Russian Ornithological Journal 2014, Volume 23, Express issue 976: 705-709
Notes on the feeding behavior of the striped shrike Thamnophilus doliatus on Margarita Island (Caribbean Sea)
Alexander Gennadievich Rezanov, Andrey Alexandrovich Rezanov. Moscow City Pedagogical University, Institute of Natural Sciences, Department of Biology of Animals and Plants, st. Chechulina 1, Moscow, 119004, Russia, E-mail: [email protected]
Received February 14, 2014
The striped shrike anttrap Thamnophilus doliatus (Linnaeus, 1764) (Thamnophilidae, Tyranni) is widespread in Central and South America (except for the southern half of the mainland). It is mainly an entomophage, collecting food mainly from leaves (foliage gleaning). In addition, these birds collect invertebrates from twigs and trunks of trees and shrubs and on the ground (Hilty, Brown 1986, Keeler-Wolf 1986, Zimmer, Isler 2003, Koloff, Mennill 2011).
In August 2011, in Venezuela, we observed striped shrike ant traps on the territory of the Ato El Sedral ranch (August 18) and on Margarita Island (Caribbean Sea, Leeward Islands - southern group of the Lesser Antilles archipelago) on August 20-22. A total of 3 birds (all males) were monitored: one in Ato El Sedral and two on Margarita Island. The total observation time was 4 hours. The main material on feeding behavior was collected on Margarita Island near Porlamar (Portofino hotel).
Fig. 1. Forest belt on the border of the Portofino hotel (Margarita Island). August 20, 2011. Photo by the authors.
The striped shrike ant traps fed in a narrow (no more than 10 m) forest belt (Fig. 1, 2) separating the hotel territory from a vast wasteland overgrown with weeds. In the forest belt, the bulk of the mass was made up of dense shrubs and the leguminous trees (abaceae) towering above it, with very large fruits, like those of hedichia. Terminalia guianensis, large trees with pear-shaped leaves, also grew here. The birds examined shrubs and trees in the height layer from several tens of centimeters to 2-4 m (Fig. 3-6), sometimes they flew down and fed on the ground.
Fig. 2. Forest belt on the border of the Portofino hotel (Margarita Island). August 22, 2011. Photo by the authors.
Fig. 3. The striped shrike Thamnophilus doliatus examines the lower layer of legumes. Margarita Island. August 21, 2011. Photo by the authors.
Fig. 4. The striped shrike anttrap Thatparbishtuch, male. Margarita Island. August 22, 2011. Photo by the authors.
It is known that striped shrike ant traps can hunt small lizards (Keeler-Wolf 1986), however, despite the abundance of these reptiles (sometimes up to several individuals were in sight at the same time) in the forest belt, we did not note any attempts by ant traps to attack lizards or even simply pay attention to them.
Based on our observations of striped shrike ant traps, we have identified the following feeding methods used by these birds:
1) Moving on the ground by jumping and pecking (picking up) food objects (small fruits) from the surface of the main substrate.
2) Inspection and collection of food from branches of trees and shrubs at a height of up to 2-4 m from the ground with the help of jumping and flipping, when jumping, the bird pulls its tail.
3) Inspection and collection of food from the leaves of the crown of a tree (bush) within a height of up to 2-4 m by jumping and flipping, when jumping, the bird pulls its tail. According to K.J. Zimmer and MKh.Ser (2003), striped shrike anttraps usually feed in the height layer 0-3 m, up to a maximum of 10 m.
4) Inspecting and collecting invertebrates from thin branches using "hanging" in the manner of tits.
5) Inspecting and collecting invertebrates from leaves using "hanging" in the manner of tits.
6) Walking and running along branches and inclined trunks (up to 60 °) and collecting invertebrates from the surface, along thin vertical branches of an ant -
Dexterity easily moves both up and down, constantly scans the space around him.
Fig. 5. The striped shrike anttrap Thatparhilis dvialem during feeding. Margarita Island. August 20, 2011. Photo by the authors.
Fig. 6. The striped shrike ant-trap Thatparbish dvialem during feeding. Margarita Island. August 22, 2011. Photo by the authors.
Fig. 7. The striped shrike ant-trap Thomparhilis dvialem during feeding. Margarita Island. August 22, 2011. Photo by the authors.
7) Finding on a perch branch and scanning the space above the perch (Fig. 6-7).
8) Finding on a perch branch and scanning the space under the perch. Thus, it is possible for anttraps to use both "grasping flight" and diving (both of these maneuvers, described as "sally" and "drop", are noted on the islands of Trinidad and Tobago - Keeler-Wolf 1986). It should be noted that in striped shrike ant traps we did not observe a long stay on the perch, as is the case in the Muscicapidae flycatchers, La niidae shrikes, and Tyrannidae battering flycatchers.
We did not observe probing and pecking of invertebrates from leaves (twigs) during hover gleaning described for this species (Keeler-Wolf 1986).
Hilty S., Brown W. 1986. A Guide to the Birds of Colombia. Princeton Univ. Press: 1-836 Hilty S.L. 2003. Birds of Venezuela. Princerton Univ. Press. 1-928.
Keeler-Wolf T. 1986. The Barred Antshrike (Thamnophilus doliatus) on Trinidad and Tobago: habitat niche expansion of a generalist forager // Oecologia 70, 2: 309-317.
Koloff J., Mennill D.J. 2011. Barred Antshrike (Thamnophilus doliatus), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology, retrieved from Neotropical Birds Online: http: // neotropical. birds.cornell.edu/portal/species/ overview? p_p_spp = 367746
Zimmer K.J., Isler M.L. 2003. Family Thamnophilidae (Typical Antbirds) // del Hoyo J., Elliot, A. & Christie, D. A. (Eds.) Handbook of the Birds of the World. Vol. 8. Broadbills to Tapaculos. Barcelona: 448-681.
Russian Ornithological Journal 2014, Volume 23, Express issue 976: 709-712
Magpies Pica pica - wall climbers
Nikolai Nikolaevich Berezovikov. Laboratory of Ornithology and Herpetology, Institute of Zoology of the Ministry of Education and Science, 93 Al-Farabi Avenue, Almaty, 050060, Kazakhstan.
Received February 13, 2014
In a wide range of feeding methods of the magpie Pica pica, the search for food on vertical surfaces is a rather rare and imperceptible phenomenon. Repeatedly had to observe forty, looking for food in clay and earthen cliffs along rivers, in the walls of ravines and quarries. In rural areas, I happened to see these birds while inspecting cracks and crevices behind the peeling plaster of houses, behind a boardwalk.