Natal origins of migratory monarch butterflies at wintering colonies in Mexico: New isotopic evidence

Each year, millions of monarch butterflies from eastern North America migrate to overwinter in 10–13 discrete colonies located in the Oyamel forests of central Mexico. For decades efforts to track monarch migration have relied on observations and tag-recapture methods, culminating with the discovery of the wintering colonies in 1975. Monarch tag returns from Mexico, however, are few and primarily from two accessible colonies, and therefore tag-recapture techniques have not quantified natal origins or distinctiveness among monarch populations at wintering sites. Such information would be invaluable in the conservation of the monarch and its migration phenomenon since the wintering sites currently are threatened by habitat alteration. Here we show that stable hydrogen (δD) and carbon (δ13C) isotope ratios of wintering monarchs can be used to evaluate natal origins on the summer breeding range. Stable-hydrogen and carbon isotopic values of 597 wintering monarchs from 13 wintering roost sites were compared with isotopic patterns measured in individuals at natal sites across their breeding range over a single migration cycle. We determined that all monarch wintering colonies were composed of individuals originating mainly from the Midwest, United States, thereby providing evidence for a panmictic model of wintering colony composition. However, two colonies showed more northerly origins, suggesting possible priority colonies for conservation efforts.

The earliest archaeological maize (Zea mays L.) from highland Mexico: New accelerator mass spectrometry dates and their implications

Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize.

Das illustrirte Mississippithal : dargestellt in 80 nach der Natur aufgenommenen Ansichten vom Wasserfalle zu St. Anthony an bis zum Golf von Mexico (eine Entfernung von ungefähr 2300 englischen Meilen) /

Cf. Sabin 40807.

The pre-Iroquoian Algonkian Indians of central and western New York,

Half-title.

General Maxwell's Brigade of the New Jersey Contintental Line in the expedition against the Indians in the year 1779 /

Mode of access: Internet.

Strength out of weakness : or A glorious manifestation of the further progress of the gospel among the Indians in New England /

Includes letters from John Eliot, John Wilson, William Leverich, Anthony Bessey, Thomas Mayhew, John Endecott, William French and Thomas Allen. The Epistle dedicatory is signed by William Steele. "To the reader" signed: William Gouge [and seventeen others].

Campbell's new revised complete guide and descriptive book of Mexico /

Includes index.

A descriptive atlas of the Cesnola collection of Cypriote antiquities in the Metropolitan Museum of Art, New York /

Published in 15 parts; v. 1 and 2 in portfolio.

A new and easy method to understand the Roman history : with an exact chronology of the reign of the emperors, an account of the most eminent authors, when they flourished, and an abridgment of the Roman antiquities and customs : by way of dialogue, for the use of the Duke of Burgundy /

Mode of access: Internet.

The seventh great Oriental monarchy ; or The geography, history, and antiquities of the Sassanian or new Persian empire,

Preface dated 1875.

New light on the early history of the greater Northwest. The manuscript journals of Alexander Henry ... and of David Thompson ... 1799-1814. Exploration and adventure among the Indians on the Red, Saskatchewan, Missouri and Columbia rivers.

v. 1. The Red river of the North.--v. 2. The Saskatchewan and Columbia rivers.--v. 3. Index and maps.

America revisited: from the bay of New York to the Gulf of Mexico, and from Lake Michigan to the Pacific.

5th ed.

A new collection of laws, charters and local ordinances of the governments of Great Britain, France and Spain : relating to the concessions of land in their respective colonies, together with the laws of Mexico and Texas on the same subject, to which is prefixed Judge Johnson's translation of Azo and Manuel's Institutes of the civil law of Spain /

Includes index.

Peruvian antiquities,

Mode of access: Internet.