Shiny Cowbirds At Carib Grackle's Nest

Female Shiny Cowbird

Shiny Cowbirds (Molothrus bonariensis) are brood parasites, which means the female lays her eggs in the nests of other birds,  relying on them to incubate her eggs and rear her chicks.  While some birds reject the eggs straight off, many species do not.  This can harm the population of the host bird and can be even more devastating when the host is a threatened species.  This appears not to be the case here on the island as the main host of these birds, Carib Grackles (Quiscalus lugubris), since unaffected.

A Barbados Bullfinch parenting a 
Cowbird's chick

What is worrying, though,  are the few sightings of Barbados Bullfinch (Loxigilla barbadensis), our lone endemic,  and Golden Warbler, our subspecies of Yellow Warbler (Setophaga petechial) parenting Cowbird chicks. If this becomes the norm rather than the exception, it can spell trouble for these important bird species, especially as the latter is making a spirited comeback to the Barbados landscape.  In the British Ornithological Society Checklist Series #24 - The Birds of Barbados (Buckley, Massiah, et al) said that "the decline in breeding of the Barbados Golden Warblers [I like that name] in the mid-1950s has been attributed to this species [Shiny Cowbird] but without supporting data" I personally think the reason for the decline was habitat loss, but that too is without supporting data.  

Even with the reputation these birds have I am still intrigued by them. Having on occasions seen them at Grackle colonies doing their thing I must say the process is quick and efficient. On Tuesday, March 23rd, I saw something I have never noticed before and it led to me writing this post.  Outside my bedroom window is a Bajan Cherry Tree (Malpighia emarginata) which was my birding oasis during COVID-19 lockdowns 1 and 2. (see here also here).  This year for lockdown number 2, three species were nesting or in the process of building a nest in the tree.  It was surprising that one of them was a  Carib Grackle (Quiscalus lugubris) because they are colonial nesters.   

Here is what happened that Tuesday morning: As I was passing the bedroom window I noticed three female Shiny Cowbirds inspecting the nest...  

Two of the three female Shiny Cowbirds

The first Shiny Cowbird entered the nest...

Shiny Cowbird entering the Carib Grackle's nest

Sat on it for a short while, most likely laying an egg, I thought... 

Then exited the nest and another cowbird took his place...

The conveyer-belt, assembly line-like process was quick, orderly, and efficient, taking just seconds for each bird to sit on the nest.  Seeing how methodically these cowbirds worked on this single nest was scary as I could only imagine what happens in a grackles breeding colony.  The number of Shiny Cowbirds across the island "appears" to be at an all-time high.  It is now customary to see large flocks going to and from roost, a sight that is relatively new to me.  This event caused me to question my original anecdotal thinking – Is the Carib Grackle (Quiscalus lugubris) population really sustaining this brood parasitic attack or is it slowly eroding one of our native species?  We, the local birders, must be on the watch to ensure our endemic  Barbados Bullfinch, or our sub-species of Yellow Warbler are not being adversely affected.  It emphasizes the need for a closer look to be taken at the effect of Shiny Cowbirds on our avianscape.  There is documented evidence of brood parasitic species* wreaking havoc on an ecosystem, but there are also examples where their coexists.  Lets hope our is the latter.

*Ecology and Management of Shiny Cowbirds (Molothrus bonariensis) and Endangered Yellow-Shouldered Blackbirds (Agelaius xanthomus) in Puerto Rico by Cruz, López-Ortiz, et al

The Yearly Return of Caribbean Martins

Caribbean Martin (M) at its
Pile Bay nesting ground

Bird migration is the regular seasonal movement of birds between breeding and wintering or non-breeding grounds.  The Caribbean region is used as a pit stop for birds en route to South America, or the wintering ground for most migrants but a few species do breed in the Caribbean and migrate.

Caribbean Martin  taking a drink - St, Lucy

Caribbean Martins (Progne dominicensis) is one such species.  Research has shown that some birds winter in South America¹ and return to the Caribbean region in February.  Here in Barbados, we are starting to see them returning and hearing them call around breeding sites.  I have heard of, or have seen over ten nesting colonies throughout the island - in and around Bridgetown, using traffic and street lights for nesting, to areas along the east coast, the sea walls at Ocean City, St. Philip, or the roof of the beach facility at Barclays Park St. Andrew to the north at Mount Gay Distillery and Animal flower Cave, St. Lucy.  The Breeding season starts in April through to August² and most birds are gone by November, with a few wintering here.

Female on the power lines preening 
Cattlewash St. Joseph

So as your move around keep an eye out for these outstanding flier, effortlessly hawking for insects over “These fields and hills beyond recall [that] Are now our very own".  Like me, I am sure you will be amazed by the quickness and agility of Caribbean Martins.

¹Geolocator Data Reveal the Migration Route and Wintering Location of a Caribbean Martin (Progne dominicensis) - Noah G. Perlut, Thomas C. Klak, Eldar Rakhimberdiev - The Wilson J. of Ornithology, 129(3):605-610 (2017)

²Birds ofBarbados An Annotated Checklist - Buckley, Massiah, Hutt, et al

Grey Kingbird - Tyrant of the Skies

Grey Kingbird

Grey Kingbirds (Tyrannus dominicensis)(Pewhittler) are part of a family of birds called tyrant flycatchers.  The name explains the aggressive nature of some members of this family in that these relatively small birds are known for relentlessly attacking and driving off much larger birds that may venture into or close to their range.  I witnessed this on Saturday as an Osprey (Pandion haliaetus) flew too close for comfort and was bravely repel by a single bird. See the drama in the images below as a tyrant of the skies goes to work.

Birding after the Pause

Adapted from the blog The Enthusiastic Birder

The first week back to work after the “pause” was surprisingly busy.  It was good to be out of the house after weeks of confinement but I was a little nervous, even a little afraid because of the pervasiveness of COVID in society.  The routine of mask and face shield has become the norm for me, and disposable gloves are added to the mix depending on where I am going. It was refreshing being outdoors, seeing the different birds as I moved around the island. After work, on most of the days, I visited a few of the birding hotspots, utilizing that activity for exercise as afforded by the government's COVID-19 protocols.  During that week I tallied 32 bird species from 8 checklists, also adding 2 yearbirds namely Caribbean Martin (Progne dominicensis), which I saw in Bridgetown and Laughing Gulls (Leucophaeus atricilla) at Pile Bay.  You can see the full list of the birds I saw below.

I continue to be impressed with the Canon 7D Mark II, even as it is paired with the underwhelming (because of reach) Canon EF-s  55-250mm f/4 – 5.6 IS II, which effectively becomes 89.1 - 405mm (x1.62 crop sensor of the Canon 7D II).  Here are a few highlight images for that week. All images were lightly edited using Adobe Lightroom CS2.

On March 1^st I had my best look at a Merlin (Falco columbarius) for the year. It was going after Eurasian Collared-Doves (Streptopelia decaocto) for dinner, and while the shots I got were not ones I would normally highlight, I love this one that shows the beautiful barring pattern in this raptor's tail. 

Merlin showing its tail feathers  (1/4000 @ f8 ISO 1000 – 250mm)

On the 3^rd, my after work exercising took me to Chancery Lane Swamp, Christ Church. While there, I tried to photograph an American Coot (Fulica Americana) with her chicks.  This was not an easy task as both mum and chicks played peek-a-boo with me, using the mangroves for cover.  While I easily got images of both of them alone, the image below was the only opportunity I had of them together.

Adult (1/1000 @ F/8 ISO 640 250mm)

 

Juvenile  (1/1000 @ F/8 ISO 640 250mm)

Mother & Chick ((1/1250 @ F/8 ISO 640 250mm)

The following day, the 4^th, I ended work in the north so I visited the irrigation ponds at Bawdens, St. Andrew, and had a short photo session with a pair of Pied-billed Grebes (Podilymbus podiceps).  

Pied  (1/1600 @ F/5.6 ISO 640 250mm)

The Pair (1/1250 @ F/8) ISO 640 250mm)

My last stop for the week was at the Woodbourne Shorebird Refuge (WSR) on Friday, March 5th.  The water in most of the ponds was evaporating making foraging by wading birds much easier.  This triggered a small feeding frenzy among various species of waterbirds.  In one pond I counted 7 species of heron/egrets tallying 22 birds, 6 species of shorebirds, and in another, 68 Blue-winged Teals (Spatula discors), only a fraction of the 111 seen just a few days before. My most exciting capture, though, was that of a Sora (Porzana Carolina). This was the best look I’ve had of this shy bird for the year.  I would’ve love to get even lower but two things prevented that: first, I would have to take my camera close to the water in the pond, too close for my comfort.  Even though it is weather-sealed I am not ready for that adventure as yet with this babe. Secondly,   I am always skeptical of lying, sitting, walking in the grass, fields, or even the paved road in the parish of St. Philip.  It is notorious for its forty legs, its big, long, ugly stinging CENTIPEDES and I don’t mess around with those things.  Here are a few of the images from WSR.

Sora (1/1000 @ F/8) ISO 1000 250mm)
 

 

Greater & Lesser Yellowlegs
(1/3200 @ F/8) ISO 1000 250mm)

Lesser in flight (1/2500 @ F/8) ISO 1000 250mm)

Little Egret in flight (1/5000 @ F/8) ISO 1000 250mm)

These are the birds I saw during the first week of March

1.  Black-bellied Whistling-Duck - Dendrocygna autumnalis
2. Blue-winged Teal - Spatula discors
3. Green-winged Teal - Anas crecca
4. Pied-billed Grebe - Podilymbus podiceps
5. Scaly-naped Pigeon - Patagioenas squamosa
6. Eurasian Collared-Dove - Streptopelia decaocto
7. Common Ground Dove - Columbina passerina
8. Sora - Porzana carolina
9. Common Gallinule - Gallinula galeata
10. American Coot - Fulica americana
11. Least Sandpiper - Calidris minutilla
12. Wilson's Snipe - Gallinago delicata
13. Spotted Sandpiper - Actitis macularius
14. Solitary Sandpiper - Tringa solitaria
15. Greater Yellowlegs - Tringa melanoleuca
16. Lesser Yellowlegs - Tringa flavipes
17. Laughing Gull - Leucophaeus atricilla
18. Royal Tern - Thalasseus maximus
19. Red-billed Tropicbird - Phaethon aethereus
20. Brown Booby - Sula leucogaster
21. Great Egret - Ardea alba
22. Little Egret - Egretta garzetta
23. Snowy Egret - Egretta thula
24. Little Blue Heron - Egretta caerulea
25. Cattle Egret - Bubulcus ibis
26. Green Heron - Butorides virescens
27. Merlin - Falco columbarius
28. Gray Kingbird - Tyrannus dominicensis
29. Caribbean Martin - Progne dominicensis
30. Carib Grackle - Quiscalus lugubris
31. Grassland Yellow-Finch - Sicalis luteola
32. Bananaquit - Coereba flaveola