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Baltimore Oriole

Baltimore Oriole. Ring-Necked Pheasant. State-colored Junco. Great-tailed Grackle. Magnolia Warbler. Blackburnian Warbler. Black-throated Green Warbler. In 2001, more than 1.9 million Minnesota spent $532 million watching wildlife. – 2001 National Survey of Fishing Hunting,

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Baltimore Oriole

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  1. Baltimore Oriole

  2. Ring-Necked Pheasant

  3. State-colored Junco

  4. Great-tailed Grackle

  5. Magnolia Warbler

  6. Blackburnian Warbler

  7. Black-throated Green Warbler

  8. In 2001, more than 1.9 million Minnesota spent $532 million watching wildlife. – 2001 National Survey of Fishing Hunting, and Wildlife-Associated Recreation

  9. Eastern Spruce Budworm • Native phytophagous insect occurring along the North America boreal-forest zone • Preferred plant species are balsamfir and spruce species • Usually present in low numbers, occasionally undergoes large outbreaks • Annually defoliates 5.7 million hectares in eastern United States • Number one forest pest in Canada. Timber losses are estimated at 51 million m3 a year. This is a 1.5 times that of wildfire and a significant proportion of the annual timber harvest volume.

  10. Outbreaks • Population sizes in outbreaks can reach 22 million larvae per hectare and 1.2 million pupae per hectare. High population densities can last from 5-15 years. • High density populations cause >80% loss of new foliage on fir for 4-6 years. This seriously retards the growth or kills the tree. Can kill almost all trees n dense mature stands of fir. • Spruce budworms strongly control therate and direction of succession. Balsam fir has already been eliminated from some western stands. • They contribute significantly to biomass decomposition, carbon cycling, nutrient cycling and energy flow in forest ecosystems. • Outbreak areas have faster cycling of calcium, potassium, nitrogen and phosphorous. • The next major outbreak in Canada is predicted to occur before the year 2000 and could affect 100 million hectares of forest.

  11. Role of Climate/Weather • Drought increases insect survival through elevated plant nutrient levels, lowered plant defenses and a more suitable physical environment • Budworms lay 50% more eggs when the temperature is 25ºC than when is is 15ºC. • Drought stressed plants are average 2-4ºC (+15ºF) warmer than well-watered plants • Drought and higher temperatures allow budworms to escape the control of some of their natural predators. • Moths emigrate at night under specific meteorological conditions Moths typically move 50 to 100 km downwind but havemoved as far as 600 km.

  12. Population Control • Birds consume up to 84% of the larvae and pupae when populations are low, 22% when moderate. Coupled with other predators this can effectively limit the population. They can stop increase and can dampen the seriousness of infestations. • Once larval density reaches 1 million per hectare natural biological control mechanisms are ineffective. • Outbreaks start from many reasons. In New Brunswick they occur approximately every 35 years. Environmental stress, especially drought and warmer springs and summers can trigger outbreaks. • In western portion of range, outbreaks tend to start in mature firs flowering after a hot, dry summer. • Some outbreaks stop for unknown reasons. In the western portion of the range, outbreaks tend to be stopped by late spring frosts.

  13. Population Control • Birds consume up to 84% of the larvae and pupae when populations are low, 22% when moderate. Coupled with other predators this can effectively limit the population. They can stop increase and can dampen the seriousness of infestations. • Once larval density reaches 1 million per hectare natural biological control mechanisms are ineffective. • Outbreaks start from many reasons. In New Brunswick they occur approximately every 35 years. Environmental stress, especially drought and warmer springs and summers can trigger outbreaks. • In western portion of range, outbreaks tend to start in mature firs flowering after a hot, dry summer. • Some outbreaks stop for unknown reasons. In the western portion of the range, outbreaks tend to be stopped by late spring frosts.

  14. Climate Change • Increasing temperatures and drought probability stress boreal forest species and set up an increasing likelihood of outbreaks. • Control of outbreaks breaks down. Natural predators are impacted greater than budworms are. • Alberta, Saskatchewan and Manitoba are all susceptible to drought – most warblers will be lost. • Probability of late spring frosts declines – outbreaks last longer. • Wind speed might increase spreading the spruce budworm moths over a greater area (the average wind speed in the central boreal forest of northwestern Ontario has already increased 50%). • Spruce budworms ca readily adapt to changing conditions. They will be able to follow the migration of the forests. • Outbreak may extend over 72 million ha and contain 7 x 1015 insects. Even with a mutation rate of 10-5/generation, billions of rare alleles will likely be present in the population.

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