Thogmartin W.E.,U.S. Geological Survey |
Lopez-Hoffman L.,University of Arizona |
Rohweder J.,U.S. Geological Survey |
Diffendorfer J.,U.S. Geological Survey |
And 18 more authors.
Environmental Research Letters | Year: 2017
The eastern migratory population of monarch butterflies (Danaus plexippus plexippus) has declined by >80% within the last two decades. One possible cause of this decline is the loss of ≥1.3 billion stems of milkweed (Asclepias spp.), which monarchs require for reproduction. In an effort to restore monarchs to a population goal established by the US Fish and Wildlife Service and adopted by Mexico, Canada, and the US, we developed scenarios for amending the Midwestern US landscape with milkweed. Scenarios for milkweed restoration were developed for protected area grasslands, Conservation Reserve Program land, powerline, rail and roadside rights of way, urban/suburban lands, and land in agricultural production. Agricultural land was further divided into productive and marginal cropland. We elicited expert opinion as to the biological potential (in stems per acre) for lands in these individual sectors to support milkweed restoration and the likely adoption (probability) of management practices necessary for affecting restoration. Sixteen of 218 scenarios we developed for restoring milkweed to the Midwestern US were at levels (>1.3 billion new stems) necessary to reach the monarch population goal. One of these scenarios would convert all marginal agriculture to conserved status. The other 15 scenarios converted half of marginal agriculture (730 million stems), with remaining stems contributed by other societal sectors. Scenarios without substantive agricultural participation were insufficient for attaining the population goal. Agricultural lands are essential to reaching restoration targets because they occupy 77% of all potential monarch habitat. Barring fundamental changes to policy, innovative application of economic tools such as habitat exchanges may provide sufficient resources to tip the balance of the agro-ecological landscape toward a setting conducive to both robust agricultural production and reduced imperilment of the migratory monarch butterfly. © 2017 IOP Publishing Ltd.
News Article | February 23, 2017
The French military is developing a new, unusual defense weapon to combat terrorism. Four golden eagles, d’Artagnan, Athos, Porthos and Aramis are being trained to attack drones that enter into restricted French air space according to the Washington Post. Terrorists are beginning to experiment with drones in Iraq and the French presidential palace has had numerous drones fly within its restricted air space in recent years. Terrorists are reportedly using store bought drones and turning them into weapons. Jean-Christophe Zimmermann, a French air force general, told Reuters the military chose to use eagles for defense to avoid using guns. If a drone appears in a crowded area, using guns to bring it down becomes extremely risky. A properly trained golden eagle poses no threat to humans and can take down the enemy drone in a safe way. Due to the recent terrorist attacks in France, officials are experimenting with protection mechanisms that are not as life threatening to humans as weapons. About a year ago, the four eagles were placed on top of a drone to hatch and kept there during the early feeding period. As soon as the eagles began drone-defense training, they were rewarded by eating meat attached to the top of a drone. Everything they have been exposed to is anti-drone oriented. Earlier this month, d’Artagnan was in a French military control tower and spotted a practice drone 200 meters away. The bird covered the 200 meters in 20 seconds and rammed into the drone, causing it to fall into the grass. The eagles will be equipped with special equipment on their heads and talons to prevent any damage a drone could do to their body. The use of eagles to take down drones was first used by Dutch police last year, according to the Washington Post. The French Air Force have already ordered a second set of eagles to train. Eagles are known as ferocious attackers and are extremely powerful. Peter Nye, an employee of the New York Department of Environmental Conservation told Journey North in a Q&A session that eagles can fly up to 50 km/hr and have four times better eyesight than humans. The grip of an eagles talons is 10 times stronger than that of an adult human. While the decision to officially use eagles as a defense mechanism is still a few months away, the training is going to be elevated. “Soon they will be casting off from peaks in the nearby Pyrenees Mountains,” said a French air force commander in an interview with Agence France-Presse.
Howard E.,Journey North |
Aschen H.,Port Lavaca |
Davis A.K.,University of Georgia
Psyche | Year: 2010
Members of the public have long had a fascination with the monarch butterfly, Danaus plexippus, because of its amazing long-distance migration to overwintering sites in central Mexico, and many participate in online citizen-science programs where they report observations of its life history in North America. Here, we examine a little-studied aspect of monarch biology, the degree of overwintering in the southern United States. We compiled 9 years of sightings of overwintering monarchs in the southern United States that were reported to Journey North, a web-based citizen science program, to map the distribution of areas where monarchs are capable of surviving during the winter (i.e., in January and February), differentiating between adult sightings and sightings of breeding activity. We also statistically compared the latitudes of adult and breeding sightings, examined differences across years in latitude of sightings, and quantified the number of monarchs reported with each sighting. Of all 254 sightings, 80 came from Florida and Texas, with the remainder coming from South Carolina, Louisiana, Georgia, Alabama, Mississippi, North Carolina, and even one in Virginia. This distribution was generally consistent with the winter range predicted by prior investigators based on climatic conditions of this region. Sightings of adults were on average from higher latitudes than reports of breeding activity and there was significant variation across years in the average latitude of all sightings. The majority of sightings (94.2) were of fewer than 10 adult monarchs per location, and there were no reports of clustering behavior that is typical of monarch overwintering in California and Mexico. The results of this investigation broaden our collective understanding of this stage of the monarch life cycle and, more generally, highlight the value of citizen science programs in advancing science. © 2010 Elizabeth Howard et al.
Davis A.K.,University of Georgia |
Nibbelink N.P.,University of Georgia |
Howard E.,Journey North
International Journal of Zoology | Year: 2012
Monarch butterflies (Danaus plexippus) in eastern North America must make frequent stops to rest and refuel during their annual migration. During these stopovers, monarchs form communal roosts, which are often observed by laypersons. Journey North is a citizen science program that compiles roost observations, and we examined these data in an attempt to identify habitat characteristics of roosts. From each observation we extracted information on the type of vegetation used, and we used GIS and a national landcover data set to determine land cover characteristics within a 10km radius of the roost. Ninety-seven percent of roosts were reported on trees; most were in pines and conifers, maples, oaks, pecans and willows. Conifers and maples were used most often in northern flyway regions, while pecans and oaks were more-frequently used in southern regions. No one landcover type was directly associated with roost sites, although there was more open water near roost sites than around random sites. Roosts in southern Texas were associated primarily with grasslands, but this was not the case elsewhere. Considering the large variety of tree types used and the diversity of landcover types around roost sites, monarchs appear highly-adaptable in terms of roost site selection. © 2012 Andrew K. Davis et al.
Howard E.,Journey North |
Davis A.K.,University of Georgia
Annals of the Entomological Society of America | Year: 2015
Declines in overwintering colonies of monarch butterflies (Danaus plexxipus) in Mexico raise questions about other life cycle phases, such as spring migration, where monarchs recolonize their breeding range in the United States and Canada with sequential generations. We used data from a long-term citizen science program, "Journey North" (now with 18 yr), to identify possible changes to the recolonization. This program asks people to report the date and location when they see the first adult monarch annually, and this database now contains >11,000 records. We examined sighting dates and migration range size, the latter based on the number of 2-degree latitude - longitude grid squares with monarch sightings, to look for evidence of change in either of these two parameters over the 18 yr. Our analyses used regression models that accounted for increasing volunteer participation over the years. We found monarchs are being sighted later at a rate of 1 d later every 4 yr. This does not appear to be related to later emergence of milkweed, based on examination of milkweed reports. Later sightings could be interpreted as a sign of reductions in monarch abundance (it takes longer to see the first monarch of the year). We also found a potential decline in the geographic range of the initial spring migration wave (a decline of 9% over 18 yr). However we detected no change in the continental area encompassed at the end of recolonization, indicating monarchs are still successfully filling their traditional breeding range in eastern North America. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America.