Are trich seeds spread by animals ?

[Quixote]

I'm wondering about how these cacti spread their seeds in the wild. Birds eat the fruits and carry the seeds to other places? Ants maybe? Or do seed pods just fall down next to the mother plant?

Edited May 16, 2014 by Quixote

[Dreamwalker.]

my guess any opportune creature, bats and birds mostly but I think I read some mention of ants

[EthnoGuy85]

I imagine with the sweetly flavored flesh that any manner of opportunistic feeder would chow down. Thus spreading the seed elsewhere within their range.

Edited May 16, 2014 by EthnoGuy85

[shortly]

I wouldn't be surprised surprised if humans haven't been very important seed dispersers for many of these plants. Given how many uses people have had for these plants i cant imagine that they didnt help disperse the favored species & varieties.

Intentionally and otherwise.

[hostilis]

We are still spreading them. I bet cacti never thought they'd be spread via internet.

Edited May 17, 2014 by hostilis

[Halcyon Daze]

small sticky sweet seeds could conceivably be spread a number of ways.

I recon birds would be major culprits.

Birds spread prickly pear and dragon fruit in SE Qld, but Tricho's are not self fertile (pollination wise) so they don't become the naturalised weeds we all wish they were.

Maybe if they reach a critical mass though...

Edited May 17, 2014 by Halcyon Daze

[Micromegas]

Sorry about the weird text layout...

Revista Chilena de Historia Natural 86: 000-000, 2013 © Sociedad de Biología de Chile

Frugivory in Echinopsis chiloensis (Caryophyllales: Cactaceae)
Frugivoría en Echinopsis chiloensis (Caryophyllales: Cactaceae)
ROCÍO A. CARES*, RODRIGO MEDEL & CAREZZA BOTTO-MAHAN

Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653,
Ñuñoa, Santiago, Chile
*Corresponding author: [email protected]

Seed dispersal is a critical segment of the
life cycle in plants. It involves fruit consumption
and seed deposition on sites where
environmental conditions are appropriate for
germination and seedling establishment (Stoner
& Henry 2008, Casado & Soriano 2010). Seed
dispersal involves the action of mammals, birds,
reptiles and insects, where seeds are often
adhered to the body of animals or ingested and
dispersed through defecation (Stoner & Henry
2008). Dispersal is a crucial process in semiarid
environments as it provides seeds a chance to
establish in safe sites. Although frugivory is a
widely studied mechanism in several types of
environments, there is scarce information for
arid and semiarid habitats (Jordano 2000). In
this report we present data on the magnitude of
frugivory by different consumer taxa on cactus
fruits in a semiarid Chilean ecosystem.
Echinopsis chiloensis (Colla) Fried & Rowl
is an endemic columnar cactus species widely
distributed in north-central Chile that inhabits
mainly equatorial-facing slopes in semiarid
environments (Medel 2000, Cares et al. 2013).
The blooming season of E. chiloensis extends
from early September to mid-November, and
the fruiting season from mid-October to late
December or mid-January (Medel 2000). This
species presents arborescent growth with
basitonic structure, with more than one trunk
near the base (Medel 2001). In spite of being
a dominant species in semiarid environments,
scarce information exists on its demography
and growth. Hoffmann (1989) suggests that
natural regeneration may be difficult and
growth rate can be extremely low, which is
consistent with previous fi ndings from a threeyear
study that indicates young individuals
height grow on average (± SE) 2.44 ± 0.4 cm
year-1 during years with average rainfall (Cares
et al. 2013).
Currently, there is no published information
about frugivor y and seed dispersal of E.
chiloensis. In this study, we report the results of
fi eld observations carried out during January
of 2013 at the Reserva Nacional Las Chichillas
(31º30’S, 71º06’W). This reserve is a protected
area located ~60 km east from the Chilean
Pacific coast. The climate of the study site
is of a semiarid Mediterranean-type with
most rainfall concentrated between June and
August (di Castri & Hajek 1976). Mean annual
precipitation is 185.0 mm, with ample variation
across years, alternating between long droughts
and unusual years of high rainfall seemingly
associated to El Niño events (di Castri & Hajek
1976, Jaksic 2001). The vegetation consists on
thorny shrubs (Luebert & Pliscoff 2006) and
columnar and spherical cactus species (Medel
2000, Medel et al. 2002, Hoffmann & Walter
2004).
In this study, we considered a species
to be a fruit consumer when it ate, pecked
or removed totally or partially the pulp of a
cactus fruit. Feeding events were instances
when an animal was observed performing
at least one of the activities indicated above
(Casado & Soriano 2010). Field observations
indicate that fruits of E. chiloensis ripe and
open on the cactus branch without drop by
abscission (Figure 1A). To identify the bird
species involved in frugivory, we performed
observations early in the morning from 7:00
to 10:00, during 13 consecutive days (total

sampling effort = 39 hours). Specifi cally, 142
cacti with at least one open fruit were scanned
with binoculars (10 × 25). Only the Chilean
mockingbird Mimus thenca (Molina 1782) was
detected picking the fruits of E. chiloensis (total
= 12 feeding events). Regarding ant species,
preliminar y obser vations revealed that ant
activity was concentrated from 17:00 until
dusk; therefore observations were carried out
between 17:30 and 20:00 during 13 consecutive
days (total sampling effort = 32.5 hours). On
the average (± SE), 8.9 ± 1.6 cacti with open
fruits/day were checked for ant presence,
from which 2.1 ± 0.3 exhibited ants. Two
ant species were recorded feeding on pulp
and transporting seeds from the open fruits,
Conomyrma goetschi (Goetsch & Menozzi
1935) (Fig. 1B) and Solenopsis gayi (Spinola
1851) (see also Medel & Vásquez 1994), with
19 and fi ve feeding events, respectively. Even
though fruits of E. chiloensis remain on the
cactus branch after opening, two mammal
species, the rodent Octodon degus (Molina
1782) and the fox Lycalopex culpaeus (Molina
1782), were observed consuming fruits of this
cactus species. It is likely that rodent species
remove pulp and/or whole fruits directly from
cactus branches by using horizontally oriented
spines to climb, and foxes lick pulp of ripe
fruits from low-heighted cactus individuals.
Because these field records do not allow
quantitative observations, wild rodent species
were collected with folding wire mesh liveanimal-
traps (24 cm × 8 cm × 9 cm; FORMA:
Products and Services, Santiago, Chile) baited
with rolled oats and provided with cotton
bedding to test for fruit consumption under
captivity conditions. Overall, 300 traps per
night were set during fi ve days, and checked
every morning. Captures included 46 Phyllotis
darwini (Waterhouse 1837), 35 O. degus, 12
Abrothrix olivaceus (Waterhouse 1837) and two
Abrocoma bennetti (Waterhouse 1837). At noon,
all captured rodents were fed with ripe fruits of
E. chiloensis. All the species tested consumed
the fruits excepting A. bennetti that rejected
consistently the offered fruit (percentage of
effective feeding: O. degus: 24.5 %, P. darwini:
9.6 % and A. olivaceus: 4.3 %). Regarding fox
species, evidence of fruit consumption by L.
culpaeus based on the analysis of feces taken
in different areas of the Reserve. A total of 48
complete fecal samples were collected, and 32
of them contained large amounts of seeds of
E. chiloensis (mean ± SE: 18221 ± 2435 seeds
per fecal sample). Additionally, it is worth to
mention that E. chiloensis seeds were found in
the stomach content of one individual of the
marsupial Thylamys elegans (Waterhouse 1839),
whose carcass was found in the study site, and
dissected and analyzed in the laboratory.
In summary, fi eld observations, no-choice
feeding test and circumstantial evidence
allowed identifying the fruit consumers of E.
chiloensis, specifically during the peak time
of the fruiting season (January). Frugivorous
species included one bird species (M. thenca),
four mammal species (O. degus, P. darwini, A.
olivaceus and L. culpaeus), two ant species (S.

gayi and C. goetschi), and one marsupial species
(T. elegans). Although several bird species
have been previously recorded in the study site
(CONAF 1996), only M. thenca was observed
consuming fruits of E. chiloensis. This result
might be due to particular climatic conditions
in the previous year, where the intense drought
during 2012 translated into low bird diversity
in the study site in the summer season of 2013.
For this reason, we cannot rule out that other
bird species belong the frugivorous guild of E.
chiloensis. It is likely that repeated sampling
across years complete the spectrum of bird
species consuming fruits of E. chiloensis.
According to our fi eld observations and nochoice
feeding test, the frugivorous guild of E.
chiloensis is diverse and not restricted to only
one taxon. The fact that E. chiloensis depends
on a generalized frugivorous assemblage for
seed dispersal conveys a clear advantage for
cactus recruitment. As birds, mammals, and
ants have different patterns of habitat use,
they provide a range of opportunities for seed
dispersal and seedling establishment.
ACKNOWLEDGEMENTS: We thank A Yáñez, MI Donoso
and P Cares. CONAF - Coquimbo Region allowed this
research at the Reserve. Financial support for this study
was obtained from FONDECYT 11090086 and 1120155.
R.A. Cares was supported by a CONICYT-fellowship for
Master studies.
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CARES RA, PA MUÑOZ, R MEDEL & C BOTTOMAHAN
(2013) Factors af fecting cactus
recruitment in semiarid Chile: A role for nurse
effects? Flora 208: 330-335.
CASADO R & PJ SORIANO (2010) Fructificación,
frugivoría y dispersión en el cactus globular
Melocactus Schatzlii en el enclave semiárido de
Lagunillas, Mérida, Venezuela. Ecotrópicos 23:
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CONAF IV REGIÓN (1996) Plan de manejo Reserva
Nacional Las Chinchillas, IV Región. Ministerio de
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Chile. Ediciones Universidad Católica de Chile,
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GUZMÁN-SANDOVAL J, W SIELFELD & M FERRÚ
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la fl ora Silvestre de Chile. Ediciones Fundación
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JAKSIC FM (2001) Ecological effects of El Niño in
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Ecography 24: 241-250.
JORDANO P (2000) Fruits and frugivory. In: Fenner
M (ed) Seeds: the ecology of regeneration in
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y Vvegetacional de Chile. Editorial Universitaria,
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[Dreamwalker.]

"naturalised weeds" I think its just a question of time.

1000 years from now I suspect the land will be richly populated in a vast selection of naturalised cacti and palms and grasses and so much more.

Some plants naturalise with in 10's of years, but almost every introduced plant will, given time and a suitable environmental niche naturalised, evolve and become an integrated element in the 'natural system.

[Micromegas]

This is better than the first article in particular the difference in nocturnal and diurnal pollination across the plants range, tied in with the first article it paints a pretty good picture of what's going on with echinopsis chiloensis (btw i can't fix the weird text):

213

Notes on the floral biology and pollination syndrome of

Echinopsis

chiloensis

(Colla) Friedrich & G.D.Rowley (Cactaceae) in a population

of semiarid Chile

link: http://www.gayanabotanica.cl/pdfs/2011/2/12_Ossa_and_Medel_2011.pdf

We report some aspects of the floral biology of

Echinopsis chiloensis

ssp.

chiloensis

in a population near to the northern limit

of its distribution. Anthesis is strictly diurnal and flowers remain open during 492 min on the average.

Echinopsis chiloensis

is self-incompatible. Flower longevity, nectar production along day, and floral visitors indicate that this population fits wel

l

to a diurnal insect pollination syndrome. These results contrast with a previous report indicating nocturnal anthesis and

mixed mellitophylous-sphingophylous pollination syndrome in populations near to the southern limit of the distribution

range. We suggest that the pollination syndrome of

E. chiloensis

is a labile rather than fixed condition that may depend on

the abiotic characteristics and geographical location of the population under assessment

[Illustro]

I dunno about in South America, but in my backyard Trich fruit are eaten almost solely by birds, they love them -- Trich fruit are perfect for bird dispersal, a smorgasbord sitting high up on a very well defended vantage point. The fruit only drop to the ground once mostly eaten.

[Micromegas]

That's pretty interesting Illustro. Are you in Oz?

I have never seen any animal eat a tricho fruit in my garden, not even ants really. And in my garden I have had lots of fruits and also a good number of birds.

I never considered a bird might eat them in Australia. Do you know what type of bird ate your fruits?

FYI, the article about T. chiloensis identified one species of bird, ants, a type of rodent, and a fox as the seed dispersers.

[Dreamwalker.]

blackbirds

[Halcyon Daze]

[incognito]

Ants tore apart a few of my ripe seed pods, whether they discarded the seed and where just after the flesh or took the seed to be eaten I don't know. Ants are by far one of my favourite creatures so I forgave them

[Illustro]

@Micromegas, not sure what birds eats them, the plants are down the back of my place where rarely go. So I guess it was conjecture, I've never actually seen them being eaten, but every time I try harvest fruit something has beaten me to it and apparently pecked all the fruit to shit.