THE NATURAL HISTORY OF THE NORTHERN BLACK RACER (COLUBER CONSTRICTOR CONSTRICTOR) IN SOUTH-CENTRAL PENNSYLVANIA

Long-term species surveys are effective tools for identifying changes in population demography which is of particular importance for those in threatened habitats such as grasslands. Due to their cryptic nature, snakes can benefit greatly from these types of surveys but multiyear surveys for snakes are rare in Pennsylvania and the surrounding region. We conducted coverboard surveys of the grassland specialist Northern Black Racer (Coluber constrictor constrictor) over eight years separated into two sampling periods (2008-2012 and 2015-2017) across a habitat-mosaic in south-central Pennsylvania. We recorded information on their body size, demography, and monthly activity. We compared these traits between the sampling periods to determine how they vary over time. A total of 70 Northern Black Racers were captured during this project. As expected, grasslands were heavily exploited by Northern Black Racers highlighting their importance to this species. There was a shift from relatively larger-bodied, older individuals towards relatively smaller-bodied, younger individuals between the sampling periods, but the sex ratio remained unchanged. Monthly activity of adults was unimodal in both sampling periods, but the month of peak activity varied and there was a possible effect of precipitation on this difference. The change in age structure between the sampling periods suggested that a widespread mortality event, possibly from exceedingly cold overwintering conditions, may have culled older individuals resulting in a younger cohort to fill the void. As Northern Black Racers are an important grassland predator, our data show the benefits of long-term surveys through detecting changes in demographics that could potentially influence long-term survival of a population.

A new coccidian parasite (Apicomplexa: Eimeriidae: Eimeria) from the southern black racer, Coluber constrictor priapus (Reptilia: Ophidia: Colubridae) from Arkansas, USA

Between April 2012 and October 2017, 18 southern black racers,Coluber constrictor priapus, were collected from nine counties of Arkansas (n= 13) and McCurtain County, Oklahoma (n= 5) and their faeces examined for coccidian parasites. One of 18 (6%)C. c. priapusharboured an eimerian that we describe here as new. Oocysts ofEimeria dunnisp. nov. were subspheroidal with a lightly pitted bi-layered wall measuring L × W 24.0 × 21.1 and L/W ratio of 1.2. A micropyle was absent but an oocyst residuum and polar granule were present. Sporocysts were ovoidal and measured 11.9 × 8.1 with L/W of 1.5. A Stieda body was present but substieda and parastieda bodies were absent. The sporocyst residuum was composed of medium-sized granules aligned along perimeter of sporocyst or in a dispersed mass. This represents the first valid eimerian reported from the southern black racer.

Snake mortality and cover board effectiveness along exclusion fencing in British Columbia, Canada

We report on snake mortalities along exclusion fencing in southern British Columbia, showing Western Yellow-bellied Racer (Coluber constrictor mormon) deaths were disproportionately higher than our encounter rates with the species within the snake community. This suggests racers were susceptible to fence mortality more so than Northern Pacific Rattlesnakes (Crotalus o. oreganus) or Great Basin Gophersnakes (Pituouphis catenifer deserticola). Datalogger recordings revealed temperatures under cover boards were well above the tolerable temperatures of the three snake species, although the boards appeared to temper ambient heat more efficiently than natural vegetation. We caution that the effects of fencing and cover boards may vary across ecosystems and snake species.

Auguste Ghiesbreght’s natural history explorations in Oaxaca and other parts of Mexico until 1854

The authors review the zoological and botanical collections by Auguste Ghiesbreght from “Oaxaca” and other areas between 1838 and 1854. Taxonomically relevant are, for instance, the holotype of the Racer Coryphodon oaxaca Jan (Coluber constrictor L.), one of various amphibian and reptile species (coll. Ghiesbreght) not on record for Oaxaca, or a number of birds from southern Mexico implicitly attributed to Ghiesbreght but in fact gathered by other collectors. Zoological items and a plethora of plants from “Oaxaca” (coll. 1841–1854) encompassing many type specimens were obtained elsewhere, in particular the inland Gulf region between Hidalgo and the Orizaba Range. These results entail consequences regarding type localities or distribution, and possibly systematics, in different animal groups andbotanical fields.