrow fat and pulled the first incisor for aging if it was not pulled at the time of capture. We also inspected the carotid arteries for presence of Elaeophora schneideri *(From Lee: seen footnote at the end of this post.) and noted external parasite loads. Ground and aerial monitoring will continue until at least 2016.
Preliminary Results
Age structure
The l4 (left #4) incisor was pulled on 43 moose during captures to allow aging using cementum annuli by Matson Laboratory LLC. In addition, age data are available for 7 other collared moose that died, bringing the total age-sample to 50. Ages at the time of capture ranged from 0.5 years to 13.5 years with a mean of 5.5 years (From Lee: see Table #1). The age structure reveals a herd consisting mostly of prime-aged individuals, with very few older individuals. We will continue to collect incisors from all dead moose to send to the lab for aging.
Table #1: Age structure for all aged moose at capture:
Age 0.5 years - 1
Age 1.5 years - 3
Age 2.5 years - 7
Age 3.5 years - 5
Age 4.5 years - 5
Age 5.5 years - 8
Age 6.5 years - 8
Age 7.5 years - 5
Age 8.5 years - 2
Age 9.5 years - 4
Age 10.5 years - 1
Age 11.5 years - 0
Age 12.5 years - 0
Age 13.5 years - 1
Pregnancy
An adequate blood sample was obtained for 113 moose during captures. Blood samples were assessed for pregnancy status using blood serum assays. Pregnancy rates between the Wasatch and North Slope units are very similar (Table #2). Overall, the pregnancy rate is lightly lower than the species-wide average of 84%, as well as reported pregnancy rates of Shiras moose in Wyoming which were greater than 90% (Becker 2008 ) However, pregnancy rates of prime-aged cows in our study were very high (94%, Table #3) and differed little between the two units. Because pregnancy rates are highly dependent on age, valid comparisons of pregnancy rates should always consider the effect of age.
Table #2: Overall moose pregnancy rates in 2013:
Wasatch-# tested-55-pregnant-41 = 74.5%
North Slope-# tested-58-pregnant-44 = 75.9%
Total-# tested-113-pregnant-85 = 75.2%
Table #3: Age specific moose pregnancy rates per each unit:
Young (1.5 to 2.5 years)
Wasatch-# tested-4-pregnant-1 = 25%
North Slope-# tested-5-pregnant-3 = 60%
Total-#tested-9-pregnant-4 = 44.4%
Prime (3.5 to 8.5 years)
Wasatch-# tested-11-pregnant-10 = 91.0%
North Slope-# tested-21-pregnant-20 = 95.2%
Total-# tested-33-pregnant-31 = 93.9%
Old (9.5 to 13.5 years)
Wasatch-# tested-0
North Slope-# tested-2-pregnant-1 = 50%
Total-# tested-2-pregnant-1 = 50%
(From Lee: The numbers on Table #3 don't match the text numbers, but the point is that prime-aged cow moose are by far the most prolific reproducers.)
We acquired age-specific pregnancy rates for 50 moose . Individuals aged 0.5 to 2.5 years ([email protected]) had very low pregnancy rates (36%) which likely indicates reproductive immaturity before age 3. Individuals between 3.5 to 8.5 years ([email protected]) had very high rates of pregnancy (94%). Individuals older than 8.5 years ([email protected]) showed very low pregnancy rates, a likely consequence of reproductive senescence.
Gasaway (1992) reviewed moose reproduction across North America and found pregnancy rates declined as populations approached and exceeded carrying capacity. The pregnancy rates of our study (75%) are comparable to populations near carrying capacity of the studies reviewed by Gasaway (1992)(76%-85%). However, per the study Boer (1992), if we only consider adult moose older than 2 years, pregnancy rates in our study are 80%.
Calving/Twinning
Calving rates were low in both study areas (Table #4), though the low rates may partly result from survey methodology. Since calf surveys took place between May and August, it is likely that some calves died before surveys occurred. Thus, all calving rates represent a minimum. In addition, we focused calf searches on pregnant females. If a cow was determined to be non-pregnant, it was treated as non-calving. All calf searches were conducted from the ground by homing in on each radiocollared cow to determine presence of calves. Surveys were only considered valid if observers had lengthy, unobstructed views of the cow. When possible, surveys were repeated on cows observed without a calf.
Table #4: Moose calving rates in 2013
Wasatch - #surveyed-51-with calf-14-without calf-37 = 27.5%
North Slope - #surveyed-48-with calf-26-without calf-22 = 54.2%
Total - #surveyed-99-with calf-40-without calf-59 = 40.4%
Twinning rates were extremely low in both areas, with only one set of twins documented in the Wasatch Unit and zero documented in the North Slope Unit.
Although few data were available, we estimated a mean calving date of 29 May.
Mortality
A total of 17 moose (8 in the North Slope, 9 in the Wasatch) died between capture and December 2013 (Table #5). Annual survival rates for both units combined were around 85% and were not significantlydifferent between the Wasatch and North Slope units.
Table#5: Summary of moose mortalities in 2013 (From Lee: ID numbers are from the radio frequencies. The dates are the first date of the dead/none movement signal.)
North Slope:
ID#-031-Date-3/15-Note-Femur bone marrow very poor.
ID#-742-Date-3/27-Note-Moose sick at time of capture.
ID#-700-Date-4/15-Note-Depleted bone marrow in femur. Mostly consumed by scavengers.
ID#-570-Date-5/16-Note-Emaciated, very poor bone marrow. Impaction in upper jaw with infection.
ID#-928-Date-5/22-Note-Tangled in barbed wire fence.
ID#-772-Date-8/12-Note-Injury to right front ankle with swelling. Bear scat at carcass.
ID#-802-Date-8/14-Note-Bone marrow solid, no injuries.
ID#-129-Date-11/12-Note-Emaciated, no body fat. Gelatinous marrow. Pus pocket in hind quarter.
Wasatch:
ID#-440-Date-4/10-Note-Possible capture myopathy
ID#-649-Date-4/10-Note-Emaciated, poor bone marrow. No kidney fat.
ID#-170-Date-4/18-Note-No kidney fat, many ticks.
ID#-561-Date-5/14-Note-Yearling. Very poor bone marrow.
ID#-501-Date-6/12-Note-Tangled in fence.
ID#-100-Date-7/01-Note-Bone marrow indicated good condition.
ID#-661-Date-8/03-Note-Very dried out, unable to collect samples.
ID#-160-Date-8/15-Note-Carcass intact but only bones /hide left.
ID#-672-Date-11/19-Note-Carcass not yet visited. (Location not certain.)
Recruitment
Recruitment surveys are scheduled to take place in March 2014 by helicopter. Multiple observers will be present to document calf presence for each radiocollared female moose.
Body Condition
Rump fat is a strong predictor of overall ingesta-free body fat in moose (Stephenson et al. 1998 ), which is accumulated during summer months and subsequently utilized for overwinter survival and reproduction costs (Parker et al. 2009, Monteith et al. 2013). Rump fat depths in the study ranged from 0 to 21mm, with a mean maximum rump fat depth of 4.47 mm (51 moose, see Table #6). Seventeen of 51 moose (33%) had a rump fat depth of zero. Rump fat depths between the Wasatch and North Slope herds were very similar and were not statistically different between units even after controlling for age and body size. Rump fat depths generally increased with age.
Table #6 : Rump fat depths in both units (51 moose).
Fat depth-0mm-# of moose-33
Fat depth-1mm-# of moose-2
Fat depth-2mm-# of moose-4
Fat depth-3mm-# of moose-1
Fat depth-4mm-# of moose-4
Fat depth-5mm-# of moose-5
Fat depth-6mm-# of moose-2
Fat depth-7mm-# of moose-2
Fat depth-8mm-# of moose-6
Fat depth-9mm-# of moose-1
Fat depth-10mm-# of moose-2
Fat depth-11mm-# of moose-2
Fat depth-13mm-# of moose-1
Fat depth-15mm-# of moose-1
Fat depth-21mm-# of moose-1
However, moose in this study had winter rump fat depths that were considerably lower than what has been reported in other studies of moose across their North American distribution (Table #7). This analysis is restricted to only adult female moose sampled during the winter to allow for valid comparisons. However, since other subspecies of moose are larger than Utah (Shiras) moose, it is uncertain how much of the variation in rump fat depths rangewide can be explained in differences in body size. We are working on acquiring body size data to control for the effect of body size in this analysis.
Table #7: Comparison of adult female moose winter rump fat depths rangewide, 1998-2013.
-Alaska-Keetch at al 1998 - Maximum rump fat depth-1.5cm
-Alaska-Testa and Adams 1998 - Maximum rump fat depth-3.5cm
-Alaska-Bertram and Vivion 2002 - Maximum rump fat depth - 1.3cm
-Alaska-Boertje et al 2007 - Maximum rump fat depth-1.2cm
-Minnesota-DelGiudice et al 2011 - Maximum rump fat depth-2.2cm
-Utah-This study - Maximum rump fat depth-0.5cm
Micronutrient Data
Only a portion of the nutritional results were available at the time of writing. Analysis of plasma for trace element content revealed that many Utah moose are deficient in copper, zinc and selenium. Copper and zinc are essential micronutrients for the immune system and selenium (deficiency) has been known to cause reproductive losses and white muscle disease in domestic ruminants (Puls 1998 ).
Logistic regression analysis of the preliminary plasma results revealed that moose with lower selenium were less likely to have calves, but low selenium did not affect pregnancy rates. Wasatch moose had significantly lower selenium content than North Slope moose which may partially explain the low calf output observed in the Wasatch unit, since selenium deficiencies are thought to cause both intrauterine losses and neonate mortality. When all micronutrient results are obtained, a more in depth analysis will be conducted. We will also investigate why selenium is lower in the Wasatch Unit (moose)(Table #8 ), and whether it is due to the amount of selenium in the soil or mediated through differences in vegetative composition between the areas.
Table #8: Selenium content in the North Slope and Wasatch moose with standard errors.
North Slope - Selenium content (in moose) in ppm - 0.07
Wasatch - Selenium content (in moose) in ppm - 0.05
Conclusion
Although it is still early in the study, our hypothesis that moose population growth in Utah is being regulated by density-dependent resource limitation is evidenced by several preliminary results, including low reproductive output (lower than average pregnancy, calving and twinning rates) and poor body condition (low rump fat levels), both of which are indicative of herds exceeding carrying capacity. Ongoing research will seek to clarify this relationship and determine if other factors, ie; climate change, winter tick loads (From Lee, disease) could be contributing to the observed results.
*Elaeophora schneideri:
Arterial worm; cause of eleaophorosis, aka "filarial dermatitis" or "sorehead" in sheep; or "clear-eyed blindness" in elk, is a nematode which infests several mammalian hosts in North America. It is transmitted by horse-flies. Infection in the normal definitive hosts, mule deer or blacktail deer, seldom produces clinical systems. In other hosts, such as sheep, elk, moose and goats, infecton with E. schneideri leads to elaeophorosis. Symptoms of elaeophorosis include necrosis of the muzzle, ears and optic nerves; lack of coordination (ataxia); or lower limb dermatitis; horn deformitives; blindness; and death.
From Lee: Basically the problem comes from some of the adult worms (2.17in to 4.72in long) lodging in the smaller arteries in the head and face of elk, moose, sheep and goats, instead of moving to the larger carotid artery as they normally do in deer.
Thanks for viewing! I'll post the 1014 report as quickly as I can get to it. It, too, will be in sections.
Lee (UWC)
PS: I'm sorry about the smiley face, but the number 8 followed by the right side ) produces it automatically. I'll figure out how to remove it later.
The reports are a bit long and have several charts, graphs and tables, and a bunch of scientific wording, so I'll have to take a few days to post both reports before posting the current updates. And I may have to do it in sections, please be patient and wait until both reports are complete before commenting. (If any of you want the original reports, please email me at [email protected]) Thanks, Lee (UWC)
First off, a bit of background on the project and the administrators:
The project is called "Determinants of Population Growth in Utah Moose" and was initiated by Joel Rupercht, a student of Utah State University as his masters project. He is assisted by his advisor, Dan MacNulty, Phd, Wildlife Ecology, USU faculty, Wildland Resources Dept., and by Kent Hersey, Big Game Project Leader, UDWR. There are other USU students also doing some of the groundwork. I don't know the financial details, but I think we can assume that USU is paying the majority of it through grants, though the DWR may be more involved than just paying Kent's salary. In any case, I think it'll be a worthwhile project if it helps us learn how to save and grow the moose population in Utah and elsewhere. In general, all species of moose in North America are suffering from decreasing numbers.
Here's the 2013 Report: (Edited by myself for clarity and easier reading.)
Introduction
Recent fluctuations in Utah's moose population prompted a collaborative study between the Utah Division of Wildlife Resources (UDWR) and Utah State University (USU) to investigate the demographic rates and population dynamics of the state's moose herds. Specifically, we seek to answer the following questions:
1) What are the sources of variation in moose population growth rates in Utah?
2) What are the demographic rates of two herds in Utah, and what is driving differences between them?
To answer the first question, researchers at USU will analyze a 50+ year time series of UDWR aerial moose counts to determine the effects of climate and weather patterns, moose density, hunter harvest, and plant phenology on moose population growth rate.
To answer the second question, UDWR deployed VHF radio collars on 120 moose in two study areas/management units: the North Slope of the Uinta Range and the Wasatch Mountains. Collared moose will be monitored between 2013 and 2016 to estimate the following demographic rates: pregnancy rates, calving and twinning rates, timing of calving, recruitment, and survival.
Our working hypothesis is that moose herds are currently at or above carrying capacity and are being regulated by density-dependent resource limitation.
Information from this study will help to set and achieve sound management objectives for the persistence Utah's moose herds.
Methods
Capture
120 female moose were captured in January and February 2013 by Quicksilver Air, Inc. However, one moose has never been detected and had no capture data recorded, so whether that collar was actually deployed is in question. Thus, the actual collared sample may have only been 119. One additional collar is believed to have slipped shortly after capture. There have been 17 mortalities since the time of capture, leaving a maximum of 102 collars currently on air.
During captures, each moose was fitted with a Sirtrack VHF radio collar, and a blood sample was obtained for nutritional condition and pregnancy assessment. In addition, the following measurements were recorded: neck circumference, hind foot length, metatarsus length, body length , and chest girth. On a subset of moose ([email protected]), a specialized crew was present to evaluate body condition using ultrasonography. For 43 of the moose with ultrasonographic measurements, an incisor was removed to determine age. Only a portion of the micronutrient results from blood samples were available at the time of writing but some preliminary results are present.
Telemetry Monitoring
Aerial telemetry monitoring took place every 1-3 months after initial captures, with monthly flights scheduled to continue for the duration of the study. A crew of 3 technicians monitored moose biweekly from the ground between 6 May 2013 and 20 August 2013. The ground crew attempted to detect signals from each moose every other week throughout the summer and conducted calving surveys to detect the presence of calves with radiocollared female moose throughout the summer months. If a mortality signal was detected, crews located the animal as soon as possible to try to determine cause of death. From each dead moose, we collected samples of internal organs for lab analysis if the carcass was in sufficient condition. We also took a sample of femur bone marrow fat and pulled the first incisor for aging if it was not pulled at the time of capture. We also inspected the carotid arteries for presence of Elaeophora schneideri *(From Lee: seen footnote at the end of this post.) and noted external parasite loads. Ground and aerial monitoring will continue until at least 2016.
Preliminary Results
Age structure
The l4 (left #4) incisor was pulled on 43 moose during captures to allow aging using cementum annuli by Matson Laboratory LLC. In addition, age data are available for 7 other collared moose that died, bringing the total age-sample to 50. Ages at the time of capture ranged from 0.5 years to 13.5 years with a mean of 5.5 years (From Lee: see Table #1). The age structure reveals a herd consisting mostly of prime-aged individuals, with very few older individuals. We will continue to collect incisors from all dead moose to send to the lab for aging.
Table #1: Age structure for all aged moose at capture:
Age 0.5 years - 1
Age 1.5 years - 3
Age 2.5 years - 7
Age 3.5 years - 5
Age 4.5 years - 5
Age 5.5 years - 8
Age 6.5 years - 8
Age 7.5 years - 5
Age 8.5 years - 2
Age 9.5 years - 4
Age 10.5 years - 1
Age 11.5 years - 0
Age 12.5 years - 0
Age 13.5 years - 1
Pregnancy
An adequate blood sample was obtained for 113 moose during captures. Blood samples were assessed for pregnancy status using blood serum assays. Pregnancy rates between the Wasatch and North Slope units are very similar (Table #2). Overall, the pregnancy rate is lightly lower than the species-wide average of 84%, as well as reported pregnancy rates of Shiras moose in Wyoming which were greater than 90% (Becker 2008 ) However, pregnancy rates of prime-aged cows in our study were very high (94%, Table #3) and differed little between the two units. Because pregnancy rates are highly dependent on age, valid comparisons of pregnancy rates should always consider the effect of age.
Table #2: Overall moose pregnancy rates in 2013:
Wasatch-# tested-55-pregnant-41 = 74.5%
North Slope-# tested-58-pregnant-44 = 75.9%
Total-# tested-113-pregnant-85 = 75.2%
Table #3: Age specific moose pregnancy rates per each unit:
Young (1.5 to 2.5 years)
Wasatch-# tested-4-pregnant-1 = 25%
North Slope-# tested-5-pregnant-3 = 60%
Total-#tested-9-pregnant-4 = 44.4%
Prime (3.5 to 8.5 years)
Wasatch-# tested-11-pregnant-10 = 91.0%
North Slope-# tested-21-pregnant-20 = 95.2%
Total-# tested-33-pregnant-31 = 93.9%
Old (9.5 to 13.5 years)
Wasatch-# tested-0
North Slope-# tested-2-pregnant-1 = 50%
Total-# tested-2-pregnant-1 = 50%
(From Lee: The numbers on Table #3 don't match the text numbers, but the point is that prime-aged cow moose are by far the most prolific reproducers.)
We acquired age-specific pregnancy rates for 50 moose . Individuals aged 0.5 to 2.5 years ([email protected]) had very low pregnancy rates (36%) which likely indicates reproductive immaturity before age 3. Individuals between 3.5 to 8.5 years ([email protected]) had very high rates of pregnancy (94%). Individuals older than 8.5 years ([email protected]) showed very low pregnancy rates, a likely consequence of reproductive senescence.
Gasaway (1992) reviewed moose reproduction across North America and found pregnancy rates declined as populations approached and exceeded carrying capacity. The pregnancy rates of our study (75%) are comparable to populations near carrying capacity of the studies reviewed by Gasaway (1992)(76%-85%). However, per the study Boer (1992), if we only consider adult moose older than 2 years, pregnancy rates in our study are 80%.
Calving/Twinning
Calving rates were low in both study areas (Table #4), though the low rates may partly result from survey methodology. Since calf surveys took place between May and August, it is likely that some calves died before surveys occurred. Thus, all calving rates represent a minimum. In addition, we focused calf searches on pregnant females. If a cow was determined to be non-pregnant, it was treated as non-calving. All calf searches were conducted from the ground by homing in on each radiocollared cow to determine presence of calves. Surveys were only considered valid if observers had lengthy, unobstructed views of the cow. When possible, surveys were repeated on cows observed without a calf.
Table #4: Moose calving rates in 2013
Wasatch - #surveyed-51-with calf-14-without calf-37 = 27.5%
North Slope - #surveyed-48-with calf-26-without calf-22 = 54.2%
Total - #surveyed-99-with calf-40-without calf-59 = 40.4%
Twinning rates were extremely low in both areas, with only one set of twins documented in the Wasatch Unit and zero documented in the North Slope Unit.
Although few data were available, we estimated a mean calving date of 29 May.
Mortality
A total of 17 moose (8 in the North Slope, 9 in the Wasatch) died between capture and December 2013 (Table #5). Annual survival rates for both units combined were around 85% and were not significantlydifferent between the Wasatch and North Slope units.
Table#5: Summary of moose mortalities in 2013 (From Lee: ID numbers are from the radio frequencies. The dates are the first date of the dead/none movement signal.)
North Slope:
ID#-031-Date-3/15-Note-Femur bone marrow very poor.
ID#-742-Date-3/27-Note-Moose sick at time of capture.
ID#-700-Date-4/15-Note-Depleted bone marrow in femur. Mostly consumed by scavengers.
ID#-570-Date-5/16-Note-Emaciated, very poor bone marrow. Impaction in upper jaw with infection.
ID#-928-Date-5/22-Note-Tangled in barbed wire fence.
ID#-772-Date-8/12-Note-Injury to right front ankle with swelling. Bear scat at carcass.
ID#-802-Date-8/14-Note-Bone marrow solid, no injuries.
ID#-129-Date-11/12-Note-Emaciated, no body fat. Gelatinous marrow. Pus pocket in hind quarter.
Wasatch:
ID#-440-Date-4/10-Note-Possible capture myopathy
ID#-649-Date-4/10-Note-Emaciated, poor bone marrow. No kidney fat.
ID#-170-Date-4/18-Note-No kidney fat, many ticks.
ID#-561-Date-5/14-Note-Yearling. Very poor bone marrow.
ID#-501-Date-6/12-Note-Tangled in fence.
ID#-100-Date-7/01-Note-Bone marrow indicated good condition.
ID#-661-Date-8/03-Note-Very dried out, unable to collect samples.
ID#-160-Date-8/15-Note-Carcass intact but only bones /hide left.
ID#-672-Date-11/19-Note-Carcass not yet visited. (Location not certain.)
Recruitment
Recruitment surveys are scheduled to take place in March 2014 by helicopter. Multiple observers will be present to document calf presence for each radiocollared female moose.
Body Condition
Rump fat is a strong predictor of overall ingesta-free body fat in moose (Stephenson et al. 1998 ), which is accumulated during summer months and subsequently utilized for overwinter survival and reproduction costs (Parker et al. 2009, Monteith et al. 2013). Rump fat depths in the study ranged from 0 to 21mm, with a mean maximum rump fat depth of 4.47 mm (51 moose, see Table #6). Seventeen of 51 moose (33%) had a rump fat depth of zero. Rump fat depths between the Wasatch and North Slope herds were very similar and were not statistically different between units even after controlling for age and body size. Rump fat depths generally increased with age.
Table #6 : Rump fat depths in both units (51 moose).
Fat depth-0mm-# of moose-33
Fat depth-1mm-# of moose-2
Fat depth-2mm-# of moose-4
Fat depth-3mm-# of moose-1
Fat depth-4mm-# of moose-4
Fat depth-5mm-# of moose-5
Fat depth-6mm-# of moose-2
Fat depth-7mm-# of moose-2
Fat depth-8mm-# of moose-6
Fat depth-9mm-# of moose-1
Fat depth-10mm-# of moose-2
Fat depth-11mm-# of moose-2
Fat depth-13mm-# of moose-1
Fat depth-15mm-# of moose-1
Fat depth-21mm-# of moose-1
However, moose in this study had winter rump fat depths that were considerably lower than what has been reported in other studies of moose across their North American distribution (Table #7). This analysis is restricted to only adult female moose sampled during the winter to allow for valid comparisons. However, since other subspecies of moose are larger than Utah (Shiras) moose, it is uncertain how much of the variation in rump fat depths rangewide can be explained in differences in body size. We are working on acquiring body size data to control for the effect of body size in this analysis.
Table #7: Comparison of adult female moose winter rump fat depths rangewide, 1998-2013.
-Alaska-Keetch at al 1998 - Maximum rump fat depth-1.5cm
-Alaska-Testa and Adams 1998 - Maximum rump fat depth-3.5cm
-Alaska-Bertram and Vivion 2002 - Maximum rump fat depth - 1.3cm
-Alaska-Boertje et al 2007 - Maximum rump fat depth-1.2cm
-Minnesota-DelGiudice et al 2011 - Maximum rump fat depth-2.2cm
-Utah-This study - Maximum rump fat depth-0.5cm
Micronutrient Data
Only a portion of the nutritional results were available at the time of writing. Analysis of plasma for trace element content revealed that many Utah moose are deficient in copper, zinc and selenium. Copper and zinc are essential micronutrients for the immune system and selenium (deficiency) has been known to cause reproductive losses and white muscle disease in domestic ruminants (Puls 1998 ).
Logistic regression analysis of the preliminary plasma results revealed that moose with lower selenium were less likely to have calves, but low selenium did not affect pregnancy rates. Wasatch moose had significantly lower selenium content than North Slope moose which may partially explain the low calf output observed in the Wasatch unit, since selenium deficiencies are thought to cause both intrauterine losses and neonate mortality. When all micronutrient results are obtained, a more in depth analysis will be conducted. We will also investigate why selenium is lower in the Wasatch Unit (moose)(Table #8 ), and whether it is due to the amount of selenium in the soil or mediated through differences in vegetative composition between the areas.
Table #8: Selenium content in the North Slope and Wasatch moose with standard errors.
North Slope - Selenium content (in moose) in ppm - 0.07
Wasatch - Selenium content (in moose) in ppm - 0.05
Conclusion
Although it is still early in the study, our hypothesis that moose population growth in Utah is being regulated by density-dependent resource limitation is evidenced by several preliminary results, including low reproductive output (lower than average pregnancy, calving and twinning rates) and poor body condition (low rump fat levels), both of which are indicative of herds exceeding carrying capacity. Ongoing research will seek to clarify this relationship and determine if other factors, ie; climate change, winter tick loads (From Lee, disease) could be contributing to the observed results.
*Elaeophora schneideri:
Arterial worm; cause of eleaophorosis, aka "filarial dermatitis" or "sorehead" in sheep; or "clear-eyed blindness" in elk, is a nematode which infests several mammalian hosts in North America. It is transmitted by horse-flies. Infection in the normal definitive hosts, mule deer or blacktail deer, seldom produces clinical systems. In other hosts, such as sheep, elk, moose and goats, infecton with E. schneideri leads to elaeophorosis. Symptoms of elaeophorosis include necrosis of the muzzle, ears and optic nerves; lack of coordination (ataxia); or lower limb dermatitis; horn deformitives; blindness; and death.
From Lee: Basically the problem comes from some of the adult worms (2.17in to 4.72in long) lodging in the smaller arteries in the head and face of elk, moose, sheep and goats, instead of moving to the larger carotid artery as they normally do in deer.
Thanks for viewing! I'll post the 1014 report as quickly as I can get to it. It, too, will be in sections.
Lee (UWC)
PS: I'm sorry about the smiley face, but the number 8 followed by the right side ) produces it automatically. I'll figure out how to remove it later.