MUSEUM SPECIMENS OF WESTERN DIAMOND-BACKED RATTLESNAKES (VIPERIDAE: CROTALUS ATROX) REVEAL TRENDS IN BODY SIZE, DIET,...

Area of Science:

• Herpetology
• Parasitology
• Climate Change Ecology

Background:

• Southwestern US climate change projections include increased temperatures, drought, and wildfire frequency.
• These changes pose risks to regional species, including the western diamond-backed rattlesnake (Crotalus atrox) and its associated helminth communities.
• Understanding these impacts is crucial for conservation efforts.

Purpose of the Study:

• To investigate changes in Crotalus atrox body size, diet, and helminth communities over the past century in New Mexico.
• To test hypotheses regarding the influence of environmental factors on these changes.

Main Methods:

• Examined Crotalus atrox specimens from three distinct time periods (1950s, 1980s, 2010s).
• Recorded morphometric data (snout-vent length), sex, age class, prey items from gastrointestinal contents, and helminth prevalence.
• Conducted a literature search to assess helminth habitat associations.

Main Results:

• Body size and diet composition of Crotalus atrox remained stable across the studied time periods.
• Significant shifts in helminth community composition were observed.
• Oochoristica osheroffi, a helminth tolerant of dry conditions, became dominant in the most recent period.

Conclusions:

• While Crotalus atrox morphology and diet appear resilient, their helminth communities have undergone significant changes.
• Observed shifts in helminth composition may be linked to climate change, altered host diet, or other factors.
• Further research is needed to fully elucidate the drivers of these parasitic community dynamics.