Progress 07/01/09 to 06/30/12
Outputs
OUTPUTS: Over the course of this project, studies were designed to test the effect of of environmentally relevant agrochemical and environmental contaminants on birds and on their ability to migrate. Homing pigeons were used as the model for migratory birds. This model has been developed and tested at the University of Nevada, Reno by this laboratory group for several years. Methylmercury was the environmental contaminant selected for testing in this set of studies as it is a very important and pervasive contaminant found throughtout the U.S. and Nevada. Experiments were initially conducted to determine relevant exposure dosages through drinking water which would impact the birds flight ability. As part of these studies, food and water consumption were monitored throughout the study in order to not only accurately determine dosage but to evaluate water and food consumption during periods of different activities such as migration. Food and water consumption were also evaluated and correlated to temperature and humidity factors. Subsequent studies were conducted on the offspring of parents either exposed or not exposed to methylmercury. These studies revealed that the offspring of parents exposed to methylmercury initially had more difficulty in learning how to "home" back to their loft. Once the exposed offspring birds learned how to "home" to the loft from a given release site, they then were able to do so in subsequent releases very similar to non-exposed offspring. These results provide us with insights into how methylmercury may be affecting these birds learning abilities and what future studies may be most informative. these results have been presented at several national meetings and field days, describing not only the specific results but the use of the homing pigeons as model for migratory birds. Publications on these results are forthcoming. PARTICIPANTS: Chris A. Pritsos (P.I.) John K. Moye Project Manager Cristina Perez - Graduate Student Dr. Michael Hooper, USGS Columbia, MO USGS, Environmental Research Center, Columbia MO TARGET AUDIENCES: Target audiences include research scientists, regulators, environmental agencies and industry persons whose operation may contribute to teh contamination of environmentally sensitive land. PROJECT MODIFICATIONS: No major changes to report during this reporting period.
Impacts
The results from this study have had generated significant data relevant to the impact of environmental exposures on avain species, particularly during migration. The studies have monitored water consumption during periods of times when our birds have been flying long distances over multiple days, thus mimicking migratory behavior. The results have shown that immediately upon returning to the loft after a long flight, the birds consumed large quantities of water which far exceed water consumption during caged periods of time. This suggests that water consumption estimates from contaminated sites for the purposes of risk assessment should take this into consideration and not use water consumption values obtained from caged birds. Most importantly, we have been developing our homing pigeon model as one which would be beneficial for Natural Resource Damage Assessment (NRDA) of Avain species. We are currently working with the Dept of Interior, U.S. Fish and Wildlife Service in using our model in their avain toxicity NRDA associated with the oil spills.
Publications
- No publications reported this period
|
Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: This project has now entered its third year. Previous work has assessed the impact of methylmercury exposure on flight time in homing pigeons. These studies begin to expand upon these previous studies by focusing on the impact on offspring of methylmercury exposed birds. Mercury is one of the most common metals found in contaminated ecosystems. It occurs naturally, but high levels found in contaminated areas derive from human use practices. Among the most vulnerable species to exposure are birds that live, nest, or feed in or near these contaminated ecosystems. Conventional avian toxicology models have shown impairment of cognitive skills from exposure to levels higher than those generally considered environmentally relevant, but little work has been conducted on low-level exposure effects. Because of the known neurological effects of mercury on birds, it is hypothesized that effects upon migratory ability would be evident after exposure to low levels of this metal, and effects may be exacerbated in young birds. Difficulties in following mercury exposed birds once they migrate away from contaminated areas have left investigators with insufficient data to establish exposure levels causing injury of migratory species due to migration disruption. Thus, we believe that our homing pigeon model (Columba livia) would be ideal for these studies. Breeding pigeons were exposed to ~1.0 mg/kg/day methylmercury via the drinking water for 2 weeks prior to breeding. First round offspring were trained to home after fledging, while also continually exposed to the same level of methylmercury in their water. The young pigeons were released individually for three flights, and flight times were assessed and compared to control young pigeon flight times from 3.5, 9, 21, 53, 65, and 98 air miles as well as two individual flights at ~50 air miles from multiple directions. PARTICIPANTS: Dr. Chris A. Pritsos is the P.I. of the project and responsible for all aspects of the project. Mr. John K. Moye research faculty is responsible for hte mainenance of the pigeon facility, training the birds and conducting experiments. Ms. Cristina Perez, student worker contributes to teh project by helping maintain the pigeons and loft and helping with the experiments. TARGET AUDIENCES: Target audiences include other research scientists, regulators and industry persons whose operation may contribute to the contamination of environmentally sensitive land. PROJECT MODIFICATIONS: No major changes to report during this reporting period.
Impacts
Data has been collected and analyzed for these studies on offspring of methylmercury exposed birds. The young pigeons were released individually for three flights, and flight times were assessed and compared to control young pigeon flight times from 3.5, 9, 21, 53, 65, and 98 air miles as well as two individual flights at ~50 air miles from multiple directions from the loft. The results of these studies show that offspring of methylmercury exposed birds are impaired in their ability to navigate back to the loft compared to offspring of non-exposed birds. In each set of experiments, birds were individually released and allowed to fly out of sight prior to the next bird being released. This allowed for each bird to be individually assessed for their ability to navigate back to the loft. The results showed that upon the first release from any specific release sight the birds from exposed parents had a more difficult time in returning to the loft (increased flight time). In subsequent releases from the same site, the birds were able to navigate back faster and more comparable to the rate of return of the control birds. This suggests that these birds have difficulty initially in navigating home when faced with unfamiliar surroundings but once having completed the flight and establishing landmarks etc, they are able to navigate back much more easily. This may imply that different aspects of navigation are impaired through exposure to methylmercury through the parents. When birds were taken out in a completely different direction from the loft and released, similar results were observed between the exposed and non-exposed young birds as was observed in the previously discussed studies.
Publications
- John K. Moye, Cristina R. Perez, and Chris A. Pritsos "Effects of Parental and Direct Methylmercury Exposure on Flight Activity in Young Homing Pigeons (Columba livia)" Society of Toxicology National Meeting March 11-15, 2012, San Francisco, CA.
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: This project has now entered its second year. Work continued on our dose escalation studies with methyl mercury exposure on flight time in homing pigeons. Birds had been trained out to 60 miles distance from the loft and control times had been established for each bird. The homing pigeons were then divided into two groups (control and methyl mercury exposed). Methyl mercury was dissolved in the drinking water of the exposed group at a concentration of 0.8 ppm. Birds remained on each dosage for 2 weeks and were flown on days 3,8 and 13. Dosages were increased every two weeks logarithmically. Flight times for both exposed and control birds were monitored for comparisons. Flights continued until a significant affect was observed on flight time. During the training period and studies, water consumption was monitored daily as well. The dose escalation studies continued for (5) two week periods with the final methyl mercury dose reaching 59.7 ppm in the water. At the end of this period, control and experimental birds were euthanized and methyl mercury levels determined in blood, liver, brain and kidney tissues. Water consumption data was monitored daily throughout the training and experimental studies. Water consumption measurements were divided into three categories: flight, fasted and non-flight days. Temperature and humidity was monitored daily. The impact of temperature and humidity were assessed on water consumption. For flight days, flight distance was assessed for its affect on water consumption. Water consumption studies continued throughout the remainder of the year. The results of some of these findings were presented as an invited talk at the 17th Annual conference of the Wildlife Society in Snowbird, Utah in October of 2010. In the latter part of the year, birds were allowed to mate in order to increase the flock size for future studies. PARTICIPANTS: Dr. Chris A. Pritsos is the P.I. of the project and is responsible for all aspects of the project. Mr. John Moye, research faculty is responsible for the maintenance of the pigeon facility, training the birds and conducting experiments. Ms. Christina Perez - Student worker contributes to the project by helping maintain the pigeons and the loft and helping with studies. Dr. Michael Hooper, USGS, Columbia, MO. Contributes to the experimental design of the project. TARGET AUDIENCES: Target audiences include other research scientists, (toxicologists, wildlife biologists and environmental scientists), regulators and industry persons whose operations may contribute to the contamination of environmentally sensitive land. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Data has been collected and analyzed for the methyl mercury dose escalation studies as well as the water consumption studies conducted during this past year. These studies are designed to evaluate the impact of environmental exposures on migratory birds, using the homing pigeon as a migratory bird model. The methyl mercury dose escalation studies were designed to provide preliminary data as to the short-term dosage level required to elicit an impact on flight time in the homing pigeons. Flight time began to significantly increase in the exposed birds beginning with flights during the fourth level of exposure at about 20.4 ppm methyl mercury and continued into the fifth level of exposure at around 60 ppm methyl mercury in the drinking water. Tissue analyses showed high levels of mercury in the blood, liver brain and kidney tissues of these birds with kidney showing the greatest mercury concentrations. These results begin to give us an idea of the tissue distribution of mercury when ingested through drinking water in these birds. Perhaps some of the most interesting data is the water consumption data collected in a series of experiments during the year. Water consumption was collected during various activity periods for the birds it was believed that water consumption would be increased during periods of activity such as long flights. Water consumption was divided into three periods, caged (non-flight days), flight days and food/fasted days which included those days immediately prior to flight when birds were taken off their food the night before flight as part of their flight day regimen. The results showed that water consumption significantly increased on flight days over the other two scenarios while caged days were slightly higher than food/fasted days. Water consumption was also shown to be increased with increasing temperature. A positive linear correlation was observed between flight distance and water consumption. These results will be useful for regulators who are trying to assess the impact of environmental exposures on migratory bird populations. Previous water consumption data has been limited to a few species under caged conditions. Our studies are showing that water consumption greatly increases under flight conditions like that seen during migration. These results will be important when generating a Natural Resource Damage Assessment (NRDA) for a contaminated water source. Assessment should consider not only the contaminant level but whether affected species include migratory birds, which may be drinking at a much higher than normal rate.
Publications
- Moye, JK, Hooper, MJ and Pritsos CA. "Impact of flight activity, temperature and humidity on water consumption and time of flight in contol and methylmercury exposed homing pigeons." 17th Annual Wildlife Society Meeting, Snowbird, UT October 2-6 2010.
|
Progress 07/01/09 to 12/31/09
Outputs
OUTPUTS: In the first 6 months of this project, we focused on setting up our pigeon facility to accomodate the daily dosing of birds to environmental contaminants such as lead acetate and methyl mercury dissolved in their drinking water. These exposures neccessitate additional environmental safety precautions not previously necessary in our studies. Working together with the UNR Environmental Safety and Health Office as well as the Institutional Animal Care and Use Committee (IACUC) we transformed our lofts to accomodate these exposures as well as receiving appropriate approvals to conduct the studies. Initial studies have focused on the exposure of these birds to methyl mercury. Birds were trained out to 60 miles distance and flight times for each individual bird from this distance have been established. Experimental birds were divided into two groups, methyl mercury and control group. Methyl mercury was dissolved into the water of the methyl mercury group at a concentration of 2 ppm. Birds remained on each dosage level for two weeks after which the dosage was increased logrithmically. During each 2 week period the birds were flown 3 times (days 3,8 and 13). Flight times were monitored and comparisons made between the exposed and control groups. Only when the flight times were determined to be significantly differnt would the study halt. To date (3 dosage levels) that significant difference in flight time has not been acheived. Once that diffence has been achieved the animals will be sacrificed and blood and tissues collected for mercury and other biological analyses. Another important aspect to this project is the determination of water consumption during the study. Water consumption is being monitored on both flight and non-flight days. PARTICIPANTS: Dr. Chris A. Pritsos is the P.I. of the project and directly responsible for all aspects of the project. Mr. John Moye, research faculty is responsible for the maintenance of the pigeon facility and training of the birds and conducting the experimental work. Karen Pritsos contributes to the experimental work on the projects. TARGET AUDIENCES: Target audiences include other research scientists (toxicologists, wildlife biologists and environmental scientists), regulators and industry persons whose oprations may contribute to the contamination of environmentally sensitive land. PROJECT MODIFICATIONS: There are no major changes to the approach used in this study, however, there will be additional work directed at collecting data relevant to drinking patterns of these birds as they will provide important data which will be relevant to drinking patterns during migration.
Impacts
This study has only been ongoing for 6 months, at the time of this report. The outcomes/impacts thus far are primarily related to the successful conversion of our pigeon facility to accomodate the use of potentially environmentally toxic compounds, lead acetate and methyl mercury. We have however obtained some interesting data relative to water consumption during the training of the birds out to the 60 mile mark. We have observed and quantified differences in water consumption patterns for the birds on flight and non-flight days. These patterns could be very important in assessing water consumption for birds during migration. We have begun assessing this water consumption with temperature and humidity levels as well but have not completed our analyses as yet. We have been in constant contact with the U.S.G.S. who are providing both input and support for the project.
Publications
- No publications reported this period
|
|