Gut passage in frugivores enhances the germination of mistletoe seeds Bakerella gonoclada, in a Madagascar rainforest
Data files
May 31, 2025 version files 7.50 KB
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germ_bak_gonoclada_metadata.csv
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germ_bak_gonoclada.csv
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README.md
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Abstract
In Madagascar's rainforests, frugivores influence Bakerella gonoclada mistletoe seed dispersal and germination. Our germination experiments show that mistletoe seeds defecated by lemurs had significantly higher germination success, germination speed, hypocotyl growth, and survival probability than seeds planted directly from mistletoe. These results suggest a mutualistic relationship between mistletoe and lemurs.
https://doi.org/10.5061/dryad.3n5tb2rtj
Description of the data and file structure
To investigate mistletoe biology, we compared the probability and speed of germination of Bakerella seeds defecated by lemurs to seeds pulled directly from mistletoe fruits by the experimenter, hereinafter referred to as ‘hand-removed seeds’, in Petri dish experiments. From January to April 2023, we followed four groups of red-fronted brown lemurs (Eulemur rufifrons) on alternate days from 8:00 am to 4:00 pm. Whenever a group defecated, we noted the age class and sex of individuals. Additionally, on January 19, 2023, we searched Talatakely trails for fresh frugivore droppings and collected seeds from one sample of a lemur, which we suspected to come from a greater dwarf lemur (Cheirogaleus major). We found that all defecated mistletoe seeds collected (from Eulemur rufifrons and, putatively, from Cheirogaleus major) were B. gonoclada. To compare the germination of defecated to hand-removed seeds, we picked 30 mature fruits from four individual plants of B. gonoclada (Table 1). We planted all defecated and hand-removed seeds immediately on the evening of the collection day. Defecated and hand-removed seeds were planted in separate disposable Petri dishes of a 9 cm diameter; seeds from the same individual source were planted in the same dish. The seeds in each Petri dish were set on filter paper with at least 1 cm spacing between the seeds. All dishes were left under the same natural conditions with no direct sunlight. We monitored seed and seedling survival and germination, defined as the first visible appearance of the hypocotyl-radicle tip. We recorded the final length of the hypocotyl-radicle after 12 weeks of observation.
Files and variables
File: germ_bak_gonoclada.csv
Description:
Variables
- seed_id: the identity of each seed
- seed_type: the seeds were collected from a feces of frugivores or directly from the fruits of plant
- source_seed: the origin of the seeds. If seeds were collected from the same plant or different plants, example BCB_A and BCB_B
- Bak_sp: Bakerella species
- germ_Y_N: seeds germinated (coded as 1) or not (coded as 0)
- time_to_germ: how many days of each seed took to germinate from the planting date
- time_to_death: days that each seed took to die after planting
- hypocot_lgth_final: the final length of the green radicle of the germinated seeds at the end of the experiment (in mm)
- leaves_lgth_final: the final length of the pair of leaves of the germinated seeds at the end of the experiment (in mm)
- plant_date: planting date
Access information
Other publicly accessible locations of the data:
- N/A
Data was derived from the following sources:
- field collection in Talatakely, a region within Ranomafana National Park (RNP), a lowland to montane rainforest located in southeastern Madagascar
The study was conducted in Talatakely, a region within Ranomafana National Park (RNP), a lowland to montane rainforest located in southeastern Madagascar (47°18’- 47°37’E and 21°02’- 21°25’S). Talatakely is a degraded forest characterized by many shrub species in the families of Rubiaceae and Myrsinaceae, bamboo, epiphytes, and mistletoes (Atsalis, 1999; Turk, 1997); some areas are invaded by the exotic plant strawberry guava (Psidium cattleianum).
To investigate mistletoe biology, we compared the probability and speed of germination of Bakerella seeds defecated by lemurs to seeds pulled directly from mistletoe fruits by the experimenter, hereinafter referred to as ‘hand-removed seeds’, in Petri dish experiments. From January to April 2023, we followed four groups of red-fronted brown lemurs (Eulemur rufifrons) on alternate days from 8:00 am to 4:00 pm. Whenever a group defecated, we noted the age class and sex of individuals. We checked defecated feces for mistletoe seeds; any feces containing Bakerella seeds were wrapped in aluminum foil for lab analysis. Additionally, on January 19, 2023, we searched Talatakely trails for fresh frugivore droppings and collected seeds from one sample of a lemur, which we suspected to come from a greater dwarf lemur (Cheirogaleus major), based on previous direct observations (Fenosoa et al., 2020), because the sample contained only Bakerella seeds wrapped in a viscin thread but no fecal matter. Attempts were made to collect Bakerella seeds from the feces of the brown mouse lemur, Microcebus rufus, using capture-release-recapture methods but were unsuccessful.
Bakerella species in RNP are identified by shape, color, and size (Fenosoa et al., prep.). We found that all defecated mistletoe seeds collected (from Eulemur rufifrons and, putatively, from Cheirogaleus major) were B. gonoclada. To compare the germination of defecated to hand-removed seeds, we picked 30 mature fruits from four individual plants of B. gonoclada. We planted all defecated and hand-removed seeds immediately on the evening of the collection day. Defecated and hand-removed seeds were planted in separate disposable Petri dishes of a 9 cm diameter; seeds from the same individual source were planted in the same dish. The seeds in each Petri dish were set on filter paper with at least 1 cm spacing between the seeds. All dishes were left under the same natural conditions with no direct sunlight. We monitored seed and seedling survival and germination, defined as the first visible appearance of the hypocotyl-radicle tip. We recorded the final length of the hypocotyl-radicle after 12 weeks of observation.