Evidence of Differential Migration by Sex in White-Throated Sparrows (Zonotrichia Albicollis)

Abstract Differential migrants are species in which one population class migrates farther than another. White-throated sparrows (Zonotrichia albicollis), which migrate into the southern United States each autumn in large numbers, have been proposed as a candidate differential migrant (Cristol et al. 1999). Using Bird Banding Lab data, we tested for latitudinal variation in the sex ratio of White-throated Sparrows in the Atlantic and central flyways. We found that the proportion of females increases with decreasing latitude in at least the Atlantic flyway, strongly suggesting that females migrate farther than males. Sex ratios calculated from those banding data were compared to those of museum specimens collected at the same latitudes, as well as single-season population samples at three latitudes in the heart of the winter range. Broad agreement was found using the three independent methods of sampling the sex ratio, so we conclude that White-throated Sparrows are differential migrants.

Download Full-text

Fire Ant Envenomation in Children

PEDIATRICS ◽

10.1542/peds.73.5.689 ◽

1984 ◽

Vol 73 (5) ◽

pp. 689-692

Author(s):

Charles M. Ginsburg

Keyword(s):

United States ◽

Solenopsis Invicta ◽

The United States ◽

Fire Ants ◽

Fire Ant ◽

Southern United States ◽

Solenopsis Richteri ◽

Large Numbers ◽

Scant Attention

Fire ants (Solenopsis richteri and Solenopsis invicta) have received scant attention from individuals other than agriculturists, entomologists, and victims of the bite and sting. Since their original importation into Mobile, Alabama, these small, seemingly benign, creatures have slowly migrated throughout most of the southern United States. Not unexpectedly, physicians working in the southern portions of the United States have been confronted with increasingly large numbers of patients, particularly children, who have been bitten and envenomated by these insects. Information regarding the pathogenesis of fire ant bite reactions and an approach to treatment are provided.

Download Full-text

Citizen Science Observations of Monarch Butterfly Overwintering in the Southern United States

Psyche A Journal of Entomology ◽

10.1155/2010/689301 ◽

2010 ◽

Vol 2010 ◽

pp. 1-6 ◽

Cited By ~ 20

Author(s):

Elizabeth Howard ◽

Harlen Aschen ◽

Andrew K. Davis

Keyword(s):

United States ◽

South Carolina ◽

Citizen Science ◽

Danaus Plexippus ◽

Monarch Butterfly ◽

Climatic Conditions ◽

Southern United States ◽

Long Distance ◽

Winter Range ◽

Breeding Activity

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.

Download Full-text