Endozoochory by black rhinoceroses enhances germination of a key arid savanna tree species

Megaherbivores are typically regarded as agents of top-down control, limiting woody encroachment through destructive foraging. Yet they also possess traits and engage in behaviours that facilitate plant success. For example, megaherbivores can act as effective endozoochorous seed dispersers. However, studies on facilitative roles are heavily biased toward the African savanna elephant (Loxodonta africana), with little attention paid to other species or to effects beyond germination across early ontogenic stages. The African black rhinoceros (Diceros bicornis), an obligate browser that exhibits frugivory and defecates in fixed dung middens, may offer ecologically distinct dispersal services. We conducted controlled experiments to investigate whether interactions between black rhinos and Vachellia erioloba, a leguminous tree of ecological importance in arid savannas, enhance germination, early seedling development, or seedling resilience to herbivory. Germination was compared among du..., Germination assays
Seed collection
Seeds were initially collected from black rhino dung to identify the study species, followed by mature pods.
Dung samples were collected over two weeks each in April and July 2023, post-wet season (November to March). By this stage, all indehiscent pod-bearing species had produced mature pods, so their seeds should have been present in boluses if consumed by rhinos and able to withstand gut passage. The two collection periods were intended to contrast seeds with minimal (April) vs prolonged (July) environmental exposure. With assistance from field rangers, fresh black rhino dung (<2 days) was located by backtracking from waterholes, and all intact seeds were removed from boluses. As rhinos have distinct territories, dung from a midden typically reflects the diet of only a few individuals. To maximize the number of individual rhinos sampled and capture variable gut passage effects on seeds, Dung seeds were collected across Tswalu. This also optimized..., , # Endozoochory by black rhinoceroses enhances germination of a key arid savanna tree species

[https://doi.org/10.5061/dryad.9ghx3fftr](https://doi.org/10.5061/dryad.9ghx3fftr)

## Description of the data and file structure

This dataset was collected to investigate the role of black rhinoceroses (*Diceros bicornis*) in facilitating the recruitment of *Vachellia erioloba*, a keystone tree species in arid savannas. The study aimed to evaluate the whether a mutualism exists, through the study of i) whether gut passage significantly enhances germination, ii)  whether seed viability is diminished by the duration between pod shedding and seed dormancy breakage (alleviated by early consumption), iii) whether legacy effects of rhino gut passage enhance the initial growth of seedlings and iv) whether seedlings grown in dung recover better after simulated herbivory (clipping) than those grown in sand.

We conducted a series of experiments to test each of these hypotheses. Surviving individuals ...,