Fig 1.
Geographical representation of the records of Desmodus rotundus in Colombia, represented by sex.
(A) Contemporary dataset. Geographic distribution of 46 D. rotundus individuals from which six morphological traits were collected (i.e., weight, head length, body length, tibia length, ear length, and forearm length.) in the departments of Tolima and Cundinamarca. (B) Contemporary and historical dataset. Distribution of 490 D. rotundus museum specimens from which forearm measurements were collected for this study. Orange: female. Blue: male. Map was created using QGIS software/ Open source geospatial foundation project [36].
Fig 2.
Morphometric measurements of Desmodus rotundus.
Six key morphological traits were measured in individual bats: (A) Weight, measured using a digital balance, recorded in grams (g). (B) Head length, from the tip of the nasal leaf to the posterior edge of the skull (in mm). (C) Body length, from the tip of the nose to the base of the tail. (D) Tibia length, measured from the proximal end of the tibia to the posterior base of the calcar (in mm). (E) Ear length, from the base of the ear to the tip (in mm). (F) Forearm length, from the wrist to the elbow when the wing is folded (in mm). Red lines indicate the specific landmarks used for each measurement to visually demonstrate the precise locations.
Fig 3.
Comparison of forearm length in Desmodus rotundus by sex.
(A) Distance tree by cluster analysis of D. rotundus according to forearm length from 490 historical and contemporary specimens. Orange: females. Blue: males. Note that the data tended to cluster in two groups based on sex. (B) Boxplot illustrating sexual dimorphism in forearm length. The median (central line) is higher in females than in males, indicating generally longer forearms in females. The 95% confidence interval for females spans 61.33–62.25 mm, and for males, 58.24–58.76 mm. The interquartile range (IQR) is slightly larger in females (3.05 mm) than in males (2.69 mm), suggesting greater variability within the female group. Outliers (red points) lie beyond the whiskers and represent individuals with forearm lengths notably outside the typical range for their sex. Mean forearm lengths were 61.8 mm for females and 58.5 mm for males.
Fig 4.
Morphometric comparisons by sex and origin in Desmodus rotundus.
(A) Boxplots of six morphological traits (body length, ear length, forearm length, head length, tibia length, and body weight) comparing females and males. Each panel includes the result of a student’s t-test evaluating sexual dimorphism. Significant differences between sexes are observed in forearm and tibia length. (B) Comparison of forearm length between historical specimens and contemporary bats. Historical specimens tend to show a slightly broader range of variation. Forearm length was significantly greater in females than in males (t-test, p < 2 × 10 ⁻ ¹⁶), indicating a clear pattern of sexual dimorphism in this trait. Similarly, tibia length was greater in females, with a statistically significant difference (t-test, p = 0.0036). In contrast, no significant differences were observed between sexes in body length (p = 0.23), ear length (p = 0.11), head length (p = 0.41), or body weight (p = 0.1), although females tended to weigh more than males.