Sunday 31 December 2023

Pick of the Year 2023 - part three

Otters 

In this last post of 2023, I would like to share some of the most amazing moments I had all year, close up views of wild otters. I had several super encounters with these amazing animals in the west Highlands and Islands of Scotland. I watched them fishing for butterfish, crabs and plaice. What a menu. I watched them from clifftops, following their sleek twists and turns underwater. I watched them exploring rivers, popping in and out of their holts, families rolling about together and those shown here, a teenage cub that had only recently left its family. She was fishing, and I reckon it was a female by the small size. Then she pulled out to sleep on the seaweed. The second sequence is of a courting pair whom I watched cruising along the coast. I crept onto a tideline rock and watched them swim past a few metres away then pull out to groom on a rock twenty metres away. 

The cub was in as deep a sleep as ottters ever seem to go, they fidget a lot. It stretched and yawned, and after about half an hour it was awakened by a few herring Gulls that swooped low to check if it had left any food scraps about. It lifted its sleepy head then dawdled down to the water, scambled over the rocks towards me and slipped in right next to me.

The pair swam right next to one another, twisting and swapping places. Then when they pulled out of the water they shook themselves like dogs, from nose to tail, scattering water droplets in a great wide spray. They seemed to know where they were going and quickly curled up, groomed, fidgeted a bit, groomed and curled up again for brief sleep. They too left after about twenty minutes. And to top it all, there was a porpoise cruising past as they swam away. 

A very special experience.


Pick of the year 2023 - part two 

The Western Isles

This the second of three summary posts of my trip to Scotland in 2023. As I mentioned in the previous post and repeat here, I had to do so much in the field that I seldom had time to upload posts to the Blog. So, now that it is the year's end, I have managed to organise and edit all the photographs I took during the year. This post, and the other two, illustrate some of the wildplaces I visited and wildlife I saw in Scotland in May and June. It was a wonderful trip and I covered so much ground, I can't cover everything here. 

Please browse through the pics below and join in my explorations. I haven't given away most of the locations, although I will share the one above which is of Heb Pods where I stayed for part of the trip, overlooking the Uig Sands on the Isle of Lewis. Lovely accomodation in a wonderful setting. 

Click on any of the photos to open them larger and follow the other photos as they link up.

  




























Pick of the year 2023 - part one

The Scottish Highlands

2023 was a busy busy year. I had to do so much in the field that I seldom had time to upload posts to the Blog. So, now that it the year's end, I have managed to organise and edit all the photographs I took during the year. This post, and the next two, are all on wildlife and wildplaces I visited in Scotland in May and June. It was a wonderful trip and I covered so much ground, I can't cover everything here. So please browse through the pics below and join in my explorations. I haven't given most of the locations, I'd rather people discovered their own little spots and appreciate the wildness.

Click on any of the photos to open them larger and follow the other photos as they link up.

 

Thursday 24 August 2023

 Lyrebird nest - raided

While surveying singing lyrebirds in the forest on the Brindabella Range near Canberra, which included recording the displaying male described in the previous post, I also checked the progress of the lyrebird nest shown above. The nest was set on a small ledge about three metres up a small crag, which is about five metres high. The rock wall is not easy to climb up as it is slightly overhanging below the nest. As soon as I saw the nest I knew something was wrong. The top of the domed nest had been ripped off and lyrebird feathers, which the female uses to line the nest to keep the single egg warm, had been scattered across the ledge and below the crag. 

The damage can be clearly seen in this second photograph. The nest is typical, formed of a large ball of sticks, larger than a basketball. This is lined with moss and then feathers, the smoky grey body feathers, which the female plucks from her belly. All three components can be seen to have been ripped open and in the third photograph, below, the single egg can be seen lying in the depths of the nest cup which once had a warm sheltered dome over it. Lyrebirds typically lay only one egg, incubation takes seven weeks, and the chick remains in the nest for a further six weeks. 

This was clearly the work of a predator that had probably managed to climb or jump down from the top of the crag onto the top of the nest. The potential predators of lyrebird nests in the area include fox, wild dog or feral pig when a nest is on the ground, and suger glider, greater glider, possum or feral cat if the nest is off the ground. A fox could climb to some nests, but I don't think they could reach this one. Footage from a trail camera set at a lyrebird nest by Matthew Higgins has revealed that a sugar glider can take an egg from a lyrebird nest, so a greater glider or possum could likely take one too. This suggests that a native climbing predator would have taken the egg if it had opened this nest. But it would have taken considerable strength to rip the nest open and the egg was left behind. There was a tiny needle point hole in the egg, possibly made by a claw. A fox would have taken the egg. So, that leaves the likely suspect to be a feral cat, as a cat would be more likely to have been after a young or adult bird on the nest. As obligate carnivores, they prefer to eat meat. Fortunately, there was no evidence of the adult lyrebird having been killed, but this breeding attempt had failed. 

Feral cats have done so much damage to Australian wildlife.  

Thursday 10 August 2023

 Song and Dance

I set a camera trap at a Superb Lyrebird display mound over two weeks in July (13-31st) and was successful in recording some wonderful song and dancing displays. Male lyrebirds display from a number of display mounds within their territory and females are attracted to them by the song first and then song and dance once they are visible as females approach through the thick undergrowth. The repertoire of the bird’s mimicry of other birds’ calls is, as its name suggests, superb, and enthralling. And how he holds and spreads his elaborate tail feathers is just as mesmerising. Follow this Video link to see a compilation of some of the sequences.

The females lay their eggs in winter, so these displays are performed during the cold months and I have watched them display in the snow. The males play no part in the nest building, incubation or tending of the young. The sexes only meet up for the purpose of mating.

Superb Lyrebirds are famous for their mimicry and although there are well-known film clips of birds imitating cameras and chainsaws, most of the sounds that wild lyrebirds copy are of other local birds that live in the same tall forests. I have only heard one bird imitate a knocking sound that resembled someone hammering on wood, which the bird could easily have heard in the forest. That bird was in the forest of the Brindabella Range near Canberra, the same area where this footage was recorded. It is always a pleasant walk along the tracks in the forest, where the lyrebirds can be frequently heard, but seldom seen as they place their display mounds in dense overgrowth. Hence the reason I deployed the camera, to see what was going on in there…

Male superb lyrebirds sing four different song types with unique associated sets of dance moves, but the individual birds vary their songs and steps and they don’t always dance when they sing (Dalziell et al. 2013, below). As can be seen in this video, they also sing without even raising their tail. The whole sequence of the different songs and dances is very elaborate, but purposeful. As these displays form part of the sexual behaviour, there is probably a strong impulse for the males to sing and dance their best to attract a female.   

Lyrebirds can sing with mimicry away from the mound, such as up on tree branches or logs, but they don’t give mimicry segments of their song while dancing. When singing his full repertoire of mimicry the male in the video stood quite still, and it was once he pulled his tail right over his back and head that he began to dance. This was induced by the presence of a female off camera, and he held that pose and dance sequence all the while a female was with him on or near the mound. In one sequence, he backs off the mound, followed by a female, perhaps, the birds copulated on another mound not far from the one where the camera was set. Each male hase several mounds where they display.

I have not yet worked out the complete list of the bird calls that the lyrebird mimicked, but the main song, mixed with the lyrebird’s own specific song, includes: Yellow-tailed Cockatoo, Laughing Kookaburra, Pied Currawong, Crimson Rosella, Red Wattlebird, Satin Bowerbird and Grey Shrike-thrush. During the intense dances when his tail is fully pulled over, the bird does not mimic these calls, but gives a frantic array of buzzing alarm calls, mimics of the alarm calls of the smaller ground dwelling birds such as White-browed Scrubwren, Brown Thornbill and Eastern Yellow Robin. He even mimics the burring of bird wings, such as when birds mob a predator.

For a more full explanation of  Superb Lyrebird display see these papers by Anastasia Dalziell et al. upon which I have relied heavily in describing the details of the bird’s behaviour in this video. 

Dalziell, A.H., Ppeters, R.A., Cockburn,A. Dorland, A.D., Maisey, A.C., & Magrath, R.D. (2013). Dance choreography is coordinated with song repertoire in a complex avian display. Current Biology 23: 1132-1135. https://www.cell.com/current-biology/pdf/S0960-9822(13)00581-2.pdf 

Dalziell, A.H., Maisey, A.C., Magrath, R.D., & Welbergen, J.A. (2021). Male lyrebirds create a complex acoustic illusion of a mobbing flock during courtship and copulation. Current Biology 31: 1970-1976. https://www.cell.com/current-biology/pdf/S0960-9822(21)00210-4.pdf

Dalziell, A.H., Welbergen, J.A., & Magrath, R.D. (2022). Male superb lyrebirds mimic functionally distinct heterospecific vocalisations during different modes of sexual display. Animal Behaviour 188: 181-196.   https://www.sciencedirect.com/science/article/am/pii/S000334722200094X